I purchased a townhome with surround sound pre-installs in the basement ceiling. I had the dudes who put it in wire it up. I have 4 JBL speakers in the ceiling, powered by a Harmon Kardon AVR 130 receiver. I also have a JBL subwoofer plugged into the same receiver. I use a Sony Wega 50" LCD for viewing.
Ever since I purchased the subwoofer (about a month after the rest was installed), I notice that during certain scenes on some DVDs (always DD 5.1 Ex soundtrack), the front speakers will pop, as if they're being overdriven by low-frequency audio.
I've pored through the HK manual, setting up the receiver to recognize my subwoofer, setting all ceiling speakers to "small," but no matter what I do, the DD 5.1 audio pops in the same places on particular DVDs (Return of the King, some of the new Star Wars discs, etc.). When I switch to normal "Stereo Surround Sound" on the HK, the popping disappears, but so do most of the dynamics of the audio presentation.
Is it a crossover frequency problem? How do I rectify it?
OK...maybe I should've investigated further before posting.
I may have solved the problem.
The Panasonic DVD player has an Advanced Surround Sound option that can be used to mimic the surround sound experience on a normal TV. I used to always have this on. Since I acquired the surround sound system, I never turned it off.
When I turned it off, the "pops" I had been hearing on DD 5.1 Ex DVDs disappeared.
I don't know if this problem is totally solved, because I'll have to break out other DVDs that had the popping problem, but I think I've reached a 90% solution.