Axiom Home Page Forums General Discussion Advice from Axiom Owners M80 Placement

I am planning a new room with a 65" plasma and an Epic 80-500. My question concerns spacing of the M80s from the rear wall. I would prefer putting them as close to the wall as possible to keep them and the VP150 from intruding into the room too far. Does anyone have real-life experience on this with M80s? Would using absorber on the wall behind the speakers (I have used OC 703 before) allow closer placement? I'm interested in good sound, but want to keep the speakers back if possible.

The rear ports need to have breathing room to let the low frequencies flow into the room. I use 703 for corner bass traps and first reflection panels. You would not want to put them behind the speakers, the would deaden/suckup even more bass which is the opposite of what you want.

I would say if you space them 4-6" at a minimum you will be fine.

I ran mine about 3" inches away and didn't find them to be too boomy, they were also corner loaded which should have really added to the effect.

I would simply try them where you want and see if the sound is acceptable, then move them away an inch or so at a time and see if the sound changes enough to justify having them farther out from the wall.

Another thing to keep in mind: You don't want the face of the VP150 to be in the same plane with the video display either. Having the speaker slightly forward will minimize reflections off the large, flat screen. So if you can stand to have the M80s out a bit from the wall, pull the VP150 out so it's face is even with the M80s also.

Actually, it is best to have a slight arc, from the left-center-right speaker, gives you a much better sounds stage. The center channel should be slightly back from the mains.

_-_

Alan has mentioned this often.

Thanks, that's what I plan, the three front speakers in an arc so that they are equal distance from the center listening position. The surrounds (plan 5.1 using QS8s) will be equal distances from the listening position, but quite a bit further from it than the fronts are, but I assume I can dial that out in the receiver.

That is best, the arc, but of course that'll have the M80s even farther into the room, which is why I didn't mention it.

Our 150 is set back a little over 17" from the face of the 80s and properly calibrated for our room is -1db from the setting of the mains.

So if one cannot accommodate the arc, would putting a time delay on the center achieve anything similar?

hmm, that is a good question...

Nearly, the same thing. That's the standard setup in a receiver, setting the actual speaker distances. Either by hand, or it's auto-setup. The distance setting computes and applies the proper delay for speakers which are not equidistant from the listening position.

I have set the distance(delay) further back for my rear surrounds than actual to help give them a more enveloping sound.

I suggest you also try having them lined up straight. I tried using an arc and found it had a slight negative impact on the front soundstage for the L/R seats while the arc gave no noticeable improvement for the main seat. Now my speakers are 10-11 feet away so perhaps if they were closer I my experience would be different.

I’m curious what advantage setting a longer delay on the center speaker would give? I can understand the deeper rear soundstage Randy would get from his surround backs but with all the direct sound coming from the front would having them all in sync sound better. Sounds like an interesting experiment.

Dean, I think the point was just that with all the front speakers lined up in a straight line, the center speaker is actually slightly closer to listeners in the center than the mains are. So, to put them in sync a slight delay for the center speaker would in effect equalize the distances.

But isn’t that, as Chris pointed out, exactly what the receiver does when you set the speaker distances.



Perhaps I miss-understood HAY’s question. I thought he was asking about adding additional delay on top of what setting the distance settings would do.

Sure, either manually or by the auto-setup the distances would be set so that the sounds arrive simultaneously.

No, I took it that Graeme wasn't considering an auto-setup, and was just asking if manually setting the center speaker distance to delay it slightly would have the same result as arranging the speakers in an arc.

You nailed it John, that's what I was getting at.