Thanks for the input.

In the house I was in last I'm pretty sure the roof trusses were made of 2x4s, and they were on 24" centres. I could be wrong. I wasn't paying to much attention to that. I'm not talking floor joists here. Around me all the new construction floor joists are those shitty engineered I-beams.

I could whip up an enclosure using blocking and plywood in probably 10-15 minutes and I have all the tools onsite already anyway. The T&M for that would cost much less than upgrading to higher end speakers that have purpose made enclosures. Especially in a non-primary listening area.

I'm just considering options for making a speaker sound as nice as possible. If KEF is providing the optimum volume why wouldn't I use it? It would take just as much effort to make a smaller enclosure of random size.

Craig

No,
​Imaging is a product of most all of the audio frequency. We take spatial cues from quite a large response. The bottom end of that is a topic of controversy, with most arguing in the range of 70-120Hz.
But certainly response differences in the 120-260Hz range (on average) can make a slight difference in imaging as well. Those frequencies can certainly be affected by enclosure volume.

Rafter trusses ARE typically 2x3 on 24.

Stick construction can be 2x6, 2x8, 2x10, or even 2x12 depending on the span, so each case will be different.

I've done pm ceiling and in wall speakers much the same as I have with recessed lights in my own home. Used rigid foam to make an enclosure. Seems to work about the same as speaker boxes in that there's some soft surface inside the box that somewhat dampens reflections.

We have done this before also. We had to route out for the driver magnet.

I may be missing a point here, but my recollection of driver design is that a driver can be made to work best with the kind of acoustic suspension offered by an enclosed structure, or that same driving mechanism can be designed to work best with no enclosed volume behind it. In the latter case the physical suspension of the driver (spider and surround) "tunes" the speaker for best performance.

You'd get the best performance out of a speaker installing it with the rear volume for which it's designed. Since in-wall and in-ceiling speaker instructions don't tell you to create a box behind them with some particular volume, I conclude that they're mostly designed for open back use.

I could be wrong.

Normally I'd be inclined to agree, hence my not investigating this until now, but in the case of these KEFs, they provide specs for an enclosure to provide the best sound. The ones I installed the other day were free air and sounded awesome. Well, like awesome sounding ceiling speakers. I'm very curious about the difference with the enclosure.

The enclosure they are specifying is very large I could put two 12" subs in a 2cuft box if I were doing this in my car. So my thinking is they've created a design which works well in an IB install, but can be improved with the enclosure for those who want to put in the effort.

Why not just install wooden in wall/In ceiling speakers?

I am not convinced that imaging and sound stage are affected by improving the bottom end. I haven't read anything that leads me to believe otherwise.

Maybe the terms are the issue. I consider soundstage and imaging to be the process that lets you close your eyes and "see" where singers or musicians are on the stage. Considering the primary frequencies of most instruments and voices, lowering the bass response from 80-100Hz down to 40-60Hz isn't going to open up the sound stage and help me pinpoint a guitar, violin, or vocalist.

I could. But my curiosity is about the possibility of adding enclosures to these speakers and whether there would be a noticeable benefit.

Craig

Have done this before, makes a noticable differance across the board, worth the very little extra time it takes.

Did you do it for a speaker that specified it, or was this with a typical IB type ceiling speaker?

Thanks.

Craig.

I always assumed that the woofer drivers in standard ceiling speakers are "infinite baffle" Q specification? Meaning they typically sound better in a large enclosure (like an attic). Not spec'd for some small sealed enclosure?

I would also assume that on most general ceiling speakers, the mfg has no idea what the specs and enclosure Q for the drivers in their ceiling speakers? Unless you mean a small percentage of mfgs that have a pedigree in higher end speakers (Triad, M.A., MartinLogan, etc...)

That's a lot of money for fifteen minutes of work, a bit of MDF, a piece of insulation and maybe a terminal.

They spec the driver to some basic numbers, but I would think the companies that have actual engineers would know how they work best. They might not want to tell us because that takes some control away from them (by us making an enclosure that might not be optimal and therefore, not performing as usual) but that's really what they get for not making this info known.

Q can be designed in, to work for any configuration- if someone (let's use Triad as an example) sells in-wall/in-ceiling speakers that have an enclosure, it's highly unlikely that the drivers will work without an enclosure. Triad uses a lot of Peerless/Tymphany woofers and they need the enclosure.

If the manufacturer won't give up the T-S parameters, you can buy a tester from Parts Express and use some kind of modeling software, like BassBox Pro or WinISD- it's not a terribly expensive part and WinISD is freeware.

I'm not saying that your idea is bad, just curious as to why no subwoofers? Is it a matter of placement? I know there are a handful of manufacturers that make in ceiling subs to match up with their ceiling speakers. Again, just curious as to why rule out the sub, not saying it's necessarily the better path to go.