Oldie but a Real Goodie 4.6 stars
I purchased my Monolith IIIx,p in 1992. They were a floor demo, since the small dealer only has 1 pair! I received a decent discount since they were 1 year old at the time. I have both the passive and active crossovers. I now use Pass Labs X3 pre and X350.5 amp ('stats) and Parasound HCA2200 II amp (woofer). The ultra high quality passive crossover only requires one stereo amplifier to drive the speaker system but like ALL passive crossovers, it really gets in the way (slightly colors) the sound when directly compared to the awesome XOS electronic crossover (IIIx version) and using a pair of great SS amps. I was advised against using my beloved tube power amps due to their high Damping Factor which causes an obvious roll-off of high frequencies in the 'stat panels. For similar reasons, tubes usually do not promote tight bass. Anyway, since excellent, powerful and musical SS amps are abundant, why not? I have used a bi-amp configuration for over 15 years now. I also use a digital room bass correction system on the woofers only. Automatic room-speaker mode (peaks) correction really helps clean up the bass and make it much more crisp and defiend - and way less boomy. I have new Peerless aluminum 500W woofer cones also, this helps bass definition also. I also have new factory buit 'stat panel since about 2009. These were built to the latest standards and do sound better than the origonal panels. BTW, the panels will eventually (15+ years) lose volume (1-2dB) and high frequency extension, even if you keep them clean and dust free. So replace them if M-L still provides that service. The sound: overall, the sound using Pass X350.5 on the panels is awesome: big, clean, clear, tight, fast, musical, detailed, dead quiet background and very 3 dimensional. However, a small region the mid bass is still a tiny touch muddy and the highs above about 5kHz are a bit subdued - but still very clean. It's as if the cymbals and triangles are 10-15 feet farther away that the rest of the musicians. But vocal clarity and depth, or solo instruments, be it guitar, saxophone, piano or drums are just amazing - they float in front seamlessly in crystal clarity across from left to right in glorious and delightful 3 dimensions. Airy, effortless and realistic sound floats on the soundstage in front of and behind the actual speakers. Wow. As a minor owner of s hifi store (no names) for the last 30 years, I periodically bring home a pair of the latest (non electrostatic) speakers for a few days of "home demo". Invariable they go right back into the store demo stock. Electrostatics are magical even if they are not perfect in their ESL-to-woofer blending - they still beat the pants off of almost everything else. They spoil you too. The soundstage they present, the clarity is just addictive its so realistic. Tiny midranges and tweeters just cannot convey this sense of size and openness. The Monolith have one feature that the latter-day M-L designers simply missed is their separate speaker inputs for the raw woofer and for the electrostatic sections. Thus bi-amplification is possible. Active bi-amping is very desirable (implying the use of an electronic crossover and/or separate digital room-bass correction while the stats are driven with pure analog signals). Active bi-amping capability allows the User to try all sorts of individual control measures on both the woofer and separately, the 'stat panels - this opens up a whole new world now that digital speaker correction is becoming commonplace. In a few yearsa, audiophile grade full spectrum automatic digital control / speaker compensation will be possible, so even the 1992 Monoliths III can be made to sound as good as anything on the market. Almost twenty-five years on, a good condition used Monolith III system can cost you $3k, if you can find one. A new Summit pair is $15k. Is the Summit 5 times better?