Summary:
Running off a clean high power older Technics class A+ amp (0.007%distortion, yes 0.007%, and 90W RMS/channel) and older SONY high-end and ADC components, these sound amazing.

They are better than almost anything now, and they're twenty years old. One refoaming job (i did it personally, keep existing fabric cooling-system dust caps if possible, NEWFOAM has original level stuff) and blowing one tweeter with an improper fuse (just buy a new diaphragm foil, not the whole tweeter) is all the maintenance in those twenty happy years.

The EMITs (Electro-Magnetic-Induction Tweeter, uses extreme high static voltage through planar diaphragm, like SENNHEISER's $12,000 headphones) cast the most lifelike, open, bright soundstage i've ever heard in the industries much neglectid highs. But without sounding overly bright, and no metallic pings, because of the 0.002 inch thickness of the resin/mylar diaphragm.

Midrange is breathy, natural, and extremely good at soundstaging. A very overbuilt mid-driver, cast aluminum frame, magnet is actually larger than the speaker itself! Huge spider for a mid also.

Bass is tight, extremely detailed due to accoustic suspension cabinet and if you really want to make walls move visibly, then play a bass test track and watch these large, pure low resonance polypropylene woofers do their biding.

The high sound quality doesn't compromise effiency (i diasagree with the previous, and with only 4ohm impedance, they're easy to drive with a good amp or receiver) or powerhandling. Each of these speakers has capacity of over 250 W RMS and over 500 peak!

They weigh in at fifty pounds each. Beefy for their relatively small size (27h, 15w, 11d) compared to the modern age of towers. but their squat design has huge volume and less surface area ie: less surface to resonate.

Beautiful thick natural oak veneer, and classic look.

I want another set for to create a 4 point high level music system!!

Strengths:
EMIT is amazing! (explained later if you don't know) These speakers can literally move walls with power! but accurate and no noticeable colouration, with immaculate soundstaging.

Weaknesses:
Heavy for their size(can be seen as good, except when sinking:angling forward/down on carpet), and could do with short stands.

Similar Products Used:
AR, Bose, CV, JBL(sounds like one big bass port rumble)

Summary:
Ran accross these beauties by accident in 1983 -- was actually shopping for a new turntable (remember those?) and these speakers happened to be playing. Sweet, seamless, musical, great sound-stage, wonderfully seat-shaking bass, and better than anything under 1000/pair at that time. They had just been discontinued, and were being blown out at half price -- $200 each. Each box has a 12" woofer, 6" midrange, and the incredible EMIT tweater. Have had to replace the woofers once, and have them re-foamed once in 16 years. The only drawback to the RSM's is that they, like most good Acoustic Suspension speakers, are VERY power-hungry. Don't think about driving these or any of the 180's Reference Series or Kappa series with a cheap amp. High Current is a must, but when these speakers are well fed they sing. Recently replaced my NAD power amp with a HK AVR 75 Receiver -- and felt like had just purchased new and even better speakers than before. If anyone finds a pair used - GRAB THEM or tlet me know where to get them.