Linn also produces in wall speakers. The sibilance that you have experienced with two different speakers may also be something else in the chain. If you can, try hooking up a pair of more conventional speakers (from your other stereo if you have one) to the in wall cables and see if the problem still exists. I am not familiar with Sonance, but the tweeters that Paradigm uses in their mini moniter are a bit grating IMO. Too bad because otherwise is is a very dynamic sounding and fun speaker.
In-wall speaker help
I am looking for a high quality in wall speaker in a 6x9 size. Currently I have paradigm and sonance and I am having real problems with sibilance (sp?). I am also open to suggestions as they are being powered with a high power sonance amp. These are being utilized as background in an exercise area and bath, but the poor performance is driving me crazy. Thanks in advance.