Acoustat 1 + 1 (sub recommendations?)
Christopher S. Kush
Medallion upgrade). My former speakers, Mirage M360s, have met their
daddy and are sitting in the corner pondering their total inferiority.
I've always wanted a pair of electrostatics, but I'm an armchair 'phile,
so I couldn't ever justify $1,000+ on speakers (I know there are cheaper
ones, but these kind of dropped into my lap...)
Anyhow, I'm currently driving them with a Carver HR722 receiver, which
claims 60WPC/8ohms, 90WPC/4ohms. I'd like to get them a subwoofer to
play with - I imagine it should probably be powered. The Carver seems
to handle the 1+1's acceptably, but I worry that the 'statics present
an exotic load, so I don't want to burden it anymore.
Any recommendations for a $400ish sub? I'd like to replace the receiver
too, at some point, so if you've got an idea for a new amp/sub combo that
totals less than a grand, that would be of interest as well. If you can
work McIntosh components in you get bonus points :)
They really are astounding compared to dynamic speakers. I am
particularly impressed with the way they handle strings - *much* better
than my old bookshelf speakers. My wife hasn't ever been interested in
stereo equipment at all - I got an indulgent smile when she first saw
them, but when I started spinning platters, she went crazy. Her comment
was something like, "I can imagine that if you turned up the volume it
wouldn't be *louder*, there would just be more sound."
--
Christopher S. Kush
(303) 661 7509
kus...@ib.stortek.com
Barry Waldron
>I just bought an associate's Acoustat 1+1's for $350 (they have the
>Anyhow, I'm currently driving them with a Carver HR722 receiver, which
>claims 60WPC/8ohms, 90WPC/4ohms. I'd like to get them a subwoofer to
>play with - I imagine it should probably be powered. The Carver seems
>to handle the 1+1's acceptably, but I worry that the 'statics present
>an exotic load, so I don't want to burden it anymore.
The "exotic load" comes from the high end rather than the low end.
The impedance of an electrostat is the inverse of the frequency,
being very low (~1-2 ohms) at 20K Hz., and several hundred ohms
at 30 Hz. Therefore, if an amplifier is going to have a problem with
highly reactive loads, it will be with the reproduction of higher frequenies
at higher SPLs.
Any low frequency burdon is primarily the result of insufficient voltage.
Full range electrostats will do better with amplifiers above 150 w/p/c,
as a general rule. (The new InnerSound ESL amplifier is capable of
developing over 10KV, depending upon the product's matching
transformer(s).)
>Any recommendations for a $400ish sub?
I recommend the Hsu Research VTF-2 at $499.00, factory direct.
It is a very nice woofer, and includes the amp.
If you want to replace your receiver with separates, try and find a
Hafler DH-500 amplifier on the used market for the Acoustats. It
should be priced under $400. I have no recommendations for a
tuner.
I hope this is of help.
Barry
ESL Information eXchange
http://www.jps.net/eslinfo
..
Dennis Moore
You might try some McIntosh 752 or 754 amps. They should
be available for $500 or so. The speakers you have could use
more power, but the Macs are enough if you don't have a huge
room. I used a 752 on some Acoustat Two's for a few years.
These Macs have a very nice clipping prevention circuit. It
means you can push them as hard as you wish and not
hurt the amp or speakers. The circuit also prevents the amp's
distortion from becoming objectionable.
If you plan on a subwoofer, I would suggest looking for a used
Conrad-Johnson MV-45 or MV-50. These are beautiful, and
reliable tube amps of about 45 watts. Electrostats just love
tube amps and these CJ's would be in your budget. It is what
I replaced my Mac 752's with and I never regretted it even
though I didn't use a subwoofer. I would even suggest you
obtain one of these CJ's without a subwoofer for what it is
worth.
Good luck,
Dennis
PS-The perfect subwoofer match with the electrostatic panel
speaker is something of a "holy grail" among audiophiles. I
would suggest you take some wise counsel from those of us
who have tried subs+e'stats and just forget about the sub-
woofer. Simply enjoy what those speakers can do that is
right just the way they are.
"Christopher S. Kush" <kus...@ib.stortek.com> wrote in message
news:8dq4iv$r9l$1...@bourbaki.localdomain...
> I just bought an associate's Acoustat 1+1's for $350 (they have the
> Medallion upgrade). My former speakers, Mirage M360s, have met their
> daddy and are sitting in the corner pondering their total inferiority.
>
> I've always wanted a pair of electrostatics, but I'm an armchair 'phile,
> so I couldn't ever justify $1,000+ on speakers (I know there are cheaper
> ones, but these kind of dropped into my lap...)
>
> Anyhow, I'm currently driving them with a Carver HR722 receiver, which
> claims 60WPC/8ohms, 90WPC/4ohms. I'd like to get them a subwoofer to
> play with - I imagine it should probably be powered. The Carver seems
> to handle the 1+1's acceptably, but I worry that the 'statics present
> an exotic load, so I don't want to burden it anymore.
>
Tony
>Medallion upgrade). My former speakers, Mirage M360s, have met their
>daddy and are sitting in the corner pondering their total inferiority.
Congratulations! I have had these speakers for close to 15yrs. I love them.
I haven't heard anything in a reasonable price range that would make me
change my mind. And at the price you got them, they are a "steal".
>Anyhow, I'm currently driving them with a Carver HR722 receiver, which
>claims 60WPC/8ohms, 90WPC/4ohms. I'd like to get them a subwoofer to
>play with - I imagine it should probably be powered. The Carver seems
>to handle the 1+1's acceptably, but I worry that the 'statics present
>an exotic load, so I don't want to burden it anymore.
>Any recommendations for a $400ish sub? I'd like to replace the receiver
>too, at some point, so if you've got an idea for a new amp/sub combo that
>totals less than a grand, that would be of interest as well. If you can
>work McIntosh components in you get bonus points :)
I originally powered my speakers with a Carver 1.5t amp (plenty of power and
reserve... 350w/p/c max 600w/p/c) with a Counterpoint SA 3 tube preamp. I
originally had DCM Time Windows with Audio Pro subwoofer. I sold the Time
Windows (wonderful speakers) and tried the Acoustats with the Audio Pro
(specially modified Monster Cables used to connect the preamp to the
subwoofer for the xover). I really didn't like the results. Yes, Pines of
Rome vibrated the the room, 1812 cannon shots bounced off my chest, but
still, I could not get it to integrate with the speakers (and the Audio Pro
at the time was a very "fast" subwoofer). So, sold that too.
You will notice the deep bass response with a more powerful amp (right now,
I am using a Counterpoint SA220 tube/hybrid 200w/p/c). I would go the route
of upgrading my components before a subwoofer. You would be surprised with
the bass response of these speakers with the right equipment.
>They really are astounding compared to dynamic speakers. I am
>particularly impressed with the way they handle strings - *much* better
>than my old bookshelf speakers. My wife hasn't ever been interested in
>stereo equipment at all - I got an indulgent smile when she first saw
>them, but when I started spinning platters, she went crazy. Her comment
>was something like, "I can imagine that if you turned up the volume it
>wouldn't be *louder*, there would just be more sound."
And your wife is right! See if you can borrow a more powerful amp, and you
will most definately be happy with the results.
Mark A. Martin
to think that any decent sub would run $2000 and up, but this little
$400 monster really put out the sound at high levels with no clipping
or cabinet buzz or rattle. Plus it has control over crossover
frequency, which would be desirable to match your speakers. Forgot
the model, but check their website for the loweset price mode. Plus
for another $150 or so, you can step up to a bigger unit with a
larger driver and a bigger amp.
"Christopher S. Kush" wrote:
>
> I just bought an associate's Acoustat 1+1's for $350 (they have the
> Medallion upgrade). My former speakers, Mirage M360s, have met their
> daddy and are sitting in the corner pondering their total inferiority.
>
> I've always wanted a pair of electrostatics, but I'm an armchair 'phile,
> so I couldn't ever justify $1,000+ on speakers (I know there are cheaper
> ones, but these kind of dropped into my lap...)
>
> Anyhow, I'm currently driving them with a Carver HR722 receiver, which
> claims 60WPC/8ohms, 90WPC/4ohms. I'd like to get them a subwoofer to
> play with - I imagine it should probably be powered. The Carver seems
> to handle the 1+1's acceptably, but I worry that the 'statics present
> an exotic load, so I don't want to burden it anymore.
>
> Any recommendations for a $400ish sub? I'd like to replace the receiver
> too, at some point, so if you've got an idea for a new amp/sub combo that
> totals less than a grand, that would be of interest as well. If you can
> work McIntosh components in you get bonus points :)
>
Christopher S. Kush
and cogitating, I've concluded that I really need to get more power.
I'd like to keep it under $500 for the power section (getting seperates
this time). Depending one what kind of a deal I can find on used
equipment, that means 100-150 watts/channel into 8 ohms.
I've perused the rec.audio.* FAQ, the ESL Circuit, eslinfo, and other
web sources, but I am unable to find any recommendations for driving
my speakers that cost less than four digits, nor any rules of thumb
for which amps tend to be stable. For instance, NAD claims 6dB of
headroom on their newer stuff. Adcom claims less, but has a better
reliability record; then again, I've heard grumbling that their new
stuff doesn't match up to the 500 series.
Currently (no pun intended), I'm leaning toward finding a used Adcom
500 series, at least a 545, because it has an established reputation
and provides an upgrade path: Buy another and bridge 'em up.
Would anyone care to weigh in? I've seen archived articles in DejaNews
from posters who own Acoustats, some with 1+1s. What do you use, aside
from Frightfully Expensive Audio and Some Dude Whose Name Sounds Cool?
Tony
>After reading the kind replies here, emailing a bit with Mr. Waldron,
>and cogitating, I've concluded that I really need to get more power.
>I'd like to keep it under $500 for the power section (getting seperates
>this time). Depending one what kind of a deal I can find on used
>equipment, that means 100-150 watts/channel into 8 ohms.
Well..... I used initially a Caver 1.5t amp. Plenty of power for
driving these speakers, and.... despite the "talk", it was a very
respectable amp. You can usually find one used for around $300. A
100-150 watter will only get the speaker "going". I also had an
Onkyo M510 (or something) with 150w/p/c. That could be bought new for
under $300. But it really wasn't as good as the Carver. No "guts" in
the low end.
>>snip<<
>Would anyone care to weigh in? I've seen archived articles in DejaNews
>from posters who own Acoustats, some with 1+1s. What do you use, aside
>from Frightfully Expensive Audio and Some Dude Whose Name Sounds
>Cool?
I currently use a Counterpoint SA220 to drive them now. Wonderful
sound. Powerful bass. And... plenty of power reserve. Still, if you
can get a hold of a Carver 1.5t, you will be MORE than happy with
it.
BEARlabs
The Carver unit is a terribly bad idea for Acoustats... the circuit
is good for getting relatively high voltage swings from a lightweight
box, but actually does effect the signal more than I'd like to think
about. In other words, NOT hi-fi.
The *best* amp for Acoustats is a high power class AB *tube* amp!
Tube amps and Acoustats are made for each other... the tube amp seems
to have the *best* mid bass. But, you need power.
If you can't build one yourself, you can try to find some old Altec
1570b's (2 x 811a outputs), or parallel some stereo tube amps, like 4
Dyna Mk IIIs...
You can build a nifty 200 watt class AB2 tube amp with about 750volts
on the plates of 4 807s... dirt cheap tubes, pretty good sound... all
you need is the iron and a chassis, pretty much.
In solid state, you need to expect to spend more money, IMHO.
I'd avoid the low end solid state stuff... it will sound like dog
poop compared to the lower power and similarly expensive tube gear on
these speakers...
The Acoustats will reveal the source very well (change the coupling
caps in the interface box for all Polypropylenes... major
improvement!), but 1+1s will *always* be shy in terms of output.
If you want output and BASS, buy another pair of 1+1s, make your own
frames, and call them 2+2s or 4s! That's what they were when Acoustat
made them. I measure the 1+1s at no better than 83dB/1w/1m! And shy
in bass.... not enough width, the cells go down... perhaps wings
would help increase the path front to back...
I just put my custom version of the IIIs back into service after
collecting dust for 5 years... I remember now why I liked them so
much... they are *very* good!
You can hear *everything* very clearly - changes to the system are
immediately apparent and clear. No mud, no blurr, no question as to
what is going on.
Ran them this week with a pair of 845s P-P... about 35 watts... sound
nice. Admittedly they don't go as fully loud as the big 128 pound
Symphony No.1 Amplifer (high bias Mosfets...), but otherwise sound
very similar in all respects.
Also, keep in mind that off axis and the perceived sound level drops
considerably... these are ON AXIS speakers, not dance around the room
speakers....
_-_-randy
BEAR Labs
"Christopher S. Kush" wrote:
> After reading the kind replies here, emailing a bit with Mr. Waldron,
> and cogitating, I've concluded that I really need to get more power.
> I'd like to keep it under $500 for the power section (getting seperates
> this time). Depending one what kind of a deal I can find on used
> equipment, that means 100-150 watts/channel into 8 ohms.
>
> I've perused the rec.audio.* FAQ, the ESL Circuit, eslinfo, and other
> web sources, but I am unable to find any recommendations for driving
> my speakers that cost less than four digits, nor any rules of thumb
> for which amps tend to be stable. For instance, NAD claims 6dB of
> headroom on their newer stuff. Adcom claims less, but has a better
> reliability record; then again, I've heard grumbling that their new
> stuff doesn't match up to the 500 series.
>
> Currently (no pun intended), I'm leaning toward finding a used Adcom
> 500 series, at least a 545, because it has an established reputation
> and provides an upgrade path: Buy another and bridge 'em up.
>
BEARlabs
> Christopher S. Kush wrote in message <8dq4iv$r9l$1...@bourbaki.localdomain>...
> >I just bought an associate's Acoustat 1+1's for $350 (they have the
> >Medallion upgrade.
>
> >Anyhow, I'm currently driving them with a Carver HR722 receiver, which
> >claims 60WPC/8ohms, 90WPC/4ohms. I'd like to get them a subwoofer to
> >play with - I imagine it should probably be powered. The Carver seems
> >to handle the 1+1's acceptably, but I worry that the 'statics present
> >an exotic load, so I don't want to burden it anymore.
>
> The "exotic load" comes from the high end rather than the low end.
> The impedance of an electrostat is the inverse of the frequency,
> being very low (~1-2 ohms) at 20K Hz., and several hundred ohms
> at 30 Hz. Therefore, if an amplifier is going to have a problem with
> highly reactive loads, it will be with the reproduction of higher frequenies
> at higher SPLs.
The Acoustat does NOT dip that low at 20Khz. It maintains a fairly
flat impedance across its entire range.
This is due to the dual transformer matching system, and the way that the
interface unit is wired. Many other ESLs *do* have this problem.
> Any low frequency burdon is primarily the result of insufficient voltage.
> Full range electrostats will do better with amplifiers above 150 w/p/c,
> as a general rule. (The new InnerSound ESL amplifier is capable of
> developing over 10KV, depending upon the product's matching
> transformer(s).)
True.
<snip>
> If you want to replace your receiver with separates, try and find a
> Hafler DH-500 amplifier on the used market for the Acoustats. It
> should be priced under $400. I have no recommendations for a
> tuner.
Excellent entry level choice for this speaker system!!
_-_-randy
BEAR Labs
Charlie Graves
> After reading the kind replies here, emailing a bit with Mr.
Waldron,
> and cogitating, I've concluded that I really need to get more
power.
> I'd like to keep it under $500 for the power section (getting
seperates
> this time). Depending one what kind of a deal I can find on used
> equipment, that means 100-150 watts/channel into 8 ohms.
>
<snip>
> Would anyone care to weigh in? I've seen archived articles in
DejaNews
> from posters who own Acoustats, some with 1+1s. What do you use,
aside
> from Frightfully Expensive Audio and Some Dude Whose Name Sounds
Cool?
>
Depending on which Medallion upgrade your 1+1's have, converting the
MK121B interface to the MK121C version can substantially improve your
speaker's bass--among other things--without adding a subwoofer.
The "B" interface is identified with a small black plastic
boilerplate with the words "ACOUSTAT MEDALLION TRANSFORMERS" printed
in *blue*; the "C" version has the same boilerplate with the same
words printed in *red*.
If you have the "B" version, and want to do this relatively cheap and
easy conversion, let me know, and I'll snail mail you the schmematics
and instructions I got from Acoustat.
When shopping around for an amp, I would pay less attention to how
much it can put out into 8 ohms, and more attention to how much it
can put into 4 ohms--or better yet, 2 ohms. The larger Acoustat
models can deliver a surprisingly visceral bass, and a pretty dynamic
overall output, but only if the amplifier is pushing an awful lot of
current through them.
I drive a pair of 2+2's with two McIntosh MC2250's configured as
monoblocks. Both amps peak a sine wave at 600 W on the test bench.
The 2+2's are rated at 4 ohms nominal, yet if I drive them from the
amps' 4 ohm taps, even mellow music at moderate listening levels
often peaks the amps out like crazy. When I use the 2 ohm taps, the
peaking problem goes away. Your 1+1's probably have an even more
insatiable thirst for this kind of juice! You'll probably spend more
than you planned, since high current amps don't come cheap...
--
~Charlie Graves <mailto:cngr...@clarityconnect.com>
Akiko Inoue
> much it can put out into 8 ohms, and more attention to how much it
> can put into 4 ohms--or better yet, 2 ohms. The larger Acoustat
> models can deliver a surprisingly visceral bass, and a pretty dynamic
> overall output, but only if the amplifier is pushing an awful lot of
> current through them.
The ESLs, which look a lot like capacitors, especially at low
frequencies, don't require a lot of current to produce bass. The
impedance of the ESLs is usually very high at low frequencies, so
what is required is high driving voltage. High powered amps are
capable of higher output voltages than low powered amps.
The reason to select an amplifier that has power rated down to 2 Ohms
is that the amp will be stable with low impedance loads, and
therefore, PROBABLY stable driving ESLs.
So the criteria for selecting an amp should be high power, rated down
to some low impedance like 2 Ohms. This usually means buying a
mega-buck amp like a Krell or a mark Levinson. On the other hand,
you could try less expensive amps. Many are stable with ESLs even
though they don't rate power output into 2 Ohms.
If you're at all handy with a soldering iron, it usually isn't too
difficult to stabilize an amp that doesn't like ESLs. Try putting a
1 or 2 Ohm ressistor in series with each speaker. It will have no
noticable affect on the sound except that there will be some, even if
the amp didn't like the ESLs before.
MR
BEARlabs
is that they are relatively LOW sensitivity devices - there is an
immutable trade-off between bandwidth and efficiency - as
such you need relatively high *voltage* swings to produce
high-enough voltage on the secondary of the drive transformers
to deflect the diaphragm fully (ie. maximum loudness).
In the case of the Acoustats, that is about 5,000 volts or better.
Since the Acoustats do NOT dip low in terms of impedance,
there is NO need for an amp that will work into 2 ohms.
Indeed, tube amps are NOT high current devices, intrinsically,
since you are always converting high voltage, low current from
the plates of tubes to low voltage, higher current on the secondary,
and the match is dependent upon a 1:1 ratio of load impedance
to secondary impedance for maximum power transfer.
Tubes work fine with ESLs, just match the *voltage* swing
to the required maximum SPL.
_-_-BEAR Labs
Dennis Moore
Folks it is true that most esl's are high impedance in the
bass and low or moderate impedance above that. And
they do need adequate voltage. And the above character-
istics make them good matches for tube amps. However,
the dual transformer configuration of an Acoustat makes
them a lower impedance at lower frequencies than other
esl's. And an amp with both voltage and current (and
hence high power) are the ticket with these. They still
will do better than might seem sensible with moderate
power tube amps. But either a big tube or high power
SS amp is what is called for with Acoustats. And having
owned some, generally the 4ohm tap of a tube amp
worked better than the 8 or 16 ohm tap. With other
esl's like old and new Quads this is not true. The higher
impedence taps worked better with those Quads.
In any case, high quality ss amps are a must, as lesser
ss amps sound pretty strained by it all. For instance
early Carver amps had the needed power and voltage,
and would play my Acoustat Two's quite loud. Even
the original Carver receiver would manage this. But
the sound was bright, bright and wiry as all get out.
Even something like a McIntosh SS amp sounded much
better. Early Adcoms sound somewhere in between.
But some good Conrad-Johnsons, or VTL's were where
you wanted to go with the Acoustats.
A fairly good budget solution was the medium sized
McIntosh amps. They seem to be able to play very
near their limits while sounding fine and not being
harmed thanks to PowerGuard circuitry used by them
during the 1980's. Unfortunately I don't know
of any inexpensive amps that sound great with
the Acoustats.
Good luck,
Dennis
Christopher S. Kush
this weekend. It was somewhat better, but not unbelievably better.
Not $600 better, anyway.
In the course of my audition, I heard some snapping. Some during
loud bass passages (think techno), some during brash upper-octave
stuff (think horn section). Was this arcing, clipping, or both?
I live on the front range in Colorado (*low* humidity). In any
event, when they power on I can hear little dust particles jumping
around -- I know people vacuum their ESLs for this reason. I'm
afraid of tearing the Incredibly Thin Membrane -- what do I do?
Can/should I eave the socks on? If I press the vacuum nozzle
against the eggcrate, won't I suck the mylar against the other
side and rupture it?
These things are the worst pet ever :)
--
Christopher S. Kush -- csk...@uswest.net
http://www.users.uswest.net/~cskush/
Windows and AIX software consulting
Akiko Inoue
> loud bass passages (think techno), some during brash upper-octave
> stuff (think horn section). Was this arcing, clipping, or both?
Probably arcing. Overdriving the speakers will cause a spark to jump
between the stator and diaphragm and or other stator. Try it in the
dark
next time. Watch for sparks. It is generally not a good idea to drive
the
speakers this hard.
> I live on the front range in Colorado (*low* humidity). In any
> event, when they power on I can hear little dust particles jumping
> around -- I know people vacuum their ESLs for this reason. I'm
> afraid of tearing the Incredibly Thin Membrane -- what do I do?
> Can/should I eave the socks on? If I press the vacuum nozzle
> against the eggcrate, won't I suck the mylar against the other
> side and rupture it?
The diaphragm is one of the toughest materials in existence. If you
held a
piece in your hands, you might just be able to break it by using all
your
strength to pull on it. Unless you poke a hole in it. In that case,
all bets
are off. A small tear will propagte through the film almost as if the
film
wasn't there. Therefore, be careful not to poke holes in the film.
Use a brush attachment on the vacuum cleaner and don't press it so hard
that the brush fibers enter the holes in the stator. Put the socks on
when
you're not listening to them, and /or switch the power off. The high
voltage
will tend to attract dust.
MR
PS- Don't believe any crap you hear about it taking a month for the
speakers to "charge up" when you switch the bias supplies. It takes no
more then a few seconds for the speakers to fully charge and sound as
good as they ever will/do.
Akiko Inoue
> ss amps sound pretty strained by it all. For instance
> early Carver amps had the needed power and voltage,
> and would play my Acoustat Two's quite loud. Even
> the original Carver receiver would manage this. But
> the sound was bright, bright and wiry as all get out.
> Even something like a McIntosh SS amp sounded much
> better. Early Adcoms sound somewhere in between.
> But some good Conrad-Johnsons, or VTL's were where
> you wanted to go with the Acoustats.
I used to have a Carver M100t amp and used to try to drive
electrostatics with it. It was the only amp I ever ran into
(not that I've tested all that many) that became unstable with
ESLs. The amp used to break into low level oscillations and
the noise at the output would rise dramatically. I have used
older consumer grade Japanese stereo stuff to drive ESLs with no
problems at all. I don't know if the newer "AV" amps would
be so happy though. I don't believe that the hybrid amp modules
in those units are very robust.
MR
BEARlabs
> Thanks again everybody. As it turns out, I auditioned a Mac 2100
> this weekend. It was somewhat better, but not unbelievably better.
> Not $600 better, anyway.
>
> In the course of my audition, I heard some snapping. Some during
> loud bass passages (think techno), some during brash upper-octave
> stuff (think horn section). Was this arcing, clipping, or both?
> I live on the front range in Colorado (*low* humidity). In any
> event, when they power on I can hear little dust particles jumping
> around -- I know people vacuum their ESLs for this reason. I'm
> afraid of tearing the Incredibly Thin Membrane -- what do I do?
> Can/should I eave the socks on? If I press the vacuum nozzle
> against the eggcrate, won't I suck the mylar against the other
> side and rupture it?
>
> These things are the worst pet ever :)
The cells can be disassembled from the frame, after removing the
grille cloth. I have sucessfully washed them, more than once. IF the
person who owned them was a smoker, then there is crud everywhere
inside the cells - they act like electrostatic air cleaners. Even the
grunge from a big city will coat the insides eventually....
Looking at them in the absolute dark is a good idea, but you need to
get the grille sock off first.
The number one problem with the Acoustat cells is the wires pulling
off the plastic stators, usually at the ends of the cells... so the
air dielectric value is decreased by the wire getting closer to the
diaphragm. This can cause arcing.
Arcing the panels from driving them is very difficult. IF you are
hearing a sound on peaks, you may be hearing the *amps* clip! Take a
look at your Rat Shack SPL meter, if you are pushing anywhere near
100 dB in the room, you are almost certainly clipping the amps!
If they are arcing from discharge, then they will do it while sitting
around... mine do it from time to time, for no apparent reason...
You can vacuum them, with the brush (wash and dry the brush first!)
attachment if you like....
_-_-BEAR Labs
Tony
>OUCH!!
>
>The Carver unit is a terribly bad idea for Acoustats... the circuit
>is good for getting relatively high voltage swings from a lightweight
>box, but actually does effect the signal more than I'd like to think
>about. In other words, NOT hi-fi.
I would have to disagree here. I drove my 1+1's with my Carver 1.5t
for many years with good results. And the sound was excellent (I had
the chance to compare it to Spectral's and other amps in my system).
Yes, there was "better" sounding amps out there, but for the
price/performance, the Carver did more than hold it's own. And it had
the power to drive them to room filling levels (room dimensions
13x24x8).
If there was a solid state amp that sounds good and will work fine
with these speakers, Acoustat's own TNT series would fit the bill.
BEARlabs
Right, there is good quality and excellent quality.
If you do not have the source to speaker signal chain gear of
sufficiently high caliber, then swapping in amps of a quality in
excess of the weakest link will not make a terrific difference in
resulting quality.
I often see posts that reflect this sort of situation.
I am sure that it is not because the poster's intend to mislead or
are not reporting their experiences accurately, but because their
experiences with sound are simply such that they have not experienced
sufficiently high quality sonic presentations to be able to discern
that there are significant differences.
I've heard the Carver line many times, it literally "modulates" the
signal, imparting its own "envelope" (these are subjective
impressions...) onto the signal.
The Acoustat TNT is good, but grainy. I have one here now for a
repair/ checkup.
The Spectral gear is thin and white sounding.
Next.
_-_-randy
BEAR Labs
Christopher S. Kush
the panels with a hazard light by shining it through from behind. The
black conductive coating had pinhole voids, the largest about 1/16 of
an inch across. There were smaller ones as well, enough to make
counting impossible. Examining the larger ones close-up, it appeared
that it was only a void in the coating, not a hole clean through the
transducer. With the really tiny ones it was impossible to tell.
They are once more reassembled and sound fine, so I'm not too worried.
Tony
>Right, there is good quality and excellent quality.
Agreed.
>If you do not have the source to speaker signal chain gear of
>sufficiently high caliber, then swapping in amps of a quality in
>excess of the weakest link will not make a terrific difference in
>resulting quality.
That is true. Maybe I should add in the equipment used to evaluate the amps
in question with the speakers. I have listened to these speakers with ARC
D250's, CJ's, Counterpoint SA220 (which I now own and use), Sunfire and a
few others that slip my mind at the moment. The analog front end is
VPI/Koetsu, Counterpoint SA2 head amp, SA3 preamp or SP-9. Cables vary from
MIT's, Distech and Monster. CD is Parasound CD/P1000.
Now I admit that isn't the "best" system in the world, but it is a good
sounding one. I think that these components would allow me to make a comment
on the sound of say a Carver 1.5t or even the TNT200.
>I am sure that it is not because the poster's intend to mislead or
>are not reporting their experiences accurately, but because their
>experiences with sound are simply such that they have not experienced
>sufficiently high quality sonic presentations to be able to discern
>that there are significant differences.
Let me add that I played classical violin and clarinet for many many years.
So I do know what "real" live instruments sound like as a reference. Also, I
have been involved in audio since 1970 (when Mac's and Bozaks ruled). I
think of myself as an audio enthusiast.
>I've heard the Carver line many times, it literally "modulates" the
>signal, imparting its own "envelope" (these are subjective
>impressions...) onto the signal.
Every piece of audio equipment that I have listened to imparts something of
their own to the signal. Some more noticable than others. Some you can live
with, some you can not. The original poster was looking for a cheap amp to
drive the 1+1's. I listed two that I thought would be fine. Remember,
*cheap* amp.
>The Acoustat TNT is good, but grainy. I have one here now for a
>repair/ checkup.
But it drove the speakers fine.
>The Spectral gear is thin and white sounding.
Agreed.
>Next.
Charlie Graves
From: "BEARlabs" <bear...@coollink.net>
Newsgroups: rec.audio.high-end
Sent: Tuesday, May 02, 2000 11:39 AM
Subject: Re: Acoustat 1 + 1, need to vacuum the panels
>
> The cells can be disassembled from the frame, after removing the
> grille cloth. I have sucessfully washed them, more than once. IF the
> person who owned them was a smoker, then there is crud everywhere
> inside the cells - they act like electrostatic air cleaners. Even the
> grunge from a big city will coat the insides eventually....
What did you wash the panels with?. I tried removing condensed
cigarette smoke from one of mine with 409 spray cleaner, but the
black coating on the mylar came off too, destroying the panel :-o !!!
>
> The number one problem with the Acoustat cells is the wires pulling
> off the plastic stators, usually at the ends of the cells... so the
> air dielectric value is decreased by the wire getting closer to the
> diaphragm. This can cause arcing.
The wires came unglued from the stators on one of my panels on three
different occasions. Each time, it was audible only when a certain
bass frequency occured, and excited a resonance in these loose wires,
making them rattle. Fortunately, Rockford honored my lifetime
warranty, and replaced the panels with new ones, which BTW, have a
lot more glue holding the wires in place than the originals did...
~Charlie Graves <mailto:cngr...@clarityconnect.com>
BEARlabs
> ----- Original Message -----
> From: "BEARlabs" <bear...@coollink.net>
> Newsgroups: rec.audio.high-end
> Sent: Tuesday, May 02, 2000 11:39 AM
> Subject: Re: Acoustat 1 + 1, need to vacuum the panels
>
> >
> > The cells can be disassembled from the frame, after removing the
> > grille cloth. I have sucessfully washed them, more than once. IF the
> > person who owned them was a smoker, then there is crud everywhere
> > inside the cells - they act like electrostatic air cleaners. Even the
> > grunge from a big city will coat the insides eventually....
>
> What did you wash the panels with?. I tried removing condensed
> cigarette smoke from one of mine with 409 spray cleaner, but the
> black coating on the mylar came off too, destroying the panel :-o !!!
I've used stronger stuff than 409 with no apparent effect on the
black coating! The stuff that Familly Dollar sells on the US east
coast called " Mean Green" is one of my favorites, it is pretty
alkaline.
I suspect that your problems may have been due to defective coating,
or perhaps an earlier vintage coating?
> > The number one problem with the Acoustat cells is the wires pulling
> > off the plastic stators, usually at the ends of the cells... so the
> > air dielectric value is decreased by the wire getting closer to the
> > diaphragm. This can cause arcing.
>
> The wires came unglued from the stators on one of my panels on three
> different occasions. Each time, it was audible only when a certain
> bass frequency occured, and excited a resonance in these loose wires,
> making them rattle. Fortunately, Rockford honored my lifetime
> warranty, and replaced the panels with new ones, which BTW, have a
> lot more glue holding the wires in place than the originals did...
Rockford will NOT honor the warranty anymore unless you can prove
that you are the original owner, with a bill of sale!
However, you can glue the wires back in place if you use some care,
acrylic cement, and more or less work overhead, so that drips fall
away from the diaphragm. You might want to make up some tools to
facilitate holding the wires in place, and teflon is a good way to
make non glueable surfaces for the tools...although I've only done
this once, since I got my cells replaced.
_-_-BEAR Labs