RoyC

Hmmm...If that means he can't see my posts, that's probably a good thing. They're really not meant for him anyway.

Not sure how you do that, but it is probably not a bad idea. Attempting to balance subjective comments/recommendations is not meant to be aggression. It often seems like you assume something must "sound" better if it is expensive. Based on you comments above, perhaps you assume that something simply must "sound" better if you are impressed with its construction. Either way, that's usually when I will show up. Btw, your comments about me are as unsubstantiated as your forum comments. For example, Carl Richards and I were friends (see attached photo of us), and I was handling much of his work in his last couple of years here. I also can't remember the last time I posted in another audio forum. It seems you have resorted primarily to personal attacks and accusations, David. I'm feeling Gene's finger getting ever closer to the Kitchen button. 🙃 Roy PS In case anyone is interested at this point. The leads of Mundorf electrolytic capacitors appear to be the same length and thickness as those of Parts Express and MDL (.8mm x 44mm). I can't seem to let that one go...

Some years ago I first found MDL capacitors as original equipment in speakers I was repairing for a local audio shop. Having been impressed with their measurements, I later purchased "buyout" MDL's from Parts Express with good luck. Since Madisound began carrying them, I've used quite a few for repairs and restorations of all types.

Careful, or we'll be heading to the kitchen :). Since we've arrived here, it seems you have dubbed yourself a capacitor expert with your apparently calibrated ears. Accordingly, you are actually the only person I have had a problem with in recent years. We've made our points. Roy

Parts Express sells 3/8" gasket tape as well as a black caulk/putty. https://www.parts-express.com/speaker-components/cabinet-hardware-speaker-grill-cloth/Speaker-Gasketing-Tape-Caulk Roy

"Parts Express has NPEs made by Solen. https://www.parts-express.com/electronic-parts/capacitors/non-polarized-electrolytic-capacitors I'm not a big fan of MDL but they work." Based on your statement above, the implication was MDL was somehow inferior to the rest of the caps mentioned in your post. I just measured the leads of some 1% Dayton film caps and found them to be .2 mm thicker (1mm vs .8mm) and about 1/4" longer than the PE and MDL npe's 1.5" leads. What would you do (or need) with the difference? If someone can't work with those slightly smaller leads perhaps they need to reconsider their installation technique. Whatever the case may be, those leads are more than long and thick enough for most any application. It is still not clear what your actual "disapproval" is based on. I'm just concerned that this type of conversation only serves to confuse inexperienced readers of the forum with inconsequential "issues". I would also be interested in where you acquired the information that PE npe caps are made by Solen. You also mentioned a manufacturer for MDL awhile back as well, but I don't recall which one (I think, you said Bennic?). Roy

See attached photo, David. The leads of both brands are identical, and the MDL capacitor is larger and heavier. In this case you are looking at 50uf caps with .032" leads. What is the basis of your "disapproval"?🙄 Roy

AR used jigs to hold the dome down to apply the foam.

The crossover of this model, as well as the others of the Jensen era Advents, is attached to the terminal cup, which is relatively easy to access by removing its screws from the rear of the cabinet. The caps are usually in good shape. Roy

David, I've actually been finding MDL caps to measure and perform as well as Parts Express npe caps. I use them interchangeably these days. ERSE is the only common npe crossover cap I have found to be inferior, but I think that company went out of business. Roy

First of all, very nice video and work! I have been at this for lots of years, and have restored many KLH speakers. The 5 ohm resistor in parallel with the KLH 5 woofer is exposed to more current, and is the only one I have occasionally found to be fried. The other potential KLH resistor issue is likely to be found with any "Rockwood" brand resistor (which can sometimes be found in Advent Loudspeakers as well). It is prudent to replace them whenever you find them, regardless of value, model, or placement within the circuit. Roy

Norman, I have worked on a number of these. The foam on the baffle is usually in the process of decomposing, making a mess of things. If it is too nasty/gooey I recommend scraping it off around the woofer hole and replacing it with conventional gasket material. I've known a few people who have scraped it off the entire baffle! The plastic ring can be pried off by twisting and lifting with a strong flat edge between it and the basket edge, under the interior of the ring. Once you get it started, it becomes easier to insert the tool and lift. Boston Acoustics 10 inch foam is the best replacement for this woofer. Let me know if you need any. Roy

AR is known to have used butyl and (later) latex rubber compounds for this type of purpose...but the type of compound is irrelevant. These were manufactured in the mid-60's, and AR was the first to try various rubber and foam formulations. If you scrape it, you will find it to be elastic and not "rock hard"...unless somebody applied some kind of additional material over it at some point. With that said, there is no doubt that it has stiffened with time, and the primary problem has as much to do with its initial degree of migration into the voice coil gap. If you are able to get it started in a "safe" area of the dome's perimeter, you can literally pull and peel it out. I have worked on many of these tweeters and have done this countless times. Before doing anything, try listening to the tweeter with no cap in line vs with. You will likely be surprised at the subjective difference. The low DCR of this driver is as instrumental in its reticent response as the material around the dome. Unlike modern designs (like your Polks), these tweeters are only meant to enhance "sss" sounds, and little else. Your impressions are not unusual for folks new to early AR-dom. I'm sure you can improve the response with your plan, but don't expect it to be a dramatic difference. Modern speakers simply have more upper mid and high frequency output. Roy

This tweeter, which is original to the AR-2ax and AR-3, was designed to cross over at a very high frequency. The stiffer suspension is deliberate, and meant to minimize the dome's excursion to limit its effect on the mid frequencies. It should also be noted that the original tweeter is not only mechanically unique, it is electrically unique, with an unusually low DCR of under 2 ohms. If a modern tweeter (regardless of brand or quality) is used to replace it, the crossover must be modified to prevent it from creating a rather imbalanced and harsh sounding mid response. A modern tweeter is really a different animal. In other words, don't mess up the original if at all possible. It is not just a simple matter of attempting to fit an aftermarket replacement tweeter into the unusually large cabinet hole. The clear (butyl rubber) material around the perimeter of the dome can be peeled away mechanically with tweezers. Great care must be taken, however, not to damage the fragile aluminum leads or the suspension "blobs". Roy

Just sent you a PM, Don.

Nice, Glenn...You are definitely the "cabinet whisperer"! Roy

Hi Jack...PM sent.

Good to know, Earthnz. The MW tweeter is a very faithful reproduction of the AR-11 tweeter, which was used with a similar capacitance value when installed as a service replacement for earlier models. Roy

The reason for using a parallel coil or smaller value cap when replacing the original 3/4" AR tweeter is to compensate for the extended midrange response of the modern type of tweeter. Since you have attempted to do so by replacing the LST's original 6uf cap with a 2uf cap, there is likely no need to use the coils at all. Try it, as is, and see how it sounds. Roy

Correct, Jeff...I've seen this is a number of times in the LST. Replacing the parallel arrangement of the old caps with a single 40uf cap is the way to go. AR was probably just using up inventory of old capacitors. I would keep the large 5000uf caps. As Aadams mentioned, replace the fuses. Their construction is such that they can be partially functional, resulting in diminished sound. Roy

Andrew, Yes...PM sent. Roy

I do. PM sent. Roy

Agreed, Steve...I have both models here. It is a 6 without a doubt.

Well, that's good news! Old KLH capacitors are often troublesome. Regarding your question...Depress the woofer cone while the woofer is installed in the cabinet. It should return relatively slowly as compared to its action outside of the cabinet. If there is no discernible difference, the surround should be treated. It is not unusual for KLH woofers to require additional treatment. Roy

Those are KLH 6's. Roy