Hello,
I have a pair of 20+ yr old Acoustic Research AR-91 speakers which are
starting to sound a bit "dark". I was told it could be the capacitors,
and, at least, upgrading the capacitors isn't likely to give the
speakers a faster response time.

Each crossover has 8 capacitors ranging from 50ufd to 100mfd, all
rated at 50volts. The capacitors do not appear to be leaking, but I
imagine they do wear out over time.

Is there a particular type or brand of capacitor that is recommended
for speaker crossovers, and where can I buy them via the Internet.

I have found a few sites claiming to have the "best" capacitors for
audio, but I have not found any reviews to substantiate their claims.
Any advise?

Thanks!

On Jun 26, 11:27 am, wrote:
Hello,
I have a pair of 20+ yr old Acoustic Research AR-91 speakers which are
starting to sound a bit "dark". I was told it could be the capacitors,
and, at least, upgrading the capacitors isn't likely to give the
speakers a faster response time.

Each crossover has 8 capacitors ranging from 50ufd to 100mfd, all
rated at 50volts. The capacitors do not appear to be leaking, but I
imagine they do wear out over time.

Is there a particular type or brand of capacitor that is recommended
for speaker crossovers, and where can I buy them via the Internet.

I have found a few sites claiming to have the "best" capacitors for
audio, but I have not found any reviews to substantiate their claims.
Any advise?

Thanks!

Check out other threads here that discuss older electrolytic caps
(search on something like "ESM" meter, if memory serves).

Your intuition seems good: if you read these threads, they suggest
that age deteriorates electrolytics - that may be your problem. Of
course, the tweeters are 20+ years old, too...

If these AR's are anything like the various speakers I used to work on
years ago, all the caps are probably *non polar* types - if you decide
to replace them, bear that in mind.

Good luck - I always liked the sound of AR's. (want to sell them?)

wrote:

Hello,
I have a pair of 20+ yr old Acoustic Research AR-91 speakers which are
starting to sound a bit "dark". I was told it could be the capacitors,
and, at least, upgrading the capacitors isn't likely to give the
speakers a faster response time.

Each crossover has 8 capacitors ranging from 50ufd to 100mfd, all
rated at 50volts. The capacitors do not appear to be leaking, but I
imagine they do wear out over time.

If they are non-polar electrolytics, and I'm sure some at least will be, it's
quite likely that they may have lost some capacitance as a result of the
electrolyte drying up over time.


Is there a particular type or brand of capacitor that is recommended
for speaker crossovers, and where can I buy them via the Internet.

Brand isn't really a big issue to be honest, although you'll find some fools
who'll tell you otherwise.


I have found a few sites claiming to have the "best" capacitors for
audio, but I have not found any reviews to substantiate their claims.

Indeed. Forget 'magic' capacitors assembled by naked virgins under a full moon
and buy good commercial quality ones.

Graham

"Mr. Land" wrote:

If these AR's are anything like the various speakers I used to work on
years ago, all the caps are probably *non polar* types - if you decide
to replace them, bear that in mind.

Btw, there's no point in replacing plastic film caps if there are some, they
don't age like electrolytics do..

Graham

Indeed. Forget 'magic' capacitors assembled by naked virgins under a full moon
and buy good commercial quality ones.

I've been trying to determine the location of that capacitor factory
for years...

Check out other threads here that discuss older electrolytic caps
(search on something like "ESM" meter, if memory serves).


Thanks - I'll search the threads.

If these AR's are anything like the various speakers I used to work on
years ago, all the caps are probably *non polar* types - if you decide
to replace them, bear that in mind.

The caps are polarized.

Good luck - I always liked the sound of AR's. (want to sell them?)

Sell them? I bought these speakers in San Francisco in 1984. For the 4
hour drive home, one sat in the front seat of my girlfriend's b210,
and the other across my lap in the backseat. How could I ever part
with them... well, maybe if I find a good pair of AR9s with their huge
tracks of woofers! ...

Indeed. Forget 'magic' capacitors assembled by naked virgins under a full moon
and buy good commercial quality ones.

Darn, and I had my wife convinced I needed to go to the factory to
pick-up these fine crafted electronics :-)

On Tue, 26 Jun 2007 08:27:31 -0700, put
finger to keyboard and composed:

Hello,
I have a pair of 20+ yr old Acoustic Research AR-91 speakers which are
starting to sound a bit "dark". I was told it could be the capacitors,
and, at least, upgrading the capacitors isn't likely to give the
speakers a faster response time.

Each crossover has 8 capacitors ranging from 50ufd to 100mfd, all
rated at 50volts. The capacitors do not appear to be leaking, but I
imagine they do wear out over time.

Is there a particular type or brand of capacitor that is recommended
for speaker crossovers, and where can I buy them via the Internet.

I have found a few sites claiming to have the "best" capacitors for
audio, but I have not found any reviews to substantiate their claims.
Any advise?

Thanks!

Our local supplier (WES) stocks the following.

Metallized Polypropylene Fast Capacitor:
http://www.solen.ca/caps/mkp.htm
http://www.solen.ca/caps/mkp2.htm
http://www.solen.ca/caps/mkp3.htm

Here is their complete range:
http://www.solen.ca/caps.htm

WES also carry the following range at about half the price:
http://www.farad.net/prodocts/prodocts_14.htm

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

Franc Zabkar wrote:

Our local supplier (WES) stocks the following.

Metallized Polypropylene Fast Capacitor:
http://www.solen.ca/caps/mkp.htm
http://www.solen.ca/caps/mkp2.htm
http://www.solen.ca/caps/mkp3.htm

Hmmm, so where are the slow capacitors ?

Graham

On Fri, 29 Jun 2007 08:50:03 GMT, Eeyore
put finger to keyboard and
composed:



Franc Zabkar wrote:

Our local supplier (WES) stocks the following.

Metallized Polypropylene Fast Capacitor:
http://www.solen.ca/caps/mkp.htm
http://www.solen.ca/caps/mkp2.htm
http://www.solen.ca/caps/mkp3.htm

Hmmm, so where are the slow capacitors ?

Graham

I presume that audiophiles understand the difference. I'm still
struggling with the concept of "warm" valve sound. shrug

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

In message , Franc Zabkar
writes
On Fri, 29 Jun 2007 08:50:03 GMT, Eeyore
put finger to keyboard and
composed:



Franc Zabkar wrote:

Our local supplier (WES) stocks the following.

Metallized Polypropylene Fast Capacitor:
http://www.solen.ca/caps/mkp.htm
http://www.solen.ca/caps/mkp2.htm
http://www.solen.ca/caps/mkp3.htm

Hmmm, so where are the slow capacitors ?

Graham

I presume that audiophiles understand the difference. I'm still
struggling with the concept of "warm" valve sound. shrug

- Franc Zabkar

I've always assumed that 'warm' means rather woolly (lacking top), with
just a hint of audible 100 / 120Hz hum - ie just like radios were like
when I was a kid.
Ian.
--

On 30 Jun, 00:40, Franc Zabkar wrote:

I presume that audiophiles understand the difference. I'm still
struggling with the concept of "warm" valve sound. shrug

- Franc Zabkar

100Hz modulation causes that. Its fairly easily replicated with
transistorised amps. lack of treble & bass response completes the
picture.


NT