I'm planning my home theater. My wife would like the speakers to be as close to invisible as possible.
I use Energy xl-16's for front and rear, and an xl-c for the center. All the speakers have rear-firing ports, and the xl-16's don't have a straight vertical front, which makes in-wall mounting a little less desirable.
Is there a general consensus on in-wall mounting speakers with ports? I'm thinking I'm going to have to manufacture some wall mounts.

Also, I notice in the galleries that most theaters have the center mounted at the bottom of the screen. With multiple rows of seats, isn't there a risk of losing sound to the bodies in the front row?

Those ports should not be blocked and, therefore, should not be in the wall or directly against the wall. It seems that you have chosen speakers that are inappropriate for the way you want to use them.

I picked the Energy speakers because they were what I wanted; the in-wall idea was secondary. I suppose brackets will have to suffice.....

I think most theaters have speakers behind the screen. My center is mounted under my screen and angled up toward the listeners' ears. Not as good as being right behind a sound permeable screen, but it works pretty well. You could also mount it above your screen and angle it down.

I've not listened to these speakers and Kal or others may have first hand knowledge of them, but here is an heretical thought. If you are going to use a separate subwoofer, try blocking the ports by stuffing them with fabric- put a sock in it so to say. That will change the low end response and impact the efficiency, but it may not matter if you are not going to run them as full range units.

The angled face is more of an issue in mounting them in wall, but if you can set them slightly proud so that the no part of the face is behind the plane of the wall it may work.

Putting these speakers either in the wall or on the wall will alter the low range balance. You should try listening to them close to the wall first.

On the wall or in the wall will change the way these speakers sound. But the change may be OK with you. If the sole or primary use is HT rather than classical piano recordings, the altered response curve might not even be noticed.

There are other ways to make things disappear.
My misses said she didn't want to see anything.

Here are the speakers with rear ports sitting on a stage and then covered with fabric frames:

http://i23.photobucket.com/albums/b393/bigmouthindc/DSC00502.jpg

http://i23.photobucket.com/albums/b393/bigmouthindc/DSC00516.jpg

http://i23.photobucket.com/albums/b393/bigmouthindc/DSC00540.jpg

Here is my equipment hidden by fabric/wood door.

http://i23.photobucket.com/albums/b393/bigmouthindc/DSCN2959.jpg


And yes I wish the center speaker was above the screen. I have plans for an acoustically transparent screen and it will be raised

I've not listened to these speakers and Kal or others may have first hand knowledge of them, but here is an heretical thought. If you are going to use a separate subwoofer, try blocking the ports by stuffing them with fabric- put a sock in it so to say. That will change the low end response and impact the efficiency, but it may not matter if you are not going to run them as full range units.No, I've not listened to these speakers but, as with all speakers, they are designed for a specific range of applications. In this case, they were NOT designed for in-wall installation and there are speakers which are designed for that. I feel the same way about blocking/stuffing the ports. The results are unpredictable, especially with 2-way speaker that use the same driver for bass and midrange. My advice is to use them as close to design intentions as possible. OTOH, if you want to experiment and be the judge of what sounds best to you, that is always recommended.