Help mismatch maybe?

"OTOH, look at a B&W 802. There is not a tube amp in the world that will play bass right on that speaker- you need transistors, as the woofers are running at 3 db less efficiency as the midrange and tweeters are. You need an amp that will double power when it encounters the 4 ohm woofer load, while the rest of the speaker is 8 ohms. That makes the woofers play at the same level as the rest of the system."

Atmasphere,

I'm not certain, but I'm thinking the Quad 21L2s (two way dynamic floor standers) of concern here are not designed for tube amps and are more like the B&W's regarding load so that an amp that doubles to 4 and 2 ohms is the right match for these particular speakers and that this will also put the owner in the best position to move them away from the walls for better imaging with sufficient and more balanced bass.

Mapman, that could be- sort of. The problem is that ESLs in general do not have an impedance curve based on box or free air resonance. It is based loosely on a capacitance. Consequently, it will require constant power with respect to impedance, not constant voltage.

Unfortunately, but like many deisgners, Quad has chosen to try to make their products operate under the Voltage Paradigm rules, but if you have spent a lot of time with Quads, you know that they have had only limited success (don't believe me? -look at all the original 57s, 63s in service and they even went so far as to reproduce the 57...) with that route.

Martin Logan has been following that route for years (trying to get a Power Paradigm technology to work with Voltage Paradigm amplifiers) and you see similar issues: it takes the right kind of amp to really make the speaker sound like real music. Yes, you can drive them (the impedances are quite low, thus favoring transistors in a way) but its really really hard to get them to not be bright and otherwise sound natural. That's what I mean by 'tonal aberration'.

Its a fact that all amplifiers (transistor, tube and class D) sound better when driving higher impedances. So its important to understand that the differences between VP rules and PP rules are not about the total impedance, and more about the behavior of the relationship between the amp and speaker. Nor is it about tube vs SS, although that debate is better understood if you know the differences between the paradigms, which in fact is what that debate is all about (as is objectivist vs subjectivist).

The bottom line is that even though ML and Quad have been taking a similar path, both would benefit by increasing impedance, if nothing else.

BTW, a set of ZEROs (http://www.zeroimpedance.com) will often allow a tube amp to easily drive either load.

Atmasphere,

OK, but the Quad 21Ls in question here are not electrostats. They are conventional box designs (2 way floorstanders) with a 6 ohm nominal impedance, I believe.

Mike
I have a second system with the Quad 21L2, Nad C325 BEE, Cambridge 640C CD player & Kimber 8tc Speaker wires, on the long wall in a room approx your size. Speakers are 2' from the rear wall and about 60" appart. Try to tilt them back to the top of the front screws, listen and lower a little at a time,see if that helps. Also while your away let the system play the Quads need time to break in.
Good luck
Mike

Tilting them can help a bit, but I was never happy with the result as it threw the sound stage up a bit and there was a slight loss of focus. That, and I'm using the 22L2's as my example which have the additional driver.

Biggest influence on bass from my experience is (a) amplification and (b) speaker placement from rear wall that doesn't exceed 24" and isn't less than say 16" when dealing with rear ported floor standers.

You may consider auditioning a MF A3.5 if the A5 is out of reach. Even an A3.2CR which can be had for around $600 used. These amps have the most low end of those I've demoed or purchased so far and they don't dissapoint. I know we all have our favorites, but I can attest that they work beautifully with the Quads as I've had both the A308I and the A5. They do wonderfully well in home theater duty as well. Some will mention MF amps add "coloration" to music like cardas golden cross interconnects, but everyone has their own taste and it sounds like low end response is what you're looking for (I can't necessarily reccomend the golden cross ICs though, I didn't care for them but others do...).