7.1 Surround Speaker Position

[hoarp001]

Hi, i am a begginer surround sound user, and i have a very odd shaped room. I have 3 doors which stop me putting the speakers at ear height, so i have been forced to mount them on the celing aimed down and angled in to point at the seating position. I have drawn a map, to show you what i mean and any help would be greatly appriciated, as i do not feel that when watching films i fell the benefit. I have tried turning the front 3 channels down so the other 4 are louder in the hope that i will hear something behind me.

Click for pic

Any help?

thanks very much.

 

[racquetman]

The first thing I would do is get a sound pressure level meter (spl meter) from radioshack or equivalent and make sure all 7.1 channels are balanced (i.e. at the same level of loudness from your primary listening position). Then you will need to set the delays for your speakers so that the sound will reach your ears at the appropriate time. This should be explained in your receiver manual, but if you need help, just post a follow up question.

I'm not sure of your level of knowledge, but there seems to be some confusion, judging from recent posts, on when a 7.1 signal will be present. Only Dolby Digital EX and DTS-ES (discrete and matrixed) soundtracks make use of a sixth and seventh speaker (7.1 is a bad name because there is never more than 6.1 channels. The sixth channel can be played back with one or two speakers, but if you use 2, you are getting the same information from both speakers, i.e. it is mono). Your receiver may also have a proprietary DSP mode that will derive an extra channel for you from 5.1 material.

Your setup should work fine (although obviously is not ideal) if you balance your channels and set the delays properly. Good luck.

 

[racquetman]

just a follow up

You may be better off placing the back 2 speakers (which you currently have in the corner) directly behind you spread out a bit. Or you could just use 1 speaker directly behind you, eliminating the use of the seventh speaker (and in my opinion not losing much in the process).

By the way, you may have to tell your receiver that you have a sixth and seventh speaker present in the setup menu if you haven't done this already. If you aren't getting any sound at all from the back speakers, this may be why. Or it is because you aren't playing a DD EX or DTS-ES soundtrack as stated in my earlier post.

 

[tbewick]

I'd certainly go along with alandamp, in saying that the rear speakers should be placed directly behind the listener, with less separation between them than the front left and right speakers.

You should listen to the tone tones from each speaker and ensure that they all sound roughly equal in volume. Most of the time the surround channels just add ambience, and you shouldn't turn their volume up so they become distracting. If you want a good DVD for trying out your surround speakers, I suggest Star Wars episode II. The surround effects on this DVD are the best I've heard.

THX favour surround dipole speakers (more diffuse sound than ordinary speakers), the argument being that the surround speakers shouldn't make you want to turn your head around when watching a movie, because there isn't 360 degrees of picture.

The lack of symmetry in your room will make the sound placement much worse (positional effects, panning, etc.), because each speaker is in its own acoustic environment, esp. the surround left and right, because the right is not near a side wall, unlike the left. The symmetry where you are seating is also important. It's better if you can have as much symmetry as possible, as this will help speaker imaging.