SPL rating on Shure Beta 57a?
HiC
find it anywhere, not on their website, not in any of the tech data
with the mic, which is odd since any other mic I've ever seen listed
this.
Analogeezer
Not to be a smartypants but does it really matter? I think you could
record jet engines with the thing before it bottomed out.
I've never crushed mine with anything loud, including snare drums that
hurt my ears in the room from 15 feet away.
Analogeezer
HiC
> Not to be a smartypants but does it really matter?
Okay. I won't ask any more questions that don't effect your life or
that you don't have a personal curiosity about. I'll run them all past
you first.
Don't worry, your answer will in no way convince me that you or your
pants are smart.
Now, anyone who doesn't feel an overwhelming urge to waste bandwidth
with pointless editorial comments have an answer? Thanks!
Harvey Gerst
>Okay. I won't ask any more questions that don't effect your life or
>that you don't have a personal curiosity about. I'll run them all past
>you first.
>
>Don't worry, your answer will in no way convince me that you or your
>pants are smart.
>
>Now, anyone who doesn't feel an overwhelming urge to waste bandwidth
>with pointless editorial comments have an answer? Thanks!
Here's Shure's answer to your question:
Question: What is the maximum sound pressure level that a dynamic microphone can
handle without distortion?
Answer: Realistic Maximum Sound Pressure Levels for Dynamic Microphones
Microphone users often ask "What is the maximum sound pressure level that a
dynamic microphone can handle without distortion?" Using the Shure SM58 as an
example of a typical dynamic microphone, Shure Engineering performed experiments
to answer this question. Like most technical matters, the answer is not simple.
As a point of reference, 140 dB SPL is the accepted threshold of pain for the
human ear. The maximum sound pressure level (max SPL) from a human voice as
measured by Shure is 135 dB SPL at 1 inch from the mouth. A kick drum played
very loudly may exceed 140 dB SPL, but has never been measured by Shure above
150 dB SPL. The loudest orchestral instrument, a trumpet, can theoretically
produce a MAX SPL of 155 dB SPL at 1 inch, but only in its upper register. Note
that the distribution of energy (sound pressure) in speech, music, and noise is
dependent on the frequency. For example, the human voice does not produce much
energy below 100 Hz and its frequency of MAX SPL would be higher than 100 Hz.
Exactly how much higher depends on the individual voice.
Unlike a condenser microphone which has internal electronics that may overload,
a dynamic microphone distorts when its diaphragm hits a physical barrier, like
the magnetic pole piece, and can move no further. The excursion of the diaphragm
is frequency dependent and the excursion is greatest at the resonant frequency
of the diaphragm. Therefore, the MAX SPL of a dynamic microphone like the SM58
is frequency dependent. This means that low frequencies will produce distortion
at a lower SPL than higher frequencies.
For the SM58, the frequency range to first exhibit distortion is centered around
100 Hz, close to the resonant frequency of the microphone's diaphragm. At 100
Hz, the measured MAX SPL is 150 dB SPL and the electrical output of the
microphone is 0 dB V or 1.0 volts. Note this is a line level signal, not a mic
level signal.
In the 1 kHz range, the SM58 measured MAX SPL is about 160 dB SPL due to the
change in microphone sensitivity at the higher frequencies. The electrical
output of the microphone at 160 dB SPL is +10 dBV or 3.2 volts.
In the 10 kHz range, 180 dB SPL is the MAX SPL of the SM58. However, this is a
calculated measurement as Shure Engineering had no means to create such enormous
and dangerous SPL. For comparison, NASA reports that a space shuttle launch
measures 180 dB SPL and higher at 10 meters.
In the 20 kHz range, the MAX SPL is calculated to be around 190, due to the
response falloff of the SM58. But now the point of absurdity has been reached
because at 194 dB SPL the sound pressure varies from twice normal atmospheric
pressure (at the wave peak) to a total vacuum (at the wave trough). Plus the
sound source must be moving at the speed of sound just to generate a wave of
this intensity.
In summary, a well-designed dynamic microphone of professional quality will
never reach its distortion point in "normal" conditions. If one does encounter
distortion when using a professional dynamic microphone for an extremely loud
source, it is most likely that the electrical output of the microphone is
clipping the input of the microphone preamplifier. [Remember that at 150 dB SPL,
the SM58 will provide a line level output!] To solve this problem, an in-line
attenuator ("pad") must be placed before the preamplifier input, or the
microphone must be moved farther from the sound source. In general, the sound
pressure level will decrease 6 dB for each doubling of the distance.
Harvey Gerst
Indian Trail Recording Studio
http://www.ITRstudio.com/
Patric D'Eimon
use the word smartypants in a sentence. In fact I get to use the word
smartypants 3 times. And don't worry about it. We are audio
professionals, we can spare the bandwidth. ;-)
HiC
> >
> >Now, anyone who doesn't feel an overwhelming urge to waste bandwidth
> >with pointless editorial comments have an answer? Thanks!
>
> Here's Shure's answer to your question:
>
> Question: What is the maximum sound pressure level that a dynamic microphone can
> handle without distortion?
>
> Answer: Realistic Maximum Sound Pressure Levels for Dynamic Microphones
> In summary, a well-designed dynamic microphone of professional quality will
> never reach its distortion point in "normal" conditions. If one does encounter
> distortion when using a professional dynamic microphone for an extremely loud
> source, it is most likely that the electrical output of the microphone is
> clipping the input of the microphone preamplifier. [Remember that at 150 dB
> SPL, the SM58 will provide a line level output!]
Thanks Harvey. Great answer. So, if it varies depending on frequency,
where do they get the SPL rating for all the mics that have a rating
listed? (like almost any other mic I've seen besides this Beta 57a)
Harvey Gerst
>Harvey Gerst <har...@ITRstudio.com> wrote:
>> Here's Shure's answer to your question:
>>
>> Question: What is the maximum sound pressure level that a dynamic microphone can
>> handle without distortion?
>>
>> Answer: Realistic Maximum Sound Pressure Levels for Dynamic Microphones
>
>> In summary, a well-designed dynamic microphone of professional quality will
>> never reach its distortion point in "normal" conditions. If one does encounter
>> distortion when using a professional dynamic microphone for an extremely loud
>> source, it is most likely that the electrical output of the microphone is
>> clipping the input of the microphone preamplifier. [Remember that at 150 dB
>> SPL, the SM58 will provide a line level output!]
>Thanks Harvey. Great answer. So, if it varies depending on frequency,
>where do they get the SPL rating for all the mics that have a rating
>listed? (like almost any other mic I've seen besides this Beta 57a)
Usually from the marketing department. And I'm perfectly serious. Max SPL is
usually measured at 0.5% or at 1% distortion, but if the number doesn't look
good, it's changed, by the marketing department.
Now that may not be the answer you really wanna hear, but that's usually the
correct answer. Once you get to 130dB or so level, nobody really can tell what's
doing the distorting anyway.
Analogeezer
Actually asking what the max SPL of a Beta 57A is pretty much a
pointless editorial question that wastes bandwith...so who is
counting?
If you had asked what one sounded like, or what people use it for,
that might have prompted a different reply. Then again it would be
just an opinion, and you obviously want your information from a spec
sheet.
As Harvey G has indicated, the max SPL of this microphone is beyond
what you are likely to generate.
If you had read my first post you would have seen that I had said
basically the same thing, only without the technical specifications.
Analogeezer
HiC
>
>
> Actually asking what the max SPL of a Beta 57A is pretty much a
> pointless editorial question that wastes bandwith...so who is
> counting?
I think I'm seeing why you're called geezer..I asked a specific
question about a specific mic. What makes this an "editorial"?
> If you had asked what one sounded like, or what people use it for,
> that might have prompted a different reply.
Well, if that's what I had wanted to know that's what I would have
asked. I already have an idea of what they get used for. However, if
you feel a quantifiable value like an SPL rating is useless, how much
more useless would someone's attempt to describe "what" a mic sounds
like?
> Then again it would be
> just an opinion, and you obviously want your information from a spec
> sheet.
I was looking for a data answer, yes. However, if someone knows an
data answer that's more accurate than the factory specs, that's even
better.
>
> As Harvey G has indicated, the max SPL of this microphone is beyond
> what you are likely to generate.
Well, actually that's not correct. I found the mic folding with a
trumpet about a foot away from the bell. From what I've read and heard
(as in with my ears) those 57's and Beta57a's are not bulletproof. I
was at a concert featuring a high note trumpet soloist and the
engineer had him blowing into a B&K mic (his own mic) as he didn't
like the SM 57's the trumpet section had (owned by this band), he felt
they were distorting. This is a guy who's done pro-engineering for
Disney and others over the years.
So, trying to get some kind of objective reference, I was curious what
kind of rating the Beta 57a had claimed for it.
> If you had read my first post you would have seen that I had said
> basically the same thing, only without the technical specifications.
Your answer wasn't an explanation, it was an editorial....
Harvey Gerst
Apparently, you didn't read my post too closely, so I'll repost what I consider
the relevant part from Shure's website:
"If one does encounter distortion when using a professional dynamic microphone
for an extremely loud source, it is most likely that the electrical output of
the microphone is clipping the input of the microphone preamplifier. [Remember
that at 150 dB SPL, the SM58 will provide a line level output!] To solve this
problem, an in-line attenuator ("pad") must be placed before the preamplifier
input, or the microphone must be moved farther from the sound source. In
general, the sound pressure level will decrease 6 dB for each doubling of the
distance."
Harvey Gerst
Harvey Gerst
Let me also add that the air blast coming from the trumpet has nothing to do
with the actual SPL of the note being played. If the mic axis is in line with
the horn bell, you can get clipping from the blast of air (which is easily
solved by moving the mic a little off axis). But that has nothing to do with
the max SPL of the mic. It's like a DC offset, limiting the travel of the
diaphragm and coil.
Mike Rivers
> > As Harvey G has indicated, the max SPL of this microphone is beyond
> > what you are likely to generate.
>
> Well, actually that's not correct. I found the mic folding with a
> trumpet about a foot away from the bell.
I suspect (from what Harvey G wrote) that the mic wasn't folding, your
preamp was. If the mic really can't take that trumpet a foot from the
bell, I would hate to be in the trombone section of that marching
band. You had a problem - a system problem or a defective mic - but
this is not normal. The only mic I've ever had a problem with on a
trumpet was a Beyer tie tack (because the Sony was on something else)
clipped to the bell. That was a bad sound.
--
I'm really Mike Rivers (mri...@d-and-d.com)
HiC
> Apparently, you didn't read my post too closely,
I read it, and thought it was an excellent answer. I was not similarly
pleased with AG's post, and didn't notice his most recent reply until
today.
However, since you posted it again, regarding:
> "If one does encounter distortion when using a professional dynamic microphone
> for an extremely loud source, it is most likely that the electrical output of
> the microphone is clipping the input of the microphone preamplifier.
I don't suppose that could be somewhat tinged with propaganda given
that it's from a mic manufacturer? Hey, it's your other gear's fault,
not our mic....
If the input level is set at some point reasonably below the max level
per the indicator lights on the preamp, wouldn't that rule out the
preamp doing the clipping? Especially if it happens with one mic and
not another at the same distance and level from the source?
Harvey Gerst
>Harvey Gerst <har...@ITRstudio.com> wrote:
>
>> Apparently, you didn't read my post too closely,
>I read it, and thought it was an excellent answer. I was not similarly
>pleased with AG's post, and didn't notice his most recent reply until
>today.
>
>However, since you posted it again, regarding:
>> "If one does encounter distortion when using a professional dynamic microphone
>> for an extremely loud source, it is most likely that the electrical output of
>> the microphone is clipping the input of the microphone preamplifier.
>I don't suppose that could be somewhat tinged with propaganda given
>that it's from a mic manufacturer? Hey, it's your other gear's fault,
>not our mic....
What possible reason would they have for claiming that their mics had such a
high SPL capability when their claim could be easily disproven with testing? If
putting a pad "after the mic eliminated the clipping, wouldn't that prove the
mic isn't the problem?
>If the input level is set at some point reasonably below the max level
>per the indicator lights on the preamp, wouldn't that rule out the
>preamp doing the clipping? Especially if it happens with one mic and
>not another at the same distance and level from the source?
That would depend on the sensitivity and maximum output of each mic, wouldn't
it? Seems like Shure's claim (that a pad AFTER the mic would solve the problem)
is easy to check to see if they're right.
Jny Vee
> > microphone
> > for an extremely loud source, it is most likely that the electrical output
> > of
> > the microphone is clipping the input of the microphone preamplifier.
In article <be867d2c.02101...@posting.google.com>,
brass...@yahoo.com (HiC) wrote:
>
> I don't suppose that could be somewhat tinged with propaganda given
> that it's from a mic manufacturer? Hey, it's your other gear's fault,
> not our mic....
please...
> If the input level is set at some point reasonably below the max level
> per the indicator lights on the preamp, wouldn't that rule out the
> preamp doing the clipping?
you haven;t been around too many blocks yet have you?
or if so maybe someone else was driving?
>Especially if it happens with one mic and
> not another at the same distance and level from the source?
more details
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news:be867d2c.02101...@posting.google.com
> If the input level is set at some point reasonably below the max
> level per the indicator lights on the preamp, wouldn't that rule
> out the preamp doing the clipping?
Not at all. The world is full of mic preamps with clipping indicators
that don't indicate all possible conditions where the mic preamp will
clip an input signal. Typically, we might more properly call these
indicators "output stage clipping indicators". Most mic preamps have
separate input stages. Just because the output stage isn't clipping
doesn't mean that the input stage isn't clipping.
> Especially if it happens with
> one mic and not another at the same distance and level from the
> source?
Not at all. The acoustical input to a microphone is dependent on more
different things than the level of the source and the distance to the
microphone. The only way I know of that two microphones can have the
identical same acoustical input is for them to coexist in the same
time and same place, which is difficult or impossible to achieve
under ordinary conditions.
The usual *right* way to address mic preamp input clipping has been
pointed out here many times, even quite recently. You put an
appropriate electrical attenuator between the mic and the preamp.
This may change more than input level to the mic preamp, but it will
reduce the clipping. If pursued sufficiently diligently, input
attenuation will eliminate mic preamp clipping. If overdone, it will
hurt noise performance.
Mike Rivers
> If the input level is set at some point reasonably below the max level
> per the indicator lights on the preamp, wouldn't that rule out the
> preamp doing the clipping? Especially if it happens with one mic and
> not another at the same distance and level from the source?
It depends on how the preamp is built and where the indicator is in
the signal chain. It's quite common with portable recorders (the Sony
Walkman DATs are particularly guilty of this) for the gain control to
follow the first stage, which always runs at a fixed gain. If there's
enough voltage coming out of the mic to clip that first stage, you can
turn it down all you want (making the meter read lower) and you'll
just make a nice clean recording of a clipped signal.
If you replace the mic with one of lower sensitivity, you'll get less
voltage going into the fixed gain stage, it (hopefully) won't clip,
and you won't get the distortion in your recording. So you think it's
the mic that's distorting because it's what you changed to make the
distortion go away, but it was actually the first gain stage after the
mic.
glenn drinkwater
> I don't suppose that could be somewhat tinged with propaganda given
> that it's from a mic manufacturer? Hey, it's your other gear's fault,
> not our mic....
No matter what you may think of their products from a sound quality
standpoint, two things are a given with Shure:
Their mics are built extremely well from the standpoint of real
world reliability, and they are a company that rates their products
very conservatively.
All companies have marketing departments, but Shure (and EV, too)
don't really engage in the fanciful specification BS that you'll see
from a lot of smaller, and newer, mic manufacturers and distributors.
If Shure says their product will perform in a certain way under
certain conditions, you can be confident it will do exactly what they
claim, at the very least. (Again, whether or not you like the sound is
a different matter) I have had the opportunity in the past to talk
with some of their design engineers, and they are quite candid and
open about the capabilities and limitations of their products.
In addition, Shure is a supportive and generous company. I used to
give sound and recording seminars at conventions aimed at folk
musicians, and Shure would send me stacks of expensive glossy
booklets, whenever I needed them, and at no charge, to use as handouts
to support my talks. These contained a lot of useful info on things
like frequency, SPL, polar patterns, PA basics, mic techniques, comb
filtering, etc., etc. with lots of charts, graphs, and photo
illustrations. The fact that they sent this stuff to _me_ is
remarkable, because I was/am an absolute nobody in the world of
professional music biz.
I may not love everything they make (and I like quite a bit of it,
BTW), but Shure is a great company by any standard of measure.
BTW, Analogeezer gave you a clear and succinct answer to your
question. I never ceased to be amazed that guys who don't know very
much want to jump ugly with pros who actually give them real answers
to their questions.
You might learn more if you decrease the amount of energy you waste
on insecure emotional reactions to relatively benign answers to your
questions.
-glenn
HiC
>
> You might learn more if you decrease the amount of energy you waste
> on insecure emotional reactions to relatively benign answers to your
> questions.
My question:
"Does anyone know what the SPL rating is on a Shure Beta 57a?"
AG's answer:
"Not to be a smartypants but does it really matter?"
You seem to have a curious concept of "a clear and succinct answer",
especially since, your acrimony aside, you and others gave excellent
answers. I was looking for a number but an explanation of what the
number really means is much more informative than "ah screw it, you
don't need to know that crap..."
I don't know if this guy is your nephew or something or you're just
feeling possessed by some "band of brothers" indignation, but since he
felt inclined to give a flip, non-specific answer to a specific
question, I gave a flip retort. I'm sure he's a knowledgeable,
competent engineer. In this case his answer may have been "relatively
benign", it was also pointless.
Jack Kontney
interpersonal stuff (always fun), a lot of good info has been passed.
As a Shure guy, long-time lurker, and occasional poster here, I just
wanted to clarify a couple things...
1. Shure's statements regarding SPL ratings and professional dynamic
microphones are pretty universal in nature. We don't publish SPL
ratings for those products because the spec, while impressive, in the
opinion of our engineering dept., is not meaningful.
2. While we don't speak for other manufacturers, our position on
stating SPL ratings for dynamic mics is more of a physics issue than a
Shure issue. At least for dynamics that are well-designed...
3. I urge Hi-C and all readers to utilize the Shure Applications
Engineering group for authoritative answers to both Shure-specific and
general audio questions. They publish an extensive, dynamic online
knowledge base and also respond directly via phone and email. Check
out www.shure.com/support.
Apologies if this is perceived as too commercial. Carry on.
-Jack Kontney
Director, Public Relations
Shure Incorporated
Kurt Albershardt
>
> 1. Shure's statements regarding SPL ratings and professional dynamic
> microphones are pretty universal in nature. We don't publish SPL
> ratings for those products because the spec, while impressive, in the
> opinion of our engineering dept., is not meaningful.
>
> 2. While we don't speak for other manufacturers, our position on
> stating SPL ratings for dynamic mics is more of a physics issue than a
> Shure issue. At least for dynamics that are well-designed...
Makes perfect sense, and I think similar info has been suggested
previously (if not in this particular thread.)
> Apologies if this is perceived as too commercial. Carry on.
Hardly. Intelligent commentary from manufacturers is always welcome
here, and will often lead to sales. The difference between
participation and spam is not hard to discern ;>