I thought that when I'd read about resealing the woofers in these classic speakers, what was meant was making sure that the original putty was still flexible, and if not using silicone caulking or something similar to make sure there were no leaks in the seal. From this excellent Audiokarma post, I learned that the cloth surrounds become porous, compromising the acoustic suspension system. I resealed the surrounds as instructed, replaced the crossover capacitors, and sat down to listen. These sound much better than the last pair, which I had a couple of years ago. They are musical and authoritative, with beautiful bass response and a real sparkle.The sealing must make the difference in the bass.
The great sound I'm enjoying puts the KLH 17s on my list of fantastic 2 way 10 inch vintage american speakers that should be heard.
The list: The Advent Loudspeaker, ADS L610, Dynaco A25, KLH 17, JBL L26.
Email me.
3 comments:
Hello. First off: I really dig the SEVENTIES STEREO blog. It's just splendid!
Congrats on your KLH 17 recap, and thanks for your informative report. I'm going to be doing the same thing to mine sometime soon. I'm curious: what sort of replacement caps did you use?
I'm planning on using plain Solen polypropylene films or similar and also contemplating replacing the resistors with 5 Watt Kiwame carbon film units. I've heard about the alleged woofer cloth surround leakage problem, and will do a close inspection and will maybe apply some quality rubber cement.
On KLH 17s in general: I think this is a really under-rated loudspeaker. I come from a vacuum tube amp and high efficiency (such as horns) speaker background, and generally steer-away from more conventional sealed multi-way loudspeakers based on my experiences. I received a 'give-away' pair of KLH 17s (1970 manufacture date) about a year ago, and actually tried to sell them, unsuccessfully, for $20 at our yard sale before I had ever listened to them! Needless to say, I was gobsmacked when I actually hooked them to my tube amps and played them. A very relaxing and organic midrange, and nice well-damped bass performance. The integration between the midrange and bass is particularly nice. Additionally, the speakers are quite easy to drive, and can "rock out" with even modest wattage tube amps! The minimalist crossover design and huge magnets surely contribute here. Sure, the units are a bit rolled-off at both extremes of the audio spectrum, but sound quite satisfying nonetheless. They image like gangbusters in my setup. And guess what... the darned things actually are quite revealing too! Differences in the quality and texture of various recordings is quite evident through the KLHs, and they really do not gloss over or filter out what is going on in the rest or the system like so many other conventional speakers I've tried. My only minor gripes: the 17s are not the final word in dynamics (compared to 95dB horns, for example!) and do sound just a bit "round" on the edges. There is also a minor tinge of harshness in the treble which is not to troublesome, but I hope will perhaps be ameliorated with fresh xover capacitors. In short, I think the KLH 17 is genuine sleeper, and a very satisfying all-rounder --who would have thought! Possibly the most ugly and unpromising looking tweeter assembly I've ever seen, but it works!
I don't have pics of my 17s up yet, but some of my other speakers and amps are on my (needs an update) blog: http://www.hotvalves.blogspot.com
Do keep up the inspirational work in SEVENTIES STEREO!
Hope that you did NOT use any kind of rubber cement or watered down caulk for the cloth "doping".
This is what should be used. It is the closest thing to the original formula used by both KLH and AR back in the day.
https://www.ebay.com/itm/ACOUSTIC-RESEARCH-SPEAKER-CLOTH-SURROUND-WOOFER-SEALANT-KIT-ALSO-KLH/163650906252?hash=item261a5aa88c:g:aUQAAOxy7rdREiMo:sc:USPSFirstClass!29485!US!-1
Post a Comment