We just installed this in three of our classrooms. We looked at 2 companies, audio enhancement and Front Row. The system was just installed on Monday and we are just getting use to it. We ended up going with Front Row, (and the model front row pro) as the company was more responsive and gave us better pricing...a discount, free shipping and installation. We also chose this one as the comparative model in audio enhancement was mono and the Front Row was stereo. Now that we have it installed, one criticism comes to rise.... one area of the room reports it is "too" loud...while the rest of the class says "fine". I would like to have had the ability to have control over the 4 speakers in the ceiling...(and I am not sure if Audio Enhancement has that feature or not). E.g. if a student in one area needs more sound than in other areas of the classroom...or in our case, less. Perhaps this is just the "newness" of the system...and the students will get use to it.... but it would be nice to have that control.
I did use Audio Enhancement for several years and never encountered the problem you are mentioning. While I don't specifically recall a separate nob for each speaker -- the sound was very balanced and never came out in the manner you describe. One problem we did have -- which wasn't necessarily the fault of the equipment; but, if the teacher had things hung from the ceiling it would interfere with the reception. But, moving a few things around the room always solved the problem.
At the March UCET conference, Lightspeed Technologies http://www.lightspeed-tek.com/ was an exhibiting vendor. I was impressed with the much better fit and finish of their products
The speakers in our elementary classrooms are surface mounted using a bracket. The wiring is exposed. In our secondary school, we have suspended ceilings, so we used flush-mounted (recessed) speakers. There was so much sound moving from room-to-room through the ceiling, that we placed inverted five-gallon buckets stuffed with insulation over each of the speakers to confine the back-draft audio. Some teachers still have a tendency to overdrive them which can be distracting in neighboring classrooms.