Well done !

Great fix and nice price

Concept 90 original price was 1650 USD for a pair. A lot of money in 1987.
The CM1 part is all cast aluminium. Very rigid and high quality work. This is not far from the smaller Genelec monitors.
Proportions are about the same.

According to Stereophile the CM1 tweeter is related to B&W 801 tweeter. The mid/bass is actually Kevlar yellow.
It has just been painted black.

My reference is the Yamaha NS1000. Before recap/repair Concept 90 were unusable. Now happy camper.
These require lots of amplification. Now running an "a-class" amp CEC AMP3300.

I like the solid sound stage. Different tweeter sound.
The Cm2 bass unit is a back firing system with 2 woofers and a reflex hole.
Front firing bass would be more immediate. I would say that bass on this system is as good as my Kef 104/2. The Kef also has indirect bass.
Modern bass heavy music is acceptable on Concept 90.

They look interesting. I’m sure that Rogers made a similar designed pair in the 1990’s.

Juha,

I hope you're still enjoying these loudspeakers. I have a pair of CM1s I bought new in 1988 and used with a lot of different equipment for 10 years until stumbling across a great deal on a pair of JMLab Micron Carats. Back in the day I had replaced the crossovers with simpler ones, using Solen poly caps and litz inductors and foregoing the APOC circuitry - paired with a modified B&K ST-140 and Lazarus tube preamp (and later vintage Marantz and Dynaco tube amps) these speakers used to truly amaze people with their sound.

I'm currently working on refurbishing these CM1s for my teenage son. Being a roaming student on a work/study program for the first few years that I owned these, they endured a lot of abuse during relocations and eventually the white paint started flaking quite badly. Also, I had mounted the crossovers externally - partly because the litz inductors were so much larger but mostly in case I wanted to tweak them further - and then when I eventually decided to put them into indefinite storage (read: "kids entered the picture") I decided to carefully relocate the crossover components inside the cabinets. Following that exercise they never quite sounded right, and only after I pulled them out a few months ago did I remember that these speakers had the same problem when brand new - back then I quickly figured out that one of the drivers was out-of-phase and my local dealer quickly fixed that - but because the polarity of the driver itself was mislabeled and I had forgotten about this, I accidentally reintroduced the original problem...

Anyhow, happy for you that you have the CM2s as well. They really sounded wonderful together - the same dealer let me demo the CM2s for a weekend but as a working student I could barely afford the $1000 CDN for the CM1s let alone the additional $1600 CDN they were asking for the CM2s. By the time I could seriously consider them, they were no longer available. For a few years I toyed with trying to build something similar myself but that eventually led to building other speakers instead. Now that information like the original crossover schematics is freely available, I have a lot more insight into what the designers intended as a starting point. If my son does like these enough (and they survive long enough) I may yet try to tackle that challenge.

Cheers,
Richard