JBP Posted July 29, 2004 Share Posted July 29, 2004 Besides Master Handbook of Acoustics, are there any other books that can be recommended that cover room treatment for HT? Specifically, one that focuses on how-to solutions. Thanks 1 Quote Link to comment Share on other sites More sharing options...
artto Posted July 30, 2004 Share Posted July 30, 2004 I personally don't know of any that specifically address HT. It seems a lot of that is currently being covered in the magazines, especially the "how to" aspect, although it seems to me that the same acoustic principals and similar treatments apply to stereo and multi-channel music systems as well as HT. You might try this link. There are other links attached to it. It addresses HT. And it's written by a credible source, renown acoustician Floyd Toole. http://www.harman.com/wp/index.jsp?articleId=default Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted July 30, 2004 Share Posted July 30, 2004 Hey artto Thanks for the webb site really good reading. Have you by chance read the book (Acoustic Absorbers and Diffusers; Theory Design and Application by Trevor J. Cox and Peter D'Antonio)of the RPG Company. I believe its about $149 new OUCH! http://www.rpginc.com/book/index.htm I would like to know what you think about it if you've seen it. Thanks mike Quote Link to comment Share on other sites More sharing options...
artto Posted July 30, 2004 Share Posted July 30, 2004 No I haven't Mike. But I have read some of their "papers". Is this book available on Amazon or anything? Kinda pricey. Quote Link to comment Share on other sites More sharing options...
Soundthought Posted July 30, 2004 Share Posted July 30, 2004 You might want to check out "Sound Studio Construction on a Budget". (F.Alton Everest) 1997 ISBN 0-07-021382-8 Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted July 31, 2004 Share Posted July 31, 2004 ---------------- On 7/30/2004 6:46:26 PM artto wrote: No I haven't Mike. But I have read some of their "papers". Is this book available on Amazon or anything? Kinda pricey. ---------------- Yes thats how I felt. Its available on Amazon($149 to $159) and signed copys from RPG but I don't know at what cost. I'd sure like to see a copy to see how much information about diffusers and small room acoustics was in it before spending that much. thanks artto mike Quote Link to comment Share on other sites More sharing options...
artto Posted July 31, 2004 Share Posted July 31, 2004 Apparently the reason the book is so expensive is that its new and was released this month. According to one book description I ran across, http://www.acoustics.salford.ac.uk/research/arc_cox_book.htm Surface diffusion is a relatively young subject area, and diffuser design, application and characterization are new to practitioners and researchers, who may not have been exposed to this information in their formal training. I dont agree with this statement. Obviously, diffusion research and application has been going on since at least the 1940s as documented by PWKs reference to noted acoustician Charles Boners use of polycylindrical surfaces in recording studios and auditoriums. And I have been experimenting with it (non professionally) for over 20 years. The Table of Contents seems to cover most of the subject matter contained in Everests Master Handbook of Acoustics, albeit, in a more technical manner (its more of a text book). Interestingly, it also covers some areas of acoustics I did my senior thesis at U of I on, Landscape Acoustics. It also, obviously covers the more recent developments of diffusor technology developed by RPG. IMO, much of this is re-inventing the wheel as polycylindrical surfaces with continuously variable radius are naturally more efficient broadband diffusors, and at the same time, double as bass absorbers, and if large enough, also can help break up standing waves in the lowest frequencies. The RPG approach, however, is much more useful when space is limited (real estate is expensive). Im considering using RPG diffusors on the ceiling of my listening room at the primary first reflection points (Klipsch uses these in some of their HT demo rooms at Indy). Part of the issue for me is a visual one. I wish my ceiling were higher. Ive created the optical illusion that the ceiling is nearly 2 higher than it actually is with the use of large curved vertical diffusors on the front wall. Im hoping that putting the RPG diffraction diffusors at several locations on the ceiling doesnt make the ceiling seem (too much) lower. I wish I could try this out before spending the money as the RPG diffusors are not cheap. Its a very small acoustic detail at this point. Ive tried using absorption (3 Sonex) at these locations and it seems like a little too much absorption, sort of like creating acoustic holes amongst the rest of the ceilings reflective area. My thinking is that the RPG diffusors might help retain the liveliness while taking out the detrimental delay effects of the first reflection points, making it sound as if the ceiling were higher. The Sonex Im using is also charcoal colored so it quite apparent that there is something hanging from the ceiling. Visually I dont like it. Quote Link to comment Share on other sites More sharing options...
artto Posted July 31, 2004 Share Posted July 31, 2004 ---------------- On 7/30/2004 7:24:49 PM Audioreality wrote: You might want to check out "Sound Studio Construction on a Budget". (F.Alton Everest) 1997 ISBN 0-07-021382-8 ---------------- This book is pretty inexpensive ($8 used). Even though a lot of what I know and have access to is probably covered in there, for eight bucks I think it's worth having. Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted July 31, 2004 Share Posted July 31, 2004 Hey artto You've probably read also that one of the design features of the skyline diffusor is that it virtually eliminates the specular component of the incident sound wave which is suppose to make it ideal for primary 1st reflection points that you want to treat. I'm using some of the 2'x2'x7" skyline diffusors on my ceiling and side walls. My current room is small so I went with these since they are recommended for situations where the rooms surfaces are close to the listening position which is definitly my situation.I like that they are very light weight for the ceiling use but they are made of expanded polystyrene foam which does make me nervous about maybe damaging them by using them in areas where someone could bump into them. I still need to try these in some different areas of the room to optimize their use but I've been very pleased with the results in my room so far. One idea I'm thinking of trying since I'm in such a small room is making some slightly angled panels to redirect the 1st reflection points on the side walls into the diffusors in the back part of the room. I believe this would maybe help by dealing with the first reflection point but delaying the diffussion to a later point in time when it would be more beneficial in my smaller room.I'm like you I've not had much success with absorption at these points it just seems to create an unnatural tonal balance and can seem to suck the life out of the music. Have you tried anything like this? By the way have you also noticed the shape optimized diffusors that RPG are developing now. It looks to me like they have basically concave and convex curves arayed on an arc shape.Kind of like a wavey poly. mike Quote Link to comment Share on other sites More sharing options...
artto Posted July 31, 2004 Share Posted July 31, 2004 ---------------- On 7/31/2004 3:18:17 PM mikebse2a3 wrote: Hey artto You've probably read also that one of the design features of the skyline diffusor is that it virtually eliminates the specular component of the incident sound wave which is suppose to make it ideal for primary 1st reflection points that you want to treat. ---------------- Yes, thats one of the reasons I'm interested in trying them, and also because the absorption materials I've tried seem to "suck the life out of the music" as you mentioned. ---------------- On 7/31/2004 3:18:17 PM mikebse2a3 wrote: One idea I'm thinking of trying since I'm in such a small room is making some slightly angled panels to redirect the 1st reflection points on the side walls into the diffusors in the back part of the room. I believe this would maybe help by dealing with the first reflection point but delaying the diffussion to a later point in time when it would be more beneficial in my smaller room.I'm like you I've not had much success with absorption at these points it just seems to create an unnatural tonal balance and can seem to suck the life out of the music. Have you tried anything like this? ---------------- I have polycylinders on the front and side walls so I don't need anything like that. I must admit I don't really like the idea of simply trying to redirect "reflection points". These are "wave" fronts we're talking about, not "beams". Also, I've found that having diffusors behind the listening position is not much better than having first reflections from the side walls or floor or ceiling. It's ok if its off to the sides of the back wall, but not behind the listening position, especially if you're closer to the rear wall than the front wall. ---------------- On 7/31/2004 3:18:17 PM mikebse2a3 wrote: By the way have you also noticed the shape optimized diffusors that RPG are developing now. It looks to me like they have basically concave and convex curves arayed on an arc shape.Kind of like a wavey poly. mike ---------------- Yes, I've seen those. I believe that was originally developed when some dumb architect who had designed a small auditorium, approached RPG after-the-fact to design the acoustics. He insisted on having a convex surface along the back wall. Thats what they came up with. Personally, I don't likr convex surfaces for acoustics, regardless of what RPG (a very reputable firm) says. I think you're better off avoiding them if at all possible. They may be workable in certain situations where you have a high ceiling, or in larger spaces. I think its easier to avoid them if you can. Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted August 1, 2004 Share Posted August 1, 2004 Thanks for the replies artto: I've observed what you said also about diffusors being to close to you and causing problems on the back wall as well as if the side walls are close you can definitly get some unpleasent coloration interference.Thats what got me to wondering about trying to delay some of the reflections to the listener by maybe redirecting them to a later point in time trying to simulate a larger space.I do realise their are problems with this since there is no way I can truely simulate a larger space full bandwidth since any panel/diffusor/absorber are bandwidth limited so I can see how some frequency would be delayed and some wouldn't which will probably just create a different coloration.I see that a small room is a limitation that can never be fully overcome (I'm trying to find ways to manipulate the room to give the room higher resolution and natural sound than its size will permit untreated) as compared to a more ideal sized listening room.I'm just trying to optimize the room I have to live with at this time.Thats why for me alot of trial and error is necessary because I can't be sure what the brain is going to accept in my situation. Again thanks for the thoughts artto its nice to talk to someone about these things because I've not met anyone around here that seems to even be aware or cares about these acoustical things. mike Quote Link to comment Share on other sites More sharing options...
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