Yes, i was already thinking the area behind me will need to be treated against reflections because i'm too close.

I have enough closet space so I’d like to solve it a  bit nicer looking than a storage racks.

I'd still rather not use the violet area if it does not bring the rewards.

I dont have much damping in my room now because the room is so big and diffuse. I like the way it sounds. I think all these reflections are helping the sound alot. The new room wont let me do it this way..

I dont want to make one side extremely dead sounding as these reflections are very beneficial as long as they are not too early.

The ceiling will probably need some sails as well.

Romy,

I value your input so don’t pull out so quickly.. I was expecting your reaction though.

I,m not the 'typical Audio Moron' type, just planning ahead of time because remodeling is involved.
Imagine YOU were forced to move into this room with your gear…. You must have an opinion.

Of course I will try positioning extensively when I move in but you must agree I need to make some more room in this smallish room and some BIG horns.

The reason for a dedicated listening room is because I cannot force my family to follow my listening schedule. I have done this for years but it’s not optimal and its always a mess when I’m adjusting and changing the setup which is not very pleasant for the eyes.

I have found that with horns i can go much farther regarding angle and create a big image while retaining a solid center image and depth. The absence of early first reflections has alot to do with this phenomenon. I might not go that far in this room but I’d like to keep the possibility open.

I thought my 30 degree notes might cause you to qualify me in that direction

Yes i just found that thread. I however do not have much freedom to do a lot of rebuilding like he does, i wish i did.

The specific acoustic system will be a low cost probably 3 way straight horn system + subs like in my thread from a while back.

Collin,
I would suggest that you abandon the idea of placing your speakers against the back wall with that reflecting/diffracting angle in front of the speaker(s). Such a structural intrusion would not be kind to the polar radiation pattern of the loudspeaker-room system. It is not just a matter of the reflections which would reach the listener but the acoustical environment of the loudspeakers would be a mess. You might want to look at Roy Allison's work on the effects of room acoustics on loudspeaker linearity in this regard.

It is far better for that angle to be behind the speakers or the listener. Changing the room structure to create a similar angle on the left side doesn't solve the problem. It's rather like breaking your left arm after you've broken your right for reasons of symmetry. Nor do I think the added space would help much acoustically or visually.

I have had a little experience placing speakers in odd rooms. I lived in a number of studios and small apartments in Manhattan with challenging layouts, particularly during my student years. Some of my more successful placements were along the LONG side instead of the short side of a room. I've had living rooms so elongated that it was the only practical way and I have generally liked the results. I was using, at the time, planar and box speakers - not horns.

My experience with square rooms has never been good and I would avoid expensive alterations from a smaller rectangular to a slightly larger square room unless the placement problems were proven to be vexing.

FIRST DIAGRAM, a conservative approach:

In the first drawing, I suggest a simple sidewall placement (black outline). A non-structural barrier such as tall shelving or cabinetry (white speckle) could be used to tame the odd angled alcove. You could enlarge the room as you indicated but it would take the room toward square - classic trade off between worsening the standing wave colorations but improving the placement issues (more coherent speaker, better early reflection characteristics).

SECOND DIAGRAM, a hexagonal model:

In the second diagram, I show an enlarged room but with a prototypical wide hexagonal room with the speakers placed along the wide side - now nearly diagonal to the original room (blue outline). The hexagonal geometry is nice acoustically. It is symmetric and has improved standing wave characteristics. You can stretch the hexagonal shape to use more of the room (red outline). Note that the short room sides (pink speckle) need not be structural, shelving would do.

The speaker placement is near to the enlarged room's main diagonal and has the effect of both visually and acoustically widening the room.

Try this visual test in a room - stand on the diagonal facing the far corner. Notice how wide the room looks compared with facing a sidewall directly. That room diagonal, with the corners of the room in the visual peripheral field, is a great asset to exploit.

THIRD DIAGRAM, Enlarged room - Diagonal Placement:

In the final diagram, I show a diagonal placement using nearly all the enlarged room (yellow outline). The hexagonal has been stretched to a nearly triangular pentagon. I must say that I have limited experience with such a triangular room shape but it has things to recommend it. In particular you have wide visual and acoustic space without structural interference between the speakers and the listener. There should not be a standing wave problem similar to a square room because the equal length sides are not parallel and there is some irregularity to the shape.

In my diagram, I show the wall behind the speakers with a small alcove for your television (in pink), if it needs depth. The short walls (with green speckle) are non-structural and again could be made with tall shelving or cabinetry.

Because this layout can be tried most directly after the room is fully enlarged, I would probably try it first and possibly work toward a more ideal shape with furniture and acoustical treatments or barriers if needed. However I wanted to show a logical progression from a superior (but smaller) hexagonal geometry to this more practical one.

Best of luck - I hope it all turns out well,
Robert


PS:  Where I mention tall shelving or cabinetry isolating a space or acting as a non-structural wall, I am referring to a full floor-to-ceiling acoustical barrier or to filling the space (packed storage). You want to avoid creating a resonant cavity or Helmholtz resonator out of these room pockets.

Wow Robert thanks for all your ideas.

I happen to be using a diagonal placement now as well and I really like it. I thought I was the only one who knew this !
 
I did not think this new room would be big enough to do it so I threw the  idea out. I only recently thought about enlarging the room over the full length. It looks like this will be my best option.

The diagonal placement is great because it excites the room modes more distributed and lower in level + the side walls are relatively far away. Thanks for opening my ears again ! Also thanks for warning me about the sidewall problem. I was also a little worried about the sidewall problem but thought I should be able to fix it with damping. That will probably not be optimal…

 I have windows behind the screen in your last setup that I can still use so that would be my best option.

Why do you consider the hexagonal placement the best? Because of the flat wall behind the listener? (less cavities ?)

If the ‘closet’ behind the right speaker would be open near the windows do you think there would be a cavity resonance? I could make a door there as well I guess.

The only problem I’m still thinking about is I’m still fairly close to the speakers If I acousticly time alight them and want to keep them away from the back wall.

Regards, Collin

Collin,
I am pleased that you found my suggestions worthwhile.

I approached the issue of your music room with two questions in mind:
1- How to avoid the structural angle from interfering with the sound
2- Would an enlarged room be worthwhile?

Exploiting the basic rectangular shape of your original room with speaker placement by the long side deals with the first.

Although enlarging the room creates a less desirable square space, one can make virtue of necessity with a diagonal placement along the extended 45-degree angled wall.

The diagonal placement approach works more naturally in a square room since the listener corner is centered. Conversely, diagonal placements are awkward in rectangular rooms because the opposing corner where the listener is placed does not lie between the speakers but off to one side. So by enlarging and squaring your room one gains the option of diagonal placement. Also since part of the room has a structural intrusion, you don't lose all that much space with this approach. I concluded that an enlarged room would be quite worthwhile with this approach.

I basically intended that the angled wall extension behind the speakers would be an architectural wall (heavy red line in the diagram) acoustically separating the small triangular space (white speckle). However I showed how the space could be tested with moveable barriers like shelving, but my original concept and continued recommendation is to eventually make that wall structural. You might possibly reuse the brick and concrete you are removing to enlarge the room in building this extension.

Since your TV is flat and doesn't need space behind, all of the triangular space could be used for something. I would tend to use some of it for an infinite baffle (or very large enclosure) woofer array. Well done, an IB woofer can be a very good approach to reproducing the bottom octave as well as useful for your video sound effects. Why not take advantage of your dedicated music room in this way? Of course you may have other plans that take into account the windows and doors - compromises may be in order.

Regarding your other questions,

a) There is nothing special about the wide hexagon shape. It is symmetrical and so might support good imaging and would have reasonable standing wave characteristics. I simply used it as the kernel of an idea of what kind of useful acoustic space your enlarged room would support and worked from there. Had your room naturally fitted a rectangular or wide octagonal geometry I would have started from one of those basically useful shapes.

b) If a small space is acoustically sealed (isolated) from the main listening room, you don't have to worry about it. But you don't want to partially block a space, as the constrained air in the cavity would be resonant. This phenomenon is the basis for a vented box/bass reflex speaker where, of course, the parameters are adjusted for a useful resonance. Better to leave the space wide open than partially enclosed (partially filled, reducing air volume is OK). Think of the space as filled by ricocheting ping-pong balls. If it tends to trap the balls it is bad, if the balls can escape easily it is better.

You do want to worry about thin panel doors, like closet doors, and windows in the main listening room. I am no acoustic purist in these matters however. I think large windows giving a lovely view are a blessing and as good a reason to pay real property taxes as any. The practicalities of family life and the courtesies of social living also must be observed. I have spent many hours listening with headphones with this in mind.

Finally, let me add a personal point of view. If you walk into a room and you are not really aware of its acoustics - it is probably a good room (good staring point) for an audio system and that should be your basic first goal in furnishing the room. If you sense that it is highly echoic or that it is sounds unnaturally dead from aggressive acoustic treatment or if you have trouble with hearing a normal conversation in it you have more work to do. Although our senses accommodate to the environment, I have never liked long-term listening in a room with a basically unpleasant or contrived acoustic no matter what advantages the acoustical treatments have on the audio system.

Best wishes on your project. May the results exceed the anticipation,
Robert

RF at Ona wrote:

Finally, let me add a personal point of view. If you walk into a room and you are not really aware of its acoustics - it is probably a good room …

RF at Ona wrote:

I have never liked long-term listening in a room …