choice of omnis for classical
jnorman
mics in the studio to see how they sounded compared to my cardioid
mics for cello, flute, violin, harp, piano, etc. i immediately liked
the way omnis sound compared to cardioids, and am looking to get
another couple of omnis. i have pairs of akg c480s w/ck61 caps,
AT4051s, and schoeps cmc64s. i plan to reserve the schoeps for use as
a main ORTF pair out front, as they are the flattest mics i have for
diffuse field work. so, i thought i might pick up a pair of ck62 omni
caps for the akgs, or a pair of 4049 omni caps for the at4051 bodies,
or just pick up another pair of the little DPAs. for my applications,
which of those options might be better? or, are the DPA 4006s SO much
better than any of the choices above that i really should just save my
money for them and not mess around with the akg or AT systems?
thanks. (btw, preamps are HV-3)
Mike Clayton
jnor...@comcast.net (jnorman) wrote:
For what it's worth a friend of mine did a shoot out with a pair each of
Schoeps and DPA omnis on a small chamber choir in a nice room, recording
them through a Midas Venice console. He sent me the samples and without
knowing what the mics were on my monitors and in my room I consistently
chose the tracks made with the Schoeps as sounding best to my ears and
aging brain.
For all practical purposes I don't think there's a lot in it between these two.
I also own the AKG 480 with the omni, cardioid and hyper capsules and have
had good results with them too. But the Schoeps mics, of which I have the
MK2 omni and the MK41 supercardioid are definitly a better microphone than
the AKG. I think, if you compare value for money between the Schoeps and
the DPA, then the Schoeps are the better deal.
Your mileage will more than likely vary quite a bit. In the end the best
course is to try them both and keep the ones you like.
Let's know how you go.
Suso Ramallo
Earthworks QTC1
Cheers
"jnorman" <jnor...@comcast.net> escribió en el mensaje
news:e340b423.04012...@posting.google.com...
Ivo
already on the way) for similar applications you mention. After
shortly testing MK2H (which I am now changing for flat and natural
MK2) I too can say that for instruments I like more the omni sound,
even in a small room with a close pick-up
Richard Kuschel
>
>Earthworks QTC1
>
>Cheers
>
If you can deal with the self noise.
They aren't all that quiet, but work fine for close miking.
Save up the money, get the Schoeps, you won't regret it.
Richard H. Kuschel
"I canna change the law of physics."-----Scotty
Arny Krueger
news:20040128083636...@mb-m27.aol.com
>"Suso Ramallo" <jram...@worldonline.es> wrote in message
>news:bv82rf$oj4fq$1...@ID-91146.news.uni-berlin.de
>> Earthworks QTC1
> If you can deal with the self noise.
> They aren't all that quiet, but work fine for close miking.
> Save up the money, get the Schoeps, you won't regret it.
A well-known local choral group - the Detroit Concert Choir use a QTC1
matched pair mounted on a high stand. That plus spot mics for the soloists.
If you want to listen to some real-world evidence of how noisy QTC1s really
are, here's where you can get their recordings for a nominal charge:
http://www.detroitconcertchoir.org/ . You can probably email them and find
out which mics were used for which recordings.
I'm using what I thought are the far noisier ECM8000s, and the noise that
shows up on my recordings is basically the room, not the mics. (see
additional comments below).
Here's a recent technical discussion of the self-noise of the ECM8000's from
one of our sister NGs.
From: Norbert Hahn <ha...@hrz.tu-darmstadt.de>
Message-ID: <lvquuvcvafp6gv381...@4ax.com>
"Today I did some measurements with some of my mics, AKG Body C 480 B
with CK61 ULS capsule (Equivalent noise level (IEC 651 A weighted)
13 dB, Sennheiser MKH50 (Equivalent noise level 12 dB) and the
Behringer ECM-8000. Microphone preamp was a Behringer UB802.
"Hm, well the ECM-8000 has about 10 dB more noise than the Senn and the
AKG, which measure the same when reduced to a single number.
As I read this, these measurements put ECM8000 self-noise in the 22-23 dB
range. But there are some other relevant issues that are discussed in more
detail about 2/3 through this post.
Note that the mic preamp used was hardly SOTA, but the mics in question are
pretty sensitive so the mic pre wasn't seeing terribly low-level signals.
Ironically 22-23 dB noise puts ECB-8000s in the same range of self-noise as
the spec on the QTC1 per http://www.earthwks.com/ns/qtc1.html . Yes, this is
pretty stinky by the standards of some large-diaphragm mics.
Note that the ECM8000 is flat up to about 25 KHz, while the QTC1 is flat up
to about 40 KHz. It's probable that the QTC1 has a far smaller diaphragm,
which makes the modest self-noise spec more impressive.
Returning to the comments of the person (Norbert Hahn) who tested various
mics for self-noise:
"However, the frequency curve of the unfiltered self noise is quite
different: The ECM 8000 has almost white noise between 300 Hz
and 15 kHz, dropping then with 6 dB per octave. Between 300 Hz and
30 Hz the self noise rises by 18 dB at lower frequencies. Thus, the
self noise of the ECM 8000 sounds like a mixture of pink and white
noise.
"The frequency curve of the self noise of the AKG looks like pink noise
between 30 Hz and 3 kHz and like white noise between 3 kHz and 45 kHz.
"The frequency curve of the self noise of the Sennheiser MKH 50 is
quite different. Between 30 Hz and 4 kHz is looks pretty much like
pink noise (a little more rise at lower frequencies though), but above
6 kHz the noise rises by 8 dB within one octave, peaking at 18 kHz.
Above that the noise drops by 18 dB/octave. So that mic has the
least amount of noise in the same octaves where the ear is most
sensitive.
This is one of those things that doesn't seem to show up on many spec
sheets - the spectral content of noise very much affects how we perceive it.
Spectral content is much of the difference between the sound of wind
blowing, the sound of sea crashing on rocks, and a 150 psi air hose hissing
its heart out given that the 20-20 KHz or A-weighted SPLs were the same.
My own take on this issue is that small-diaphragm omnis can get a bad rap
for noise because they are so truly omni. If there's a noise in the room
they'll probably pick it up. For example, many of my recordings include
trivial but personal comments made by the musicians and people in the
audience, made in low voices and whispers while they are waiting for things
to start. Not so with cardioids in the same general vicinity.
I still lust after a pair of QTC1s, but its probable that I am getting a
fair simulation of them with my ECM8000s. Probably good enough of a
simulation to judge a number of relevant issues, like "Are small omnis for
me and my application?"
Suso Ramallo
I have a pair, isn't the quietest mic, but works fine for classic recording
(I have too the more noisy brother Earthworks M30, and works well like a
spot mic).
The self noise is the price that you need to pay for a very small capsule,
but you win in other aspects.
Cheers
"Richard Kuschel" <rickp...@aol.com> escribió en el mensaje
news:20040128083636...@mb-m27.aol.com...
Len Moskowitz
jnorman <jnor...@comcast.net> wrote:
>i just picked up a pair of DPA 4061 miniature omnis to use as close
>mics in the studio to see how they sounded compared to my cardioid
>mics for cello, flute, violin, harp, piano, etc.
The 4060s, with their lower self noise, might have been a slightly
better choice for studio work. They're both fine sounding mics, in my
opinion the best sounding miniature mics in the world.
>or, are the DPA 4006s SO much better than any of the choices above that
>i really should just save my money for them and not mess around with
>the akg or AT systems?
The 4006 (and the higher voltage 4003) are among the world's great
mics. If you can afford them, you should get 'em.
[Disclaimer: Core Sound is a full-line DPA dealer.]
--
Len Moskowitz PDAudio, Binaural Mics, Cables, DPA, M-Audio
Core Sound http://www.stealthmicrophones.com
Teaneck, New Jersey USA http://www.core-sound.com
mosk...@core-sound.com Tel: 201-801-0812, FAX: 201-801-0912
Ty Ford
I was extremely impressed with the Microtech Gefell M296 1/2"+ omni. I have
a short recording in my audio archives. It's not classical, but it may give
you an idea.
Regards,
Ty Ford
**Until the worm goes away, I have put "not" in front of my email address.
Please remove it if you want to email me directly.
For Ty Ford V/O demos, audio services and equipment reviews,
click on http://www.jagunet.com/~tford
Benjamin Maas
time. I like changing the grills on them to change the mic sound- black for
diffuse field where the high-frequency rise is needed, silver for
all-purpose and I've been experimenting with taking the grills off which I
find really opens up the sound on them. I also really like the Sennheiser
MKH-20s.
I'm not as much of a fan of the Schoeps as I've mentioned before because
they can really show you the deficiencies in performance as well as room-
much more than other mics can. With a great room and performance, it is
great to have, but with my work, that isn't always the case.
--Ben
--
Benjamin Maas
Fifth Circle Audio
Los Angeles, CA
http://www.fifthcircle.com
Please remove "Nospam" from address for replies
"jnorman" <jnor...@comcast.net> wrote in message
news:e340b423.04012...@posting.google.com...
WillStG
>i immediately liked
>the way omnis sound compared to cardioids, and am looking to get
>another couple of omnis.
If you like omni's (and I know I do), it is worth buying a couple or three
Behringer ECM8000's. They are extremely flat/pretty 4006-ish I think, they are
a tad bit noisy but that won't matter if you're close micing or the if the
environment is noisy. And they're a very inexpensive addition to the mic
collection...
Will Miho
NY Music & TV Audio Guy
Off the Morning Show! & sleepin' In... / Fox News
"The large print giveth and the small print taketh away..." Tom Waits
Arny Krueger
news:20040129124747...@mb-m28.aol.com
>> jnor...@comcast.net (jnorman)
>> i immediately liked
>> the way omnis sound compared to cardioids, and am looking to get
>> another couple of omnis.
> If you like omni's (and I know I do), it is worth buying a
> couple or three Behringer ECM8000's. They are extremely flat/pretty
> 4006-ish I think,
From about 100 Hz to 15 Khz the differences between the samples I compared
were within the calibration limits of the 4006. Below 40 Hz and above 25 KHz
the 4006 is considerably flatter. You get what you pay for. The 4006 also
has a stated sensitivity that historically could be taken to the bank.
>they are a tad bit noisy but that won't matter if
> you're close micing or the if the environment is noisy.
Measurements suggest that they have self-noise in the 23 dB range. The noise
spectra is kinda pinkish, so it's hard to find a room where their self-noise
would be intrusive.
> And they're a very inexpensive addition to the mic collection...
Change from $50 almost without regard to where you buy them.
Suso Ramallo
The ECM8000 are super-noisy, far from flat response, and big distortion over
100dB SPL (Is a Panasonic capsule based mic).
Frec. response of the ECM8000 against Earthworks M30:
http://www.lasalademaquinas.com/behrin.jpg
Cheers
"WillStG" <wil...@aol.comnospam> escribió en el mensaje
news:20040129124747...@mb-m28.aol.com...
Arny Krueger
> The ECM8000 are super-noisy,
Compared to what?
> far from flat response,
Even your own plot suggests otherwise, see below.
> and big distortion over 100dB SPL (Is a Panasonic capsule based mic).
I've clipped out Panasonic omni capsule based mics many times, but I've
never clipped out any of my ECM8000s. I've definitely subjected ECM 8000's
to SPLs > 100 dB.
On balance, the element in the ECM8000 is a ca. 1/4" two-terminal electret
element that looks a lot like a Panasonic. But looks could be deceiving.
> Frec. response of the ECM8000 against Earthworks M30:
> http://www.lasalademaquinas.com/behrin.jpg
I suspect that a lot of the roughness shown in this plot is at last
partially due to the procedures used to make it. It would be interesting to
see a similar plot comparing two M30s.
If you smooth the plot it shows response that is about +0, -1.5 dB 32-16
KHz.
The ECM8000 is mostly reading low in the 8 KHz to 16 KHz range in this
comparison.
http://www.earthwks.com/ns/m30.html# shows that in that range, the M30
should be reading up to 0.5 dB high.
IOW, the non-flat response shown is partially due to a combination of test
procedures and the fact that the "reference" microphone is a tad hot.
WillStG
>>"Suso Ramallo" <jram...@worldonline.es> wrote
>> The ECM8000 are super-noisy,
SNIP
>> Frec. response of the ECM8000 against Earthworks M30:
>> http://www.lasalademaquinas.com/behrin.jpg
>I suspect that a lot of the roughness shown in this plot is at last partially
due to the procedures used to make it. It would be interesting to see a similar
plot comparing two M30s.
>If you smooth the plot it shows response that is about +0, -1.5 dB 32-16 KHz.
>The ECM8000 is mostly reading low in the 8 KHz to 16 KHz range in this
comparison.
>http://www.earthwks.com/ns/m30.html# shows that in that range, the M30 should
be reading up to 0.5 dB high.
>IOW, the non-flat response shown is partially due to a combination of test
procedures and the fact that the "reference" microphone is a tad hot
Maybe you could post your ECM8000 vs. B&K4006 plots on your website for
a comparison to Suso's "Test data" Arny. Mine haven't clipped on me either,
and aren't what I would call "super-noisy", so I wonder exactly how he made his
comparisons and how much experience he has in testing gear.
Scott Dorsey
>
>The ECM8000 are super-noisy, far from flat response, and big distortion over
>100dB SPL (Is a Panasonic capsule based mic).
No, it's not a Panasonic capsule in there.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
David Satz
> After shortly testing MK2H (which I am now changing for flat and
> natural MK2) ...
Hello again, Ivo. For this type of microphone, "flat and natural" depends
on the mixture of direct vs. reverberant sound at the point in space where
you place it. If you are picking up mainly direct sound on axis, then yes:
the Schoeps MK 2 capsule comes extremely close to having flat response.
But no microphone of this size (20 mm diameter) can possibly have the same
high-frequency response on-axis as it has off-axis. That is a matter of
basic acoustical physics. The major dimensions of the microphone, for some
given range of high frequencies, form a significant fraction of the sound
wavelengths. The microphone then begins to bend the sound field around it.
20 mm = 1/2 wavelength just above 8 kHz, so that is where the on-axis peak
tends to be. But if there is no on-axis peak, then for a microphone of that
size there must be a corresponding reduction in response off axis--and the
Schoeps MK 2 has just such an off-axis rolloff, as physics would require.
As a result, if you record sound which is an equal mixture of direct and
reverberant energy, the MK 2 can begin to sound dark, because the sound
which arrives from off axis will be picked up with a falling high-frequency
response; only the direct sound arriving on axis will be picked up "flat."
This is why Schoeps offers four different omni capsules. They are designed
for use [a] with the intention of getting flat overall response with various
styles of miking (i.e. different distances, with different mixtures of
direct/on-axis and reverberant/off-axis sound) and/or [b] different tastes
and expectations for the high-frequency response overall.
The directional response of all four capsules is essentially identical,
because that is mainly determined by their (identical) physical size. In
an earlier message you mentioned this as an "opinion" of mine, but I would
really like you to understand that this is not subject to anyone's opinion.
If you use some other medium than air to carry sound, you can change this
relationship--but otherwise you cannot.
It certainly is possible to build very small pressure microphones which
are flat at all angles of incidence, and which therefore don't require a
range of different high-frequency characteristics for the sake of purpose
"[a]" just mentioned. (Purpose "[b]" will always be with us.) However,
such microphones tend to be too noisy for many modern applications. In
addition, many people simply don't like the way they sound.
That's not a defect of the microphone; more often, I think, it is because
of the hall. Many modern halls are supposedly "multi-purpose" in their
acoustical design, but in fact are not really suitable for any purpose
whatsoever! They are too muddy for theatre, but too thin and dry for music.
In particular, not every recording venue has adequate sound absorption at
high frequencies; the reverberant sound may have a rather harsh character.
In such halls it is quite helpful when a microphone is directional at high
frequencies--even though that doesn't correspond to the Platonic ideal of
an omnidirectional transducer. In fact some engineers pay huge premiums
for exotic, small-capsule pressure microphones in which the capsule is
embedded in a larger sphere (e.g. the Neumann M 50 as used in the classic
"Decca Tree"). This causes a presence boost, but also an even further
narrowing of the high-frequency response. The users of those microphones
don't object to that--and having used some M 50s myself, I tend to agree.
I apologize if this is more than you wanted to know, but it's important to
understand that the relative importance of a microphone's on-axis response
depends greatly on how the microphone is being used. This is true all the
more with omnidirectional microphones, where in many applications, a great
proportion of the sound which you are picking up will arrive off-axis.
Suso Ramallo
My two M30's:
http://www.lasalademaquinas.com/m30vsm30.jpg
M30 against DIY made Panasonic mic with the Linkwitz mod:
http://www.lasalademaquinas.com/panasoniclinkwitz.jpg
Photo of the DIY Panasonic:
http://www.lasalademaquinas.com/panasonic.jpg
Cheers
"WillStG" <wil...@aol.comnospam> escribió en el mensaje
news:20040130102918...@mb-m28.aol.com...
Suso Ramallo
Calibration Certificate of the M30 (Used against Behringer)
http://www.lasalademaquinas.com/earthwks.jpg
Metod of test:
-The two capsules in coincident mode like XY, but close angle (>45º).
-Speaker with noise for excite the mics (Mics on axis).
-The final ajust between mics made with the "impulse mode" for close the two
in perfect axis.
-Measured by transfer mode
-Long samples (128)
Devices:
-Sound card Sound Devices USBpre 1.5, 2.5.3 driver, 24/48 mode.
RightMart test of USBpre:
http://www.lasalademaquinas.com/USBPre%20Miic%20in.htm
-Dell CHxP P3@500 Windows 2000
-Siasoft Smaart 5.1
Cheers
"Suso Ramallo" <jram...@worldonline.es> escribió en el mensaje
news:bve6h5$rsqm1$1...@ID-91146.news.uni-berlin.de...
Arny Krueger
>> "Arny Krueger" ar...@hotpop.com
>>> "Suso Ramallo" <jram...@worldonline.es> wrote
>>> The ECM8000 are super-noisy,
>>> Frec. response of the ECM8000 against Earthworks M30:
>>> http://www.lasalademaquinas.com/behrin.jpg
>> I suspect that a lot of the roughness shown in this plot is at last
partially
> due to the procedures used to make it. It would be interesting to see
> a similar plot comparing two M30s.
>> If you smooth the plot it shows response that is about +0, -1.5 dB
>> 32-16 KHz.
>> The ECM8000 is mostly reading low in the 8 KHz to 16 KHz range in
>> this comparison.
>> http://www.earthwks.com/ns/m30.html# shows that in that range, the
>> M30 should be reading up to 0.5 dB high.
>> IOW, the non-flat response shown is partially due to a combination
>> of test procedures and the fact that the "reference" microphone is a
tad hot
> Maybe you could post your ECM8000 vs. B&K4006 plots on your
> website for a comparison to Suso's "Test data" Arny.
I'm usually pretty obsessive about holding onto data like this, but so far I
can't find it. There have been a few recent hard drive crashes on my audio
test work machine, so any data not already uploaded one of my sites may or
may not still be around.
Some of the data I took showed the jagginess above 2 KHz shown by
behrin.jpg. However, I had two 4006's, and when I compared them, there were
the same jaggies. I concluded that the jaggies were mostly due to the test
procedure. BTW, if you do this sort of thing in the electrical domain, the
results are usually pretty smooth if you average enough data. In the
acoustical domain, I got the jaggies, even with quite a bit of averaging.
BTW, I used Spectra Lab, not SMAART. My thinking is that it's not the tool,
it's not the UUTs, it's the way the acoustics of the test works out.
BTW, the 4006s were borrowed, and eventually went back to the large
corporate owner, never to return.
> Mine haven't clipped on me either, and aren't what I would call
"super-noisy", so
IME ECM 8000's seem to be exceptionally noisy because they are pretty
sensitive, and accept acoustical inputs from all directions. My recollection
is that the ECM8000's got attenuated quite a bit during my transfer
function-based measurements. I used my Symmetrix SX-202 mic pre and a
CardDeluxe to capture the data.
> I wonder exactly how he made his comparisons
My (similar) results were made using Spectra Lab's transfer function
analysis. I used a far-field loudspeaker to excite the test (just about
anything reasonably broadband gives similar results, pink noise, white
noise, music, etc ) and calculated the transfer function based on the output
of the ECM8000 divided by the output of the 4006, with both outputs
adjusted for unity at mid frequencies, and the mics acoustically aligned for
zero measured phase shift at midband.
I'm not a SMAART user, but I understand it has similar capabilities.
>and how much experience he has in testing gear.
When it comes to acoustical testing, I feel like I still have my training
wheels on.
Suso Ramallo
> -The two capsules in coincident mode like XY, but close angle (>45º).
Sorry: <45º
Cheers
WillStG
>
>http://www.lasalademaquinas.com/earthwks.jpg
>
>Metod of test:
>
>-The two capsules in coincident mode like XY, but close angle (>45º).
>
>-Speaker with noise for excite the mics (Mics on axis).
>
>-The final ajust between mics made with the "impulse mode" for close the two
>in perfect axis.
>
>-Measured by transfer mode
>
>-Long samples (128)
>
>Devices:
>
>-Sound card Sound Devices USBpre 1.5, 2.5.3 driver, 24/48 mode.
>
>RightMart test of USBpre:
>http://www.lasalademaquinas.com/USBPre%20Miic%20in.htm
>
>-Dell CHxP P3@500 Windows 2000
>
>-Siasoft Smaart 5.1
Suso, when you did your tests did you supply phantom power to the ECM8000
from the USB Pre, or did you use an external power supply? They will work with
as little as 12 volts, maybe they aren't getting full phantom power from your
USB Micpre powered test setup and this is affecting their noise spec. Also
sometimes micpres which power one mic well have trouble with supplying full
voltage to two, the USB pre works off it's USB 5volts power to supply phantom
yes? I wonder if that might account for the divergent experiences.
I have played with a couple of ECM 8000's with my Millennia HV3's and
sure they have a little noise, but I wouldn't describe them as "super noisy".
Suso Ramallo
I tested all the microphones with the phamton power of the USBPre (Includes
the two M30, the M30 needs 48 volts and 10mA each), the USBPre have a 48
volts phamton up to 10mA.
http://www.sounddevices.com/tech/usb_earthwks.htm
http://www.usbpre.com/specs.htm
I make some takes with the ECM8000 with a GML and the USBpre with the same
amount of noise, much higher than the M30 (The M30 have a high noise level),
but I didn't measured the noise of the ECM8000.
Cheers
WillStG
>I tested all the microphones with the phamton power of the USBPre (Includes
>the two M30, the M30 needs 48 volts and 10mA each), the USBPre have a 48
>volts phamton up to 10mA.
>
>http://www.sounddevices.com/tech/usb_earthwks.htm
Yeah, but not all micpres supply all the power they claim to, so I was
wondering if that might be the case and account for some noise, also I have
read the USBPre adds about 4 db of "whine" noise at 1k on the output due to the
isochronous sampling rates of the A/D and the D/A's bleeding through.
Contributing noise factor maybe?
But anyway I'm really am not that experienced at acoustic testing, but
your plots look somewhat different than the Behringer's and the Earthworks
published plots, above 5 k your plots seem to roll off slightly comparitively
on both. Could this be because your USBPre only does 16 bit out even at 24/48
in? It has been known to cause problems with some measurement software
resulting in a high end inaccuracies; that's why the "WinMLS" guys recommend
the Digigram cards, but I dunno.
http://www.nvo.com/winmls/discussion1/list.nhtml?profile=discussion1
Scott Dorsey
>
> But anyway I'm really am not that experienced at acoustic testing, but
>your plots look somewhat different than the Behringer's and the Earthworks
>published plots, above 5 k your plots seem to roll off slightly comparitively
>on both. Could this be because your USBPre only does 16 bit out even at 24/48
>in? It has been known to cause problems with some measurement software
>resulting in a high end inaccuracies; that's why the "WinMLS" guys recommend
>the Digigram cards, but I dunno.
I could believe that, but you should also know that the published plots are
usually VERY strongly smoothed by the marketing department.
The thing is that unless you have a calibrated microphone that you know really
is flat, you can't make an accurate narrowband measurement. To do so would
require a sound source that was flat, and that doesn't exist.
A 5 KC rolloff, though, would not surprise me. And you should know that the
capsule the Behringer uses is a Chinese knockoff of the Japanese capsule
design that Earthworks uses. It's a surprisingly good knockoff, though,
considering it probably costs less than a quarter.
Suso Ramallo
I'll reply you between lines.
> Yeah, but not all micpres supply all the power they claim to, so I
was
> wondering if that might be the case and account for some noise, also I
have
> read the USBPre adds about 4 db of "whine" noise at 1k on the output due
to the
> isochronous sampling rates of the A/D and the D/A's bleeding through.
> Contributing noise factor maybe?
I tried the ECM8000 with a GML pre with same results, my conclusion: is
noisy
You can find in other post of this tread the performance of the mic in of
the USBpre, is a loop test in 24 bit mode. The USBpre out are of 16 bit, but
20 by spdif, I use a external DAC (Benchmark DAC1) for test the input,
because I expected results over 96dB, this is the limit of a very good 16
bit output.
PC + Rigthmark to USBpre>spdif>benchmark DAC1>USBpre mic in>PC + Rigthmark.
But in transfer mode between mics I don't use the output of the USBpre.
Simple, Mics connected to the USBpre>USB bus>Analysis software (Smaartlive),
I don't see the use of the USBpre output, only for generate noise to the
speaker, but I didn't measure the speaker, only the mics (With a loudspeaker
acting like stimulus).
The USBpre can't send the inputs to the outputs, need a software for this
(Don't work like a conventional preamp). The reason of the 16 bits out is
because was conceived for monitoring, and is good for a "dropout" free work
(spend less USB bandwidth)
> But anyway I'm really am not that experienced at acoustic testing,
but
> your plots look somewhat different than the Behringer's and the Earthworks
> published plots, above 5 k your plots seem to roll off slightly
comparitively
> on both. Could this be because your USBPre only does 16 bit out even at
24/48
> in? It has been known to cause problems with some measurement software
> resulting in a high end inaccuracies; that's why the "WinMLS" guys
recommend
> the Digigram cards, but I dunno.
Every mic are different, the companies only show a standart graph, and few
manufacturers offer a production range alternative graph +/-1dB over the
regular (I don't seen the Behringer published plots, the ECM8000 don't comes
with any plot). If you see my older posts, you can see the diference between
two M30 (Not is a mached pair), is a difference of +/-0,5dB on the worse
case, very good for me. The diferences between mics of the same brand/model
are the reason of the mached pairs.
I don't use the USBpre outs.
Smaartlive guys recomend the USBpre, different software, different requests.
Cheers
Scott Dorsey
>
>I tried the ECM8000 with a GML pre with same results, my conclusion: is
>noisy
It's noisy, but hell, what do you want for $35? The fact that it works at
all at that price is a miracle.
That said, it should be pretty immune to loading, since it doesn't have
an output transformer, and it should be reasonably immune to variations in
phantom voltage, since it's an electret and doesn't have particularly high
current output stages. So it should work reasonably well with cheap preamps.
It's designed as a cheap measurement mike, for God's sake. This is an
application where low distortion and low noise floor aren't really very
important, but reasonably flat frequency response and good off-axis response
are important. It does a better job of meeting the requirements than you
would expect for a $35 mike. It's no Schoeps, but it's $35.
WillStG
<< I tried the ECM8000 with a GML pre with same results, my conclusion: is
noisy >>
I guess it depends on what you are comparing it to noise-wise, note that
I didn't say they were 4006-ish in terms of noise but in terms of how they
*sound*. As I said originally on loud sources/for close micing/in rooms with
some background noise present I don't think the self noise is that big an
issue.
<< The reason of the 16 bits out is
because was conceived for monitoring, and is good for a "dropout" free work
(spend less USB bandwidth) >>
As a side comment, I should have been more specific, the reason the
WinMLS guys say you can get inaccuracies in the high end of MLS measurements
when you use the USBPre is because the input and output converters are not
clock synchronized, not because they operate at different bitrates per se. But
maybe that doesn't matter here anyway.
<< Every mic are different, the companies only show a standart graph, and few
manufacturers offer a production range alternative graph +/-1dB over the
regular (I don't seen the Behringer published plots, the ECM8000 don't comes
with any plot). >>
There is a spec pdf with a transfer plot at
http://www.behringer.com/02_products/prodindex.cfm?id=ECM8000&lang=ENG&CFI
D=908867&CFTOKEN=79982689
I don't doubt your Earthworks mics are quiet and more accurate, but the
Behringers *sound* pretty good for a cheap mic, and are usable tools I think.
( Maybe yours is broken? One person who complained that the ECM8000 was "really
noisy" turned out to have one that was broken, but many people have agreed they
have found the mic, self noise and all, is still quite usable. )
Bob Cain
either no objects (including mic stand) in the vicinity of
the microphones or they occupy the exact same point in space
in an unchanging environment (which is pretty much
impossible) then the raggedness you see is due to reflection
and refraction. It's amazing how little it takes to create
that kind of "noise" on the response plot and how difficult
it is to eliminate.
This has lots of other implications in recording that follow
rather logcially.
Bob
--
"Things should be described as simply as possible, but no
simpler."
A. Einstein
Suso Ramallo
For 35$ is a big deal, but for 10$ you can DIY a better mic (With a real
Panasonic). The ECM8000 have a transformer.
I agree with you that the noise and distortion aren't important for the
work, but Will said that is a good mic for recording and I don't agree.
Cheers
"Scott Dorsey" <klu...@panix.com> escribió en el mensaje
news:bvf0kt$p5q$1...@panix2.panix.com...
Suso Ramallo
> I don't doubt your Earthworks mics are quiet and more accurate, but
the
> Behringers *sound* pretty good for a cheap mic, and are usable tools I
think.
> ( Maybe yours is broken? One person who complained that the ECM8000 was
"really
> noisy" turned out to have one that was broken, but many people have agreed
they
> have found the mic, self noise and all, is still quite usable. )
For 35$ is ok. I tried two, I don't have a ECM but many friends have one.
You can use this mic with a high SPL source for mask his self noise, but I
have doubts about his distortion over 100dB SPL.
I saw the graph and I agree with Scott, is marketing drawing. Is curious the
need of use big steps (5dB).
Cheers
Suso Ramallo
Is the best measure I can afford with my material (Devices/room), is enough
for getting an idea. I agree with you, to many factors can distort the
measure.
All the mics was prove in the same room (very dead) with the same stand and
same position, the good and the bad affects all the mics equal. You can see
in my graphs, better frequency responses than the ECM8000.
I tested the ECM because I was search a cheap mic for measure. Is good by
35$, but IMMO is not a good mic (No price consideration).
Best regards
"Bob Cain" <arc...@arcanemethods.com> escribió en el mensaje
news:401B3536...@arcanemethods.com...
Scott Dorsey
>
>For 35$ is a big deal, but for 10$ you can DIY a better mic (With a real
>Panasonic). The ECM8000 have a transformer.
Do they? The one I took apart had no transformer and actually drove only
one leg of the output. It was "impedance balanced" more or less. I would
be curious to see if there is more than one model out there.
I would bet that if you have one with a transformer that the frequency
response is very different than the one I got.
>I agree with you that the noise and distortion aren't important for the
>work, but Will said that is a good mic for recording and I don't agree.
It's probably the best under-$50 mike available for recording. Certainly
it beats the C1000 hands-down. It would not be my first pick, personally,
but then I have more than $50.
Ty Ford
<ar...@hotpop.com> wrote:
>IME ECM 8000's seem to be exceptionally noisy because they are pretty
>sensitive, and accept acoustical inputs from all directions. My recollection
>is that the ECM8000's got attenuated quite a bit during my transfer
>function-based measurements. I used my Symmetrix SX-202 mic pre and a
>CardDeluxe to capture the data.
I would offer that the best way to determine the noise factor would be to
check for it on a a NOT noisy environment.
Hey Arny, anyway you could send one to me for a short time so I could put it
up against some of mine in the studio?
A 23-24 dB A selfnoise is not inconsiderable in today's digital recording.
It was a lot more acceptable years ago with anaolog tape hiss to mask and
"dither" it.
Today, with the quieter moments of a symphony, I'm guessing the selfnoise
would be quite audible. Especially if the recording then undergoes any sort
of gain reduction processing.
Arny Krueger
> Hello Scott,
> For 35$ is a big deal, but for 10$ you can DIY a better mic (With a
> real Panasonic).
Been there done that, and it didn't end up being a better mic.
BTW, if you check the archives of the universe, you might find that decades
ago I was co-author of one of the first, or the very first Panasonic
electret mic articles that was ever published in the US or perhaps even the
world. I built literally dozens of them, right up until a couple of years
ago. I think I still have at least 4 unused capsules in inventory.
>The ECM8000 have a transformer.
Suso, Now I know for sure that you're talking out the back of your neck.
I took an ECM 8000 apart yesterday.
No transformer! For the price of an ECM8000 there would be a transformer as
good as this mic? I don't think so!
Inside an WCM 8000 there is a transistor, an IC, two electrolytics, and
assorted small resistors and capacitors. Seems like there should be a zener
but I didn't find it right off. Given that only one of the electrolytics is
rated at 50 volts, there's a real good chance that its output is not fully
balanced.
BTW, I don't recommend that anybody take an ECM 8000 apart just for fun.
They're not that hard to take apart and I was very gentle with mine. But it
took a some fine soldering to get mine to work, when I tried to put back
together. There are some hair fine wires that broke when I tried to gently
shake the circuit card out of the case. Mine didn't have enough lead length
to reassemble in any practical way.
> I agree with you that the noise and distortion aren't important for the
work, but Will said that is a good mic for recording and I don't agree.
BTW, Suso your claims about distortion are 100% unsubstantiated. Given that
the ECM 8000 is basically a measurement mic, there's an extreme likelihood
that its acoustic clipping point is someplace above 114 dB, given that this
is the SPL that is commonly used for SPL calibration.
Arny Krueger
> << "Suso Ramallo" jram...@worldonline.es >>
> << I tried the ECM8000 with a GML pre with same results, my
> conclusion: is noisy >>
>
> I guess it depends on what you are comparing it to noise-wise,
> note that I didn't say they were 4006-ish in terms of noise but in
> terms of how they *sound*. As I said originally on loud sources/for
> close micing/in rooms with some background noise present I don't
> think the self noise is that big an issue.
According to user investigations I've already detailed on this thread, the
noise of a ECM 8000 is around 23 dB.
According to http://www.dpamicrophones.com/eng_pub/Products/Item-4006-2.html
the noise of a DPA 4006 is 15-17 dB.
We don't know is the spectral content of the DPA 4006's noise, so we don't
know exactly how they would compare subjectively. But we do know that the
measured amplitude of the noise of a DPA 4006 is about 6-8 dB less than that
of an ECM 8000.
However, the world is full of popular microphones with noise levels in the
23 dB range - including the Earthworks QTC1.
Arny Krueger
news:nottford.1...@news.jagunet.com
> In Article <ve2dnQ8IZKr...@comcast.com>, "Arny Krueger"
> <ar...@hotpop.com> wrote:
>> IME ECM 8000's seem to be exceptionally noisy because they are pretty
>> sensitive, and accept acoustical inputs from all directions. My
>> recollection is that the ECM8000's got attenuated quite a bit during
>> my transfer function-based measurements. I used my Symmetrix SX-202
>> mic pre and a CardDeluxe to capture the data.
> I would offer that the best way to determine the noise factor would
> be to check for it on a a NOT noisy environment.
I agree.
> Hey Arny, anyway you could send one to me for a short time so I could
> put it up against some of mine in the studio?
Sure. Send me your address at my *for-business* email address which is named
just like the one I use for posting, except its at comcast.net.
> A 23-24 dB A selfnoise is not inconsiderable in today's digital
> recording.
That may be true, but there are a lot of popular mics that are in this range
including the Earthworks XTC-1. . And, the DPA 4006 measures only 6-8 dB
better.
> It was a lot more acceptable years ago with analog tape hiss to mask and
"dither" it.
Yes, but we are still cursed with relatively noisy rooms.
> Today, with the quieter moments of a symphony, I'm guessing the
> selfnoise would be quite audible. Especially if the recording then
> undergoes any sort of gain reduction processing.
Dynamics processing is a place that I don't go to very much.
Suso Ramallo
Sorry is in Spanish
http://www.imagendv.com/altavoces/micro_med.htm
Cheers
"Scott Dorsey" <klu...@panix.com> escribió en el mensaje
news:bvgheh$ch7$1...@panix1.panix.com...
Arny Krueger
> Sorry is in Spanish
> http://www.imagendv.com/altavoces/micro_med.htm
The ECM 8000 internals pictures and the schematic absolutely DO NOT RESEMBLE
the ECM-8000 I took apart yesterday.
FWIW 9 out of 10 of the Panasonic capsules tested seem to be reasonably
linear up to 114 dB.
Scott Dorsey
Suso Ramallo <jram...@worldonline.es> wrote:
>Hello Scott,
>
>Sorry is in Spanish
>
>http://www.imagendv.com/altavoces/micro_med.htm
Wow! That doesn't look anything like what I found inside my Behringer!
That transformer doesn't look like a particularly high quality product
either.
Suso Ramallo
Maybe the USA mic are different type than the Europe model, or two different
editions. The ECM mics that I tried are old (more of 3 years).
I will try to get a new ECM for see if Behringer changes the mic inside.
Cheers
"Scott Dorsey" <klu...@panix.com> escribió en el mensaje
news:bvh7bh$emc$1...@panix2.panix.com...
WillStG
<< A 23-24 dB A selfnoise is not inconsiderable in today's digital recording.
"dither" it.
Today, with the quieter moments of a symphony, I'm guessing the selfnoise could
be quite audible. Especially if the recording then undergoes any sort of gain
reduction processing. >>
Hey, I never recommended using them as mains on an orchestra or for far
micing! I may appreciate cheap mics but I am still a little bit sane. What I
said was they are bit noisy, but if you can work around that (loud sources,
close micing or a room with some background noise), they do sound pretty good
and are very inexpensive.
Suso disagreed the ECM8000's are good mics because of 1. Noise and 2. he
says they are prone to distortion at high volumes. He did plot the frequency
response of the mic, but that doesn't tell you how a mic _sounds_. And
listening on a system (USBPre) that is known to add 4db of noise at 1k may be
overly handicapping a mic that is noisy in the first place, the extra 4 db
kicking around could be enough to do that. As for distortion I certainly
haven't experienced any problems, and people who have used them on drums
haven't reported that either. However.
I was enjoying playing a little fingerstyle jazz on my archtop Gretch New
Yorker into one of my ECM 8000's at 8-10" out, and was hitting 0VU with the
self-noise being far enough in the background that it wasn't really a problem
for me. Then my 4 year came downstairs, grabbed the mic around the head, put
it to his lips and screamed into it "CAN YOU HEAR ME!!!!" as loud as he
could... YOW! Lucky I didn't have the headphones on and didn't have a KM83 or
MKH40 out. And lucky that the Behringer has a 1 year warranty, because it's
signal to noise ratio is _really_ awful right now....
Scott Dorsey
>
>Maybe the USA mic are different type than the Europe model, or two different
>editions. The ECM mics that I tried are old (more of 3 years).
I bet there are at least two different editions. I know that, for example,
there are at least three different circuits inside the Oktava 219 mikes.
They all have the same model, but depending on when you bought it, it could
have something different.
>I will try to get a new ECM for see if Behringer changes the mic inside.
I would think that just ohmmeter readings between the signal pins and
ground would make it very clear if a unit has a transformer or not. You
should be able to check that in the shop without actually buying one.
Bob Cain
WillStG wrote:
>
> listening on a system (USBPre) that is known to add 4db of noise at 1k
Huh?
Bob
Les Cargill
>
> Hello Scott,
>
> For 35$ is a big deal, but for 10$ you can DIY a better mic (With a real
> Panasonic). The ECM8000 have a transformer.
>
> I agree with you that the noise and distortion aren't important for the
> work, but Will said that is a good mic for recording and I don't agree.
>
Dunno - I'd rather have a set of Schoeps, but those things work *VERY * well
for $35 microphones. For home based multitrack, they find lots and lots of
uses. I'm particularly fond of them on electric guitar.
> Cheers
>
> "Scott Dorsey" <klu...@panix.com> escribió en el mensaje
> news:bvf0kt$p5q$1...@panix2.panix.com...
> > Suso Ramallo <jram...@worldonline.es> wrote:
> > >
> > >I tried the ECM8000 with a GML pre with same results, my conclusion: is
> > >noisy
> >
> > It's noisy, but hell, what do you want for $35? The fact that it works at
> > all at that price is a miracle.
> >
> > That said, it should be pretty immune to loading, since it doesn't have
> > an output transformer, and it should be reasonably immune to variations in
> > phantom voltage, since it's an electret and doesn't have particularly high
> > current output stages. So it should work reasonably well with cheap
> preamps.
> >
> > It's designed as a cheap measurement mike, for God's sake. This is an
> > application where low distortion and low noise floor aren't really very
> > important, but reasonably flat frequency response and good off-axis
> response
> > are important. It does a better job of meeting the requirements than you
> > would expect for a $35 mike. It's no Schoeps, but it's $35.
> > --scott
> >
> > --
> > "C'est un Nagra. C'est suisse, et tres, tres precis."
--
Les Cargill
Les Cargill
>
<snip>
> I took an ECM 8000 apart yesterday.
>
> No transformer! For the price of an ECM8000 there would be a transformer as
> good as this mic? I don't think so!
>
Arny, I just took the XLR out of the XLR end of mine, and there was a
transformer. Maybe there's more than one version about?
A measurement mic with a transformer? Bizarre.... wish I could chamber
test it to see whassup...
> Inside an WCM 8000 there is a transistor, an IC, two electrolytics, and
> assorted small resistors and capacitors. Seems like there should be a zener
> but I didn't find it right off. Given that only one of the electrolytics is
> rated at 50 volts, there's a real good chance that its output is not fully
> balanced.
>
> BTW, I don't recommend that anybody take an ECM 8000 apart just for fun.
> They're not that hard to take apart and I was very gentle with mine. But it
> took a some fine soldering to get mine to work, when I tried to put back
> together. There are some hair fine wires that broke when I tried to gently
> shake the circuit card out of the case. Mine didn't have enough lead length
> to reassemble in any practical way.
>
> > I agree with you that the noise and distortion aren't important for the
> work, but Will said that is a good mic for recording and I don't agree.
>
> BTW, Suso your claims about distortion are 100% unsubstantiated. Given that
> the ECM 8000 is basically a measurement mic, there's an extreme likelihood
> that its acoustic clipping point is someplace above 114 dB, given that this
> is the SPL that is commonly used for SPL calibration.
--
Les Cargill
Bob Cain
Les Cargill wrote:
>
> Arny Krueger wrote:
> >
> <snip>
>
> > I took an ECM 8000 apart yesterday.
> >
> > No transformer! For the price of an ECM8000 there would be a transformer as
> > good as this mic? I don't think so!
> >
>
> Arny, I just took the XLR out of the XLR end of mine, and there was a
> transformer. Maybe there's more than one version about?
Yeah, the ones I bought several years ago to accompany the
Ultra-Curve (which hasn't seen power in slightly less than
several years ago) also had transformers.
WillStG
<< WillStG wrote:
> listening on a system (USBPre) that is known to add 4db of noise at 1k
Huh? >>
This is what I have read about the USBPre.
http://wahiduddin.net/tech/usbpre.htm
" There are noticeable harmonics at 1 kHz, 2 kHz, 3 kHz and 4 kHz that pop up
about 12 dB above the noise floor when using the mic inputs with the gain knobs
set around the 3 o'clock position and the phantom power turned off.
With the phantom power turned on, the 1 kHz whine is only about 3 or 4 dB
above the noise floor, but still easily noticeable, and quite obnoxious.
A 1 kHz audio whine that rises 12 dB above the noise floor is quite a curse
on a piece of audio equipment. In many cases the audio background noise will
mask this flaw, but nonetheless, the whine is still undesirable.
It is interesting to note that the Roland UA-30 jack-of-all-trades USB
audio device suffers from the same audio whine, occurring at exactly the same
frequencies and at a slightly greater amplitude.
Sound Devices acknowledges this problem and says that it is caused by the
1ms isochronous data transfer in the USB stream which is leaking into the
audio. They do expect to have it fixed in all future deliveries, and they will
upgrade the existing 80 or so units that have been shipped.
I recently upgraded to version 1.5 and I am happy to report that the 1 kHz
whine has indeed been removed from the recorded audio, but unfortunately the 1
kHz whine is still present in the audio playback."
http://www.nvo.com/winmls/discussion1/list.nhtml?profile=discussion1
"The USBPre is a USB device with built-in microphone preamplifier and phantom
power (48 Volts). Very nice, but because of synchronization problems it can’t
be used for MLS measurements. This is because the AD and DA do not use the same
clock. If you use the device peforming MLS measurements, you will see that the
high frequency will roll off, and the roll-off will increase as you increase
the total length of the measurement (the small difference in sampling frequency
becomes more important when the measurement length increases)."
Bob Cain
WillStG wrote:
>
> " There are noticeable harmonics at 1 kHz, 2 kHz, 3 kHz and 4 kHz that pop up
> about 12 dB above the noise floor when using the mic inputs with the gain knobs
> set around the 3 o'clock position and the phantom power turned off.
Thanks for the heads up. Several other forums and lists I
attend recommend this box highly and I haven't heard this
problem reported.
>
> "The USBPre is a USB device with built-in microphone preamplifier and phantom
> power (48 Volts). Very nice, but because of synchronization problems it can’t
> be used for MLS measurements.
This is of even more signifigance to those same folks.
Thanks.
WillStG
<< Thanks for the heads up. Several other forums and lists I
attend recommend this box highly and I haven't heard this
problem reported. >>
Well - they were supposed to fix it the USB bleed problem on the outputs
but I haven't read that they have, and the guy who wrote about it didn't have
anything more recent to say on the matter beyond his first update where they
fixed the problem on input.
The asynchronous A/D - D/A situation is only supposed to be a problem with
WinMLS if you're doing MLS, if you're using sine sweeps they say it's ok.
Arny Krueger
news:401C8ABC...@arcanemethods.com
> Les Cargill wrote:
>>
>> Arny Krueger wrote:
>>>
>> <snip>
>>> I took an ECM 8000 apart yesterday.
>>> No transformer! For the price of an ECM8000 there would be a
>>> transformer as good as this mic? I don't think so!
>> Arny, I just took the XLR out of the XLR end of mine, and there was a
>> transformer. Maybe there's more than one version about?
I guess. I was pretty shocked when I saw the pictures at
http://www.imagendv.com/altavoces/micro_med.htm
My apologies to Suso for saying that he was talking out of the back of his
neck. He was just looking at different microphones that were sold under the
same model number.
Whoda thunk?
> Yeah, the ones I bought several years ago to accompany the
> Ultra-Curve (which hasn't seen power in slightly less than
> several years ago) also had transformers.
Wow, that's a big change. Whoda thunk?
I wonder if we can figure out when the big change was made, and what effects
it had on the performance of the product.
A major difference between the ECM-8000 and the corresponding Panasonic
capsule relates to how the capsule in each is mounted.
http://www.lasalademaquinas.com/panasonic.jpg shows no mounting at all.
It's pretty well known that the performance of mic capsules is often
degraded by mounting them. When I use Panasonic capsules, they are generally
press-fit into the end of a piece of roughly 1/4" brass pipe, shimmed a
little if necessary for a tight fit.
Because of the mounting of the capsule in an ECM8000, it is impossible to
put its capsule really close to a Panasonic capsule or the diaphragm some
other microphone. Therefore a raft of small measured differences can be
expected when it is compared to other mics.
In case someone doesn't have an ECM8000 to look at, it uses an approx 1/4"
capsule mounted in a brass fitting that is about 3/8" in diameter. A number
of radial grooves have been cut from the edge of the capsule to the outer
circumference of the brass fitting. This probably reduces or eliminates a
number of acoustical effects that could be expected if the capsule were
mounted on a flat piece of metal.
http://www.imagendv.com/altavoces/images/behring1.jpg shows a rear view of
the brass fitting. At least I presume that the fitting was brass at the
time, as in any case, it's got a silvery coating on it. The case of ECM-8000
I disassembled seems to be composed of three pieces, that press fit
together. I was able to get the two largest diameter pieces to separate, but
not the brass fitting at the tip.
http://www.imagendv.com/altavoces/images/ecm8000.jpg kinda shows the radial
grooves.
If you compare
http://www.sweetwater.com/images/products/Earthworks/M30-large.jpg , you see
that Earthworks also mounts the capsule at the end of a smaller piece of
pipe, without the slotted adaptor place that Behringer uses.
http://www.sweetwater.com/images/products/DPA/DPA4006-large.jpg shows
another variation, but with radial grooves.
Based on how the capsules are mounted, close comparisons with two Earthworks
M30s and Panasonic capsules mix or match, should give close results because
the capsules can be places quite close to each other. This would not be true
for comparisons involving 4006s or ECM 8000s because of how the capsules are
mounted on slotted adaptor plates.
Suso Ramallo
The USBPre are the 1.5 with the last drivers, no noise on the input (Like
say your artichle), repeat: I only use the input.
Loop test of my USBpre
http://www.lasalademaquinas.com/USBPre%20Miic%20in.htm
Where is the noise?
Cheers
"WillStG" <wil...@aol.comnospam> escribió en el mensaje
news:20040201004418...@mb-m28.aol.com...
Suso Ramallo
> Thanks for the heads up. Several other forums and lists I
> attend recommend this box highly and I haven't heard this
> problem reported.
This box are very good, the best USB powered box, the best box for
Smaartlive.
This problem is only for the WinMLS, curious.
Cheers
Suso Ramallo
> Dunno - I'd rather have a set of Schoeps, but those things work *VERY *
well
> for $35 microphones. For home based multitrack, they find lots and lots of
> uses. I'm particularly fond of them on electric guitar.
I didn't talked about the price tag (Only the mic quality), for measure you
can DIY a 10$ with better response.
Of course that a 35$ can't offer so much, and the electric guitar are a high
SPL instrument , perfect for a high self noise mic.
Classical recording isn't a good work for this microphone.
Cheers
Scott Dorsey
>
>A measurement mic with a transformer? Bizarre.... wish I could chamber
>test it to see whassup...
You don't need to. Remove the capsule and inject some signal through a
coupling capacitor into where the capsule was. You should be able to get
a nice response plot of the electronics, less the capsule.
I know what the response of those capsules is like, and it's really not
all that bad. I'll see if I can dig up a plot. Those are basically Chinese
copies of the Panasonic cheapies. And they come pretty close to the
Panasonics.
WillStG
<< The USBPre are the 1.5 with the last drivers, no noise on the input (Like
say your artichle), repeat: I only use the input. >>
Actually the article clearly says the problem on input was fixed, but still
remains on the output. I wasn't clear on if you evaluated the noise factor by
listening to the outputs of the USBPre or not.
<< Loop test of my USBpre
http://www.lasalademaquinas.com/USBPre%20Miic%20in.htm
Where is the noise? >>
You did an input to output line loop test, the reviewer at
http://wahiduddin.net/tech/usbpre.htm did his test a little differently with
resistors accross the mic inputs.
"For this test, I used no input, just an XLR connector with a 150 ohm resistor
from pin 2 to pin 3 at each mic input."
And I don't really know how to read test data so well Suso, but it seems
to me that his reports of audible whine at 1k and and harmonics of that
occuring in the USBPre look a _lot_ like your charts of THD + Noise, look at
the massive spike at 1K and the harmonics. Did he test the device incorrectly
do you think? If not, maybe you could try his method of testing the micpres
(you just tested the line in to lineout in loop, yes?) and see what the results
are.
"There are noticeable harmonics at 1 kHz, 2 kHz, 3 kHz and 4 kHz that pop up
about 12 dB above the noise floor when using the mic inputs with the gain knobs
set around the 3 o'clock position and the phantom power turned off.
With the phantom power turned on, the 1 kHz whine is only about 3 or 4 dB above
the noise floor, but still easily noticeable, and quite obnoxious.
A 1 kHz audio whine that rises 12 dB above the noise floor is quite a curse on
a piece of audio equipment. In many cases the audio background noise will mask
this flaw, but nonetheless, the whine is still undesirable."
Will Miho
Suso Ramallo
> And I don't really know how to read test data so well Suso, but it
seems
> to me that his reports of audible whine at 1k and and harmonics of that
> occuring in the USBPre look a _lot_ like your charts of THD + Noise, look
at
> the massive spike at 1K and the harmonics. Did he test the device
incorrectly
> do you think? If not, maybe you could try his method of testing the
micpres
> (you just tested the line in to lineout in loop, yes?) and see what the
results
> are.
The 1kHz is a tone for check the THD, the armonics are the distortion (thrid
armonic at 95dBFS). I used a automatic measure software.
The only spike I found is a 15 kHz on the noise floor chart,. and small
spikes at 50Hz, 200Hz, 250Hz, 300Hz, 550Hz, 850Hz and 950Hz, all below
120dBFS, is really very good for a mic preamp with ADC.
Is not a reference, but is a very good preamp with ADC/DAC, IMMO the best
USB powered sound card.
I don't agree with the review, he tested a old unit (v. 1) with old drivers,
he upgraded the unit to 1.5 version and resolve the problem, sic. "I
recently upgraded to version 1.5 and I am happy to report that the 1 kHz
whine has indeed been removed from the recorded audio", but he tested the
unit with a old drivers (2001 review).
Cheers
Arny Krueger
> Hello,
>
> The USBPre are the 1.5 with the last drivers, no noise on the input
> (Like say your artichle), repeat: I only use the input.
>
> Loop test of my USBpre
>
> http://www.lasalademaquinas.com/USBPre%20Miic%20in.htm
> Where is the noise?
Where is the mic input being used as it would be used with a mic? You know,
with a low-level signal, more specifically a signal so low that the gain
would be set at 3 o'clock.
This test obviously shows either a line input, or a mic input with the gain
turned down so far that it is effectively a line input. If it's the latter,
its pretty impressive all by itself, but it is still irrelevant to the
question at hand.
WillStG
<< The only spike I found is a 15 kHz on the noise floor chart,. and small
spikes at 50Hz, 200Hz, 250Hz, 300Hz, 550Hz, 850Hz and 950Hz, all below
120dBFS, is really very good for a mic preamp with ADC.
>>
Umm - but isn't that a line level test? The reviewer was getting 1k noise
and harmonics from the _micpres_, do you use the micpres on the USBPre?
Suso Ramallo
Yes, is a mic preamp test. The line in are a bit better.
Cheers
"WillStG" <wil...@aol.comnospam> escribió en el mensaje
news:20040202080747...@mb-m05.aol.com...
WillStG
>Yes, is a mic preamp test. The line in are a bit better.
Could you try the micpre test with a dummy load and the gain set higher, to
around 3 oclock where the reviewer was getting all the anomalies? Because if
the USBPre has actually solved the problems that people were having with it in
practical use, that info would be good to put out.
Len Moskowitz
David Satz <DS...@msn.com> wrote:
>But no microphone of this size (20 mm diameter) can possibly have the same
>high-frequency response on-axis as it has off-axis. That is a matter of
>basic acoustical physics. The major dimensions of the microphone, for some
>given range of high frequencies, form a significant fraction of the sound
>wavelengths. The microphone then begins to bend the sound field around
>it.
Have a look at the DPA 4003/4006 omni with the UA0777 nose cone: it has
a near perfect polar pattern at all frequencies.
--
Len Moskowitz PDAudio, Binaural Mics, Cables, DPA, M-Audio
Core Sound http://www.stealthmicrophones.com
Teaneck, New Jersey USA http://www.core-sound.com
mosk...@core-sound.com Tel: 201-801-0812, FAX: 201-801-0912
Peter Larsen
> David Satz <DS...@msn.com> wrote:
> >But no microphone of this size (20 mm diameter) can possibly have the same
> >high-frequency response on-axis as it has off-axis. That is a matter of
> >basic acoustical physics. The major dimensions of the microphone, for some
> >given range of high frequencies, form a significant fraction of the sound
> >wavelengths. The microphone then begins to bend the sound field around
> >it.
> Have a look at the DPA 4003/4006 omni with the UA0777 nose cone: it has
> a near perfect polar pattern at all frequencies.
This because the cone prevents the "druckstau" that is the cause of the
treble boost on axis.
> Len Moskowitz PDAudio, Binaural Mics, Cables, DPA, M-Audio
Kind regards
Peter Larsen
--
*******************************************
* My site is at: http://www.muyiovatki.dk *
*******************************************
Bob Cain
Peter Larsen wrote:
>
> > Have a look at the DPA 4003/4006 omni with the UA0777 nose cone: it has
> > a near perfect polar pattern at all frequencies.
>
> This because the cone prevents the "druckstau" that is the cause of the
> treble boost on axis.
Whoosh, right over my head. Could you explain that, Peter?
Thanks,
Peter Larsen
> Peter Larsen wrote:
>>> Have a look at the DPA 4003/4006 omni with the UA0777
>>> nose cone: it has a near perfect polar pattern at all
>>> frequencies.
>> This because the cone prevents the "druckstau" that is the cause of the
>> treble boost on axis.
> Whoosh, right over my head. Could you explain that, Peter?
Baffle Diffraction Step in reverse ... in effect it causes a 6 dB on
axis bulge if you want off axis linearity. See also
http://www.dpamicrophones.dk, ask again if need be.
> Bob
Len Moskowitz
>Baffle Diffraction Step in reverse ... in effect it causes a 6 dB on
>axis bulge if you want off axis linearity. See also
>http://www.dpamicrophones.dk, ask again if need be.
DPA puts it like this:
[Begin]
The Nose Cone UA0777 is available as an optional accessory . As with the
Diffuse-field Grid DD0297, the Nose Cone is simply screwed onto the
microphone cartridge in place of the Nearfield Grid DD0251. When fitted,
the Nose Cone gives the microphone a true omnidirectional response even
at high frequencies (see Fig. 7) and a linear diffuse-field response
(see Fig. 5). These qualities are useful at any distance for an even
tonal balance of sound arriving at all angles of incidence, e.g. room
reverberation or several sound sources placed around the microphone. The
diaphragm is placed in a slot behind the solid cone and sound waves only
have access to the diaphragm through the side of the Nose Cone. This way
the Nose Cone prevents an on-axis, high frequency sound pressure
build-up on the microphone, which is the reason for normal flat fronted
omnidirectional microphones becoming more and more directional for
higher frequencies. There is, however, a slight high frequency boost on
axis.
[End]
You can see the polar and frequency response curves here:
http://www.dpamicrophones.com/eng_pub/Products/Item-4003-5.html
--
Len Moskowitz PDAudio, Binaural Mics, Cables, DPA, M-Audio
David Satz
> This because the cone prevents the "druckstau" that is the cause of the
> treble boost on axis.
whereupon Bob Cain wrote:
> Whoosh, right over my head. Could you explain that, Peter?
"Druckstau" is usually translated as "pressure buildup". The flat front
surface of a cylindrical microphone capsule causes reflections similar in
principle to what happens in a PZM, except that they happen only at high
frequencies because the reflecting surface is so small.
David Satz
> Have a look at the DPA 4003/4006 omni with the UA0777 nose cone: it has
> a near perfect polar pattern at all frequencies.
Did you notice the scale of that graph? It's 10 dB per division, unlike
all the other polar response graphs on the same Web page. So in reality
the polar response above 1 kHz is actually quite, um, interesting. It's
mostly in the range of 4 - 5 dB below normal above 4 kHz, at most angles
of sound incidence beyond an extremely narrow front angle, but with
rather "turbulent" characteristics; at some angles and frequencies it's
off by as much as 7 dB.
This indicates a general lessening of the "beaminess" that would be typical
of microphones of this size, but not a categorical improvement--particularly
for audio recording, as opposed to making acoustical measurements that are
intended to be averaged anyway (which would help to overcome the roughness
of the polar response).
--On the same Web page is a frequency response graph which they give for
this same range of capsules with the nose cone attached. It is labeled
"On-axis and diffuse-field responses"--yet it shows only a single curve,
with no tolerance field indicated. This would imply that there is no
significant difference between the on-axis and diffuse-field response.
But if you take the polar response graphs seriously then you must realize
that this frequency response graph _cannot possibly_ represent all angles
of sound incidence simultaneously, except in a highly prettied-up fashion.
Nor, in fairness, is that curve presented visually as the result of a
particular measurement the way the polar graph is; it's clearly the work
of a graphic artist or draftsperson. Still, this assumes that the reader
will be attentive enough to recognize and understand it as such.
The kicker is this: For sound recording purposes they've got the whole
idea backwards anyway--they've put the nose cone on a capsule which already
has an elevated high-frequency response for use in the diffuse sound field.
The result is a curve that I think rather few engineers would choose.
The neat trick would be if they could produce a nice, quiet microphone with
flat response that doesn't peak in front _or_ roll off to the sides and back.
But that would require magic, or some other acoustical medium besides air.
Len Moskowitz
David Satz <DS...@msn.com> wrote:
>"Druckstau" is usually translated as "pressure buildup". The flat front
>surface of a cylindrical microphone capsule causes reflections similar in
>principle to what happens in a PZM, except that they happen only at high
>frequencies because the reflecting surface is so small.
Another way to look at it is as a sudden change of impedance. For a
speaker, the propagation of the wave from the driver at first encounters
the baffle; at the edge of the baffle it no longer "sees" the baffle but
rather open space.
A symmetrical effect occurs with sound waves impinging on a microphone
element.
The UA0777 nose cone trades off frequency flatness for polar pattern
uniformity.
--
Len Moskowitz PDAudio, Binaural Mics, Cables, DPA, M-Audio
Len Moskowitz
>--On the same Web page is a frequency response graph which they give for
>this same range of capsules with the nose cone attached. It is labeled
>"On-axis and diffuse-field responses"--yet it shows only a single curve,
>with no tolerance field indicated. This would imply that there is no
>significant difference between the on-axis and diffuse-field response.
It's mislabeled -- that graph is on-axis only and shows the expected
nose cone trade-off of a roughly +5 dB peak.
The diffuse-field graph is a few graphs below that one. It shows
essentially a flat response to 15 kHz and then a roll-off to -6 at 20
kHz.
>The kicker is this: For sound recording purposes they've got the whole
>idea backwards anyway--they've put the nose cone on a capsule which
>already has an elevated high-frequency response for use in the diffuse
>sound field. The result is a curve that I think rather few engineers
>would choose.
I don't understand what you're saying here. The diffuse field frequency
response graph for the 4003/4006 with the DD0251 near field grid (the
standard silver one) shows a gentle 10 dB roll-off from around 3
kHz to 25 kHz. The on-axis response is flat within +/- 2 dB (typicallyb
much tighter) from 10 Hz (20 Hz for the 4006) to 20 kHz.
With the UA0777 nose cone, the diffuse-field response is essentially
flat to 10 kHz and then it rises roughly +1 dB at around 12 kHz and then
drops to roughly -6 dB at 20 kHz.
How is it a "capsule which already has an elevated high-frequency
response"?
>The neat trick would be if they could produce a nice, quiet microphone
>with flat response that doesn't peak in front _or_ roll off to the sides
>and back. But that would require magic, or some other acoustical medium
>besides air.
Well, it is nice and quiet (typically 15 dBa) and does have a very flat
frequency response. That's quite a lot already, no?
If you heard it with the nose cone you might change your mind: it really
sounds like it has a uniform polar pattern, more omni than any other
omni I've heard.
And by the way, it's a 16mm capsule.