AVS Forum banner
Status
Not open for further replies.
1 - 18 of 18 Posts

·
Registered
Joined
·
274 Posts
Discussion Starter · #1 ·
I'm getting ready to pre-wire for 7.1 surround, and need some advice on speaker placement. The room is 18' wide x 19'6" front to back. I plan on having two rows of seating. The room is open to bar/game/pool table areas on the sides; the side walls only go back about 8' from the front on the right side, about 6' on the left. There is a wall at the back of the room, but the room is a step-down, and the back wall is about 5' behind the step, so it's not really IN the room per se. There are four columns at the back of the room (right at the top of the step), two are even with the side walls, the other two are approx 4'-5' from the sides, so about 8'-10' apart. The ceiling is about 8'6" high.


From what I understand about 7.1, (please correct me if I'm wrong) the side surrounds should be about even with the listener, which raises the question, what if I plan on two rows of seating? Also from what I've read, the rear surrounds should be "closely spaced", so I think the columns would be too far apart. Which probably leaves me with all of my surrounds on the ceiling; I'm sure the side speakers would be beyond the side walls regardless of where I position them relative to the two seating rows. So my questions are...


Where should I position the side speakers relative to the two rows of seating? What is an ideal spacing for the rear surrounds? Is 8-10' too far apart to consider using the columns? Would I want to even consider the columns since I'm almost positive my sides will need to be on the ceiling? Or should I avoid putting any of them on the ceiling if I can? How about the front speakers - how far apart should they be? Would either side be preferable for the subwoofer?


Thanks for any assistance anyone can provide.
 

·
Registered
Joined
·
607 Posts
Quote:
Where should I position the side speakers relative to the two rows of seating?
I split the difference on mine and placed them even with the aisle; ie., behind the first row but in fron of the second row
 

·
Registered
Joined
·
36 Posts
I'm not an expert on speaker placement, but I remeber something in physics class about how sound coming from above, like speakers in the ceiling, isn't as good as if its coming from ear level, I forget exactly what happened to the sound. It has something to do with how ears are shaped or something, maybe it just wont' be as loud?


Suke
 

·
Registered
Joined
·
1,665 Posts
I would place the side surrounds approximately to the sides of the back row (the text-book placement of side surrounds is to the sides or slightly behind the listener, and 2'-5' above the listener). As for the back surrounds, I do not think 8'-10' is too far apart; if you prefer column-mounting, I would go for it. Ceiling-mounting is fine, as long as the mounting bracket creates at least 3"-5" of clearance from the ceiling and walls (in case of bookshelf surrounds, which needs some clearance around them). In case you use the surround speakers designed for wall-mounting, obviously you do not worry about the clearance behind.


Regarding the fronts, the rule of thumb is that they should be apart from each other by approximately the same distance from the listener, so that the front speakers and the listener make a regular triangle.


Subwoofer placement is a totally different issue. The acoustically best location might not even be close to the front wall; it might be, say, somewhere like behind the listeners' couch... You cannot really predict. Even if you have to restrict the placement along the front wall, it is best to experiment with several different locations; bass sound are markedly influenced by room modes and the placement of the sub relative to room modes.



btw, if you allow me to digress here, can you make the room dark? If so, you should seriously consider front projection instead of a plasma or big-box TV. :D
 

·
Registered
Joined
·
415 Posts
Just wondering about something, how would it sound to use speakers like the Rocket RSS300's for both side-rears and for rears in a 7.1 system?


Has anyone ever run a setup like that?
 

·
Registered
Joined
·
274 Posts
Discussion Starter · #6 ·
Brian: That sounds like a plan. I'm sure the front row will get used most, so that would fit in with sushi's "textbook" recommendation most often. Of course, I'm still guessing where the couches/chairs will actually be, but at least I know what I'm guessing at.


Suke/Sushi: That's sorta what I've heard on the height issue, just not sure how hard I should try to avoid placing them that high. It would probably be right at 5' above ear level. There's no way I can use walls on the sides. I could put them at a more "ideal" height in the back using the columns, but I don't know if it would be more important to have the rears at the same height as the sides, or to take advantage of the columns in the back to mount them a little lower. (assuming they're not too far apart, I might be misunderestimating that 10' measurement). Also, the WAF might be low or even zero on the column mounting, with the pretty woodwork and all.


So if I go with ceiling-mounted for the rears, any recommendations for how far apart?


Sushi: Sounds good on the fronts, I think I recall now seeing a diagram to that effect. I may end up running several pre-wires for the sub. In addition to the front corners, I could probably try it on the side near the end of the longer side wall.


Good suggestion Sushi, however you actually already commented on that for me in my thread in the under $5000 projector forum, when I was wondering whether to go with one precisely because of my "open" HT room. I can get it dark enough and I am definitely going with the front projector. :D
 

·
Registered
Joined
·
1,665 Posts
Jeff, HAHAHA... sorry about my duplicate FP pitch. I thought I had heard of the room configuration before... LOL


I would not be worried about placing the surrounds 5' or 6' above the listener at all, as long as they are not too close to the ceiling. I would not mind if the heights of the side/rear surrounds are different, either. If you end up with ceiling-mounting the rears, I would place them so that they divide the room width into equal parts, i.e., 6' from the walls and from each other.
 

·
Registered
Joined
·
832 Posts
Should the rear surround placement divide the room width into thirds or quarters? Does optimal placement have anythign to do with how far apart the front left and right are? Or how about how far the rear surrounds are from the side surrounds?


My room is about 15.5 x 19.75, I was going to put my sidewall surrounds about 7.3 feet from the back wall, which is slightly behind the main seating (12' from the screen wall). The side surrounds are Paradigm ADP 370 dipoles, the rears are Paradigm mini monitors. The distance between the rears is perplexing me.


Any advice is appreciated!
 

·
Registered
Joined
·
274 Posts
Discussion Starter · #9 ·
lol Sushi. I have a feeling I'm going to end up with ceiling mounted. Low WAF and no real need to mount them on the columns.


Eameres I interpret Sushi's suggestion to mean divide the room into thirds - which I think would be the only possibility given we're talking two speakers. I understand what you're saying about the rear spacing being dependent on how far back the side surrounds are, but I don't know the answer. I've seen a rule of thumb for the sides (even or slightly behind the main seating) and a rule of thumb for the rears ("closely spaced"). But nothing about one distance as a function of the other. I would tend to think that if the sides were especially far back, you'd want the rears even closer together as to be farther from the sides (doesn't sound like your situation from your measurements provided). Sushi's "thirds" plan sounds like a good suggestion to me.
 

·
Registered
Joined
·
250 Posts
There is another camp of enthusiasts which subscribe to the thought that dipole/bipole speakers are not necessary in a HT environment and direct radiators provide a better all-around solution (movies and music). With direct speakers, you would want to spread your rear speakers further apart and keep the height of your surrounds and rears the same as the fronts.


The THX recommendations are appropriate for those using di/bipole rears and surrounds, and are strictly aimed at providing the best movie experience.
 

·
Registered
Joined
·
832 Posts
I've seen the dolby site (visited it many times) which disusses 5.1 and 6.1 placement, but www.thx.com is very sparce with real information about speaker placement. I guess they are keeping it close to the vest in the interest of increasing the "black art factor" that is beyond mere mortal's understanding ;-) .


THX certification specifically calls for dipole side surrounds and direct radiating rears. From the info at THX, one of the differences in Ultra (old school) and Ultra 2 certification was that they paid more attention to music only listening in addition to movie viewing.
 

·
Registered
Joined
·
274 Posts
Discussion Starter · #13 ·
Nice link Sushi, that helps a lot, esp with the front and sides. It seems counter-intuitive to aim the side speakers directly at each other, instead of slightly downward (especially in my case where they'll be a little higher than ideal), but I can play with that when the time comes, doesn't really affect me as far as pre-wiring. I'll just have to leave some slack for those since I don't quite know where the seats will be. Fortunately my ceiling joists run front-to-back. I'm pretty much set on the rears too, 6' spacing should be a good setup for my room. Thanks.
 

·
Registered
Joined
·
274 Posts
Discussion Starter · #14 ·
I have a possible change in plans.


I was thinking around 10' back for the side speakers, however, the wall on the right side is now going to come back a little farther than I had previously thought. Because of the sump pump closet, it will come back 12', with the left wall only coming back 6'. I'm still thinking ceiling mounting for both, but is it going to matter if one side speaker is next to a wall and the other is not? Or should I move them back a little bit more?
 

·
Registered
Joined
·
274 Posts
Discussion Starter · #16 ·
I'm thinking approx 10' and 15' for where people will be seated. That could change slightly if 10' is too close to the screen or 5' apart is too close, but that's my best guess right now, and it shouldn't change much from that.
 

·
Registered
Joined
·
1,665 Posts
Well, in that case, I would place the side surrounds to the side of the rear row (as I suggested above). Having side surrounds in front of the listeners is not very good. Plus, you do not have to worry about timbre alteration by the wall on one side then.
 

·
Registered
Joined
·
274 Posts
Discussion Starter · #18 ·
Yeah, I guess that would solve my problem, huh? I guess I had been thinking I wanted them to the side or slightly behind the front row, but if placing them to the side of the rear row isn't too far back, either from the front row or too close to the rear speakers, I'll just do that. I have a feeling the effects of having one close to a wall, and not the other, would be worse.
 
1 - 18 of 18 Posts
Status
Not open for further replies.
Top