Bob Crites Klipsch speaker upgrade kits
Ok, there I was… of little spending cash, and a lot of free time. I thought I’d refurbish a set of speakers on the cheap. I wanted to keep it affordable, but not trap myself within limits. Classic Infinity? Nah, parts are hard to come by and expensive. Polk? Nice stuff, but a bit dated. The silver litzwire tweeters were nice and I could beef up the xover for something better than the original. Nice, but bedroom speakers. What about something closer to fullrange? Hmmm. I scoured the net for weeks. I came to the conclusion, a model of heritage Klipsch would be in order, but which one? Heresy speakers are a hot item, and tend to be overpriced. Cornwalls are way expensive and often in less than stellar condition. La scala? They need a sub to work IMO, and no one had any local. And no one shipped them. KG4? No, because they had no separate mid horn. I found the perfect answer. Some Quartets in VG condition. I paid $260 for the pair. They were equipped with the phenolic diaphragms and horn throats. Tractrics! Cool…much easier to work with than metal throated horns. Wait…this speaker has the same separate tweeter and mid that the heresy does, but a 10” woofer, and a 12” passive radiator on back. Hmm, they do everything a heresy can, have better bass by a long shot (38hz vs 60hz -3db) and they cost ½ as much. Sold!!!Stock, rusted and faded. Rust never sleeps.
They were shipped quickly. The cabinets had some fine scratches , a faded oak oil finish and rusted screws. That was just the start. My research told me that the crossover was a few bucks in electrolytic caps that was designed to last maybe 5 years. Electrolytics degrade and dry up in a few years. A speaker’s electrolytics after 15 years will have degraded over 60%, and weren’t that good to begin with. 10% tolerance, higher than acceptable ESR (Equivalent Series Resistance) and the ability to smear a signal. THIS handicaps the drivers and produces a less-than-stable stereo image with the tendency to become strident or choked. This needs work.Stock xover
I found Bob Crites (www.critesspeakers.com
) and his site was loaded with replacements and upgrades. He has a trusty meter capable of meaningful ESR readings, so his claims can be backed. What I found was crossover repair and mod kits galore. I said…ok, looks affordable enough---lets roll. I ordered the crossover replacement kit, which consisted of sonicaps and 1 electrolytic cap for both speakers. The idea is, that the higher value cap is only a blocking cap for the woofer. It’s not directly in the signal path like the tweeter cap. I also found something unique. Bob has titanium tweeter diaphragms! Gimme! The phenolic diaphragms Klipsch used are clearly limited in response and pistonic linearity. This was another source of harshness at volume and even a bit of veiling---a roll off. Klipsch met a price point…at the expense of a less-than-great crossover and some diaphragms that could be better. Now, they would be.Phenolic (stock) diaphragmNew Ti diaphragm
I removed the binding post panel of the Klipsch quartets to reveal the crossover. These were clearly cheap caps. The wire was pretty simple and I was ready to put my Hakko soldering station and cardas quad eutectic solder to use. I desoldered the old components. Even though the xover kit came with schematics, I carefully annotated what went where. I replaced the stock caps with the sonicaps. That took about 20 minutes on one side. I also replaced one tweeter diaphragm with the new ti. I installed Audioquest stranded OFC wire inside to replace the zip cord. If you are a good solderer, you too can ditch the cheap clips and direct-solder the internal wiring to the diaphragms, crossover and binding posts. I played the speakers side by side (modded and unmodded). There was a pretty ear-opening gap in the performance. The ti/sonicap Klipsch wasn’t just smoother, it had a brilliantly open soundstage that clearly exceeded the stock by a mile on top. It really amazed me. I modded the second speaker and let them run many hours for break in.
The sound was as far beyond stock as a NASCAR race car is over a street model. I did not expect to like Klipsch this much. But wait…this isn’t anything Klipsch ever made. These are quartets done right. Stridency, blur and image shift were ameliorated to the point that I forgot these were once midfi horn speakers. It’s like they have been unleashed into a realm of detail and smooth dynamics they never realized from the factory. Nobody that is used to stock Klipsch speakers would be able to deny the amazing transformation. These components elevated these speakers well beyond what they were. They went from pretty good speakers to outstanding. The side by side was as if the stock speakers were under a thick blanket by compare.
Now about the cabinets. Scratched, and faded. Hmm. I made a shopping list and went to home depot. I got some caustic snot err “stripper” to remove the old finish. Think: That yellow acidic blood that came out of the Alien and ate through the deck.
Yeah…it does that to YOU instantly if it gets on you. 1st
degree chemical burns in a few seconds. I know this because my forearm came in contact with a few drops. Owwwie. After rinsing off, I scraped the remnant of caustic sludge from the speaker cabinets. The old finish came off pretty easy. I sanded with 60 and 100 grit sanding blocks. I decided, instead of the normal light oak, or deep, dark brown I’d go for a cheery red. I found a suitable minwax stain called “Red chestnut”. This was a nice medium red, not pink-ish or too bright, but not dark and obscuring. It took 4 applications to get the desired shade. I let it dry, sanded and applied poly clear coat. I sanded between coats with 320 grit and ended up with 3 in all. The speakers were also visually transformed into a nice cherry-like color that showed the grain. I ended up using some end table tops as speaker bases. Viola! A pair of speakers, smoother, more revealing and better looking than Klipsch made. Cheery cherry look. Please ignore the sanding dust in the grill...it's gone now. Ooh...shiny!
This was a cool project, and it cost me under $475 to complete. I’d like to one day treat some la scalas like this. Incidentally, Bob Crites says a titanium midrange diaphragm is in the works. When it’s ready….I am sooo there!Post script
: These mods made a *far* bigger difference than attempting to compensate with different tube amps or paper-in-oil (high ESR) caps that roll off the highs. That was old school. These mods are new school, and they work much better. Just remember: at the end of the day, a great tube amp is still playing though a poor stock crossover and is subject to the physical limits of the phenolic tweeter.