5.2, 6.2 or 7.2 what do you have

Posted by: axiom_man

5.2, 6.2 or 7.2 what do you have - 10/05/12 08:05 PM

Just wondering if my movie room is 13.5 x 18.5 x 7.5
is there really a big difference with the rear channel given I will be using the QS8's for side rears ?
Posted by: JohnK

Re: 5.2, 6.2 or 7.2 what do you have - 10/05/12 10:29 PM

Troy, it depends not on room size alone, but on the amount of room behind the listening position for a rear sound field to develop. I suggest that at least 4' be available to make 7.1 back surrounds useful.
Posted by: tomtuttle

Re: 5.2, 6.2 or 7.2 what do you have - 10/05/12 11:47 PM

My room is a little bigger, with cathedral ceiling. I was relatively unimpressed by adding the rear speakers. In retrospect, I'd probably have been happier with 5.2 than with 7.1.
Posted by: nickbuol

Re: 5.2, 6.2 or 7.2 what do you have - 10/06/12 12:32 AM

For me I went 7.1 (will be 7.2 if I ever build my second sub - have all of the electronics for it), but that was really mainly because I had 2 rows of seats and I wanted the larger surround sound-field to envelop both rows of seats. If I didn't have a 2nd row I would probably have just stuck with 5.1 (or 5.2).

For reference, my room is 14' wide, 24' deep (but with a 2 foot deep false wall up front) and 7'9" tall.
Posted by: Adrian

Re: 5.2, 6.2 or 7.2 what do you have - 10/06/12 03:29 PM

I WAS at 5.1 until I sold my house. When the reno's are complete I'd like to build a couple of subs and add a couple of extra surrounds.
Posted by: tomtuttle

Re: 5.2, 6.2 or 7.2 what do you have - 10/06/12 07:35 PM

Adrian!!
Posted by: CV

Re: 5.2, 6.2 or 7.2 what do you have - 10/06/12 08:04 PM

Yeah, nice to see you, Adrian. Now when is Dean coming back?
Posted by: mapatton

Re: 5.2, 6.2 or 7.2 what do you have - 10/06/12 09:20 PM

Neat timing for this conversation.
My room is 16'2 by 22' with ceilings starting at 8 going to 12.

The 22' wall is the viewing wall. Viewing is at 11' from it with 5'2" to the rear wall.

I am finalizing location for the rear surrounds and unless I come across some really bad angles and where I can place them, going 7.1.

Later on I will probably go to .2 . Going 7.1 already is over budget as I had budgeted for 5.1 initially.
Posted by: JohnK

Re: 5.2, 6.2 or 7.2 what do you have - 10/06/12 09:51 PM

Mark, you appear to have enough room behind the listening position to make back surrounds in a 7.1 channel system worthwhile. They should be mounted about 3' above ear level and separated about as much as the distance from the listening position, say about 6'.

Incidentally, on a point of terminology, if by ".2" you mean two subs, that remains .1 with two subs in the .1 LFE channel. The numbering(e.g., 5.1, 7.1)refers to the number of channels, not the number of speakers. There are no .2 channels formats, and a 5.1 system with two or four subs is still 5.1, not 5.2 or 5.4.
Posted by: mapatton

Re: 5.2, 6.2 or 7.2 what do you have - 10/06/12 11:22 PM

yes by .2 I was referring to a 2nd sub.

Here's a Q. For rear surrounds, what I have planned is left surround at 132* (recommendation is 135-150*). I can not increase this angle.
The right, to keep some symmetry on the back wall, is planned at 146*

Thoughts on that?

Also as far as height, I am planning on the sides to be the same elevation as the rears. Planning on QS8s for those positions, and not sure how much clearance is desired to the ceiling.

Currently I have the bottoms of the sides and rears at 95 1/2 " (just shy of 8 ft). that places them roughly 49 1/2" above listening level.

On the sides that allows the tops of the speakers to clear the
the ceiling by 27 1/2 ".

I can not lower the sides, I can raise them though if desireable.

Keeping the sides and rears bottoms level, the rear tops of the speakers have clearance to the ceiling of roughly 41 1/2".

Thoughts?

Other Facts: The sides are at 90*. I could if needed increase this slightly.

The front mains are at 14* each. I can not change that. I know 22-30* is desired.
Posted by: mapatton

Re: 5.2, 6.2 or 7.2 what do you have - 10/06/12 11:30 PM

Reading now what you said that the rears should be separated by as much space as the are different back from the listening area. Thats a much different spacing than the degrees of separation that I got.

With the current degrees of separation, that places the rears about 12'6" apart (ctc), with only 5' 2" from listening wall to rear wall.

Which should I offer more leverage to?
Posted by: mapatton

Re: 5.2, 6.2 or 7.2 what do you have - 10/06/12 11:49 PM

Think I am calling Axiom next week to get their thoughts. Need to know their thoughts before my electrical guy drops lines.
Posted by: JohnK

Re: 5.2, 6.2 or 7.2 what do you have - 10/07/12 01:39 AM

As I replied in the other thread, that should be okay. The rear surrounds shouldn't be too close to the side surrounds.
Posted by: mapatton

Re: 5.2, 6.2 or 7.2 what do you have - 10/07/12 07:18 AM

Thank you John. Curious on what would be "too" close?
Currently it is planned that the center of the rears would be
56 3/4" from the wall with the sides on them.

Looking at another item, the centers of the sides are 58 1/2" from the wall with the rears on them.
Posted by: FordPrefect

Re: 5.2, 6.2 or 7.2 what do you have - 10/07/12 08:54 AM

Moving over to 7.1 from a 5.1 set up, 2 subs in a 17'x25' room.
Posted by: SirQuack

Re: 5.2, 6.2 or 7.2 what do you have - 10/07/12 09:02 AM

7.3 for me...
Posted by: axiom_man

Re: 5.2, 6.2 or 7.2 what do you have - 10/07/12 11:47 AM

John,

There is 4.5 ft behind. there is a half wall at that point with pillars on each side about 3.0 ft in from the wall.
The halfwall is 7.5 ft long. I will be sitting 4.5 ft in front on this wall. Behind this wall is a 3 ft walkway.
From the front of the room my seat is 13 ft. I am 11 ft from the from of my L/C/R .I allowed 2 ft in the front from the speakers and tv.
Posted by: axiom_man

Re: 5.2, 6.2 or 7.2 what do you have - 10/07/12 12:00 PM

Ok, I guess 7.2 wink just wasn't sure if there was that much of a distance to warrant and extra $600.
I am mounting the side rears 6 ft from the floor and 95* off the sides. Given the room dimension I will be 6'9" to each side wall. mY rears I have calcualted to be 4'6" and 110*. I think, the paper work is upstairs. that puts them 3'6" from the side walls.
OOPs I guess the room is 17.5' with a 3' walkway

Posted by: JohnK

Re: 5.2, 6.2 or 7.2 what do you have - 10/07/12 09:35 PM

Mark, no specific distance, just that the side surrounds should be distinguishable from the back surrounds by putting them directly to the side while the back surrounds should clearly be coming from a rear rather than side angle. What you describe still sounds okay.
Posted by: SirQuack

Re: 5.2, 6.2 or 7.2 what do you have - 10/08/12 10:34 AM

My rear Qs8's are now mounted on the rear wall right behind my couch in the 2nd row and about 2 ft up, sound great.