What capacitor values?

Mr H- No risk at all. It would bring the mid in at about 1kHz which is probably closer to the the neighborhood of the 12's natural roll-off. See if you can find the data on your 12". Often that will supply you with a freq response plot. Check it's 3db down point(upper) and design accordingly, if you don't want to use an inductor.

If you like the sound: Leave it as is! You've no one to please but yourself. Based on the impedances you gave, the values/points/slopes should be as noted. I was suggesting what generally works well for x-over points. Especially with a 12"/5 1/4"/and tweeter. Happy experimenting/listening!

If the sound has been excellent with the existing values, why would you change them? Keep in mind- When the new caps are installed, it will take a number of hours(perhaps 200+) for them to sound right.

If those speakers are 8ohm: the 200uF cap will cross at 100Hz and the 1.76uF over 10kHz. If they are 4ohm drivers: 200uF= 200Hz, and 1.766uF=somewhere over the rainbow, I mean- over 20kHz. I seriously doubt the mid-range actually has the ability to reproduce that range of frequencies accurately. If it does, I'll buy a truckload of 'em from you! If the tweeter is a nominal 16ohm piece, it would come in at 5kHz, but the cap on the mid might as well not be there at 16ohms. Or are those the values you were thinking about substituting? Most people use 8ohm drivers when building their own systems. It would be good to know with what you're dealing. Do you have a multimeter? Here's the formula for capacitance per your impedance and cut-off desires(for a 6db/oct slope): C1(in uF)= 1,000,000/6.283 X speaker impedance X desired x-over freq.

Well- That would bring your tweeter in a little above 10kHz, and your mid- right about 4kHz. The mid isn't doing much midding that way. I'd say 80uF on the mid(500Hz) and about 5.5uF on the tweeter(about 5kHz). I suppose if you were to go with an iron core inductor on the woofer, you wouldn't have as much insertion loss(though it may become non-linear at high input levels). If I were doing it, I would use either Solo or Alpha-Core air core inductors(very low insertion loss and phase shift, very transparent). The value of the coil would depend on the impedance of course(8ohm=2.5mH, 4ohm=1.27mH for 500Hz). I suppose a .13mH to roll off the mid at 5kHz wouldn't hurt either. You may find yourself having to pad the tweet and/or mid to match their outputs with the woofer.

I'm not certain of the response of your midrange, never having seen the data. BUT- Most don't operate smoothly up to 7500Hz. If you look at this response: (http://www.madisound.com/catalog/PDF/scanspeak/12m_4631g00e.pdf) You'll note how erratic the response becomes after 5k. In the case of this mid: I would use it between about 700 and 5kHz where it's response is the smoothest. You may be able to find data for your particular driver, and choose roll-off points accordingly. On the other hand: Most tweeters are designed to function smoothly from somewhat below 5k to above(what's generally considered) audibilty.

Not at all. Just add the coil I mentioned in the previous post to roll the mid's top-end off, which will eliminate that peakiness from the reproduction and avoid a major overlap in reponses. Don't forget an inductor on the 12" to avoid the same in the woofer/mid region. It may take you a while to adjust to the new-found accuracy of the speakers and don't forget: The caps are going to take a while to sound right too(maybe 200+ hours of play-time).

I haven't had any electrostatics since my Acoustat Model III's. But- I almost bought a pair of ML Sequels a few years back. A local store was blowing their last pair out for 1/2 price(whatta temptation that was). I've been using modded Maggies for mains for a number of years now. My bi-amped transmission-line woofers just work too well to replace, and most ML's are hybrids. NOW- If I could find a pair with blown woofers for cheap.... OH- BTW: If your mid-range rolls off smoothly around 5k(and is already 3db down at that point), you could get away w/o an inductor on it. I try never to underestimate another's ears, unless they give me an obvious indication that they don't know what they're hearing(or can't hear at all, as the case may be). I hope some of this helps you out, and: Happy re-designing!

Hi Mr H: I'm glad those values worked out so well for you. I'll bet they sound even better after a couple hundred hours of music. As far as older box speakers that sound like "real" music: The Dahlquist DQM-9 is an excellent system still. Actually built by Magnat(a German co.) with a very complex crossover, they still deliver a wonderfully open, accurate sound with great imaging. I bought a pair for my son some years back(we restored them, without any actual "mods"), and he's found no reason to replace them yet. There are still a number of the old LS3-5A systems out there cranking out accurate sound/excellent imaging, so- they DO exist! Glad I could help. Enjoy the music!!