Guys,
I'm having a problem with some fatal ear-piercing screeching distortion sound coming from my speakers.
For a receiver, I'm using the Panasonic SA-XR70 which suggests 6-8ohm speakers.
However, I recently bought the ORB Audio Mod2 speakers for a 5.1 HT system. These speakers are 4ohm, but Orb says , "Mod2 is compatible with all popular receivers & amps rated at 6-8 ohms". These Mod2 Orb 4ohm speakers are actually 2 8ohm speakers connected in parallel.
So... here's my experience:
DAY 1 -
I hooked up the system with 16 gauge wire and everything sounded fine at first. Then, after a while, I started getting this horrendous distortion (screeching) from at least one of the back speakers. This sound would come out regardless of how low I had the volume (increasingly loud as increase volume). I proceeded to turn the receiver off and play with the wire connections and then the sound seemed to go away, only to later return. I then disconnected the back speakers and proceeded to watch a movie with just the front ones (to test). At one point, after turn the volume up fairly loud, the ear piercing horrible screech returned (sound as if the speakers will explode, along with my head).
Other notes:
With the 5.1 setup, I was using "Dolby® Pro Logic® IIx" to give the back speakers something to do since didn't look like I was receiving dolby signals.
DAY 5 (I didn't do anything for days because so traumatized) -
Lastnight I reconnected all the speakers in the 5.1 setup, trying to make sure all the connections were solid. I then changed both the HD cable box and DVD player to output Dolby Digital signals. Now I see the Prologic IIx only kick in on 2 channel signals (not that this has anything to do with anything).
I then listen to several source cable channels including some broadcasting 5.1, others plain stereo. I raise the volume to about -10db (which seems pretty darn loud) and no problems on any of these. Then I play some scenes from 5th Element (where the Opera signer sings and where Bruce Willis begins fighting in the Opera House). Again, I raise the volume to about -10db (which is louder than I'd listen to give it's an apartment). Anyway, once again, no sign of the heart stopping sound. Everything sounded wonderful.
But I have no confidence. I'm scared. I sit there waiting for something evil to happen since I can't reason with certainty why it happened to begin with.
QUESTIONS:
1) What could have caused this? Bad connections? Bad audio processing? Thoughts?
2) I've been told the receiver could be unstable or oscillates. Is there some test I can perform that would make it fail if we assumed the amp was oscillating or otherwise unstable? I'd like to know somethings wrong before trying to replace one of the components. I've heard good things about both, and I do *love* the way they sounded lastnight.
3) What does clipping sound like? I read something about "hysteresis" and sound distortion?
Any suggestions, thoughts, or opinions are welcome...
thank you and take care,
Shell
