6.1 on a 7.1 receiver? (1 Viewer)

[jim.vaccaro]

Dumb question...

On a 7.1 receiver, if I only want to hook up six speakers for DD 5.1EX and DTS 6.1, how do I do that? My understanding is that 7.1 receivers have a left back surround and a right back surround...so which does the single back surround speaker plug into?

 

[John Garcia]

The manual for whichever receiver you get will tell you which one to use, and there should be a selection in the receiver's speaker setup menu to tell it to use only one.

 

[Paul Padilla]

Depending on your receiver there should be a setting to choose between one surround back or two surround back speakers.

If you can manage and your room dimentions are adequate, go with two speakers. (Or while you're at it, run both sets of wires until you can swing a second speaker.) Our brains can't localize a sound eminating from directly behind our heads. It actually seems to come from in front of us which blows the whole back surround concept. They should be 3 feet or more back from the listening position and 6 feet apart. Get things tweaked just right and you would swear the Balrog's whip cracks right behind your skull.

 

[jim.vaccaro]

Thanks guys. So 7 is better than 6, huh? I might have known. Problem is that my setup is the following:

Mains: AR-11s
Center: AR 4C
Surrounds: AR-17
Back Surround: AR 4C

Unfortunately, the AR Hi-Res series are next to impossible to find. Ideally I'd like four AR-17s in the back as opposed to the two with the AR 4C...but AR-17s are rarer then hen's teeth these days.

 

[John S]

Well, 6.1 and 7.1 aren't really far enough apart performance wise to worry about it all to much at all.

It is cool your center and rear center match. I like it.

 

[jim.vaccaro]

Thanks John. When I eventually pick up a 1015TX to replace my aging JVC 6000 series receiver, I hope it sounds as cool as it "sounds". Heh.

 

[John Garcia]

I don't know why people keep saying this, because it is false. I had a 6.1 setup for a year and never once did I think the sound was coming from behind me. The ONLY time this will happen is in a poorly configured/setup system.

If this were true, then it would still occur for an improperly setup 7.1 system, because the rear surrounds, with normal 6.1 processing, are both playing the same information and would basically give you the same effect.

I do agree though, if you're going to run the wiring, wire for 7.1 even if you don't use it righrt now.

 

[Paul Padilla]

Correct me if I'm wrong, but your objection to the rear sound concept would lead me to believe that this quote is a typo and that you meant "never felt that the sound wasn't coming from behind you."

This concept isn't something THX thought up to sell speakers, it's a known auditory principal. Perception is everything when it comes to psycho-acoustics. Objectively, however, the ear's physiology is geared to hear sounds in front and to the side. The majority of sound radiating directly from the rear is heard indirectly in reflection which is what usually creates the inability to localize. If your perception and your room's acoustics minimized that effect that's great. But the reason that spec recommends two surround back speakers separated is so the sound is better able to enter the ears directly. This allows your brain to combine the input and decide that the sound came from behind. The fact that even an EX or ES descrete track is playing the same info on both sides is precisely for this purpose. (until we get an 8 9 or 10.1 spec )

It's the same reason that the voice in a standard 2 channel stereo appears to come from the center, even though there is no center speaker. A standard vocal track has the same information coming out of the left and right speakers. The frequencies (ideally) converge on the ear drums at the same time which leads the brain to decide the sound is coming from in between the two speakers.

In any case, Jim, it won't hurt a thing to try it with one and see what you think. If you're feeling really ambitious you could take your other AR 4C for evaluation purposes and try it with two.

 

[John Garcia]

As I said, an improperly setup system may give this effect. In my particular setup, it did not. Again, I said in an improperly setup 7.1 system, say with the rear speakers too close together, the same miscue would theoretically happen.

My point was, that 6.1 should not simply be dismissed because some feel this may be an issue, when the issue is largely based on system configuration (correct speaker selection and placement) and proper setup.

 

[Paul Padilla]

These are the phrases on which I based most of my response. My point was that "it is false" is simply not correct. The phenomenon is genuine.