Is an eight sided oval room acoustically correct?


I was in the process of building a 13 foot by 17 foot stereo sound room when I got an idea. Why not avoid 90 degree walls with four smaller walls? This will create an eight sided oval room. Won't this avoid the need for bass traps? I know that traditional room corners accentuate bass resonance. What do you think about this solution?
redwoodgarden
Interesting question. My initial reaction is that this shape might work well, since I have heard audio systems in dome homes (circular in structure) that sounded very good. There is still a chance you could some standing waves, however, since there will be four pairs of parallel wall surfaces.

This sounds like a question for Sean and/or Rives Audio...
If the cuts are minimum it's a good idea. It will relieve the corner pressure. However, if they get too large it begines to create some pretty interesting interactions that are not easy to describe, but suffice to say that more than about 15% of the length of wall cut as you propose and you may encounter some problems. As to the "dome", well, I don't like to disagree, but about the only worse scenario would be a round room. The dome will focus energy in one place. If you go to our listening room you can see what a bay window can do to the sound field. A dome compounds the problem. It can create a "neat" effect, but is not advised for a dedicated listening space.
Rives, you have a great deal of useful information on youre site.

Looking it over brings up some questions that I am giong to try and solve. I have a bay window directly behind my speakers and a sliding glass door to the left. I know that these both contribute some problems to the sound. The bay is not easly coversed by drapes or blinds as it is home to my wifes huge philodendron. This is the only place in the house that it fits and is very happy there. I am wondering if you have any experience with Murigo Audio Labs window tuning dots. I know that it is not the ideal situation or solution, but the room does need to serve as living space to some degree. I am fortrunate enough to be able to set the room up for the Hi Fi and nothing else other than the computer and as an area to relax and read.

Another product that I am curious about are the Golden Sound Company's Acoustic Discs. Any thoughts on these?
Maxgain: I do have experience with these types of products. What they do is reduce the resonance in the glass. This may be a problem for you (it depends on the glass insert), but it's not the problem we discuss regarding bay windows on our website. These materials will do nothing for "focus effect" problem that bay windows have.
Red, I am also building a room, as you may know because you pointed me in the direction of some books. But, while researching this I ran across a site in the Audiogon archives: psaudio.com/articles/listening_room_3.asp
These guys built a room with diagonal corners that were built-in bass traps. They looked good and appear effective at dealing with the issues of resonant node, "bass peaks" etc.
I am still trying to find a good answer to my problem of room dimensions. I have this much room to work with 15x 26. I keep getting confusing info on the best dimension to minimize resonant modes. It appears that 10x15x21 is the answer, but am still waiting for feedback.
good luck
joeb
Rives, thanks. I understand that the dots won't change that issue. It's a compromose I have to live with.My image is suprisingly good though.I know I can't have stats or Maggies in here. Perhaps the BIG plant in the window
acts as enough of a defuser to help some of it. It's an Anderson window with a 4 1/2' picture window and two doubble hung windows set on a 45, the bay is 8' wide and 22" deep. I have wondered if two small tube traps set at the edges of the picture window might help.
Maxgain: The tube traps will help. The other option would be to use heavy drapes but just close them enough so that the angled portions of the window are hidden from view. Then the plant does help with diffusion and you've minimized if not eliminated the bay window focussing issue. The drapes would probably look nicer than the tube traps and might get siginificantly better spousal approval ratings.
Thanks Rives. The damn plant is so big that it sticks out two feet out into the room, so curtains are out. My wife already thinks I'm nuts and since this is the basicly the Hi Fi room she doesn't say much about what I do in here.
This is more or less my room. I am the one that isn't into uglying it up. It's nice to have a listening space that isn't so bizare looking that no one but me feels comfortable in it. I would probably choose the 9" full rounds in a light fabric so they wouldn't call a lot of attention to themselves.

Have you seen the Golden Sound Acoustic discs? Odd little critters. I wonder if they work?
Haven't seen those. I have seen some descent pruning sheers at home depot though:)
Rives, I have some Swiss Felco's(pruners) but I guess I like the jungle effect and more leaves = more diffusion, right? Just for fun, what do you think of that new Shakti "hat rack". That is a bizare looking contraption. I can imagine a room all done up in RPG stuff, Tube Traps every where,several Argent Room Lenses and a few of those crazy looking Shakti things! Talk about WAF!
Joeb, thanks for the info on psaudio. It looks like I can build those four 3.5 foot "walls" in each corner of the room and construct a bass trap as well. Great idea!
Rives, thanks for all your help at your "listening room" website above. It's great to know that I can get professional help just a few miles away in Jessup, MD. I'm just around the corner in Annapolis.
The biggest problem that I see now is where to place the K-horn speakers in the eight sided room. Obviously, each speaker is going to need two 4x4 foot false walls for the bass. Won't pulling the speakers and baffles out one third the length of the room interfere with sound staging, etc?
I tried my first Apogee dipoles in a room with a wide three sided bay window and it just sounded confused and imageless.
Muralman1, that's why I have box speakers in this house! I love stats and planars but the room is part of the system. The room, as a component of my system, dictates what I need to use to get music.

It would be fun to be able to start with a blank sheet of paper.I should say that overall I'm pretty happy to have the room I have. Their are the less fortunate who have to share their rooms with all sorts of crazy goings on!
Sorry if I stepped on your toes, Maxgain. I was just hurrying through topics and I saw this one and it brought back memories.
Muralman1, I never thought of it like that. There is no substitute for a little experience in this crazy endevor.
The Hat Rack: I'm here at CES and it's on display at a few places. There are many things in this audio world that make large differences that you wouldn't expect to. So far everything I have ever heard that made a difference has some sort of physical reason that it made a change--sometimes not for the better. As a physicist, I can't find any physical reason how the hat rack would have any effect on the sound (unless it's placed in front of the speakers). There's virtually no band width by it's design and thus it can't effect the sound waves. I would really like to read some scientific explaination (or anything even plausible) on how this can effect the sound waves.
Okay after my post I made it a point that day to listen to the "hat rack". I think it's really called something like the hologram something or other, but it looks like a hat rack--so I like Hat Rack better. In a room with absolutely bare corners and a very high resolution system, I could hear a difference with it in and out. It broke up a very small band of frequencies in the lower mid band enough to add a little clarity in that range. However, I think it's only useful in a room that has little or no diffusion. There are much better ways of accomplishing more for far less money. For example, in a bare room take one panel of slatted shutter doors and put one in each corner--compare that to the hat rack--it will make a huge difference (not always for the better mind you). I think that's one of the issues with some tweaks--make them benign enough that they don't do harm. I doubt seriously the hat rack will ever cause any problems in a room--but it's not going to fix too much either.