flat speaker quandary

Nick, Perhaps if you describe your room, its dimensions, where you have placed your speakers and your listening seat, and describe your floor and wall coverings etc some one can give you some help. I had a similar experience with large panels when I moved into my new home and found it was all due to placement and room conditioning.

Just wanted to mention that they might not be broken in yet and if they take as long as Magnepan speakers that might not be for 500 hours! So I advise not to even think about it until then. Martin Logan owners can tell you how long they take to break in, I would be guessing as I have never owned them. But the difference can be amazing once equipment breaks in.

ok...the real details.
philips 963 as transport >
smART DIO boulder mod >
audio experience symponies pre >
McCormack DNA1 >
MIT term3 biwires
cheap monster and AR interconnects

Room is open concept living room/kitchen.
living room area is 17' wide and 24' deep.
I have the SL3s pulled 50" from the back wall and 4' in from each side wall. They are toe'd in approx. 2.5"
Lots of big bushy and tall plants in each corner behind speakers, and media racks / book cases on back wall center. TV in between.
Walls are new sheetrock.
Listening spot is center couch, 10' from dead center.

strengths: awesome holographic sounstage and imaging
weakness: not very musical, no punch or impact, always movign the speakers to tweak them "just right". Even a half inch makes a big impact w/thes SL3s.

Nick, Magnepan and Martin-Logan both make some excellent, high value speakers, but there are differences in their sonic signatures. From your comments I suspect that you really would be better off going with one of the newer Magnepan models rather than any of the Martin-Logans. That said, M-Ls don't need as much toe-in as you've indicated and they can benefit from even more distance to the rear wall. You might also want to upgrade your interconnects. I would recommend something like Cardas or Discovery. My final comment is that you have a good size room and if you're driving the M-Ls hard that your amp may be clipping. They are a difficult load.

Nick -

The situation you describe makes perfect sense to me. Briefly, your room's too big for the SL-3's. But please read my explanation as to why this is so, because it isn't obvious at first glance.

The woofers on your Martin Logans approximate a point source, while the panels approximate a line source. And sound propagates differently from the two - under anechoic conditions, sound pressure level falls off by 6 dB for each doubling of distance from a point source, but by only 3 dB for each doubling of distance from a line source. If we match the levels of a true point source and true line source speaker at 1 meter, then measure again at 10 meters distance, the point source speaker will have fallen off by 20 dB but the line source speaker by only 10 dB!

In a real-world room, the reverberant field fills things in somewhat, and the panels aren't tall enough to truly approximate a line source. But I took some measurements in my living room once, using a pair of hybrids (SoundLab Dynastats), and the results were rather interesting:

With a pink noise source, at one meter the woofer was 1 dB louder than the panel; at 3 meters (normal listening distance) the levels were exactly the same; and back at 8 meters (the practical limit in my room) the panel was 4 dB louder than the woofer. So as you can see, the perceived tonal balance will change with listening distance.

The tonal balance also depends on room size, as a larger and/or more acoustically porous room (lots of hallways or doorways) would have given an even greater discrepancy between woofer and panel because the reverberant field would provide less fill-in in the bass region.

So I hope you can see that a hybrid electrostat is even more of a juggling act that it appears at first glance - the relative levels of woofer and panel have to match up for your general room size and listening distance. Some hybrid electrostat manufacturers build a great deal of level adjustability into the speaker, and some build a wide range of models so that you can match the right size model to your room. Martin Logan falls into the latter category.

If you read a lot of consumer comments on Maggies and Martin Logans, you'll find that comments on the tonal balnce of the Maggies are fairly consistent, whereas comments on the tonal balance of the Martins vary much more - one person says they are too bass-heavy, another that they're thin and anemic, and yet another that they're just right. I strongly suspect that the variation in perceived tonal balance of the Martins has more to do with how that particular room interacts with their combination of line source and point source propagation than anything else.

As I recall the crossover on the SL3 is in the 300 Hz ballpark, so adding a subwoofer would still leave a hole in the midbass and lower midrange. But it would still improve the overall tonal balance. My suggestion would be to add two small subs - one for each channel - so you can run them up fairly high without spoiling the imaging. Look for a sub that is smooth and sounds good up into the midbass region, and that can be crossed over fairly high, rather than putting maximum emphasis on bottom-octave extension. What you'd like to do is add a pair of level-adjustable woofers to augment the ones in the SL3's, rather than adding a deep-bass-only subwoofer. I would imagine there are some rather inexpensive subs that would fit this description, though I don't know of any offhand.

Best of luck to you,

Duke