B&W Matrix 801 Series II

****The speakers are rated 50 - 600 wpc at 8 ohms. From my experiences
what actual wattages are needed from a capable amp will be based on size
of space, how close you will be sitting to them, the kind of music genre you
will be playing, and how loud. **** - Ct0517

****I recently acquired a Parasound Halo A31 (250 watts per channel) for a
system in a bedroom and hadn't heard it yet. The difference between this
amp and the MAC with the B&Ws was really huge. Of course, the
Parasound added a bunch of really good tight bass slam as you would
expect but the little MAC was no slouch in the bass department either.
What really surprised me was playing Patti Griffin in a very laid back
acoustic track was how much more definition and clarity the MAC had over
the Parasound through the B&Ws. The Parasound was also a little muddy.
It is a $3k amp and really not up to what I would want to run through these
speakers. I was surprised comparing these amps through the 801s. You
could go out and have a cup of coffee and come back and you would have
no trouble telling which amp was playing. They sounded that different from
each other. **** - Wemfan

Personally, I would not get hung up on the wattage only; within reason, of
course, since you do seem to like your music fairly loud. IMO, the above
comments demonstrate that to a significant extent that is not what will
guarantee satisfying results. You seem to have a clear sense of what
qualities you are looking for in the sound of the system and you mentioned
that you are a musician. Being a musician you are probably very sensitive
to things like subtle instrumental texture, micro dynamics and the kind of
tonal fullness that is not always heard from many audiophile rigs; this is not
meant to slight audiophiles, but is simply about priorities.

Some really good amplifier suggestions so far. But, IMO, short of the very
best, solid state amplification does not excel in the areas mentioned to the
degree that decent tube amps do. But, given your listening habits and your
speakers I think you will need some significant wattage. One amplifier that
comes to mind for your 801's that comes up used fairly regularly and for a
very reasonable price is the VTL 300 mono; lots of power and good
bass control with the classic tube attributes. When you say that the Mac
"simply doesn't have enough horsepower" is it a borderline case
or not even in the ballpark? You describe bass and drums as incredible
with the Mac; you seem to really like the sound. Have you considered
adding a second Mc275 in a vertical biamp arrangement? Might be
enough power and guarantees the sound you already like and probably a
refinement of that. Good luck.

I agree that a second MC275 might be an option, however, it should be identical to the one you currently have. Looking at the Berners McIntosh Site, you can see that there are 9 different versions of the MC275. While some may sound the same, it is well known that some do sound different, especially the original. Also, it would be best to use them configured as mono, and not vertical bi-amp. With the woofer being the most demanding for power, it makes better sense to have 150w on the entire speaker, than to have 75w on the woofer and another 75w on the midrange/tweeter separately. When bi-amping, it is generally recommended to use an active external crossover bypassing internal crossover, which complicates things even more.

IMHO, since you have just acquired the speakers, it would be best to keep things simple for a while in trying to achieve some system synergy. I agree with others that crossover mods should be on the back burner.

Did you ever say what preamp you are using with the MC275?

Excellent points. I was not aware that the MC275 can be easily configured for use in mono (nor that there are nine different versions-yikes!). That makes a second Mac an even more attractive option IMO.

Tls49 posted: "IMHO, since you have just acquired the speakers, it would be best to keep things simple for a while in trying to achieve some system synergy. I agree with others that crossover mods should be on the back burner."

Great advise. Congratulations and enjoy!

When you say that the Mac "simply doesn't have enough horsepower" is it a borderline case or not even in the ballpark?

Frogman
this reminded me of something that I feel is really important regarding the 801 but also the other matrix line as well.
We have already discussed how the speakers were designed to work with the bass alignment filter - aka an equalizer.
The BAF has two benefits and if your amp is borderline SS or Tube - the BAF can only help and this is why.

First - it makes the speaker more efficient. I have had discussions with B&W on this to confirm it. But they don't have the measurements.

Secondly and one of the reasons they become more efficient.
If you play vinyl, much of it has subsonic frequencies recorded in the grooves. The BAF has a 19 hz cutoff.
This means the amp's energy reserve is not wasted playing those sub 19 hz frequencies, making the woofers pump. leaving its power reserve for what you can hear feel above 20hz. In effect giving it more headroom. All speakers benefit from amps which have lots of headroom.

This is why its important for Wemfan or any one else to try to get the most powerful amps they can SS or Tube and not just amp/s that will work for the situation. Too many 801s are just hooked up to HT receivers because it works.

There is a rumble filter on my preamps but I choose not to use them as they are too close to the vinyl source for me. Since the speakers are designed to be used with their own spec'ed out factory filter - this is much different.
When you set up the BAF there are two rows of pins on the circuit board, one for each speaker with 10 pins locations that you set either (on or off) for each matrix speaker 800 - 805.
All 800 series matrix line utilize different pin arrangements per B&W testing.

An observation
When I got the 800's I pulled the woofers and brought them in to get checked out. One of the tests they do is placing the woofers magnet end on the table and hooking it up to a cd that plays a test signal at 20, 25, 30 hz.
This signal is stronger than anything we will ever (or should ever send the woofer) through normal use.
With the test the woofer starts oscillating up and down the cone. This shows if all parts are working properly.

So if your amp is borderline - the BAF will only help you. At first when you hook it up it will seem as though you have made the sound more lean as the 100 hz plateau is removed. This also allows for better positioning in smaller rooms.

Wemfan - are you able to identify music you have with 20-30 hz material in it. if so in your large room there may be enough space,
as ZB said to allow them to bloom without the filter.....

I can recommend a few from last night.

Count Basie - Party
Patricia Barber - Companion
Beatles - Abbey Road - side two
Dead Can Dance - Anastassis
Lorde
Sarah McLachlan - Solace, Fumblin for Ecstasy

Frogman you mentioned VTL - Poster Vegasears uses VTL's.
I know people who use various SS, and Tube. Tube including Push Pull (most common), OTL's and even one that uses a SET with his 801 in a small room. he doesn't listen to music with a lot of bass however.

So the type of music you like to listen to plays a big factor here.

TLS49 - do you recall the type of music you demoed the 801's with when people auditioned them ?

Cheers