5.1 installed, but doesn't work right

You didn't mix up the connections on the speakers, did you?

Are you using bare wire directly to the speaker and receiver, or did you add banana connectors?

Why do you think "-30" is high? It all depends on calibration, but if you had to turn it up to -10 or 0 to get decent volume, I'd find that a bit odd. -30dB or so is probably where my knob is most of the time, for normal TV viewing. Higher for DVDs.

Secondly, the surrounds shouldn't be that loud in normal material - things generally are going to be happening in front of you, not behind you. Only with test tones should you normally hear the same volume from the surrounds.

But it sounds like you've got a wiring problem with the left surround. Something's shorting out somewhere. Check for stray strands of wire at the two ends. Make sure you're going in to the correct connectors in the receiver.

Sounds like KMO hit it.

Either stray wire(s) are causing the overload problem or the wire has been pierced by a drywall screw.

If you had a multimeter you could check the circuit resistances to the rear speakers from the receiver end of the cables, but if you don't find any problems with connections at the speakers or at the receiver, it's pretty safe to assume the problem is in-wall.

I suppose you could swap the left and right rear speakers to test for a defective speaker, but that it much more rare than a loose/stray strand of wire or pierced cable causing a short. Checking the connections at the speakers and the receiver is the best place to start.

My ex-girlfriend woke one morning to find a wet 1st floor from a copper water pipe that had been pierced by a drywall screw. The odd part was, she had been living at the place for almost a year before it finally leaked (first occupant of new townhouse).

That happened to me, too, almost 20 years after the screw pierced the pipe. It took that long for the screw to rust away enough that it no longer served as a stopper for the hole. Finishers are supposed to put a metal plate over a stud anywhere that a pipe runs through it so that can't happen. SUPPOSED to.

Anyway, to the OP - I had a similar problem with one of my systems. Turned out that while I was swapping cables, long after the calibration scheme was run, I mixed up the sub and LR cables.

check your settings of the source and make sure its set to output. Before I knew too much about HT (I dont know your level of knowledge) but I had to turn it way up and couldnt hear anything either and I had the DVD player set on the wrong thing.

Pretty easy for this, actually.

Get the multimeter and set it to the Ohms setting. This is the Greek Omega symbol (looks like a horseshoe).

Leave the test probes apart and see what the display looks like - probably will say something like "OL". Now touch the probes together and see what the display looks like - probably will show something like 0.2, give or take a little.

Now, with the speaker cables disconnected from the receiver, connect the test leads to the speaker cables at the receiver end of the cable(s)- one lead to each wire of the pair going to the left rear or right rear, etc. For an 8 ohm speaker, the DC resistance will probably be somewhere around 4 ohms, give or take an ohm or so lower to a couple ohms higher.

If you see a resistance that is 0-something, or way below 4 ohms, there is probably a fault in that circuit. Next, disconnect the speaker on the other end of that cable and make sure the disconnected ends of the cable are not touching. If the resistance measurement stays very low, there is a short in the cable somewhere. If the resistance goes back to that "OL" reading, the cable should be good to go and would tend to indicate a problem in the speaker.

Also once you're all finished testing and things are working properly you must use an SPL meter to calibrate the channel levels correctly.

I can't believe it took 9 posts to get the most basic and logical solution.

Did you calibrate with an SPL meter? If not, you need to.

And -30 is not high, for me it would be considered pretty low. I typically watch movies right at the 0 point and tv at about -10. It's all about how the system is calibrated.

Just get a run of speaker wire, connect it to the receiver, lay it on the floor, connect it to the speaker, and run the test tones again. Don't go out buying a meter. If it works like it's supposed to, it's the wire.