I am close to ordering a pair of M3s, but had a question about placement, because I have no flexibility there. I need speakers that will literally go on a bookshelf. They will be about 32" high and 7' apart, but only 3-5" out from the books. I could remove the books behind, but that would create an empty shelf which may do weird things with the bass? How touchy are the M3's about placement and especially about how far out they can be placed? I've never had rear ported speakers and don't know what sort of space they need. The room is probably about 12x30 and the speakers will be along the short wall. Thanks for the help.

Placing a speaker in an enclosed area is not really the ideal, but in the real world most of us are forced to make compromises when it comes to placement.

If you can place the M3s so that the front of the speaker is a half an inch to an inch, or so, out past the edge of the shelf. That will help minimize reflections.

If you can get 3", or so, of space behind the speakers, that should give the rear port enough room to "breathe."

agreed.. i dont think the placement of bookshelf speakers is as critical as floor standers.. like jack says, try and place the front of the speaker out to the front edge of the shelf, and make the best of it.

it is very hard for everyone to get the 'perfect' placement. ya just gotta work with what ya got!!

bigjohn

Thanks. To be clear: the shelves are on top of a built in cabinet which extends about 10" beyond the bottom shelf into the room. The speakers will be on that cabinet - not inside the enclosed shelf, but out just a few inches. One review I just found of the M3s says that they should be out in the room about 3 ft but I can't come close to that. I just don't want to end up with boom or muddle because there's too little room for the port to breathe. I guess I'm really not clear on what the port does.

P.S. So the port doesn't add a complication to placement that a non-rear-ported speaker doesn't have?

The port does add a complication, just not a very big one on a small speaker.

On a big floorstanding speaker there seems to be more complication, I imagine partly becase the back ports are a couple of feet from the front port and woofer. The M3s just aren't that big.

I did find with M2s that positioning the front of the speaker behind the "shelf" (in my case behind the top of larger speakers the M2s were sitting on) did make a huge difference, ie a very "boxy" sound.

I picked an M2 off the stand and "swung it back and forth" getting closer to the wall. There is a slight difference in the bass starting maybe 6-8" from the wall. I don't think this is related to the port, just normal "room acoustics affecting the bass" stuff.

Keeping the front of the speaker "sticking out" from the shelf (or at least not behind the front edge of the shelf) is the main thing you want to worry about. Sounds like you have a pretty good situation here because the cabinet sticks out further than the shelf above it (do I have that right ?).

What is the distance from the front of the cabinet to the back wall ? I imagine if you had "no space" behind the speaker you could probably just pull the cabinet out from the wall a couple of inches and nobody would notice...

It sounds like this setup is going to be acceptable. The cabinets and shelves are all built-in. The shelves come out from the wall 12" and the cabinets another 12" beyond that or 24" total. If I remove the books on the shelf at speaker level, that leaves me a good 15" or so behind, without books, if my math si right. I can put the speakers at the front edge of the cabinet top with no problem.

JM, welcome. As Jack and John pointed out, the arrangement that you propose for your M3s should work very well. Keep at least 3" of "breathing room" behind the rear port and have the front edge of the M3 slightly protruding from the shelf. Removing some books probably isn't necessary, but you can experiment, of course. Don't worry about having the speakers very close to one room surface as long as the distance of the woofer cones to the other two room surfaces(floor and sidewall)are different from that and from each other.

I have M3's and what you describe, I'd say they will be fine.