fixing old speakers - worthwhile?
Nate Nagel
was over at Goodwill today in an effort to avoid having to buy a new set
of flatware for Thanksgiving (don't have enough place settings, and
didn't realize it until I thought about it yesterday)
ANYWAY...
there was a pair of Advent speakers there for $15. No way to test them.
Couldn't pull speaker grilles off to look. Figured, what's $15?
Then I can have my bookshelf KLH's back for a garage stereo. Took 'em
home. No bass. Destructively removed grilles (easily fixable; they're
held on with Velcro, when I pulled them off the little wooden blocks
that the Velcro attaches to pulled off the box) found surround of woofer
completely gone. Is there a cheap easy way to DIY repair this? Or did
I just gamble and lose $15 and get some free exercise humping those
heavy mothers out to the car?
nate
--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel
Pete Bertini
"Nate Nagel" <njn...@roosters.net> wrote in message
news:hecjm...@news1.newsguy.com...
They probably had the old foam speaker surrounds.
Sure, they are easily repairable, and many companies
sell do it yourself kits for replacing the surround.
I don't have a URL handy, but if you do some internet
for replacement speaker surrounds, you will
find scads of vendors who have the kits.
Those old ARs and KLHs had that unique "Boston"
sound back in the 60s and 70s. I have still my old
KLH-5s kicking around. I think they are well worth
saving.
Pete
philo
Since the cases are good I'd just replace the speakers inside
if they are 12", it won't cost that much
William Sommerwerck
> Couldn't pull speaker grilles off to look. Figured, what's $15? Then I
> can have my bookshelf KLH's back for a garage stereo. Took 'em home. No
> bass. Destructively removed grilles (easily fixable; they're held on with
> Velcro, when I pulled them off the little wooden blocks that the Velcro
> attaches to pulled off the box) found surround of woofer completely gone.
> Is there a cheap easy way to DIY repair this? Or did I just gamble and
> lose $15 and get some free exercise humping those heavy mothers out to
the
> car?
There are people and companies selling repair kits for the Advent surrounds.
Do a bit of Googling.
William Sommerwerck
> if they are 12", it won't cost that much
They might not cost much, but the Advent was considered a very good speaker.
It wouldn't be a good idea to replace either driver.
Pete Bertini
"William Sommerwerck" <grizzle...@comcast.net> wrote in message
news:heckjt$cdd$1...@news.eternal-september.org...
They might be acoustic suspension speakers as well. Drop ins won't
be cheap.
Pete
philo
Ah
then I guess go for the fix-it option
Nate Nagel
Heh. My dorm stereo in college was an old Harmon/Kardon tuner/amp.
Bought it from a grad student for $35, he threw the speakers in for
free. Speakers were KLH AV-2000 (I think? small bookshelf speakers
anyway.) I still have 'em and they still sound great. (the H/K is out
in the garage now, but the speakers are being used to replace the cheap
cube things that came with SWMBO's "surround sound in a box" thing
that's hooked up to the TV downstairs. Hence my quickly perusing the
speaker section at Goodwill.)
I didn't realize that refoaming was common/easy/apparently DIYable. The
exact speakers I bought are Advent/2W, worth doing it to? Obviously
before I order anything I will verify that the woofers are actually moving.
I really just picked them up primarily because I recognized Advent as
being a good name from back in the day, and I actually do kind of need
some more speakers, just not badly enough to pay real money for them.
thanks
paul @removeppinyot.removecom Paul_P
> Ah
>
> then I guess go for the fix-it option
http://www.circuitshop.com/
https://taweber.powweb.com/parts.htm
http://www.speakerex.com/
http://www.recone.com/
etc., etc., etc.
PP
Bill Noble
burned out - they should still move
"Pete Bertini" <radioco...@cox.net> wrote in message
news:mukOm.63266$Xf2....@newsfe12.iad...
William R. Walsh
> Couldn't pull speaker grilles off to look. Figured, what's $15?
Worth taking a chance on to me...I'd have guessed that the surrounds were
gone, though.
> Is there a cheap easy way to DIY repair this?
I don't know of one. However, I bought a pair of Acoustic Research AR25
speakers for $5 or so at a public television station used audio equipment
sale. They too had degraded surrounds. So what did I do? Surround repair and
reconing is expensive. Even in their degraded state, these speakers were
making a very good argument to be saved.
I went to Radio Shack and bought two of their "better grade" 100 watt rated
woofers of the appropriate size. I realize that some of you might be
grumbling about that, but I kept the original drivers (in case someone wants
to repair them) and the Radio Shack replacements sound *fine* to me. The way
I've got it figured, the enclosure is more important anyway.
I listen to vinyl, tapes, CDs and the radio through a $0.50 Pioneer SX-253R
receiver* with these and some Sony bookshelf speakers. I have no complaints
at all. What I've got sounds a lot better than some much more expensive
stuff I've heard. People who have been in my music/computer room have said
the same thing.
I've got about $35 in them all told IIRC.
William
* I bought it at a hamfest even though I'd been told it didn't work. Got it
home and it turned out to work fine. It replaced an ailing Optimus STA-795
receiver. That was fully five years ago, and it appears to have had little
use. However, I don't have a top cover for it. If anyone has a similar
receiver kicking around that is only good for parts, I'd love to get a top
cover for it.
D. Peter Maus
The drivers are matched for the acoustic space in the cabinets.
Resonant frequency is often marked on the basket or on the back of the
cone for reference. Finding drop-ins will be more expensive than
replacing the surrounds.
Foam surround kits will cost you about $25. And the process is not
difficult. You can find instructional videos on the web to show you how.
Care, attention to detail will be all that's required to do a functional
job. By the time you start the second one, you'll be an expert.
Advents for $15. Definitely worth the repair.
> nate
>
William Sommerwerck
Might be? They were designed by Henry Kloss, one of the founders of AR.
I find it amusing that the current AR (is it still around?) manufactures
only bass-reflex speakers. (How dare they call themselves AR!) And you can
buy an "Accutron" watch that's crystal-controlled -- no tuning fork. For
that matter, Corning makes "Pyrex" bakeware that is /not/ heat-resistant.
William Sommerwerck
It's not easy. Especially with the lousy instructions supplied by the
company I bought my surrounds from.
John Stone
Peter Maus" <DPete...@worldnet.att.net> wrote:
> Is there a cheap easy way to DIY repair this? Or did I
>> just gamble and lose $15 and get some free exercise humping those heavy
>> mothers out to the car?
>>
>
> The drivers are matched for the acoustic space in the cabinets.
> Resonant frequency is often marked on the basket or on the back of the
> cone for reference.
The Advent woofer is very unique, and finding generic replacements is
virtually impossible. Kloss, always the spendthrift, designed a 10" woofer
that was built on a 12" basket, using a masonite spacer on the basket edge.
This allowed him to get longer throw out of a very cheap, off the shelf
basket. There wasn't much precision to any of it, but it worked well.
Acoustic suspension woofers have very soft suspension, and because of this,
are prone to quite a wide tolerance in free air resonance. +/- 20% is not
unusual. But since the dominant compliance is supplied by the air spring in
the box, the final result ends up being quite consistent. Nominal free air
resonance of the Advent woofer was around 20 Hz. System resonance was about
40Hz, Q=1 (a bit under damped). Replacement foam surrounds will likely not
have the same stiffness as the originals, but again, it doesn't really
matter much because of the design.
> Advents for $15. Definitely worth the repair.
A good value for the day, especially for bass performance. I never much
cared for the tweeter though, and always thought the Dyna A25 had a lot
cleaner highs.
Kenneth Scharf
D. Peter Maus
> On 11/22/09 9:55 PM, in article hed13n$tin$1...@news.eternal-september.org, "D.
> Peter Maus"<DPete...@worldnet.att.net> wrote:
>
>> Is there a cheap easy way to DIY repair this? Or did I
>>> just gamble and lose $15 and get some free exercise humping those heavy
>>> mothers out to the car?
>>>
>>
>> The drivers are matched for the acoustic space in the cabinets.
>> Resonant frequency is often marked on the basket or on the back of the
>> cone for reference.
>
> The Advent woofer is very unique, and finding generic replacements is
> virtually impossible. Kloss, always the spendthrift, designed a 10" woofer
> that was built on a 12" basket, using a masonite spacer on the basket edge.
> This allowed him to get longer throw out of a very cheap, off the shelf
> basket. There wasn't much precision to any of it, but it worked well.
> Acoustic suspension woofers have very soft suspension, and because of this,
> are prone to quite a wide tolerance in free air resonance. +/- 20% is not
> unusual.
Which would be about 4hz at these resonance points. An easily
managed tolerance.
I'd forgotten about the 12/10 design strategy.
> But since the dominant compliance is supplied by the air spring in
> the box, the final result ends up being quite consistent. Nominal free air
> resonance of the Advent woofer was around 20 Hz. System resonance was about
> 40Hz, Q=1 (a bit under damped). Replacement foam surrounds will likely not
> have the same stiffness as the originals, but again, it doesn't really
> matter much because of the design.
Actually most of the foam surrounds are about the same weight
with similar stiffness. It's the neoprene and live rubber surrounds
that become the problem.
I read an article about a guy who rebuilt a pair of AR-94's,
replacing the foam with neoprene surrounds. As fine as they were,
they changed the entire character of the sounds of the 94's. And
they became stiffer with time. Something foam doesn't do. It
fractures, instead.
But for the purist, original surrounds are still available. For
the practical, generics are serviceable. And cost less.
And as you point out, the design absorbs much of the variance.
>
>> Advents for $15. Definitely worth the repair.
>
> A good value for the day, especially for bass performance. I never much
> cared for the tweeter though, and always thought the Dyna A25 had a lot
> cleaner highs.
I started to have problems with my KLH 23 tweeters. I was getting
a dry, scratchy distortion on one. After searching, and doing a lot
of tests, I found a JBL tweeter from a pair of 4312's was a near
drop in. The were more linear, had about the same output, so no pad
was necessary, and crossed over at a point below the originals. With
a little relief in the baffle face for the flange, they mounted,
connected, and perform nearly identically to the original. Same
Boston sound, a bit higher top end, but without the screaming highs
one usually expects from JBL.
The best part is that with a thick gasket, the originals drop
right back into the holes in precisely the same position.
>
Kenneth Scharf
sealed (no round "port" tube in the front baffle board or out the back
of the box) then it is of the acoustic suspension type. If the box IS
ported, then it's a 'base reflex' type. The driver requirements are
different for each of these. Base reflex boxes are usually larger than
sealed ones. In general the drivers for a base reflex have a lower QTS
parameter (around .25 or so) while a sealed box speaker has a higher QTS
usually .33 - .5 or so. Good makers of replacement speakers will list
the TS parameters with the speaker specifications. The other note
worthy TS spec is the VAS, which gives an idea of the size of the box
volume required. The larger this number, the larger the required
volume. (But QTS also affects the box volume, in a way the product of
the VAS with the QTS along with the desired F3 cutoff frequency give the
required box volume).
You should look for a speaker with a rubber surround, this material will
have a much longer life than the foam surround. You might be lucky to
get 5-10 years out of a foam surround, a rubber surround should last
many times that. I have a pair of speakers I built in 1995 that show NO
signs of wear in their rubber surrounds.
Repairing the surround in an existing driver can be done, but requires
care to make sure the voice coil remains EXACTLY centered. You'll
probably have to remove and replace the dust cap over the center of the
cone as well (to shim the voice coil while centering and gluing down the
new surround).
If you don't replace the surround with an exact match you will change
the TS parameters of the driver somewhat. In a sealed box the exact TS
parameters are not too critical as a change in the QTS will also change
the VAS in a way that the overall effect is to cancel out any change in
box volume. The desired box QTC may move a bit, but the result will
still sound correct. OTOH in a base reflex box the TS parameters are
more critical and the box might have to be re-tuned by changing the
length of the port tube.
GregS
I would try to order rubber surrounds whenever possible. If
I do fool with foam, I always coat them with silicone rtv.
Even old foams I have made work for many years.
I have siliconed old foams 22 years ago, and they still work.
I have my own methods. I have used Airflex 400 on foam but it
stiffens it up.
greg
Michael A. Terrell
Apparently Corning sold the production & use of their name to a third
party to make cookware. At least, that has been reported by a lot of
people who have had the newer Corning ware glassware explode.
Anchor-Hocking does make tempered glass cookware. I bought something
the other day at K-Mart made by Anchor-Hocking and it was labeled as
tempered glass.
It isn't on their website, but it was a 9 inch pie pan. Here is the
image from another vendor:
<http://www.kitchencollection.com/prodimages/lg234721.jpg>
--
The movie 'Deliverance' isn't a documentary!
GregS
I thought they still made stuff and that every home should have that stuff.
I'm talking about the Corning Ware that has the pans and cannisters
with the glass see through tops, and those handles that clamped
on to the ceramic.. I use that stuff all the time, and was very upset not seeing
stuff like that when i went out to investigate. I ended up with a casserol
that has no handles, where you have to figure out how to hold it, but
the snap on plastic top is handy for putting it in the fridg.
I like the large pan to basically steam cook corn, fish, or other
foods. My mother was using the ware to cook well before we had a microwave,
and now thats its perfect use.
greg
GregS
How did I get to cooking from speakers ?
Parts Express has had some great deals on the now current AR series.
Well When Ken Kantor designed the "magic speaker"
at AR it seems like it was an acoustic suspension design.
I also got the NHT Ken Kantor acoustic suspension designed
1.3's. Maybe he just like them that way.
I wanted to ask him why he changed the design from tweeter
up, to tweeter down, and how was I supposed to listen to
it for the best sound. I would have imagined they changed the crossover
in some small way.
Interesting to follow the man and check out his site.
http://www.kenkantor.com/
I forgot the name of the driver sales company,
oh yes, Tymphany, and not sure if he left that company he helped start.
greg
GregS
It was not long ago Parts Express had these on , and I was considering
trying a couple oout, maybe for the car ??? Maybe someone
can explain these in detail, maybe Ken ??
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=299-850
http://www.tymphany.com/datasheet/printview.php?id=360
greg
Robert C
http://www.simplyspeakers.com/2doityourself.htm
this company sells replacement foam surrounds for just about every speaker
made that uses them.
William Sommerwerck
> I bought something the other day at K-Mart made by
> Anchor-Hocking and it was labeled as tempered glass.
It's not just the tempering. The original Pyrex conducted heat very rapidly,
which reduced the stress if the item were quickly heated or cooled.