Soffit question

When soffit mounting speakers, is it better for the side walls most near the soffit/baffle to be absorbtion or reflective? I notice in some of John's designs, he uses slot absorbers in that location.

You do need absorption on all of your first reflection points. Maybe that is what you are seeing?

I guess I've seen it in a few pictures, such as the one near the bottom of this page: http://johnlsayers.com/Studio/Pages/Sonar2.htm where the side wall has slats..is there absorbtion underneath those slats? Also, does anyone know if two sets of speakers can be soffited in the same wall? I don't have any specific plans or ideas, just trying to gain some knowledge.

I guess I've seen it in a few pictures, such as the one near the bottom of this page: http://johnlsayers.com/Studio/Pages/Sonar2.htm where the side wall has slats..is there absorbtion underneath those slats?

Actually, in those photos I see slot resonators on the front and back walls, not in the side walls. I see only glass doors on the side walls. And it looks to me like John carefully angled those side walls such that the glass is not at the first reflection points. But yes, slot resonators usually do have absorption inside. AFAIK it isn't strictly necessary, since a slot resonator is basically just a Helmholtz resonator, and they work fine without absorption, but putting absorption inside widens the Q, so you cover a broader range of frequencies. At least, that's the way I understand it. Maybe the acoustic experts here can correct that, if I'm wrong. - Stuart -

Oh I see, my perspective was off!! ok, that's making sense now. Is there a advantage to using slot resonators as opposed to broad band absorbtion? Do the wood slats reflect more high end for a more lively sound?