rear surrounds - max distance

[mike c]

I read an article some time ago how the rear surrounds should not exceed X distance from the listening position, otherwise the left to right sweep of the surrounds and rear surrounds will be messed up ... I can't find that article anymore, so can someone tell me the max distance I can locate the rear surrounds?

here is my situation ...

the room is 21 feet long;
two rows of seating,
one is 38% from the front wall;
one is 38% from the back wall;
if I place the rear surrounds on the back wall, this will i'm sure be too far from the LR surrounds and the rear LP, and more so from the front LP.

comments? help?

 

[Dolby CP-200]

mike c

Mate you’ve got the formula all wrong this is how its done no ifs no buts this is how its done.

Note the height surrounds that are positioned at the back, and thou I still have at least a few more to add around four more so that’s six for the height surround.

Plus a few more for the sidewalls one for each just in-between the two sidewall surrounds and one on each sidewall again placed nearer to the back, and with careful balancing of the levels as well as equalization and loudspeaker management system to customize the performance.


Most home cinema rooms I’ve looked at seem to have only four loudspeakers for the surrounds and this where you guys get confused even muddled up with all the home cinema magazines.

5.1 doesn’t mean that the surrounds should be comprised of just two same with 6.1 7.1. The rule is the surround loudspeakers should be set-up in horseshoe configuration.

I’d say a room that size would need at least 4 or 6 loudspeakers for the back wall and 4 to 5 spaced out evenly along the sidewalls, that’s if you really what to make it surround the listening area as well as sound darn right impressive.

Now I’ve been using this array in my home cinema now for 1 year and it sounds like the cinema in a small room with big impact, now then.

The total cost for the surround array set me back £249.99.

 

[mike c]

unfortunately, I can't afford that many pairs of speakers

if I was to add a pair, it'd be for surrounds aimed at the second row of seats

 

[MDS]

I read an article some time ago how the rear surrounds should not exceed X distance from the listening position, otherwise the left to right sweep of the surrounds and rear surrounds will be messed up ... I can't find that article anymore, so can someone tell me the max distance I can locate the rear surrounds?

I've never heard of such a thing but many receivers limit the distance setting; eg. mine says that the surrounds can be set up to 5 feet less or 20 feet more than the distance to the front speakers.

Maybe they do that for the reason you mention, but I don't really know.

 

[AVRat]

Mike you didn't mention the location of your side surrounds or how wide your room is. What would the actual distance between the sides and rears be? Surround sound processors do a pretty good job integrating the sound between the surrounds for a coherent pan given the data provided to them via channel levels, distances, etc.. I don't remember what processing your using, but this is where a good room-correction system comes in handy. I don't think you have anything to be concerned about in your space.

 

[mike c]

oh, sorry I forgot to add the width of the room.

the room is 4.7 meters wide (I think around 15 feet)

each row of seats will have its own left and right surrounds.

my problem is finding the "right" location for the rear surrounds.

most of the layouts on the web from THX, DTS, DOLBY show degree locations and does not give max distance.

the rear row of seats will be 100" (38%) away from the back wall, so now I'm thinking the back wall is a no-no, and will have to place the bookshelves on stands.

 

[AVRat]

IIRC your using separate ampage so speakers at 100” & 152” to the LPs should be no problem with the system calibrated. It also looks like your rear sets of surrounds (rears – sides) will be spaced less than 10’ apart so there shouldn’t be any problem there either. Sometimes you can go nuts over-analyzing a situation.

 

[mike c]

you're right, if I do a two row system ...

the first row I will designate: "M" row
the second row will be: "FR" row

M - means ME or MY
FR - means friends or relatives

If I do setup the rear surrounds, I figure I will stick the rear surrounds as close as possible to the "FR" row, screw the FR's, "M" is the most important here

 

[MDS]

The 'M' row is the king's seat. It's my house, therefore I am the king and the king gets the best seat in the house.