KLIPSCH RF-3 35 25 and ZEN's?

[rongon]

I tried to remove the tweeter from the RC-3 cab, but failed. Removed the wood screws, but the horn housing is flush-mounted with a sticky gasket of some kind. I couldn't get enough of a grip on the horn to pull it out of the cabinet. Will try again.

In the meantime, I also found a pair of older Klipsch KG4.5 2-way floorstanders. The drivers are a cinch to remove from these, so I removed the tweeter horn from one. Wow, what a surprise. The horn is made of really cheap-feeling black plastic. The driver doesn't look all that impressive either.

I applied a layer of Duct Seal to the back of one of the tweeter horns, and then listened in comparison to the untreated one. There is a definite tightening and smoothing of the upper mids gained from the Duct Seal dampening. Dampened the second tweeter horn, reinstalled and have been listening to the stereo pair for a few days. Clarity is most definitely improved, but the highest upper frequencies now sound more recessed, more typical of a horn loaded 2-way. In other words, no "air" to the sound. I think the Klipsch folks may have used the extra "zing" from the undamped horn to make bells and cymbals "sing."

My next step will be to remove the woofers and coat the stamped steel frames with a layer of Duct Seal, or maybe Mortite since it's easier to work with. I'm hoping that will clean up the mids around 500 Hz. I hopefully can do that tonight.

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[rongon]

OK, I did it. In the KG4.5's, Duct Seal is now applied to both the back of the tweeter horn and the woofer's stamped steel basket.

Damping the woofer basket makes a huge difference. Mids around 500 Hz are much cleaner and less muddy. The biggest surprise was immediately apparent while listening to an announcer's voice on the radio (the first thing I played). The excessive sibilance on 's' and 't' sounds is just about gone. Jazz ride cymbal is no longer spitty. The speakers sound like they have a warmer tonal balance. It seems to me that these speakers really need their woofer baskets damped to sound acceptable. Why damping the woofer frames improves the sound of the tweeter is a mystery to me, but I'll take it!

Before Duct Seal, the tweeters had a nice way of making orchestral bells and upper notes on the piano "pop" out to the front of the mix. After Duct Seal, the tweeters sound more like other good cone 'n dome speakers I've heard, and the orchestral bells no longer have that "pop" to the sound. On the other hand, jazz ride cymbal sounds pretty good after Duct Seal, but was spitty and harsh before Duct Seal. My hunch is that the Duct Seal treatment has tamed a resonance that used to make the horn tweeter sound more exciting and "impressive," but caused fatigue after more extended listening.

So I suspect that most cheaper Klipsch speakers can be improved with Duct Seal. I'll get to the RF-3's asap. First thing I'll have to figure out is how to get the drivers out without damaging anything.


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PS - The dynamics from these speakers are amazing. A drum solo becomes a real drama. Very exciting, sort of like in real life. High efficiency speakers sure are fun!

[moray james]

there are a number of KLF 20 for sale as low a $500.00 the pair, 100 db check them out. You may have to shore up the front and back baffles but they are excellent and the KLF 20 has the lowest inductor values of just about any Klipsch so upgrades are inexpensive. Hope this is of interest. Best regards Moray James.

[rongon]

Thanks Moray. I checked around and can't find any KLF-20 for sale locally (I don't want to deal with shipping for something that large). 100dB sensitivity (probably "only" 96 or 97dB anechoic) and low-value inductors sounds like it would make an easy load for a weenie tube amp... and that's exactly what I'm looking for.

How different is KLF-20 from RF-3? A totally different sound?

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