What is a B&W 801M?

Thought I would get more specific. Pair of B&W 801's I'm looking at are labeled on the plate on the back 801M. Is this a matrix cabinet or a series 80 non matrix ?
I believe those are the earlier Matrix series. Could you give more specifics as to the construction/appearance of the speakers?
Barry - these have the bass eq box and seem to have metal dome tweeters. My memory(always suspect) is that the series 80 had the soft dome (brown colored) tweeter?they appear to be bi-amp/bi-wireable (jumpers plus to plus ,minus to minus on the back of the speakers.No level controls on the back of the heads - hmmm - I think that would mean they aren't series 80 (non matrix) 801s?
Do they look similar to these?


These are the early matrix cabinets.

I'm not a B&W historian by any means, but I had a friend back in my college days (mid '80s) who had a set. The "Matrix" moniker referred to the construction of the cabinets as there was an internal "Matrix" of bracing to reduce cabinet resonance.
Barry, those in the photo are NOT matrix cabinets. The first 801 with a matrix cabinet was a ported design.

and these?

Yah - these are ported - think they might be first generation Matrix 801s. I remember the matrix cabnet making a big difference in bass and midrange clarity on these.
You had better have a amp with very healthy output for these to work well....also, they are very bass heavy. I've seen them working with a Crown 1000 watt amp, and pegging the meters.
When I sold the original 801s I used the Crown SA2 [I think this was the designation], it would pulse 1600 watts at 2 ohms and it never felt like too much amp. B&W used the same amp at CES.
Well aware of the power needs. Talked to John Bowers about this issue at one of the Chicago CES shows - a long time ago.Had just finished being blown away by how good these speakers sounded at their demo.B&W were using something humongo ( big class A mono's IRR?) - simply stunning! Had to point out to Mr. Bowers that on my sales floor - customers weren't put off by the price - but were trying to drive 'em with things like the famous/notorious Carver Cube and big Receivers - he seemed very puzzled by this and pointed out that it wasn't rational to expect this kind of combination to sound good.He was a real Gentleman and certainly one of the more patient people I ever ran into in the upper echelons of the industry.
At any rate- have a old Counterpoint SA-20 which I think might be up to the task.