Yamaha Protection Mode & Speaker Wiring (1 Viewer)

Hey everyone, I just upgrated my HT system and am looking for some help with what I hope is not a real problem. For background, I have a Yamaha HTR-5460 receiver with Monitor Audio Silver 4i fronts, 10i center and 3i rears. Until today, I had only the fronts and center and was very pleased with the sound and my ability to play music and DVD movies pretty loud. I finally completed my in-wall wiring for the rears and went to test out the 5 speakers together. In the process, I upgraded all my speaker cabling to a good-quality 12 gauge wire (more on this later).
Well, the first thing I noticed was the volume was somewhat less at comparable settings with 5 speakers than it was with the just the front 3. Then, on music the receiver shut off at -50db and for movies it shut off at -42db. When I told the receiver I had no rear speakers, I could achieve much high volumes with no problem. Note that I am not talking about ear-shattering loudness, but certainly enough volume to give a movie-theater-like feeling. Also, when the receiver shut down, it did not seem at all hot like it was being overloaded or anything.
Anyway, I consulted my Owners Manual which mentioned the receiver's "protection circuitry" which would turn off the receiver if there was a problem with speaker wiring. In fact, after I would turn the receiver back on following a shut-off, it would display a message to check the speaker wiring. So... I pull the unit off the rack and I did notice that some of the 12 guage wiring may have had a strand or two that did not fit into the binding post completely (due to its thickness) and might have been touching the receiver case AROUND the binding post. The Manual specifically mentions that speaker wiring should not touch anything but the binding post.
My questions are these: Before investing in 5 pairs of good banana plugs or other connectors, can this wiring as described be causing my problem? It seems strange to me that the receiver would only shut down at higher volumes. Is anyone familiar with the protection circuitry and whether my symptoms sound familiar? Any help would be appreciated... I am hoping that I didn't just buy a receiver that cannot realistically power 5 speakers at a decent volume level.
Thanks,
Ron

I suspect a short in your wireing is causing the problem. Since the rears cause a huge reduction in sound, I would suspect they are the culprit.
Dont forget to check the wires at the speaker end as well. A short here will cause the same problem.
The Yamaha units tend to be fairly good and they will play loud at the cost of some distortion (as any amp will). Most of the Yamaha units are calibrated to produce their max output with the volume control in the 12 o'clock position so you should usually stay about the 10-11 o'clock position and have pleanty of volume.
I like the dual-banana plugs from Radio Shack just because of the ease-of-use. For behind the receiver, they have a 2-piece that unscrews and then clamps down on the copper. Makes it easy to do a neat job. About $6 each.
Another point: do you have the speakers defined as LARGE or small? Defining the rears small will route the lower frequency sounds to the fronts and reduce the load on the receiver.
Good Luck.

I have a 5490, and have not had any problems with increased volume, and would suggest spending the extra money on decent banana plugs. That way your sure of avoiding a short problem. To me it's like buying a sports car and putting cheap tires on it.

Will: Actually the audiophile convention is to wire with bare-wire and Not bananas. This goes with the theory that "...the fewer breaks in the signal-path, the better".
I agree with this to a point. Fewer breaks mean fewer places for something to come loose.
But they group those binding posts on the back of the receiver so close and the side-holes are barely big enough for 12 ga copper that I just cannot Knit them through. (I was heading for the tweezers when I tried wireing up my speakers the first time.)
The side-hole dual bananas are a god-send. They make it quick and easy, and they prevent shorts if a kid/dog trips over the wires while the power is on because of that solid spacer bar.
Note: www.partsexpress.com has similar dual-banana plugs for about $3.60. But Radio Shack is so convient.
Good Luck.

Well... I "banana'ed" all of my speaker connections and cut my receiver-binding post connections to exact-length so as to avoid any side contact (I agree, tough to do with 12 gauge-- may have to eventually go with the dual banana plugs there) and.......... VOILA' no more protection-mode shutoff.
It is still hard for me to understand why a short would cause cutout only at higher volumes, but it does. Sound levels are great and I got to debut the system for my wife with the Star Wars Episode 1 intro in all of its glory!
Thanks,
Ron