Since making this post in the Maggies thread I have replaced the NAD M25 with a McIntosh 8207. I'm still getting indications from the Mac that I'm occassionally clipping - even with 200+ "Mac Watts" per panel! (I'm about 12' from the panels and I listen to music in the high 80s to low 90s dB SPL (movies can obvioulsy hit higher transient peaks). For my ears I like the Mac/Maggie combination. Anyway - here's the system as of a month ago. I'm adding a few cable tweaks (I'm a marginal believer based on some more-or-less blind A/B listening).
From a post on 6/7 (without photos - http://www.avsforum.com/t/1086093/the-official-magnepan-owners-thread/2700_100
Update on our B&W 803s Replacement:
It's been a while since I posted - to recap I replaced B&W 803s/HTM-3s/Musical Fidelity XP200 x 3 with Maggies and a NAD M25 (more on that later). The front end of our HT now consists of 2 x DWMs + 2 x 3.7s with a CCR + 2 x MMC2 (non-motorized) for a tri-center set up. I've included a few photos, listening notes, and comments from Wendell Diller who visited me yesterday to check out the installation. Sources include an Opp BDP93, Comcast DVR, Wadia iPad base, XBox, and AppleTV. Control is through a Meridian G61r + HD621 combo. During the process I replaced my Paradigm Seismic 12 (which integrated very well) with a Paradigm SUB1 (which adds an increased amount of musicality plus lower reach for HT LFE). Our HT has 14' wide u-shaped sectional as the listening position and the 3.7s are in a triangle of about 12 feet apart and from the listening position.
1. The system is set up per Magnepan instructions and the NAD M25 is set up with one amp channel per panel. Note that I am returning the M25 to my dealer here in Seattle and replacing it with a Mac MC8207 - still one panel per channel. When a source is really well recorded/mixed and is an excellent performance the tendency I've found with Maggies is to turn up the volume. I know extended listening in the low 90dB level (at the listening position) isn't good for one's hearing, I just can't resist increasing the volume on some material. The NAD just couldn't sustain that level (the tri-center is really a 3-ohm load). The dealer was supportive enough to loan me an MC207 for a weekend and although I on some material the Mac "red lights" flickered off and on, the amp kept up. As a side note after the weekend I can say that for my ears the "Mac sound" and Maggies are a good fit.
2. Our guests vary from "interested in music/movies" to music lovers to music performers - everyone has commented on the level of detail they are able to hear. This was often with their own source material. I can confirm that poorly recorded/mixed/mastered content sounds really bad on this system. Nowhere to run, nowhere to hide.
3. Although Wedell's time here was brief (he had to get to Portland OR), he provided additional input for my sales rep from Definitive to use for some adjustments and the additional tweaks paid off. At least during the time he was here it was clear that Wendell doesn't crank the volume as high as I do (hey - I'm nearing retirement and I have tinnitus). What was clear is that properly set up, there weren't any discontinuities in the soundstage resulting from the tri-center. The additional layering and depth was noticeable when comparing stereo with Dolby Pro Logic Movies (the setting Wendell has typically used) and with Meridian Trifield. The lack of center "collapse" from side to side was very noticeable comparing stereo to tri-center. For movies the audio is seamless including wrapping to a pair of second model from the top B&W 8" ceiling speakers (powered by a 125 wpc Rotel stereo amp). We have the CCR and MMC2s at the same output levels from the amp and the center channel is at the same level as the 3.7s. The MMC2s do a good job of pulling the sound "up into the screen". Wendell noted that he prefers to use classical music in Dolby (or now Trifield) for checking out the tri-center set up since classical music isn't typically close-miked and therefore the width and depth of the soundstage are more dependent on the speakers' ability to reproduce the soundstage rather than having the sound engineer/mixer make these determinations as they might well do with jazz, rock, etc..
4. With 2 x 3.7s + 2 x DWMs the mid-bass slam is incredible. Combining Maggies' quickness with the additional surface area is very effective. I haven't heard 20.1s, but with even more "bass panel area" the sound must be awesome. We're crossing over the system to the sub at about 55Hz. When the Mac arrives and we replace the NAD we're also going to rewire and put the sub into the system full-time. Right now, following Wendell's suggestions (the logic of which I now understand), the sub is only active on multi-channel material and not during any two-channel listening (including Dolby or Trifield). I want to have the sub engaged and contributing for all music.
5. Although I mentioned the urge to crank up the volume, I'm actually finding that I'm listening at lower levels, particularly with highly dynamic material. The reason, I think, is that I can hear so much more detail at lower levels that I don't need to constantly fiddle with the volume control or listen at higher levels in order to hear the low-level detail.
6. I have added Magnepan-supplied wall treatement behind the center and the two MMC2s (1/2 inch material wrapped in Magnepan-supplied cloth). I'm running with NO resistors, only jumpers and the overall system sound is very balanced, especially with the Mac.
7. No surprise here - there is a lot of really poorly recorded/mixed music out there. That being said, even Pandora at the premium 192kbps streaming level sounds amazingly good.
8. I invested in Mye stands for the 3.7s. I notice improved coherence and slightly tighter bass. So did my sales rep - and he has two pairs of Maggies at home connected to two separate systems. I chose the "stealth" stands with no foot extension in front of the speakers. I used some leftover cabinetry wood as a platform, then went to Pier One and purchased two black suede pillows. I removed the stuffing, then put a heavy duty plastic bag in as a liner and filled each one with 60# of builders sand. It looks good and combined with the spiked feet from Mye the speakers are rock-solid.
In closing I'll dispense with the "reviewer hyperbole"; the system works extremely well for Redbook CDs, lossless streaming from my iTouch, DVD/Blu-ray concerts, and movies. Based on my dealer listening sessions, attendance at several "Music Matters" type events, and input from others I will state that as a multi-channel system with a total cost of approximately $30K, I have not heard a system that costs less than $100K that sounds any better (e.g., Wilson/ARC, Mac/Mac, Meridian, Sonus/Mac, Focal/Parasound, etc.). So although this is not an inexpensive system, for me/us it is extremely high value.