I'm hoping to benefit from the clearly superior Google-Fu that you folks here have.

I currently have bookshelf speakers for my surround speakers. I need to get these out of toddler reach and we don't have furniture to put them on (they've just been on the floor behind furniture). Due to the layout of the room, wall-mounted speakers won't look good (they'll peak out over at least one window casing). I'd like to put some in-wall speakers in, and I'm having trouble finding ones that will work because of the weird construction on one side.

The right-rear speaker will have no problems. Just a standard wall with a slightly undersized stud bay, probably around 10-12 inches of space. Plenty of room for most speakers. But the left-rear speaker is the problem. It needs to be put into a small section of wall that juts out into the room a little bit. No more than about 10" TOTAL, and the framing likely takes up most of that. So from my measurements, I'm left with a cavity about 4" wide.

There are no speakers like this. Not that I can find. And that's where I'm hoping you guys can do better than I did.

These are surround speakers, and I'm not much of an audiophile anyway, so all I'm really looking for is some atmosphere. The stuff coming out of a surround speaker is icing to me, so I don't care if it's coming out of 4 2" drivers. I just need something back there. Can you folks find this for me?

*edit*
Oops, I should mention that I'm not looking to spend a lot here. I've found one or two items in the hundreds of dollars, and that's more than I spent on my front three speakers together. I'd like to keep this under $100 for the pair, or at least for each.