Passive sub for Magnepan 3.6r?

Duke,

At 30,000 feet, I'd agree with every word you said. However...

IME, dipole bass doesn't look just like 2 monopoles. True, the deep suckouts are dramatically reduced as they would be with a pair of monopole bass generators, but smaller suckouts occur more frequently with dipoles. It's a different (maybe more benign) problem, but a problem, noetheless.

As to EQ, your point re: "the sweet spot" is probably more relevant in theory than in practice. If EQ'd on-axis response is good, you needn't sit with your head in a vice. For most high end listening rooms, my guess is that EQ is extremely effective. It's certainly been the case for me.

OTOH, if a given system is in the "party" room, there may be more teeth in your argument.

Marty

Marty

Duke,

Thanks for the reply.
My comment re: a dipole = 2 monopoles was intended to illustrate my actual
experience measuring such designs in my room. I assume (as you allude to
in your post) that the problem with the analogy is that it's frequency
dependent. The bass region, where we're lurking, finds monopole speakers
delivering omnipolar response, so perhaps the analogy is least applicable
here.

As to dipoles being "easily matched" in the x-over region, I've had
the opposite experience. I get pretty smooth reponse from my Maggies down
to app 80hz (I use bass busters which help in the octave or so above this
frequency), but it gets pretty ragged below there. IME, the smoothest
"handoff" occurs when the subs and mains are precisely level
matched through a region that is both free of "humps/divots" and
appropriate in level for good overall octave to octave balance - no mean feat.
The Maggies have proved tougher than either omnis or monopoles for me. I
eventually got good results - with a fair bit of EQ - but it was WORK.

The point about local vs global EQ is simply that - if you look at the virtual
systems links - almost all of these set-ups limit the listening area sufficiently
to allow effective EQ while ignoring any "global" room issues.

BTW, I use 2 subs and this helps reduce the need for EQ. However, fine
tuning with EQ, particularly right around the x-over point, is still - IME -
extremely beneficial, particularly for dipoles.

These points are only based on my own (reasonably extensive) in-room
experience and measurements. It's always possible that my specific
experience is idiosynchratic.

Marty

Duke,

I checked that link. If you can get that kind of in-room response (app +/- 4db down to 25hz!) without EQ, my hat's off to you. I've never gotten close in any of my rooms with monopoles, omnis, di-poles, or even bi-poles (Sunfire CRM) until I added EQ. Pretty impressive.

Marty