leemichaelbrian

me too - sent a DM

To echo a previous statement about damping factor, I'm driving 3a's with a Mac MC2100 which is not a particularly high damping factor design, but does have a decent amount of (if not quite Crown-level) power. I've heard tighter from more modern solid state, however there is something very musically "right" and organic to the 3a's bass with the MC2100 - as well as a sense of abundant reserve power on tap, even with higher listening levels.

Hello all! There are threads issuing guidance and warnings about storage to ensure that woofer spiders (particularly for the earlier 12" woofer) do not develop a sag, but are there any confirmed and documented best practices around attempting to restore proper alignment once damage has been incurred? I have seen a few ideas, but relatively little feedback around efficacy. I have a spare woofer that I purchased locally whose resting point is notably deflected from where it should be. I'd love to see if I can restore it in as non-invasive a fashion as possible. Any thoughts would be appreciated; perhaps with enough data it might even suggest an update to the restoration guide PDF Mike

This was one of those restoration projects that was involved enough that I really became attached over the process. I'll be sad to see these go, but it is time to pass them along to a new owner who will appreciate them and give them a good home. These KLHs were relatively early production models, so they were completely sealed. The woofers were epoxied into place and the grills were permanently affixed to the front baffle. The crossover components were completely ensconced in hard yellow epoxy behind the back connection plate. Think peanut brittle but with resistors, wires, and capacitors. As is often the case with this model, the tweeter capacitor had failed and was an open circuit, however the rest of the speaker was in very solid cosmetic condition. I'll detail my work below so you can understand what has and has not been done. Perhaps my notes will also benefit of anyone looking to do a similar restoration in the future. I cut away the original grill material (both the black nylon and the cream boucle) hoping to reuse it, as there is no comparable material available. I was able to fabricate new frames and reuse the nylon inner grille, but the boucle is not particularly elastic so it was not possible to stretch the material sufficiently. Instead I used a tea stained linen that is pretty close to one of the tyes of linen used by KLH for other contemporary models. The original emblems have been retained and glued back in place. The speakers were exhibiting symptoms consistent with undesirable air leakage through the woofers. Therefore both the surround and dust caps have been resealed with sealant sold by vintage AR on That Auction Site. The compliance of the suspension is not affected when you use the correct compound. As is the case with this vintage of KLH speaker, it was necessary to cut open the cabinet to gain access to the internal components. I chose to cut around the back crossover plate. The larger capacitor was mounted to the front baffle and has been replaced by two 4uF Dayton NPEs in parallel. I also chipped out just enough of the yellow epoxy to gain access to the other capacitors. These two were replaced with Dayton NPEs. All other crossover components measured well and were left in place. There is just the faintest distortion/deflection to the back plate as a result of the mechanical force required to free the components from the epoxy. To reseal the cabinets, some oak hardwood strips were screwed to the interior of back of the cabinet around the hole and then the crossover plate was screwed to that. The screws were finish-grade so the screw heads are fairly small. I used latex caulk between all mating surfaces to ensure there were no air leaks, and then used walnut wood putty to fill in the rest. The cabinet shows no signs of an air leak, although naturally you can see the surgery scars on the back side. The putty was sanded smooth, though you can still see and feel where the cabinets were cut. The cabinet finish was already in excellent shape, however the veneer was pretty dry and parched; I suspect the cabinets had not been oiled or waxed in many years. Additionally, the veneer was beginning to separate on the front fascia of one speaker. This was repaired by applying wood glue using a fine paintbrush and weighting the veneer back down until the glue cured; the flaw is now fixed and the veneer is secure. The was also a small chip in the veneer (very small) which I filled in with some walnut wood filler. If you look for the flaw you can find it, but it truly is minor. All veneered surfaces were treated with Howard Restor-A-Finish (walnut.) All surfaces including the back were treated with Howard's Feed-n-Wax. The bottoms have the original KLH plastic feet, so they are in pretty nice shape, though one speaker appears to have some paint or discoloring. The photos don't do these justice!! I truly believe you'll have a hard time finding a pair in nicer shape, cosmetically or functionally. I'm not looking to turn a huge profit on these - I'd just like to recoup what I put in, plus maybe a little pocket change for a future project. My original purchase price was $50. Crossover components ran about ~$25 total. Grilles (cloth, frame material, velcro) were probably another ~$25 total. The woofer sealant was about ~$20. Miscellaneous construction materials (oak stripping, finish screws, wood filler) and cosmetic refinishing products ran probably another $30 or so, though naturally not all of it was used up for this project. Let's call it $200 or best reasonable offer. I am located in Boston, MA, however I travel regularly to NH and NYC, so I am able to deliver if you are flexible on timeframe. For those who are local, I am of course happy to audition. (They sound fantastic! - warm and punchy) I am also happy to answer any questions anyone may have (whether there is the intent to purchase or not.) Photos to come later today!