IB or Dipole?

[gbegland]

Help. After reading up on both for weeks now, I can't decide which style to try, but I am leaning towards IB. I can easily accomodate either. Listening would be primarily music on CD and DVDA or SACD with occasional HT, so I don't need teeth rattling bass.

They would be used with Maggie MMG/MMGC fronts and homade BG/Morel rears. I have a pair of DIY sealed 10's for below 100hz right now and they are fun, but not good enough for critical listening with well produced material.

If dipole is used, they could go directly behind the MMG's, but if IB, then they will be mounted in the wall about 6 feet behind the Maggies. This wall ajoins the closet in my spare bedroom. I'm assuming that this will work out ok acoustically. Is 6ft too far away? Should I use a delay for the Maggies given the distance BTW the two? I would rather not, but if it is crutial, then OK. I would also like to keep the Maggies where they are. Any closer to back wall and the sound goes down hill fast.

Thomas, what are the general feelings from the "cult" about mounting the woofers in the front wall versus attic with manifold? Will normal interior drywall construction need much bracing to not vibrate like crazy?

Thanks in advance guys.

Greg

[ThomasW]

I can't decide which style to try, but I am leaning towards IB.

I experimented with IB vs dipole about 18 months ago. I give the 'absolute' sound quality nod to dipole (this only is a slight difference though), but at the expense of needing double the displacement, and quite a bit more EQ compared to a comparably performing IB.

I'm assuming that this will work out ok acoustically. Is 6ft too far away? Should I use a delay for the Maggies given the distance BTW the two? I would rather not, but if it is crutial, then OK. I would also like to keep the Maggies where they are. Any closer to back wall and the sound goes down hill fast.

I've never heard of any planar requring 6' of clearance, mine certainly don't and they're about 6 times bigger than MMG's. Since you can compensate for the 6' difference I don't see it as a problem

Thomas, what are the general feelings from the "cult" about mounting the woofers in the front wall versus attic with manifold?

This particular FAQ page describes the differences between line array and manifold IB's.

Will normal interior drywall construction need much bracing to not vibrate like crazy?

Obviously not it's a problem since excluding floor mounted designs, all other IB's build are using standard drywall construction. This is also in the FAQ. Note that an IB won't rattle any more than a box sub turn up to the same SPL. The front and rear waves equalize the pressure on the drywall

[jdybnis]

If you go the dipole route put them adjacent to the MMG's not behind them so that the MMG's are in the null formed by the dipole. Some planars have a problem with being pushed around by bass frequencies because the membrane is very light. It may or may not be a problem with the MMG's, they don't have the ribbon tweeter, but it's worth experimenting with.

[gbegland]

OK, so lets say I get the Maggies back to around 4 feet out from the wall. Sound better for the integration?

When you mention OSB in the FAQ, is that what I usually just call "sound board"? Comes in sheets like MDF, but is much more fiberous looking. We used it in making the layered walls at the studio I tech at.

So, I guess I am leaning most heavily towards 2 * 18's in the front wall about 4 feet behind the MMG's. Opinions?

Greg

[ThomasW]

I'm not familar with the term 'sound board'.

OSB is Oriented Strand Board, aka flake board. Virtually as strong as plywood but less expensive. Available at any home center store

Line arrays provide the 'best' sound since there's an opening the size of the Sd for each driver, but they are seldon on axis with the mains.

A manifold can provide optimal placement given the ability to align it with the mains. But generally speaking they don't have an outlet that's as large as the sum of the combined Sd.

So one choses the compromise they prefer.

[Paul W]

You may be on the right track in considering delay for the Maggies. My dipole mains are delayed and integration with the subs is noticeably better than just matching phase with the IB. "Seamless" is overworked, but it's a good description of the result.