Recapped AR90 and listening results

[mister_roboto_hal]

OK everyone,

Please understand that this was done entirely by ear and as such is completely subjective. I can only relay what I heard then and the end result. I did a/b the change before doing the other tower so I could get a point of reference.

First of all, I want to add support and "my 2 cents" to my new friends here that I have come to exchange ideas with (Diamonds&Rust and Pete B in particular), that you should recap these old speakers. Chose whatever flavor floats your boat on caps, read all the reviews/comments on CSP, the net, etc., decide if you want to spend a couple hundred or a couple thousand and go for it. Bypass, don't bypass, whatever! Just recap them.

Into the cabinets:

I did not measure any of the caps. These speakers are 30 years old and felt it was not necessary-and listening results supported this assumption (more on that later). My speakers are only about 40 units apart in serial #'s. This is important for two reasons:

1) the crossovers were different in final assembly from the factory for the respective towers

2) that little disclaimer all consumer electronic companies make about "subject to change without notice"

was very true in this case

All the cap/resistor/inductor values were identical in each speaker. In the speaker with the lower serial # the resistors for the attenuation switches are mounted on a pcb board and mounted to the termination plate covering the switches and the resistors are very neatly arranged in an aligned row. In the higher serial # speaker, the pcb board is nonexistent and the resistors are soldered to the termination board on riveted connection tabs and are not neatly aligned. Therefore, AR exercised its right to "change without notice" and this drives home what I have read in other boards concerning vintage speakers. If you want to ensure you have a project that will yield close to similar results in your restoration - get speakers as close together in serial # of factory production as possible - otherwise you may be in for a few surprises. That board may have saved the company $5 in materials and labor - who knows - maybe more - it could have been because of defect ratio ( doubtful in my opinion). It is what it is. Caveat Emptor!

I removed each cap one at a time soldering monster cable speaker wires (its what I had on hand) to the cut leads left by the caps and replaced/rewired the upper board first and then the lower board. Solen MPP caps were used for all values - uF for uF - one for one - except for the 350uf on the lower board. I paralleled a 250uf and 100uf electrolytic from PartsExpress for the bass cap. This was a monetary decision, period. No other reason. The cost of 2 caps in MPP would have exceeded what I spent on the entire recap project combined. In addition, these caps are very easy to replace in the future should I chose to do so.

I completely upgraded the first tower, hot-glued all the caps to the internal floor of the cabinet, checked continuity and remounted the woofers. On to the the sound check, but first...

Room environment:

20' x 30' modern home living room (built 2003) with 10' ceilings. Speakers are placed on the long wall approximately 1' from rear wall, 4'+ from adjacent walls. Placement is approximately 10' apart - towed in to the sweet spot 8' from each tower. Carpet on floors, no drapes on rear wall, 1" vinyl blinds on 3 86" windows on opposite wall of speakers. Large oversized chair, recliner (in the sweet spot! :-) ) and large fabric sofa.

Listening test:

There have been many comments about recapping and various claims on what was gained or lost. I can tell you that regardless of what you read - your personal experience will be just that; personal. There are too many variables, not the least of being personal preference, that will affect the in-room response and final result.

The original unchanged tower - upper range was soft, muted, and veiled. Bass was extended but boomy in upper registers. Imaging was still good, however, the midrange was muddy, strings, horns and voices tended to be blurred.

Recapped tower - bass extension even deeper (yes, bass improved). Upper range was crisper and better defined. The best analogy I can give is focusing a pair of optics on a projector. You are looking at the image but there seems to be "fuzz" around all the letters. You twist the focus bezel and voila', everything is crisp and legible. Acoustically, this is exactly what the recapped tower sounded like. Panning the output (left to right) and then even listening to one channel at a time (mono) confirmed this. In each case the recapped tower sounded sharper, crisper, with more instrumental and vocal detail than the unchanged tower.

The recapped speaker did get "louder". I stress this because this is a common human anomaly when it comes to listening to speakers. The "louder" speaker will sound better - at first. Which is to say, it is human nature to chose the louder speaker regardless of the tonal character, imaging, balance, etc. That is why all the "pro's" will tell you to go, sit and listen to multiple soundtracks from multiple recordings of your own music for an extended listening session before you purchase a speaker.

I did not like the "brighter" stage at first. After several hours of listening, many tracks and artists, and still a/b'ing the speakers, I realized what I was NOT hearing in the original tower. And I understand why AR put those switches in the speaker. My speakers are still set for 0db - ie, flat. Yet, if my listening room was more "live" and had lots of reflections, I would be using those switches. So again, please be aware of your listening environment.

After recapping speaker 2, the end result was simply beautiful. Imaging was wider, tonal balance was restored, bass was tighter, deeper, and more controlled. What an amazing loudspeaker!

Conclusion, comments, observations:

So what did I learn? Well, the speakers sounded good before I did this - which is to say I was happy with the sound. Afterwards, I realized what the speaker was not producing. The network had simply fallen out of its design tolerance - which is to be expected after 30 years! The recap was worth the effort. I paid $400 dollars for the speakers and spent about $200 dollars on internal components/supplies and about 8 hours of sweat and tears. For $600 dollars these are the best speakers I have ever owned, period.

This recap was done in situ - simply put - I did this WITHOUT removing the masonite boards. All the original inductors and resistors were left in place and no changes to the original design were performed (with the exception of the caps of course). I soldered high quality wire onto the cap stubs left after cutting out the old ones. So yes, I did add another 2-3 feet of internal wire to the cabinet. This was done primarily for convenience, skill level (or lack thereof - it was much simpler to solder wires on caps, etc outside of the enclosure - then twist and cap connections to existing internal wiring), and it allowed me to position all the caps on the floor of the speaker enclosure for future upgrades, tweeking and what not.

I used the speaker foam tape from PartsExpress that Carl, one of the members had suggested to seal the woofers. It worked beautifully - Thanks Carl!

In retrospect, if I was more skilled in wood tools, etc., I would have removed the boards and sent them to Carl @ Carls Custom Loudspeakers. I simply did not have enough confidence to remove the staples, glue, wire connections, etc.

on the premise I would be able to reseal the boards and wire the complex crossover. This was done step to step to ensure each cap pair and lead went to the proper side of the network and pushed my limit and skill of crossover design/knowledge - even with a schematic. I checked and rechecked many times before sealing up the cabinets. In addition, cosmetically my speakers are very good with very little damage on their facades with intact grills, etc.

The point here is simple. If you figuratively have more thumbs than fingers - I would take it to a professional. This took all of day in what would have taken a professional a hour or 2. Or get a friend to help you that has more experience. There is the self-satisfaction of having executed this project successfully.

Conclusion - recap these wonderful dinosaurs - you will not be disappointed! If choose not to replace them, be aware that high volume - ie current may damage the very rare and almost irreplaceable drivers!!

The admin may decide to move this post - as it may belong in the mod section - so if it does - sorry Admin, I am new and just put it in the AR forum!

Thanks,

Lonnie

[rrcrain]

I'd say the lack of responses is because you've heard what the rest of us have heard and expressed it in similar terms. i used the analogy of removing a veil, another used the analogy of removing a cow. no matter how you state it, the change is dramatic.

I believe your post is in the right place. Your describing an upgrade, not a modification to the original design.

OK everyone,

Please understand that this was done entirely by ear and as such is completely subjective. I can only relay what I heard then and the end result. I did a/b the change before doing the other tower so I could get a point of reference.

First of all, I want to add support and "my 2 cents" to my new friends here that I have come to exchange ideas with (Diamonds&Rust and Pete B in particular), that you should recap these old speakers. Chose whatever flavor floats your boat on caps, read all the reviews/comments on CSP, the net, etc., decide if you want to spend a couple hundred or a couple thousand and go for it. Bypass, don't bypass, whatever! Just recap them.

Into the cabinets:

I did not measure any of the caps. These speakers are 30 years old and felt it was not necessary-and listening results supported this assumption (more on that later). My speakers are only about 40 units apart in serial #'s. This is important for two reasons:

1) the crossovers were different in final assembly from the factory for the respective towers

2) that little disclaimer all consumer electronic companies make about "subject to change without notice"

was very true in this case

All the cap/resistor/inductor values were identical in each speaker. In the speaker with the lower serial # the resistors for the attenuation switches are mounted on a pcb board and mounted to the termination plate covering the switches and the resistors are very neatly arranged in an aligned row. In the higher serial # speaker, the pcb board is nonexistent and the resistors are soldered to the termination board on riveted connection tabs and are not neatly aligned. Therefore, AR exercised its right to "change without notice" and this drives home what I have read in other boards concerning vintage speakers. If you want to ensure you have a project that will yield close to similar results in your restoration - get speakers as close together in serial # of factory production as possible - otherwise you may be in for a few surprises. That board may have saved the company $5 in materials and labor - who knows - maybe more - it could have been because of defect ratio ( doubtful in my opinion). It is what it is. Caveat Emptor!

I removed each cap one at a time soldering monster cable speaker wires (its what I had on hand) to the cut leads left by the caps and replaced/rewired the upper board first and then the lower board. Solen MPP caps were used for all values - uF for uF - one for one - except for the 350uf on the lower board. I paralleled a 250uf and 100uf electrolytic from PartsExpress for the bass cap. This was a monetary decision, period. No other reason. The cost of 2 caps in MPP would have exceeded what I spent on the entire recap project combined. In addition, these caps are very easy to replace in the future should I chose to do so.

I completely upgraded the first tower, hot-glued all the caps to the internal floor of the cabinet, checked continuity and remounted the woofers. On to the the sound check, but first...

Room environment:

20' x 30' modern home living room (built 2003) with 10' ceilings. Speakers are placed on the long wall approximately 1' from rear wall, 4'+ from adjacent walls. Placement is approximately 10' apart - towed in to the sweet spot 8' from each tower. Carpet on floors, no drapes on rear wall, 1" vinyl blinds on 3 86" windows on opposite wall of speakers. Large oversized chair, recliner (in the sweet spot! :-) ) and large fabric sofa.

Listening test:

There have been many comments about recapping and various claims on what was gained or lost. I can tell you that regardless of what you read - your personal experience will be just that; personal. There are too many variables, not the least of being personal preference, that will affect the in-room response and final result.

The original unchanged tower - upper range was soft, muted, and veiled. Bass was extended but boomy in upper registers. Imaging was still good, however, the midrange was muddy, strings, horns and voices tended to be blurred.

Recapped tower - bass extension even deeper (yes, bass improved). Upper range was crisper and better defined. The best analogy I can give is focusing a pair of optics on a projector. You are looking at the image but there seems to be "fuzz" around all the letters. You twist the focus bezel and voila', everything is crisp and legible. Acoustically, this is exactly what the recapped tower sounded like. Panning the output (left to right) and then even listening to one channel at a time (mono) confirmed this. In each case the recapped tower sounded sharper, crisper, with more instrumental and vocal detail than the unchanged tower.

The recapped speaker did get "louder". I stress this because this is a common human anomaly when it comes to listening to speakers. The "louder" speaker will sound better - at first. Which is to say, it is human nature to chose the louder speaker regardless of the tonal character, imaging, balance, etc. That is why all the "pro's" will tell you to go, sit and listen to multiple soundtracks from multiple recordings of your own music for an extended listening session before you purchase a speaker.

I did not like the "brighter" stage at first. After several hours of listening, many tracks and artists, and still a/b'ing the speakers, I realized what I was NOT hearing in the original tower. And I understand why AR put those switches in the speaker. My speakers are still set for 0db - ie, flat. Yet, if my listening room was more "live" and had lots of reflections, I would be using those switches. So again, please be aware of your listening environment.

After recapping speaker 2, the end result was simply beautiful. Imaging was wider, tonal balance was restored, bass was tighter, deeper, and more controlled. What an amazing loudspeaker!

Conclusion, comments, observations:

So what did I learn? Well, the speakers sounded good before I did this - which is to say I was happy with the sound. Afterwards, I realized what the speaker was not producing. The network had simply fallen out of its design tolerance - which is to be expected after 30 years! The recap was worth the effort. I paid $400 dollars for the speakers and spent about $200 dollars on internal components/supplies and about 8 hours of sweat and tears. For $600 dollars these are the best speakers I have ever owned, period.

This recap was done in situ - simply put - I did this WITHOUT removing the masonite boards. All the original inductors and resistors were left in place and no changes to the original design were performed (with the exception of the caps of course). I soldered high quality wire onto the cap stubs left after cutting out the old ones. So yes, I did add another 2-3 feet of internal wire to the cabinet. This was done primarily for convenience, skill level (or lack thereof - it was much simpler to solder wires on caps, etc outside of the enclosure - then twist and cap connections to existing internal wiring), and it allowed me to position all the caps on the floor of the speaker enclosure for future upgrades, tweeking and what not.

I used the speaker foam tape from PartsExpress that Carl, one of the members had suggested to seal the woofers. It worked beautifully - Thanks Carl!

In retrospect, if I was more skilled in wood tools, etc., I would have removed the boards and sent them to Carl @ Carls Custom Loudspeakers. I simply did not have enough confidence to remove the staples, glue, wire connections, etc.

on the premise I would be able to reseal the boards and wire the complex crossover. This was done step to step to ensure each cap pair and lead went to the proper side of the network and pushed my limit and skill of crossover design/knowledge - even with a schematic. I checked and rechecked many times before sealing up the cabinets. In addition, cosmetically my speakers are very good with very little damage on their facades with intact grills, etc.

The point here is simple. If you figuratively have more thumbs than fingers - I would take it to a professional. This took all of day in what would have taken a professional a hour or 2. Or get a friend to help you that has more experience. There is the self-satisfaction of having executed this project successfully.

Conclusion - recap these wonderful dinosaurs - you will not be disappointed! If choose not to replace them, be aware that high volume - ie current may damage the very rare and almost irreplaceable drivers!!

The admin may decide to move this post - as it may belong in the mod section - so if it does - sorry Admin, I am new and just put it in the AR forum!

Thanks,

Lonnie

[Guest winters860]

Congratulations, Lonnie!

I refoamed my AR-90 about a month ago and have been looking forward to recapping them at some point soon. Thanks for adding fuel to my fire!

[mister_roboto_hal]

Congratulations, Lonnie!

I refoamed my AR-90 about a month ago and have been looking forward to recapping them at some point soon. Thanks for adding fuel to my fire!

No problem winters860- glad I could help

Some other points not mentioned in the post. I did not replace any of the sand cast resistors or air core inductors. I also did not bypass or remove the attenuation switches. I am confident that there is oxidation and what not, but chose to clean them and leave them in. If you have a more "dynamic" room you are probably going to need them. These speakers were designed for as close to flat response with wide imaging, etc. May not be your cup of tea! In addition, it would have been a far more complex effort to replace or design these switches out of the network.

The people at AR loved music and pushed to produce an accurate loudspeaker that would deliver a complex soundstage and reproduce the recording exactly as the source. They also loved listening to music. Products like these come of passion - not the desire to be rich. Doing a singular something and doing it well...

Good luck in your restore!

[mister_roboto_hal]

I'd say the lack of responses is because you've heard what the rest of us have heard and expressed it in similar terms. i used the analogy of removing a veil, another used the analogy of removing a cow. no matter how you state it, the change is dramatic.

I believe your post is in the right place. Your describing an upgrade, not a modification to the original design.

Thanks rrcrain,

I did not expect any replys - I was simply adding my experiences to the forum so others could read the end result. this forum, in my opinion, is unique. The webmaster is strict and does not tolerate abuse, flame wars, etc. In addition, this board is dedicated to the enjoyment of music. AR has made its mark in acoustical and loudspeaker design. One would be hard pressed to find anyone to argue against this statement.

I guess what "gets my blood flowing" is the founders, designers, etc., behind this company and several other companies of this time period - truly loved music. The desire was to produce something close to the live event. I mean, these guys/gals went from AR to form other companies with their own "zealot" following. These innovators did go to concerts and listen to live events and probably played instruments, etc. Music was the passion.

Music is what it is all about!

“Music is enough for a lifetime, but a lifetime is not enough for music”

Sergei Rachmaninov

[blastinbill1]

I have a pair of AR-90's that I purchased new in 1979. They have been used non-stop since then in different locales and I have listened to Command, London Phase Four and various direct-to-disc recordings of various types of music in that period, and I play trumpet in various local music groups. Many of the recordings I have today I listened to in the 1980's so I can subjectively compare how the AR's sounded then and now. The lower midranges and woofers were replaced with AB Tech replacement drivers in the early 90's and three of the woofers were replaced three years ago to provide proper 8 ohm matching impedance of all the woofers. The crossover components are all original. Six months ago I disconnected the original 350 microfarad capacitors from the crossovers and checked their capacitance. One measured 356 and the other 361, both within 2 percent of stated capacitance. Not bad after 29 years!

What I'm getting at is that, after reading all the posts about recapping, I can't convince myself that any portion of the sound spectrum reproduced by these babies has changed. I know the consensus is that, with the original caps, the sound is more veiled now than when new. Maybe, but I can't be sure. I remember that from 1973 until I bought these I had tried many other speakers, some good, some not so good (including some KLH and Altec Lansing Model 15's) and many of them seemed to have a brighter top end than these. I have copies of reviews from High Fidelity and Stereo Review of the big brother AR-9's which showed on-axis high end frequency response to slope down a little in order to have a more uniform off-axis power response. The rest of the audio spectrum with these has always (then and now) sounded very transparent, especially compared to any speaker placed next to them in an A-B comparison over the entire 30 years I have had them. In that period I aged from 21 to 51 and my hearing probably deteriorated at the top end, but I just don't think the AR's have.

[genek]

Six months ago I disconnected the original 350 microfarad capacitors from the crossovers and checked their capacitance. One measured 356 and the other 361, both within 2 percent of stated capacitance. Not bad after 29 years!

What I'm getting at is that, after reading all the posts about recapping, I can't convince myself that any portion of the sound spectrum reproduced by these babies has changed.

I've particpated in the recapping of maybe a dozen pairs of old speakers over the years (but not any of mine). Most of them definitely needed recapping, because the caps had leaked or otherwise failed and had an unmistakable effect on sound (nothing coming out of the tweeters). Only two cases where the owner decided to "upgrade" caps that tested within spec. In one case the owner was convinced he heard a difference, but the speakers sounded the same to me; in the other, none of us could hear any difference. I'm definitely in the skeptics camp on recapping speakers that seem to be working ok.

[rrcrain]

I've particpated in the recapping of maybe a dozen pairs of old speakers over the years (but not any of mine). Most of them definitely needed recapping, because the caps had leaked or otherwise failed and had an unmistakable effect on sound (nothing coming out of the tweeters). Only two cases where the owner decided to "upgrade" caps that tested within spec. In one case the owner was convinced he heard a difference, but the speakers sounded the same to me; in the other, none of us could hear any difference. I'm definitely in the skeptics camp on recapping speakers that seem to be working ok.

I can appreciate your opinion and to be honest, I was once a hard skeptic myself. Other than my own speakers (AR90), I've heard a fair range of speakers before and after recapping and there was a notable change/improvement in every case. We heard this on inexpensive speakers with simple two cap crossovers to speakers with very complex crossovers such as the large Dhalquist, Snell and JBL speakers.

I've read that if the speakers are old enough, the caps used contain PCB's which never dries out, the caps supposedly never drift out of spec. I've no first hand experience here and to be frank, don't want it. I'm not sure I'd feel comfortable having 40 year old caps containing PCB's in the house.

[Carlspeak]

With regard to the recapping debate, I refer you to the voluminous posts contained in "Capacitor Myths" and Capacitor Myths Revisited" here at CSP and, this one over at AK http://www.audiokarma.org/forums/showthread.php?t=78978 with 268 posts over 18 pgs.

IMHO, beauty is in the eye of the beholder. OTOH, significant audible differences are in the ear of the beholder........

[genek]

I can appreciate your opinion and to be honest, I was once a hard skeptic myself. Other than my own speakers (AR90), I've heard a fair range of speakers before and after recapping and there was a notable change/improvement in every case. We heard this on inexpensive speakers with simple two cap crossovers to speakers with very complex crossovers such as the large Dhalquist, Snell and JBL speakers.

I've read that if the speakers are old enough, the caps used contain PCB's which never dries out, the caps supposedly never drift out of spec. I've no first hand experience here and to be frank, don't want it. I'm not sure I'd feel comfortable having 40 year old caps containing PCB's in the house.

I would never try to tell someone who believed that a recap would improve speaker performance, or has improved speaker performance, that they're wrong. Even if improvement is all in someone's head, why ruin their enhanced enjoyment of their speakers?

PCBs can be dangerous if you're exposed to high levels, or to low levels for prolonged periods. Exposure as in skin contact or consuming contaminated food or water. PCBs in the capacitors of loudspeakers wouldn't represent a sufficient level of exposure to be dangerous. You just need to wear oil-resistant gloves anytime you work near them and clean up any leakage.

[Guest spazmochad]

I'm just about the do my first re-cap and feeling a little worried that I've chosen AR-90s. I don't suppose you could post any extra pictures and a list of parts to order from PE?