[brj]

I have a room with a flat 12 foot ceiling over much of it's area.  Along one of the long walls, however, it slopes from 12 feet down to 8 feet at about a 40 degree angle.  Would you place your speakers along the opposite wall facing the sloped ceiling, or under the sloped ceiling facing out?  Why?
(I seem able to argue both cases.)

Ok, now the same question with a variation (corresponding to a different room): The  long wall under the sloped ceiling has floor to ceiling windows, thus preventing the use of acoustic treatments.  The opposite wall under the flat 12 foot ceiling and facing the sloped ceiling can be treated.  Does your answer change in this case?

Thanks!

[John Casler]

I have a room with a flat 12 foot ceiling over much of it's area.  Along one of the long walls, however, it slopes from 12 feet down to 8 feet at about a 40 degree angle.  Would you place your speakers along the opposite wall facing the sloped ceiling, or under the sloped ceiling facing out?  Why?
(I seem able to argue both cases.)

Ok, now the same question with a variation (corresponding to a different room): The  long wall under the sloped ceiling has floor to ceiling windows, thus preventing the use  ...

What are the other room dimensions (Length and Width)

[brj]

What are the other room dimensions (Length and Width)

I was hoping that there would be some form of general guideline that might help others as well as myself, but in my specific case, I have a room for each of the cases I described (with and without relevant windows).

The first, without the windows, is the master bedroom and measures a bit over 15' by 15' (although there is a jog on one wall that narrows the room width to 13' 6" for about 6 feet of its length.).

The second, with the windows, is the living room and measures 18' by 18'.  It extends into a 10' x 10' dining area with no intervening walls at all (basically, it is one big room).  Unlike the bedroom, all room corners are "cut" - think "octagon" rather than "rectangle".  In addition, it also opens into a foyer on one end and a kitchen on the other.  

General or specific comments welcome!

[JLM]

In the bedroom (no windows under bottom of the slope) I'd put the speakers on that shorter wall.  The room shape would work with the speakers as a clamshell or orchestral hall design.

In the living room (with windows under bottom of the slope):

1.) WAF/common sense architectural considerations would preclude large speakers in front of the windows.  (All those windows imply a good view.)  

2.) OTOH with heavy drapes and small speakers placement could work well in front of the windows.

3.) If heavy drapes/large speakers/WAF/view is/are factors related to the windows I'd try one of those side walls (with varying 8 - 12 foot height) first.  But do experiment, don't suffer trying to be loyal to anyone else's advice.

4.) An octagonal (or near octagonal) room could be a real acoustic nightmare with multiples of a frequency (in your case about 60 Hz) being reinforced by room reflections in two directions.  Non-symetry is ideal for room acoustics, except with all the possible options they're not well researched.  Fortunately you do have large openings.

[John Casler]

I think JLM nails it pretty well, but I am confused about one thing.

In an 18 x 18 room how do you have a "long wall"?  I assume this must be one of the walls that "continues" into the next room and is acually "longer" than 18'.

Sounds like the speakers in front of the windows with a good grade of acoustically absorbant curtains (floor to ceiling) would do the trick.  Or at least get you started.

[brj]

Many thanks for the responses!  Comments inline below...

In the bedroom (no windows under bottom of the slope) I'd put the speakers on that shorter wall.  The room shape would work with the speakers as a clamshell or orchestral hall design.

I had the same thought.  It would be a bit awkward, but workable.

WAF/common sense architectural considerations would preclude large speakers in front of the windows.  (All those windows imply a good view.)

I wish it was so, but about 4 feet outside all those windows is a privacy fence... which is really rather boring!  

An octagonal (or near octagonal) room could be a real acoustic nightmare with multiples of a frequency (in your case about 60 Hz) being reinforced by room reflections in two directions. Non-symetry is ideal for room acoustics, except with all the possible options they're not well researched. Fortunately you do have large openings.

Yeah, I'm expecting several acoustic problems with the room, but right now, I'm trying to figure out if the room has any natural acoustic strengths.

In an 18 x 18 room how do you have a "long wall"?  I assume this must be one of the walls that "continues" into the next room and is acually "longer" than 18'.

Correct, that "longest" wall runs about 29'.  In addition, the "short walls" are short because they give up space to the walkways into and out of the room.

Sounds like the speakers in front of the windows with a good grade of acoustically absorbant curtains (floor to ceiling) would do the trick.  Or at least get you started.

Actually, I posted that exact question a couple of weeks ago, but didn't get a very favorable response.

Thanks again for the suggestions!

[John Casler]

John Casler wrote:
Sounds like the speakers in front of the windows with a good grade of acoustically absorbant curtains (floor to ceiling) would do the trick. Or at least get you started.

Actually, I posted that exact question a couple of weeks ago, but didn't get a very favorable response.

While I may not have a "clearcut" picture of the room(s), I think the Long Wall with the floor to ceiling drapes offers the best option.

1) The drapes damp the front wall reflection  (can be heaven for the soundstage realism)

2) No side walls mean little to no sidewall reflections.

This only leaves the floor and celing reflections and if you have carpet then the ceiling is your only major worry.

If this happens to be one of the walls with a high ceiling that "clinches" the position.  If it is one with the low 8' ceiling then it might require further attention for the "best" result.

You haven't mentioned what speakers you are using, and that makes a difference.  For example, I use VMPS 626Rs which have a more limited vertical dispersion and speaker height.  Subsequently less attention might be needed to the ceiling bounce.  

If you are using a tall floorstander with greater vertical dispersion with an 8 foot ceiling, then it might require some additional contemplation.

(as well as a more nearfeild listening position)