Guest aster Posted February 18, 2009 Report Share Posted February 18, 2009 Hi all. New to the board and to audio maintenance & repair as well, but happy to learn...I just got a pair of AR-7s on eBay. At first glance, physically they're in nice condition. However, they don't sound very good at all - a bit muddy and with rather feeble bass. After testing them out I reinstalled the cheap-o Aiwa speakers that were being used on that system, which sounded a hell of a lot better than the ARs.Can anyone help me troubleshoot these? Would be much appreciated... Link to comment Share on other sites More sharing options...
mister_roboto_hal Posted February 19, 2009 Report Share Posted February 19, 2009 Hi all. New to the board and to audio maintenance & repair as well, but happy to learn...I just got a pair of AR-7s on eBay. At first glance, physically they're in nice condition. However, they don't sound very good at all - a bit muddy and with rather feeble bass. After testing them out I reinstalled the cheap-o Aiwa speakers that were being used on that system, which sounded a hell of a lot better than the ARs.Can anyone help me troubleshoot these? Would be much appreciated...Hello Aster,First, remember you are dealing with speakers that are almost 40 years old. The first thing to find out is if the drivers are original. These speakers to retain their original sound would have had to be refoamed at least twice. Second, the crossover network, if original, is no longer even close to original design specifications. Only the solid copper inductors would still be close to spec. Any paper/wax or other such capacitors for the hipass filter, if original, is no longer functional.Second, the high pass pots/switches, if they have not been replaced are most assuredly corroded and shot. This is the attenuation network for the tweeter and was made with common controls of that time. I have not seen the schematics for this loudspeaker system, but in addition, if there are any of the old sand cast resistors of this time period, these are also prone to disintegrate .Third, the cabinet is acoustic suspension. The cabinet must be sealed. You woofer should have a tacky feel when pushing on it gently in the center around the dust cap if the "acoustic spring" is still intact. Finally, this board and all the enthusiasts here are enamored with what is affectionately called the "New England" sound. I have a pair of AR90's made during the Teledyne era. I had to spend money to reseal the cabinets, redo the crossover networks, and clean the attenuation switches for the passive network. And they are beyond a doubt, for me, the finest pair of speakers I have ever owned. I stress the "for me" part. These speakers can sound very good. But the sound is unique because of the dispersion and output characteristics the designers of these speakers engineered toward. But they do not age like fine wine and like all things concerning sound are subject to personal preference. You will have to spend some money to restore these speakers - assuming the drivers are original! If not, if they have been replaced with other drivers not of this period, then you are simply not hearing what AR designed and intended. Modern woofers for the most part are designed for vented or ported cabinets to achieve low end bass response, are generally higher in efficiency and require larger enclosure volumes. Modern tweeters for the most part have tighter dispersion patterns as opposed to the wide fields of classic AR. In addition, no modern drivers will be optimized with the existing network even if it was fully functional and up to spec.So, pull the drivers, take some pictures and post them here, and then let the expansive expertise available on this board help you in getting these speakers back to the original glory. That is of course based on the assumption you are ready and willing to invest the time, effort, and money to undertake such a project. If the drivers are original and they need the passive side reworked, you can always resell them here in the for sale section. As these are part of the original AR line during the Vilchur era, they are very much in high demand.I have been looking for AR9/AR90's for over 10 years. I was finally able to acquire a pair of AR90's this year. Without the help of the people here, I simply would not have been able to get these speakers sounding the way they do now. So, like you, I am also a noobie to restoring these old classics. I do have some electrical and acoustical knowledge and know how read a schematic - so I did the work myself - WITH the help of the people here. If you are lacking in these skills, you can remove the networks and send them to someone like Carl at Carls Loudspeakers where he can rework with modern caps and send them back to you. Carl is a member here. The point being, is the people on this board are great and will help you if you truly want to get these classics singing again. Also, check the library section and posts. There is a wealth of information on people who have been where you are before. I spent 2 months reading posts and advice from members before I restored my AR90's.Hope this helps and good luck! Link to comment Share on other sites More sharing options...
mister_roboto_hal Posted February 20, 2009 Report Share Posted February 20, 2009 Hi all. New to the board and to audio maintenance & repair as well, but happy to learn...I just got a pair of AR-7s on eBay. At first glance, physically they're in nice condition. However, they don't sound very good at all - a bit muddy and with rather feeble bass. After testing them out I reinstalled the cheap-o Aiwa speakers that were being used on that system, which sounded a hell of a lot better than the ARs.Can anyone help me troubleshoot these? Would be much appreciated...Sorry Aster - Welcome to CSP! I totally forgot my manners :-) Link to comment Share on other sites More sharing options...
dick Posted February 20, 2009 Report Share Posted February 20, 2009 Hi all. New to the board and to audio maintenance & repair as well, but happy to learn...I just got a pair of AR-7s on eBay. At first glance, physically they're in nice condition. However, they don't sound very good at all - a bit muddy and with rather feeble bass. After testing them out I reinstalled the cheap-o Aiwa speakers that were being used on that system, which sounded a hell of a lot better than the ARs.Can anyone help me troubleshoot these? Would be much appreciated...Hi Alster. Several months ago, like you, I came across some AR speakers. If it were not for the many hands & voices of this CSP AR Forum, I would not today have a fabulous pair of speakers. I only knew how to melt solder on the end of a soldering iron and how to read schematic drawings. What you might want to do is as suggested: post some photos of your speakers and let the Forum members give you advice. Ohhh, and get out your soldering iron too. Link to comment Share on other sites More sharing options...
JKent Posted February 20, 2009 Report Share Posted February 20, 2009 Hi all. New to the board and to audio maintenance & repair as well, but happy to learn...I just got a pair of AR-7s on eBay. At first glance, physically they're in nice condition. However, they don't sound very good at all - a bit muddy and with rather feeble bass. After testing them out I reinstalled the cheap-o Aiwa speakers that were being used on that system, which sounded a hell of a lot better than the ARs.Can anyone help me troubleshoot these? Would be much appreciated...Hi AsterDon't give up on the 7s. They're real nice and not very common. Do you have the vinyl clad or the real walnut veneer version?I would suggest you download and look over the AR3a restoration manual for some general idea of the classic AR speaker and what may go wrong:http://www.classicspeakerpages.net/library/acoustic_research/original_models_1954-1974/original_models_schematicss/restoring_the_ar-3a/Just remember the 3a is the big brother to the 7: More complex.I don't agree that the swiches are probably shot. Those switches are fairly rugged.OTOH, your foam surrounds are very probably shot and this may be the proble. If the speakers were played at anything approaching rock music levels with rotted surrounds the woofers may have been irrevocably damaged. First thing I would do is remove the front grilles and inspect the woofers. Maybe take a photo.You will get lots of help here. We don't all always agree, but we are all enthusiastic!Welcome to the club!Kent Link to comment Share on other sites More sharing options...
AR_nut_in_Oregon Posted February 20, 2009 Report Share Posted February 20, 2009 aster,The previous comments are "spot on". AR-7's have a great sound if they are put together correctly. Get those Woofs re-foamed, replace the old electrolytic cap, and re-seal the drivers with some duct seal. Oh, and make sure that the original fiberglass filling is intact. Not sure how much is in an AR-7 (12oz?) someone here will no doubt, chime in.I am presently using mine as centers in my surround system....they do a wonderful job. Link to comment Share on other sites More sharing options...
Shacky Posted February 21, 2009 Report Share Posted February 21, 2009 Hi all. New to the board and to audio maintenance & repair as well, but happy to learn...I just got a pair of AR-7s on eBay. At first glance, physically they're in nice condition. However, they don't sound very good at all - a bit muddy and with rather feeble bass. After testing them out I reinstalled the cheap-o Aiwa speakers that were being used on that system, which sounded a hell of a lot better than the ARs.Can anyone help me troubleshoot these? Would be much appreciated...These Vintage AR's are great speakers but usually require a good amount of work to bring them up to snuff. Refoam or have your woofers refoamed. If foam surround is old, cracking, turning to dust... it is not a good idea to play them till they are refoamed. You can burn out the voice coil in no time.You will need to clean or replaace the pot for attenuating high freq. And replacing the old capacitor is always a good idea.Read up on things here. You will learn a lot reading through the guide to AR 3a restoration - though your 7's will be much easier. If you need help there are plenty of folks here with intimate knowledge and vast experience. If you happen to live in NE or don't mind shipping these - check out Carls Customer Loudspeakers. Carl can make these like new for you. And once you get them up to snuff, you will regret ever saying your Aiwa sound "better" EDIT - Sorry for some reason I didn't see all the replies you already received. Mine remarks are certainly redundant.And how about posting some pictures? Naked of course Link to comment Share on other sites More sharing options...
genek Posted February 21, 2009 Report Share Posted February 21, 2009 You will need to clean or replaace the pot for attenuating high freq. And replacing the old capacitor is always a good idea.7's don't have pots. They were AR's "budget" speaker, with woodgrain vinyl cabinets and hi/lo switches.Ken Kantor thinks the odds of AR caps from the mid 70's (the 7 came out in '73, during my college years) still being good are better than in earlier models. Link to comment Share on other sites More sharing options...
JKent Posted February 21, 2009 Report Share Posted February 21, 2009 7's don't have pots. They were AR's "budget" speaker, with woodgrain vinyl cabinets and hi/lo switches.Ken Kantor thinks the odds of AR caps from the mid 70's (the 7 came out in '73, during my college years) still being good are better than in earlier models.GeneYou are right about no pots, but as I noted above these also came in real walnut veneer--I have a pair.Kent Link to comment Share on other sites More sharing options...
genek Posted February 21, 2009 Report Share Posted February 21, 2009 You are right about no pots, but as I noted above these also came in real walnut veneer--I have a pair.Any idea when yours were made? I remember when the 7's came out. AR's advertising for them was all based on how they had reduced costs in areas that had no effect on performance in order to make real AR performance available to people with limited budgets. There was never any mention of a real walnut veneered model that I can recall. Link to comment Share on other sites More sharing options...
JKent Posted February 21, 2009 Report Share Posted February 21, 2009 Any idea when yours were made? I remember when the 7's came out. AR's advertising for them was all based on how they had reduced costs in areas that had no effect on performance in order to make real AR performance available to people with limited budgets. There was never any mention of a real walnut veneered model that I can recall.Sorry--don't know when they were made. SNs are 008517 & 008518. I bought them on ebay about 2 yrs ago. The seller was a stereo repair shop and he had refoamed them (good job), so I haven't been inside yet. The cabinets had been refinished--poorly--so I concentrated on refinishinjg the wood and replacing the linen. Logo plates are kind of cool--brass with a black/bronze sort of finish and engraved AR 7.Kent Link to comment Share on other sites More sharing options...
Rich W Posted February 21, 2009 Report Share Posted February 21, 2009 Hi all. New to the board and to audio maintenance & repair as well, but happy to learn...I just got a pair of AR-7s on eBay. At first glance, physically they're in nice condition. However, they don't sound very good at all - a bit muddy and with rather feeble bass. After testing them out I reinstalled the cheap-o Aiwa speakers that were being used on that system, which sounded a hell of a lot better than the ARs.Can anyone help me troubleshoot these? Would be much appreciated...Hello Aster,Welcome to the CSP Forum. You'll get a lot of good advice on refurbishing your AR-7's here, and fellow members have already pointed you in the right direction. Don't give up on these speakers based on what your hearing now. A refoam of the woofers, cleaning on the tweeter level switch and replacement of the single 6 uf capacitor will have those speakers singing.Here's an old post of mine discussing the results of my own AR-7 refurb: http://www.classicspeakerpages.net/IP.Boar...amp;#entry62625One thing that makes the AR-7 special is how similar it sounds to its more expensive brethren. In fact, and I've stated this elsewhere in this forum, in smaller rooms you'll probably get better overall sound with a pair of AR-7's than with a pair of top-of-the-line AR-3a's, especially in the elusive "soundstage" and "imaging" department. This assumes of course, that you'll be playing them at a moderate volume level.Best of luck with your AR-7's.Rich W Link to comment Share on other sites More sharing options...
genek Posted February 21, 2009 Report Share Posted February 21, 2009 Logo plates are kind of cool--brass with a black/bronze sort of finish and engraved AR 7.That black/bronze is probably really tarnish on the brass, but if you like it the way it is that's all that really matters. Link to comment Share on other sites More sharing options...
JKent Posted February 21, 2009 Report Share Posted February 21, 2009 Gene, I don't mean to be so consistently contrary, but the dark finish really looks intentional to me. Kind of hard to capture in a photo but here it is. Also--I've seen photos of some with back-wired tweeters and Masonite blanks covering the oval cut-out for the posts. Mine have the front-wired tweets. Wonder what the difference was. Now I'm curious about the xo so think it's time to open these up!KentOK--That didn't take long. The woofers were on foam gaskets--not putty. As Ken predicted, those big ol' Sprague NPEs were still good. But I had some Mylars in my parts box, so in they went. Left the 3 ohm resistors--didn't even have to remove the xo!Thanks for the Flitz recommendation--I'll search it out. Link to comment Share on other sites More sharing options...
genek Posted February 21, 2009 Report Share Posted February 21, 2009 Gene, I don't mean to be so consistently contrary, but the dark finish really looks intentional to me. Kind of hard to capture in a photo but here it is. Also--I've seen photos of some with back-wired tweeters and Masonite blanks covering the oval cut-out for the posts. Mine have the front-wired tweets. Wonder what the difference was. Now I'm curious about the xo so think it's time to open these up!That's because the uncoated brass tarnishes gradually and evenly. My 2ax plates got to looking just like that because I didn't clean them until something like 10 years had passed. The brightness at the corners is the real finish.There's an easy way to test it, but if I'm right and you prefer the current look it would be destructive. Get a bottle of "Flitz Instant Brass & Copper Tarnish Remover" and spray it on one of the plates. If the color is a real finish, nothing will happen; if it's tarnish, you'll be looking at shiny, clean brass in about 30 seconds.AR changed most of its drivers over to back-wired sometime around 1974. I don't think there's any difference to speak of in the performance, and it was just a manufacturing process change done to speed up production and reduce costs by simplifying cabinets and eliminating the need to fuss with thin front wires on drivers. The blanks would have been done to use up existing cabinets. Link to comment Share on other sites More sharing options...
JKent Posted February 22, 2009 Report Share Posted February 22, 2009 I don't know if this is helpful or confusing, but some CSP forum member suggested this woofer as a replacement for the AR-7. Sorry I can't give credit, and I don't know how it worked out, but here's the link:http://www.mcmelectronics.com/product/55-1940 Link to comment Share on other sites More sharing options...
Guest JonM Posted February 22, 2009 Report Share Posted February 22, 2009 Kent -I didn't believe there were walnut veneered 7's till I saw your picture. My brother had a pair from the early 70's and they were vinyl. I have a used pair I bought at a flea market, and they are vinyl. (Well, they were vinyl till I took a hair dryer to them, and removed the vinyl, in preparation to do my own veneer job. Haven't gotten around to it, so they are currently naked particle board. I supposed that's sacrilege. Oh well...) All the literature I have ever seen on them from when they were first announced, shows them in vinyl. They look nice in walnut - I guess I should find some place to get the veneer I need to finish that project!JonM Link to comment Share on other sites More sharing options...
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