PMA4000
We called it the "Scappoose" project when the development began on the PMA4000. I think this is the airport that Mr. VanGrunsven used as his airport.
It can be installed like an intercom or in a 2 /14" hole.
Two Coms, Two Navs, 4 place IntelliVox intercom, music input with muting.
The biggest advantage of having an audio panel rather than using switches is that an audio panel has the means of "summing" audio signals. So if the pilot wishes, they could listen just to Com 1, or to both Coms, Nav audio, or some other switched audio.
For those pilots still wanting to use a speaker, there is a cabin speaker amplifier in the panel as well.
http://psengine.com/pma4000.shtml
There are 1000's in the field and has proven over the years, to be an extremely reliable product. While it is very unusual to get any of our products in for repair, the PMA4000 gets a standing ovation when it comes back in for repair, the unit usually has physical signs of sever abuse