Axiom Home Page Forums General Discussion Home Theater reverse rear speakers (in 7.1)?

I was reading this thread over at AVS:

http://www.avsforum.com/avs-vb/showthread.php?s=&threadid=467073

Someone mentions in the thread that if you have dipole rear speakers (yes, I know Axioms aren't really dipoles), they should be reversed (left speaker on right, right speaker on left). He also includes a diagram later on to illustrate his point. I have QS8's on the side and QS4's on the rear. Has anyone ever heard of this? Do I need to reverse my QS4's?



Stew

not only have i never heard of this, i would say its a ridiculious idea. when dvd's utilize a 7.1 recording, the sounds are engineered to flow from back to front or left to right, or vice versa. the same effect is achieved when using the pro logic IIx or discrete features avail on your receiver. if you were to 'switch' your rear surrounds, it would defeat, or cancel out the desired effects.

EXAMPLE- if a car was driving thru the TV screen, or a cannon ball/gun shot was being fired, you would want the sound effect to replicate the action on the screen. if you reverse the speakers, then a car driving from left to right, would sound like it was coming from right to left.. same with a bullet shot or cannon blast. ? make sense?

just my opinion...

bigjohn

All drivers on the QS series speakers fire in-phase. Swapping the surrounds will make absolutely no difference.

The guy does have a point about swapping the rear surrounds in a 7.1 setup. This ONLY applies in 7.1 setups that use dipoles in both the side and rear surround positions.

bigjohn, the idea is to switch the location of the speakers, but to wire them correctly. Most dipole speakers are internally wired so that the left and right models are mirror images of each other. Here's the diagram that was mentioned:

OK, i was confused.. i didnt look at the diagram before.

still not completely sure if the idea makes much sense, much less that much of a difference.. but, i will leave it to the 7.1 guys.. i will keep my 5.1 just the way it is.

pardon for my ignorance. i manage to hide it most of the time!!

bigjohn

bigjohn.........................................
oh, nevermind.

I forgot

pmbucko In a 5.1 set-up, using 2 rear surrounds, when I hook up my connections isn't the RIGHT REAR SURROUND facing the right front. In other words the REAR RIGHT SURROUND would be behind my right shoulder when seated facing the TV..............correct???????

Correct.

Dipole surround speakers are often labelled as LEFT or RIGHT by the manufacturer. That is what the diagram referrs to.

Yes Jon you are correct. But, the reason the diagram shows a "left" surround in the right hand rear surround position (and vice versa) is to keep the drivers in both the surrounds, and the rear surrounds, facing the back corners, and along the back wall, in phase with each other. In order to achieve this with dipolar speakers, it is necessary to reverse the positioning of the rear surrounds.

Looking at the left surround in the diagram. Notice that the negative (-) driver of the left surround and the negative driver of the speaker in the left rear surround position are facing the same corner. Same thing on the right side of the room. And notice that the rear surrounds have their positive (+) drivers facing each other. Notice the phrases "same phase" with the arrows pointing to the speakers.

THIS IS ONLY DONE WITH DIPOLE SPEAKERS; speakers with the drivers wired OUT OF PHASE, and specifically designated as "right" or "left" surrounds. Axiom QS series speakers are wired IN PHASE, are NOT designated as specifically "right" or "left," and are thus the same as bipole speakers, NOT dipole speakers. So, this is unnecessary with Axion QS surround speakers.