The explanation was in the latest Axiom newsletter. I have copy and pasted from my email below:

Clearance on End-of-Line Products!

After nearly a 10-year run, it's time to phase out the in-wall / on-wall hybrid speaker. The in-wall / on-wall was our first entry into the Architectural speaker family and they got rave reviews (read excerpt below) but our more recent separate in-wall and on-wall versions have made the original hybrid somewhat redundant.

"Unlike loudspeakers for which much is promised, but that end up being little more than patchwork designs, Axiom's M22 On-Wall/In-Wall is an extremely well-thought-out speaker that gives you Axiom's trademark sound quality in a package much more convenient and spacing-saving than the norm. . . . dead-simple to install. . . .a unique solution for the audiophile who wants it all, but wants it on -- and in -- the wall." -- Doug Schneider, SoundStage.com

While supplies last, the in-wall / on-wall hybrid line is on sale at a deep discount of 20% off. Perfect for that home theater renovation you're planning this winter! The slim profile fits in beautifully with today's flat-screen displays, and the innovative wall mount makes installation easy. Check out the complete in-wall / on-wall line here.


And to add to what Chesseroo said, nothing to worry about - they use the same parts as the M22's, so replacement parts will be available for a long time. If it's a style that works for you it is a good time to get them and save some $$.

Cheers,
Dan


Dan
On-Wall M5HP LCR, QS8 & EP500 in 7.1