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optimus Pro LX5II dipole lineaum

RS woofer problem

Sir: Gentle suggestion... try this: turn your bass tone control all the way down while listening to natural sound...voice and music. Listen to it for about a half-hour.If your setup no longer offers tone controls, then please find one that does, and then proceed.. You may have discovered that in a way everything sounds much better. The problem is that the benefits of open baffles or dipoles apply pretty much to frequencies 300-500 hz and below. My Spendor BC1 s and in fact all of my many box speakers have trouble in that range...so much so that the only practical solution for me was to turn the bass knob down so that the honk and hoot at those frequencies no longer annoyed me. A little thin? of course. But I could deal with that .I listen currently to my old DQ-10 s for reasons of space. The box effect is least bothersome to me with these than any of the other box speakers I still own. This suggestion is as an experiment only...intended to help you nail-down the problem you seem to have with the RS boxes.........I still crank the bass down with the DQ 10s as needed.........usually for speech and vocals. When I can't stand it any more on music, I switch over to BIG full-range tympanis and ESL s. As an experiment once, I substituted a number of tweeters-some still in the boxes, for the dead esl JansZen tweet in one of my KLH Nines. Hardly noticed the difference. Whether the tweeter is mounted in free-air and radiates in a dipole pattern or not is of relatively small sonic consequence. Lower mid and bass matters a lot. A whole lot. The JansZen module ESL boxes sound glorious.... box or no. The little RS woof is unhappy in its box at exactly those frequencies that you find musically troublesome. So long as you try to make it sound happy in that range by swapping tweeters and caps and so-on when the problem lies elsewhere, in my estimation, is a use of your time best spent by seeking--out an eq tool that can tame the hoot, or to find a new home for the RS and keep trying. Find any old planar or open-baffle setup and see if your tastes run along those lines. It sounds to me that you just might be sensitive to box hoot. Good luck, Paul (first stereo in 1958....been around the block.)
 
Another little trick is to stuff the ports with plastic drinking straws cut to size. I would imagine a piece of foam would work just as well.
 
I have a pair of them and really unimpressed with them. I had heard and read great things about them back in the day. I used to sell them too, and what I would notice about them (Much more than any other speaker I had ever carried) each one had it's own characteristics. They were sold individually and I would have to take out 4, 5 or 6 of them and hook them up to get a pair that matched well and sounded good. I kick myself for not paying attention when they went discontinued, they got down to $19.99 a piece and we had two good matched pairs. Alas, 20-20 hindsight. The pair I have now are flat sounding The tweets if hooked up separately sound good, but there must be something in the caps that needs attention. We used to sell the Linaeum as a sort of super tweeter add on, oddly enough these were consistent and good. I did buy a pair of those that I mounted on my Clarke's, and have used them for 15 years still sound great. They are for lack of a better word, non offensive. They even still have the replacement tweets available NOS I guess.
 
budgetaudio6 said:
the II i have do have the plastic woofer. And the cross over cutout is smaller than the woofer so no way to get it out that way.

But it does appear to have a ring around the woofer that with some nudging can come off, but may be prone to getting cracked, not sure.

If i have the inkling to put it on my bedroom rig ill do it tonite and get a feel for it in stereo.
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I have some little Radio Shack speakers with the Linaeum tweeter and Kevlar woofers.
 
I have a pair of RCA branded PRO-LX55 (40-5007) with magnetically shielded 5" polypropylene woofers. My cabinets open according to the method described by TerryO. There is a very thin (and delicate) gasket between baffle and cabinet.

If I could tame the cabinet resonance they'd be in rotation instead of stored in a closet inside their cartons. I can feel strong vibrations when touching the walls as well as hear it. In fact, clamping both hands against the sides improves things quite a lot. Tried laminating sound deadening material to the inner walls without much improvement. May try bracing the sides with dowel rods next. If that works, then maybe visit crossover mods.

Note that Murphy measured a significant null above 9kHz in on-axis tweeter response. You may want to avoid toe-in when positioning these.
 
Yes they're branded RCA and they don't really sound much different than the previous generation, which I also have. There are several speakers in that line, including the LX-8, which is supposed to have a Peerless woofer and the little LX-4, which is supposed to be the best sounding one of the bunch.

I don't have either of those, but I do have two pairs of LX-10s. They were the biggest of that series and pretty rare for something sold by Radio Shack.
 
budgetaudio6 said:
stuart pedaso, what did you use for sound deadening?
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I applied alternating layers of double-sided, self-adhesive, modified bitumen ("kwikwrap" brand product) between foil-faced bitumen tape to fashion a sort of constrained layer dampening system. Similar principle as Dynomat, Hushmat and other such sound deadening products. Bitumen and butyl based tapes are available in hardware stores as "flashing tape" in a variety of widths. Has been used effectively by some of the car guys in lieu of much pricier audio-marketed products.

This treatment on the PRO-LX55s took some of the edge off, but hasn't completely tamed resonance. Could try more layers I suppose. Though internal bracing is looking like a more promising approach.

Maybe both methods combined will do the trick ... :scratch2:
 
thanks for that extra bit of info. In the excitement over my klipsch find i replaced these with paradigm monitor nine v3s as surrounds.

but will try them out in BR system.
 
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