Due to the dimensions of the wall where my PJ screen will go, I have two choices:
1. 110" Stewart screen with microperf, and place L/C/R speakers behind the screen.
2. 90" (or less) screen and use "regular" speakers.

The current front-runner is the Sonance Cinema Ultra II LCR, along with four Cinema Ultra II SUR's, for a 7.1 system. Retails for $6500, my price $3990. I like them especially because they have their own enclosure, eliminating one of the main "unknowns" with in-wall speakers: the enclosure.
I could get a 7.1 Axiom setup for much, much less. I'm especially interested in the QS8's. But if I can't flush-mount the W-Series speakers, then I obviously don't want to mix 'n match my surrounds (even if they are half the price of the Sonance Ultra's). It would not really matter if recessing them into the wall made them look ugly. The screen will hide them from the front, and behind the wall is just a utility room.
So, could the In-Wall/On-Wall Axiom speakers be flush-mounted? How? What might happen, sonically, if they were sunk 3.4" deeper than they were engineered to be?

One final question for now: Has anybody listened to the Sonance Cinema Ultra II's?

You could call Axiom and ask, but I'm sure they will not recommend installing the AS speakers as a flush mount type, this would defeat the design of them. Also the way the metal wall bracket is desigend, it wil not work for flush wall mounting, so the mounting of them could be a problem as well.

I just emailed Axiom. As for mounting being a "problem".... Almost everything else in this HT is a problem, too, so I almost expect it! Or, can stick with the Sonance for a couple thousand more and have a more "proper" installation. I'm sure I'll be happy with whatever I end up doing. But I am impressed with everything I read about Axiom. I'm 99% set on ordering and EP600 and EP500, and if I could get the other 7 speakers from Axiom, it would almost be like getting the EP600 for free!

Below is a picture of a W3 installed here, they do not protrude that far from the wall. For the cost of return shipping, you could try a pair and see how you like them. I tested the W3s here before installing them, the sound only improved once installed. So in my opinion you can get the feel for them without installing them, they will only sound better installed, not worse.
You can do a search as I have made several posts as to how I like the W3s, and there are some pics of the installation as well. Good luck on whatever you decide to do.

W3 installed

In my case, it is not about looks for the L/C/R speakers. THEY HAVE TO BE FLUSH-MOUNTED. I don't have room on the left & right outside the screen, nor do I have room below the screen for the center!!! That is, unless I shrink the screen, but I'm not willing to cut my image by 20% in order to fit speakers outside the screen frame.

Just attemping to give some info on the AS series, so do as you like, and good luck.

I don't see how flush mounting the speakers would do anything detrimental to the sound quality, especially because the Architectural series is designed to be on the wall. Having them flush mounted isn't going to do anything bad.

You could cut out pieces of drywall the size of the speakers, and make a neat little "indented" box for the speaker, then put it in there, having it completely flush with the existing wall.

why could you not bring the screen out say 6" from the wall, make a "sub wall" for the screen? your already going to spend a decent amount of time and money.. doing somthing like what i said wouldnt cost "that" much money not just for the brackets and what not, and the 6" you would lose, would that throw off your projectors throw? is that another issue? dont know if this helps, but it is what i would do in an ideal world.

Without confirming with Ian, I would have to say that the W series are designed to be mounted on wall. I recommend not to attempt flush mounting them as you will increase the boundary effect and produce a hump in the lower frequncies, thus "colouring" the sound.

If you absolutely must have inwall, I would also suggest looking at Monitor Audio CP series. They (as doother flush mounted inwall speakers) have switches that allow you to customize the crossover settings to reduce the hump created by the boundary effect depending on the proximity to adjacent walls (or have no compensation).

As for surrounds, you CAN mix and match unless you have a desire for a matching set of speakers. Heck, I have a friend who would not buy a receiver unless it had blue LEDs.

If you are thinking of inwalls for surrounds I would not recommend it unless, again you have a desire of everything blending in with the walls. Companies like Triad build nice inwall dipole spakers but I think you lose some performace as they tend to become a little more directional (which is not really what you want in a surround effects speaker). However, I believe they do this primarily for aesthetic reasons and I am sure it does not "sound bad".

Perhaps you should look at mounting your acoustically transparent screen about five inches from the back wall (ceiling mounted?). That way you can mount the W series with no interference with the screen.

I sense that you are trying to achieve the best possible sound quality and have them "invisible". Unfortunately you can not really have both. Inwalls will never quite be as good as properly positioned floorstanders or bookshelves. The W series are IMO a step up from most inwalls due to their design inherantly reducing the boundary effect that colours the sound. There is only so much one can do to compensate for acoustics. That being said, you can still achieve a decent sound with inwalls.

They are ported speakers, the ports on the bottom. Can’t flush mount them and expect them to sound right.

You could probably recess them into the screen wall if you built it out of 6” dimensional lumber, then “box” the speakers inside the 6” framing with 2X4’s. Just leave the stud space under the ports open to the bottom of the wall.

Clear as mud???