Is this a Peerless tweeter?

[JohnMac]

The plot thickens. I don't understand why it would be impossible to successfully re-foam them but it might be true.

This is interesting. I spent quite a bit of time listening to them with a variety of music. I was sitting in the "sweet spot" where I normally audition speakers. When I walked to a different part of the room and got at about twenty feet away and at about a forty five degree angle to the speakers, everything changed. The bass opened up. Deeper and punchier. At a position parallel to them it was even more pronounced. I got back in front of them and they went flat again.

Thinking I had listening fatigue I had my wife check it out, and without telling what I heard, she noticed the same thing. As she walked from in front of them to a position farther away and closer to parallel with them she said "what did you just change?". Pretty dramatic difference.

I know that placement can be important but I've never experienced this with any other speakers in the same room.

 

[rnorton]

Just for grins, change the phase on one speaker.

 

[ken kantor]

Interesting, Ken - guess my elderly AR-14 isn't worth refoaming, then? :-(

An AR-14 should have prodigious LF. I have a pair of Teledyne-era AR-14s (with different drivers than the early AR-14), which I did refoam successfully. I spent some quality time listening to them once with an older, borrowed Parasound power amplifier and they were pretty stunning actually

Of course, one can make a working speaker, possibly even an excellent one. But, it simply won't sound much like the original AR.

The AR drivers were built with parts, adhesives and assembly procedures that simply are not available these days. For example, nobody makes a surround that even comes close to the original AR-14 woofer. This alone will alter the F3, Qts and midrange flatness of the driver. Likewise, the adhesives used, and their application and curing, had a large influence on sound quality that it is almost impossible to duplicate.

I've seen a lot a nicely repaired AR woofers over the years, but none that my tests indicated would pass AR's original QC.

Perhaps there is a modern woofer that can be used as a good replacement, instead of going the re-foam route?

-k

 

[mhardy6647]

...

Perhaps there is a modern woofer that can be used as a good replacement, instead of going the re-foam route?

-k

Likely so (although perhaps not, as the sealed box alignment is out of fashion these days). I guess, akin to the unique status of the old EPI/Epicure LF drivers, the trick is not just to match the T-S parameters (LF performance) but also to find a 10" driver with adequate performance into the midrange for a two-way loudspeaker application.

 

[WilsonCreek]

...When I walked to a different part of the room and got at about twenty feet away and at about a forty five degree angle to the speakers, everything changed. The bass opened up. Deeper and punchier. At a position parallel to them it was even more pronounced. I got back in front of them and they went flat again.

I have had this happen a few times, and it has always been because I managed to get something out of phase. Go over everything again and/or switch the phase on one speaker as per rnorton, and see if the effect persists.

 

[michiganpat]

I find them really disappointing. The tweets sound great and there is pretty nice mid-range but where's the bass? I'm by no means a bass hound but this pair is definitely lacking.

The guy I got them from re-foamed them. A nice, neat looking job but I wonder if that has something to do with it. There is a slight buzz in one woofer that I didn't catch when I auditioned them. I think the driver is OK but his alignment is off. It can only be heard on some very low frequencies on certain songs and is slight. I think that's probably a separate issue from the lack of bass.

did he use a generic 10" foam surround, like what MAT electronic sells? if so, that'd do it. they're much too stiff and will raise the driver's Fs to much. AFAIK there's 2 surrounds that work adequately for an AR 10" driver. 1 is a large roll, very compliant JBL surround, the other is a boston acoustics "filled fillet" surround, again, very compliant....John at Msound can get them. might be worth re-refoaming them....

another issue, is older AR speakers, being intended to be "bookshelf" speakers, don't really have any baffle step compensation built in, and need some boundary reinforcement. they need to be up against a wall, not out from the wall. if you have them out on stands, back them up against the wall or put them in the corner of the rooms and you may find your missing bass.

and as far as the tweeter, isn't there a chinese clone of that peerless that was floating about for a few years? I know Midwest Speaker still sells a rectangular faceplate version

 

[michiganpat]

Interesting, Ken - guess my elderly AR-14 isn't worth refoaming, then? :-(

An AR-14 should have prodigious LF. I have a pair of Teledyne-era AR-14s (with different drivers than the early AR-14), which I did refoam successfully. I spent some quality time listening to them once with an older, borrowed Parasound power amplifier and they were pretty stunning actually

technically, teledyne bought AR in '67 IIRC, so all AR14's are "Teledyne era"....

 

[michiganpat]

Of course, one can make a working speaker, possibly even an excellent one. But, it simply won't sound much like the original AR.

The AR drivers were built with parts, adhesives and assembly procedures that simply are not available these days. For example, nobody makes a surround that even comes close to the original AR-14 woofer. This alone will alter the F3, Qts and midrange flatness of the driver. Likewise, the adhesives used, and their application and curing, had a large influence on sound quality that it is almost impossible to duplicate.

I've seen a lot a nicely repaired AR woofers over the years, but none that my tests indicated would pass AR's original QC.

Perhaps there is a modern woofer that can be used as a good replacement, instead of going the re-foam route?

-k

I respect your opinion Ken, as you've forgotten more about speaker/driver design than I'll ever hope to know, but I don't think I agree that you can't repair a vintage AR driver and keep the AR sound. I doubt there are many modern woofers that would fit the bill better than a refoamed original, as most newer woofers are designed for ported alignments, and many have stiffer cones and breakup modes that need to be buried by steeper order low pass filters. You have to find the right foam, but RoyC and others have found some specific 8" & 10" JBL and BA replacement foams that have a low enough compliance to maintain the original Fs spec, and empirically, I've refoamed some AR18's with the proper foams, and they don't sound any different to my untrained ears than they did before needing the refoam. I looked, and couldn't find a reasonable modern replacement, as Fs was either too high, or it didn't have the nice natural roll off at around 2khz than the 120001-1 driver has, and needs, since the 18's crossover is a single 6uf cap. the closest replacement I could find were probably Human Speakers' EPI replacements...

 

[toxcrusadr]

The fact that the bass disappears when sitting in the sweet spot - with equal signal from each speaker - is a telltale sign of a phase problem. When you go elsewhere the signals from the two speakers are not equal, so one predominates and the bass is louder. I'd recheck everything from the woofer terminals through the crossover all the way back to the amp terminals.

 

[Mystery]

The fact that the bass disappears when sitting in the sweet spot - with equal signal from each speaker - is a telltale sign of a phase problem. When you go elsewhere the signals from the two speakers are not equal, so one predominates and the bass is louder. I'd recheck everything from the woofer terminals through the crossover all the way back to the amp terminals.

A simple way is to check with 1.5 volt battery.
+ve to +ve terminals and -ve to -ve terminals should pop the driver out not in.
If they go in on +ve, then out of phase.

 

[JohnMac]

This is pretty embarrassing but I've got to let you guys know what's going on.

I decided to re-check everything from the amp to the speakers and this time from the x-overs to the drivers. The first one checked out but...the second one, which I checked last night in haste and poor light, was connected wrong at the woofer. What can I say? :sigh:

Man, what a difference. Very well balanced and I like the tweeter.

I moved some other speakers out of the way and put the ARs closer to the wall and that seemed to help too.

I know that these are completely different animals than the older ARs but I like them better. I've had 2s, 2As and several 2AXs, all restored, and as hard as I tried I really had no love for them. The only ones from that era that I like are the 4Xs.

I noticed that the surrounds on these are very stiff. Thicker than any I've ever worked with. I would have to think that would have some effect.

 

[Mystery]

This is pretty embarrassing but I've got to let you guys know what's going on.
...

Not at all John. Embarrassing would be listening them out of phase.
Now it's all good.

I had the same issue with my Polk CRS+.
I was not getting SDA effect and later found that the red and black terminal caps were switched by PO.

 

[michiganpat]

This is pretty embarrassing but I've got to let you guys know what's going on.

I decided to re-check everything from the amp to the speakers and this time from the x-overs to the drivers. The first one checked out but...the second one, which I checked last night in haste and poor light, was connected wrong at the woofer. What can I say? :sigh:

Man, what a difference. Very well balanced and I like the tweeter.

I moved some other speakers out of the way and put the ARs closer to the wall and that seemed to help too.

I know that these are completely different animals than the older ARs but I like them better. I've had 2s, 2As and several 2AXs, all restored, and as hard as I tried I really had no love for them. The only ones from that era that I like are the 4Xs.

I noticed that the surrounds on these are very stiff. Thicker than any I've ever worked with. I would have to think that would have some effect.

if the surround is too thick and stiff, the woofer's Fs and the system Q have most likely been raised, which will raise the F3/F10 of the speakers (so you don't have as much low bass) as well as probably create somewhat of a mid-bass hump, and make the bass more "boomy"

these are the foams that seem to be the consensus best choice over at the CSP forum

http://www.ebay.com/itm/AR2ax-AR2a-...mplifier_Parts_Components&hash=item3cc95ce19b

 

[ken kantor]

I respect your opinion Ken, as you've forgotten more about speaker/driver design than I'll ever hope to know, but I don't think I agree that you can't repair a vintage AR driver and keep the AR sound. I doubt there are many modern woofers that would fit the bill better than a refoamed original, as most newer woofers are designed for ported alignments, and many have stiffer cones and breakup modes that need to be buried by steeper order low pass filters. You have to find the right foam, but RoyC and others have found some specific 8" & 10" JBL and BA replacement foams that have a low enough compliance to maintain the original Fs spec, and empirically, I've refoamed some AR18's with the proper foams, and they don't sound any different to my untrained ears than they did before needing the refoam. I looked, and couldn't find a reasonable modern replacement, as Fs was either too high, or it didn't have the nice natural roll off at around 2khz than the 120001-1 driver has, and needs, since the 18's crossover is a single 6uf cap. the closest replacement I could find were probably Human Speakers' EPI replacements...

Well, thanks!

Of course, it is a matter of degree. I stand by my assertion that none of the refoams I have encountered would be even close to passing AR's own Quality Control tests. That doesn't mean they don't sound good, or are not worth doing. Of course, a working speaker is much nicer than a bunch of scrap.

Sure, it isn't that difficult to obtain the original tonal balance and timbre. But, I don't believe it will be possible to properly recreate all the subtleties of the midrange performance. (Which may or may not be a problem for someone.) Also, there is much more to bass performance than small signal parameters.

Anyway, to be clear, my point was not to disparage refoaming in all cases. Rather, I want to argue against making critical sonic judgements about the performance of classic speakers based on repaired units. (And it's a bit strange to me how the same audiophiles who are incredibly sensitive to restoration cosmetics, soldering techniques, wires and PCB materials, capacitors, etc, so readily tolerate gross changes and degradations from rebuilt speakers.)

-k

 

[michiganpat]

Well, thanks!

Of course, it is a matter of degree. I stand by my assertion that none of the refoams I have encountered would be even close to passing AR's own Quality Control tests. That doesn't mean they don't sound good, or are not worth doing. Of course, a working speaker is much nicer than a bunch of scrap.

Sure, it isn't that difficult to obtain the original tonal balance and timbre. But, I don't believe it will be possible to properly recreate all the subtleties of the midrange performance. (Which may or may not be a problem for someone.) Also, there is much more to bass performance than small signal parameters.

Anyway, to be clear, my point was not to disparage refoaming in all cases. Rather, I want to argue against making critical sonic judgements about the performance of classic speakers based on repaired units. (And it's a bit strange to me how the same audiophiles who are incredibly sensitive to retoration, soldering techniques, wires and PCB materials, capacitors, etc, so readily tolerate gross changes and degradations from rebuilt speakers.)

-k

true...and of course, with my experience with my uncle's AR18's, I never heard them in their "as new" original configuration, I had never hear them until he retired from the Air Force in the late 18's or early 90's and the original foams were on their way out.....and to your last point, I do chuckle at times when I read people using, say, generic $.99 MAT electronic foams to refoam their equipment, and then later opine if they should buy some super-duper magic speaker cables over standard 14ga lamp cord, or for that matter, even, when restoring their speakers that originally came with relatively low grade NPE caps with very expensive and high-end caps that most likely have different ESR specs than the originals, which could end up altering the sound from "as stock"....

but I'm a bit of a luddite anyway. I have no problem using the tone controls on my receiver to make the music sound how I want it to....and yes, I even on occasion use the dreaded "loudness" button...oh the travesty!

 

[ken kantor]

true...and of course, with my experience with my uncle's AR18's, I never heard them in their "as new" original configuration, I had never hear them until he retired from the Air Force in the late 18's or early 90's and the original foams were on their way out.....and to your last point, I do chuckle at times when I read people using, say, generic $.99 MAT electronic foams to refoam their equipment, and then later opine if they should buy some super-duper magic speaker cables over standard 14ga lamp cord, or for that matter, even, when restoring their speakers that originally came with relatively low grade NPE caps with very expensive and high-end caps that most likely have different ESR specs than the originals, which could end up altering the sound from "as stock"....

but I'm a bit of a luddite anyway. I have no problem using the tone controls on my receiver to make the music sound how I want it to....and yes, I even on occasion use the dreaded "loudness" button...oh the travesty!

Could be a Luddite, but probably in the Avant Garde.... tone controls could be the IT feature in a few years.

We definitely agree on basic principles. My point of view on refoams comes from my decades dealing with production lines, and having to scrap $M's of minorly out of spec drivers. Very different from an end user's perspective, and probably overly fussy.

-k

 

[michiganpat]

Could be a Luddite, but probably in the Avant Garde.... tone controls could be the IT feature in a few years.

We definitely agree on basic principles. My point of view on refoams comes from my decades dealing with production lines, and having to scrap $M's of minorly out of spec drivers. Very different from an end user's perspective, and probably overly fussy.

-k

just think what a gold mine you could have been sitting on had you snuck out those minorly out of spec drivers, vacuum sealed them for a few decades, and then put them up on ebay now (have you seen the prices places like VintageAR charge?).......you could possibly be able to afford your very own island....:thmbsp:

 

[ken kantor]

just think what a gold mine you could have been sitting on had you snuck out those minorly out of spec drivers, vacuum sealed them for a few decades, and then put them up on ebay now (have you seen the prices places like VintageAR charge?).......you could possibly be able to afford your very own island....:thmbsp:

If I could see into the future, there are rather more portable ways to make a fortune. $1M worth of speakers is a lot of palettes!

Kidding aside, it's rather sad for me to see how much driver tolerances have gone down the drain as so many serious mass-market manufacturers have bit the bullet. AR, Foster, Peerless, Jensen... these are among the folks that set the bar for consistency and quality in mainstream drivers. Now days, I can count the number of companies that can even hit those tolerances on one hand, and all are 5x or 10x the price.

It also used to be that speaker factories were hardcore about never letting reject drivers even live for a day, for fear that they would somehow find there way out the door. Rejects were destroyed and/or rebuilt almost immediately. These days, manufacturers are too financially stressed, or too mercenary, to toss much stuff.

Oh, and the kids these days with their noisy "music," sexting and green hair! Why, when I was a kid, the cell phones had rotary dials...

-k