5.1 vs 7.1

[ZX14NINJA]

Hi all -- 1st post here but I need some talent to help me out --

I'm now planning the installation of my home theater in my freshly renovated bedroom. I have some questions and concerns I'd like to address here. Everything will be run in the walls or ceiling with remote IR's, so I only get one chance at this, unless I want to repaint again, which I don't - LOL

PS. I'm not changing the layout of the room to fit anything, so that's not an option here.

1) The bedroom layout is 44' wide by about 17' deep and has 8'+ ceilings.

2) I have a 65" Sharp LCD directly facing my bed @ 17' from the bed/back wall. Bed center is about 15' from the right wall and 29 ft from the left wall. I have partial wall space at 13' from the left (from center of bed) and wall space @ 15' to the right, measured the same as the left (center of bed)

I'vg just purchased a Denon AV3808ci and was hoping to go 7.1, but from the posts I've read here, 7.1 would be a bad thing considering that the listening area will be basically flush with the rear wall/headboard. I'd like some opinion on that. I already have 2 pairs of Axiom Q8's and an Axiom V150 center. I also have 2 Axiom subs as well as a Polk Audio, but the subs aren't the issue here.

I have to order a set of Axiom M22's for the front whether I go 5.1 or 7.1 in any case.

So my questions are --

1) 7.1 -- beneficial or detrimental in this case?

2) Height of surround/rear speakers (Q8's) -- Do I go to the ceiling and angle down towards the listener, or can I go almost flush with wall mounts at the rear behind and above the bed? Wall mount looks way better in the room, but I also want optimum imaging and sound, so I'm willing to sacrifice looks for sound, if I have to.

3) I can go as wide as 6 ft from the center of the TV for the fronts and as wide as around 10 ft from center of bed/tV for the rears. What would be optimum placement in this case?

-- I'm betting I'll also have an echo issue in the room as it's modern and lots of empty walls with minimal furniture, as I prefer it. Either way, I need to know if I can go to 7.1, or am I better off just staying @ 5.1. Cost isn't the issue here, but I'd like to re-use part of all of what I have before tossing stuff out. If there's a 7.1 solution that works well in this setup, I'd look at it even if it means not re-using what I have.

What more or less will I notice with 5.1 vs 7.1 in this setup? I've had both in the past but I'm not sure of what I'd really be missing in a 5.1 setup, considering everyone's now offering 7.1.

Any help and comments would be helpful -- thanks!

I've included a final layout plan to make it easier --

 

[the grunt]

I just boxed up my big Axiom speakers in preparation for moving and set up a temp HT in the bedroom of my apartment using my 2xM22s as mains VP150 center and 2xQS8 surrounds. I don’t have any discrete 7.1 sources (Blu Ray) but do have some DTS ES 6.1 so I hope I can give you some perspective as I tried a bunch of configurations until settling on this one.

Before addressing your specific questions here is the thread I started at the Axiom forums showing what I’m talking about. Remember this is very temporary.

http://www.axiomaudio.com/boards/ubbthreads.php?ubb=showflat&Board=4&Number=238160&Searchpage=1&Main=15915&Words=bedroom+grunt&topic=0&Search=true#Post238160

Here is what it looked like previously for perspective on what I changed from.

http://www.axiomaudio.com/boards/ubbthreads.php?ubb=showflat&Board=5&Number=219121&Searchpage=1&Main=15077&Words=configurations+grunt&topic=0&Search=true#Post219121

Also some of the folks at Axiom might have more experience with your situation and those speakers so you might want to start a thread over there.

1) 7.1 -- beneficial or detrimental in this case?

The only downside I see is your likely spending money for not much return. It might be worth ordering them if you can experiment with positioning but it sounds like that’s not an option so I’d have trouble recommending 7.1.

2) Height of surround/rear speakers (Q8's) -- Do I go to the ceiling and angle down towards the listener, or can I go almost flush with wall mounts at the rear behind and above the bed? Wall mount looks way better in the room, but I also want optimum imaging and sound, so I'm willing to sacrifice looks for sound, if I have to

For the surround speakers I found the higher I put them the further away from the bed they needed to be to image properly with the mains and not pull the soundstage up excessively. About 45 degrees up from horizontally from my ears seemed to work best. Since you already have 2 of them you might want to grab a couple ladders or something and see if you can experiment with them and see were they sound best.

Wall mount should work fine. I haven’t noticed any difference with my surrounds angled in or flush mounted as long as they were off to the side and not directly above the bed. I just left them angled because it was the last position I tried.

When I tried rears both 6.1 DTS ES and 7.1 w/DD PLIIx I didn’t notice much. The QS8s are already so good at creating ambient sound the extra speakers didn’t help. It also didn’t help any, that I could notice, having them flush mounted horizontally along the back wall. However, having one QS8 mounted pointing straight down or flush mounted vertically along the back wall did help a little with directional sounds from the rear. Might have sounded better with 2 rears but setting up 1 was a big pain so I didn’t try 2. A directional speaker or 2 pointing down at the listeners might work better but I’m skeptical since it might sound to directional. I wouldn’t waste any time with flush mounting the rears horizontally that close behind. Pointing 1 or 2 QS8s straight down from the ceiling or a little lower mounted vertically (so one tweeter is point up and the other down) flush with the back wall might be worth a try since discrete 7.1 may sound better.

3) I can go as wide as 6 ft from the center of the TV for the fronts and as wide as around 10 ft from center of bed/tV for the rears. What would be optimum placement in this case?

6 ft for the mains should be fine. I found that here in the smaller room the closer the QS8s mirrored the M22 mains placement from the center line the better they imaged with the M22s. However, in the larger room they sounded better when about 4-5 feet further from the center line than the mains.

If money is no object or you are willing to experiment a little with optimum positioning then trying out rears will only cost you time (experimenting) and the money to ship them back if you decide it’s not worth it. However, without any room behind you for a rear sound field to develop I think any improvement you get will be minimal.

If you have any particular configuration you’d like me to try out let me know. I have 3xM80s, 2xM22s, 1xVP150, and 4xQS8s. My room is much smaller than yours so YMMV however, it’d be worth trying out other ideas so that if anyone else ever has questions I might have an answer.

Cheers,
Dean

P.S. Sorry if there are any gross spelling or word errors as I’m dyslexic and way to tired to proof read this again.

 

[GregS351]

I believe that a 7.1 system needs to be highly tuned including room acoustics to see a real benefit. There are so many different sound sources and direction the need to work together to get good results. It is better than 5.1 but I think you need to be able to have the proper room setup to make it work well.

 

[lsiberian]

Now that I've heard the difference. I can attest that 7.1 is a superior format to 6.1 and 5.1. My reasons

1. The surround field is less localized. In a 5.1 system it is always easier to figure out the direction the sound is coming from. In a 6.1 system this is even worse on the rear channel which is captain obvious.

2. Direct channel pass through of 7.1 lpcm has the highest quality sound and get's very close to movie theater quality.

3. Even on a 5.1 track a THX down mix to 7.1 sound does wonders to a better surround experience

4. the 4 surround speakers are louder and more defined for special effects.

5. The movement of planes gunfire and other sounds is clearly more accurate.

6. Placement isn't that finnicky in most rooms. Just put the couch 3 to 4 ft or more off the wall and place the rears at the edge of the couch facing forward. And the sides slightly behind the sides of the couch.

There is a difference and it's worth the money in my view to go 7.1 if you can afford it with good speakers. For my system it was a clear upgrade. And I can tell the difference. Especially on a 7.1 lpcm track.

This comparison is based on my own experiences in my own home. Results may vary with speakers, setups and layout. As always it's better to get good 5.1 speakers over bad 7.1 speakers.