Fun/cautionary tale for anyone installing in-walls...
So, now that my basement is nearly finished I've finally gotten to try out the 7604s I installed in the walls (I've had lots of in-wall/in-ceiling Monoprice speakers, but never the 7604s). Fun test to see what kind of punch they have without a sub, because that hasn't arrived yet. Attached is a picture of my 70" Vizio with three of the 7604s around it -- I installed 7 of them.
Anyway, upon firing them up, I rather quickly experienced two alarming things:
1. Crackling/weak sound from the front left speaker (not good)
2. My Denon X-4000 would shut down and go into safety mode whenever there was a spike in sound output (REALLY not good)
A little research reveals that one of the common reasons the Denon does this is when the positive and negative signals are shorting on one of the speaker channels. OK...so I verify the connections on the back of the receiver are fine, rip out all my wall jacks, make sure nothing is touching there, and finally (reluctantly, since they were already painted while on the wall) I remove the left front 7604 from the wall. After removing it from the wall with the speaker just resting on the floor, I rerun my test, and everything works fine.
I look in the wall cavity and realize what's happening -- there was thin aluminum-like flashing/covering on the insulation batt. It was contacting the two large metal terminals on the back of the speaker when it was installed in the wall, causing a weak (but significant) signal short. Covered the terminals with some tape, reinstalled the speaker, everything works great.