RCA/RS monitors with linaeum driver

This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
More info please

What model name/number "monitors" do you have there? I have some of the old LX-5's that I did a simple mod-job on. The stock x-o on those was a simple first order on the woofer & tweeter. I changed that to a second order BW with a low pass od 2kz on the woofers and a high pass at 2.5hz on the tweeters. Along with some minor tweaks to the factory enclosures, they improved alot. One day I'm gonna take it the next step and build some real enclosures (wood).
It appears that you have a newer model of the LX-5. Do these have the yellow woofer cones? I know the earlier (Optimus era) ones had woofers that benifited mightily from a Zobel network and a steeper x-o.

I went with a 7.5uF cap/.50mH coil on the tweeter, a .7mH/9.4uF combo on the woofer.
I also stiffened up the front baffle by adding epoxy glue to the back of it.
Also added some "dynamat' type material to the inner walls of the enclosure and on the woofer magnet shield.
Added in some poly-fil stuffing too.

Impatient me did this all at once so I can't say what had the most effect. But rest assured, the improvement was major.
I have the same model number (40-5007 labeled as RCA brand) and it does not have the yellow woofer. Then again, I only paid $50 ea., when RS was trying to blow them out the door, so I think it was a good deal.

I have always wanted to mod the speaker a bit, but my soldering skills are very poor, so the simpler the better for me. Thanks for posting the link to the diagrams! (Dennis' site.) I think I'll go and do some research to see if I can simplify any further, but if anyone has any tips, I'll take 'em. :) (Like, can I get rid of the resistors in the "scaled down" diagram? That should be easy enough to handle -- only 3 new parts, and re-use one of the stock parts. :cool: I guess I'm wondering if the resistors are in there for a good reason. :) )
If your refering to the resistors that are like 0.26 ohms, those are not actual resistors. Thats the resistance of the inductor directly after it. If your looking through the Parts Express website or catalog at inductors, you'll see they list "DCR".....thats that number.

So the technical goal would be to match those values....but matching the actual inductance value (mH) is more important. Though they can both be off a little.
Thanks, I get it now. The 10 ohm resistor in front of the capacitor is the only resistor I'd need to get, then. Hmm, I think I can do this...

Even though I have a slightly different model, I would expect that the stock XO is probably the same. What could go wrong? I expect that the worst I can do is do a messy job. (I opened up the speaker to see what I would be dealing with, and the stock XO is kind of tidy; I'd like to try to get the new, extra peices to fit similarly without needing a custom board...)

My experience with these speakers.

I stuffed a little fiberglass insulation in the cabinets. Before they were boomy and un-natural nowthe bass is very smooth. These speakers desperately need a sub.

If you pry off the little rubber caps off the front of the speaker that hold the front grill there are screws behind them to open the cabinet.

Dave (planet-10) one of the mods here said the Lineaum tweeter really starts to shine when 4 are stacked together.

Over the last year I scrounged as many of the LX-55's as I could off of ebay to use the Lineaum tweeter for a line array. A few months ago a thread here pointed me to Aura

The last speaker on the page is the front firing Lineaum used on the Optimus & RCA center channel I bought 3 from them at $15 each. I also bought 4 of the omni-directional ones (like on the top of your LX-55's for $20 each. Shipping was reasonable. The omni's are not listed on their webpage but call them & they're very helpful.

Hope the link & info are helpful, best,
Ralph, that's great that there's a source for these tweets! However, I'm not ready for anything as elaborate as a line array. If I can redo the crossover, that'll be a big accomplishment. :cool:

I'll put some extra stuffing into the cabinets too. I was thinking of something like the typical fiberfill tho....

I'll save the line array for a future project. :)

So did you redo the crossover. I opened up a speaker and there is not much of an x/o there. All the new x/o parts would run about $60, and the size of the air core inductors seems like the new x/o would use to much interior volume, them 18 GA PERFECT LAYER INDUCTOR's are not small, would almost have to go outboard with the x/o, are these speakers worth this much trouble.

New x/o


This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.