Axiom Home Page Forums General Discussion Home Theater QS8 location for 5.1

Good day all

I am building a home theater room (dedicated). It's deminsions are 17' x 25' x 9'. Screen will be on the 17' wall. Question; should I place the QS8s on the side walls or the back wall. Going to be running the wire in a few weeks and need to know best location for 5.1.

Thanks

Worf, for a 5.1 setup the surrounds should be on the side, rather than back, wall unless the listening position is right up against the back wall; in that case it makes little difference if they're on the side walls very close to the back wall or on the back wall spread out almost to the side walls. If the side wall position is used, they should be slightly farther back(maybe 2')from being directly to the side of the listening position, to give a little more "back" imaging in the absence of actual back speakers.

Incidentally, in a room that long there probably is going to be enough room behind the seats(say at least 4')to make a 7.1 setup worthwhile.

From the Axiom FAQ:

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Where should I place my surround speakers?
Ideally, surround speakers should be either wall-mounted or stand-mounted to either side of the couch or primary listening area, from one to six feet higher than seated listeners' ears, and slightly forward or rearwards of the listening area if you wish. Axiom's Quadpolar surrounds are especially versatile and can yield excellent performance with stand or wall-mounting to the rear as well as at side locations. (see our dedicated stands for the QS Surround speakers in the Store). Rear center speakers for 6.1 and 7.1 installations are intended to go on the rear wall at about the same height as the surround speakers.

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In addition to what the others have mentioned, you might want to plan for the future. Why not pre-run wires for a 7.1 setup, even if you only start with 5.1. That is a good sized room, a little wider than mine, but not as long, and for me I'm glad I planned for 7.1.

I am pre wiring for 7.1 however that still requires 2 more speakers and one more amplified channel (not in this years budget). The reason for asking is. I am not planning to put speaker jacks in the walls for the QS8's. I will just wrap some extra speaker wire in behind the drywall until i am ready for 7.1. Ya, I know I am penny pinching by not putting in the jacks, but they arn't cheap and the QS8's cover them anyways. So I didn't want to have wires hanging out of my walls. So I need to know where to put them for a 5.1. Seems like the sides is the better spot.

Thanks all

Worf,

I will be also pre-wiring for 7.1 even though my room is medium sized (1800 cu.ft.)

I plan on just having a small hole drilled in the drywall and bending out the wire and leaving it in there, not exactly sticking out, but enough that I can get to it when I am going 7.1

I agree with your wall jacks. You do not need such things if you are using QS8's. Just drill a good sized hole in between where the T Bracket will be going, it will hide the wire all together.

If you are going to be going with a 2-tier seating arrangement with a riser, I would suggest something similar to the following picture. This is almost exactly how Randy (SirQ) has his 7.1 set up for the surrounds. It would be alot better If i had room behind the riser, but I don't. You will for sure though.



I will be starting with 5.1 as well. In which case the back 2 speakers will not be purchased until later. 5.1 was intended for side surrounds, not the rear which is when 7.1 comes into effect.

Good luck!

Hey Robb,

I noticed from your diagram that your rear 7.1 QS8s are very far apart. I was under the impression that the rear "centre" speakers should be no more than about 2 feet apart. I has been recommended to me in the past that a centre channel speaker, much like the front one being used, is a good idea for that setup. I think, again, I could be mistaken here, that the rear channel in today's encoded formats is in fact mono, so in a 2 rear speaker setup, it's the same encoded track being sent to both rears speakers. Is that correct or is it better to have them as far apart as the side surrounds ?

Stephane

Stephane,

You are correct in that the rear channel is in fact a mono channel. The most channels in theatre right now is 6 channels but the rear channel is most effective utilizing 2 rear speakers. In order to get proper dispersion to your right and left ear, they need to be wide enough so that your ears percieve the sound from coming from behind you.

If you put your rear channels too close together and directly behind you (depending on the type speaker) could sound like its coming from the front of the room. Direct radiating speakers will do this to your brain. If using a single Quadpolar like the QS8 directly behind you, it would be alot better (for 6.1).

As well, Dolby Digital recommends a 135 degree to 150 degree angle for your rear surrounds like the following picture...



Keep in mind that dolby is not the end all be all, but their recommendations for rear surround placement has had good success with others on this board.

The rear speakers in my diagram are at about 150 degrees to the primary listening position (which is between the 2 front recliners)

Excellent, Thanks Robb, I had not seen that diagram before.

It's a really good starting point for sure.

Steph

Steph,

No Problem. Alan (the resident Axiom Expert) has alot of A/V learning articles (which also include setting up your theatre).

I suggest reading through some of these articles as I have to learn more about making your theatre as optimal as it can be.

Axiom's A/V Learning Centre

Also, Steph, if you're using Dolby Digital EX or DTS ES, the rear channel is, indeed, mono. But, If you use Dolby Digital PL IIx, the rear channels are matrixed from the left and right surround signals, and carry different information so they aren't mono.

From Secrets Of Home Theater and Hi Fidelity's Guide to PLIIx:

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Dolby Pro Logic IIx. There are actually two parts to Pro Logic IIx. The first is its role as a classic Matrix decoder. It distinguishes itself by delivering up to seven channels (as compared to Pro Logic II's five, or Pro Logic's four). Like Pro Logic II, it includes Music and Movie modes. Note that both the side channels and rear channels are stereo.

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Good point Ajax, that had slipped my memory.

Thanks Jack for the reminder, It's been a while since I was "verbose" in the formats, just to many other interest and only so much room in the brain

The one thing that I have not yet figured out, mainly because I did not spend the time to, is that my Anthem defaults to Prologic IIx + THX with DD5.1 movies and I just don't like the sound at all. I then manually remove the THX settings and use good old DD5.1 settings. I probably have to fiddle with the options, it has MANY of them. With the default mode, the centre is not loud enough and the overall sound is not punchy, again I know that I have many THX settings I can adjusts, just need to spend the time doing it.

Thanks all, and sorry for skewing this thread into a different direction.. Perhaps this should be a new post.
Steph