Satellite midrange 2.5 m from bass?

[rick57]

After many ideas, I finally hit upon an idea that seems the best compromise for me in the room that I listen most in (as opposed to a room with space, no family and not much furniture - ie with more flexibility!): -

The compromise (with boxes smallish & against or near the wall) is - Separate midrange enclosures hanging from the 3m ceiling (eg Pivotelli), with 40 litre sealed bass boxes.
The bass will use a pair of Peerless XLS, to XO actively to mids (which won't go below 200: a true mid)/ ribbon satellites.

If the subs were just used up to say 80 Hz, I would probably use 25 mm MDF, maybe with lead lining.

Two questions:
- But to give best sound up to 200 Hz - the high end of bass – do you think I should bother with constrained layer damping (CLD) or another method?

- With an XO of 200Hz and the drivers 2.5 m apart, I’ll need to work out the time alignment somehow. But are boxes 2.5 m apart otherwise a bad idea?

Thanks

[rick57]

Being keen to get a basic reasonable sounding box sooner rather than later, an approach I’ve read of is – build a quick simple one layer box, tune the XO etc.

Then add the constrained layer on the *outside. The drawback is this would look very odd.
However eg if you are happy with grille cloth wrapped around the box, the look and finish of the box doesn’t matter!

[Pan]

"- With an XO of 200Hz and the drivers 2.5 m apart, I’ll need to work out the time alignment somehow. But are boxes 2.5 m apart otherwise a bad idea?"

No, Tact sem to pull it off well. For a normal living room I see this as a very good solution... keeps the wife/spouse happy also.

/Peter

[rick57]

I imagine that Tact would do a good job, but that's well outside the budget.
I since heard that with an XO of 200 Hz, the wavelengths are long enough that time alignment *may* not be necessary.
If it is, I know this can be done with eg a Behringer DCX2496 for about US$450, and I think (but am not 100% sure) that this can also be incorporated into a passive XO.


The remaining question is - to get best sound from bass boxes up to 200 Hz - should I bother with constrained layer damping (CLD), or use some other method?
Any ideas?

Thanks

[Pan]

"I imagine that Tact would do a good job, but that's well outside the budget."

I understand, but I just wanted to mention that it is possible to do this with very good sonic results.

"I since heard that with an XO of 200 Hz, the wavelengths are long enough that time alignment *may* not be necessary."

Unless very high order slopes you will get troublesome ripples around the Fc, and then you have the group delay. I would not bet money on that solution turning out good.

/Peter

[rick57]

Peter

What do you mean by "troublesome ripples around the Fc, and then you have the group delay"? Is:

ripples around the Fc = a non-smooth frequency response around the XO frequency?

and then that causes phase shift?

Thanks

[Hertzschmerz]

Originally posted by rick57
The remaining question is - to get best sound from bass boxes up to 200 Hz - should I bother with constrained layer damping (CLD), or use some other method?

Don't bother. Solid bracing is enough for a bass cabinet. Bracing pushes panel resonances up in frequency so they won't get excited.