Hi scholl,
The "Top Acoustic' site has just a 2ft and 4ft length of Tim's diffusers so they appear to be the right design but without any technical information, it's anyone's guess if they're any good or not - perhaps they'll develop their website further and add some technical information, and maybe add some appreciation to Tim's design too - at present, eBay sellers do it better!
Now, the cost!
The 4ft long panels/segments cost U$99 - that's about U$25 per linear ft - this is up in the pricing of pro-audio products like 'skylines' schroeddes, etc - not cheap! At least, Vicoustic are a more reasonable price for home/diy people and are well proven products.
As you need multiples of the panels for most effective performance, and if using the 4ft panels of the 7 segment/panel design for the back wall for example, at nearly U$100 per unit, this will cost about U$700 and still need further assemble to build the array as it's not 'flat-on-the-wall'- and maybe a 3 unit assembly at each first reflection point will add another U$600 without looking at the ceiling
Looked up Google and the closest thing is the Swiss design company 'Topakustik' (or 'TOPAKUSTIK') who obviously know what they're doing ...
The "Top Acoustic' site has just a 2ft and 4ft length of Tim's diffusers so they appear to be the right design but without any technical information, it's anyone's guess if they're any good or not - perhaps they'll develop their website further and add some technical information, and maybe add some appreciation to Tim's design too - at present, eBay sellers do it better!
Now, the cost!
The 4ft long panels/segments cost U$99 - that's about U$25 per linear ft - this is up in the pricing of pro-audio products like 'skylines' schroeddes, etc - not cheap! At least, Vicoustic are a more reasonable price for home/diy people and are well proven products.
As you need multiples of the panels for most effective performance, and if using the 4ft panels of the 7 segment/panel design for the back wall for example, at nearly U$100 per unit, this will cost about U$700 and still need further assemble to build the array as it's not 'flat-on-the-wall'- and maybe a 3 unit assembly at each first reflection point will add another U$600 without looking at the ceiling
Looked up Google and the closest thing is the Swiss design company 'Topakustik' (or 'TOPAKUSTIK') who obviously know what they're doing ...
This is the optimized fractal design presented by Tim Perry here:
Sound Diffusers 101: Free Designs for DIY Diffuser Panels
When used in multiple you are supposed to "modulate" them, otherwise the result is quite bad.
Sound Diffusers 101: Free Designs for DIY Diffuser Panels
When used in multiple you are supposed to "modulate" them, otherwise the result is quite bad.
IT does add up quickly. That's why I was considering simple curved panels of about the same width, depth but 3 foot long as the TopAcoustics. I can cover those with photo prints.
Ah, it depends on how much diffusion you want to obtain, I guess - the curved panels won't give you the amount of diffusion or the even freq response, but maybe this isn't necessary for your situation - some systems and users like a lot of indirect sound and/or their speakers radiate widely so building 'better', more controlled diffusers are well worth the extra trouble.
If the curved diffusers are enough for your setup, you could maybe combine these with bass traps, if you need them ...
To me, the fact that you're making some positive moves to improve your acoustical listening room is the most important thing - it's where you can easily get a really significant improvement in sound quality.
There's is a service provided by Jim Smith (USA) about getting the best out of your system - he wrote a book about it "Get Better Sound" and it's an excellent manual in plain simple terms, not "studio-speak" techno language - you can chase it up on 'getbettersound.com' and it includes follow up Blog issues every 3 months
If the curved diffusers are enough for your setup, you could maybe combine these with bass traps, if you need them ...
To me, the fact that you're making some positive moves to improve your acoustical listening room is the most important thing - it's where you can easily get a really significant improvement in sound quality.
There's is a service provided by Jim Smith (USA) about getting the best out of your system - he wrote a book about it "Get Better Sound" and it's an excellent manual in plain simple terms, not "studio-speak" techno language - you can chase it up on 'getbettersound.com' and it includes follow up Blog issues every 3 months
While looking around and finding ideas to copy only to also find the finer dimensions are void
There are some really nice looking difusers that wouldn't be difficult to make.I have a decent sounding room. It is very long and reasonably wide with a ceiling that starts a little over 8 feet at the speaker end and rises to just under 20 feet where I listen. The length of the room to this point (the fireplace wall) is 23 feet. The width of the room is 17.5 feet.
There is a fireplace at this point in the room which is 90 inches wide (not the firebox but the whole assembly is brick which has been covered with plaster. Behind this fireplace is an extension of this room that goes back another 14.4 feet. There are two opening on each side of the fireplace of 39 inches each. The listening chairs are about a foot in front of the fireplace. The firebox is never used and is stuffed with fiberglass.
I have read that one should not have the diffuser behind the listening chair. I have found this position to sound better than sitting any closer. Everything seems to converge well here. Moving the chairs out into the room, at this point, does not make the system sound better. I am using horn loudspeakers.
I am wondering if I mount three of these panels (the ones discussed in this thread) about eight feet above the floor would I eliminate the problems mentioned from sitting too close? There is not another practical place I could put them. I am hoping that placing them there would also be good way to break up reflections from the angled ceiling along with back wall reflections. Is height of the diffuser placement a substitute for depth behind the listening position?
Sorry for all of the details. Any opinions would be appreciated.
Thanks,
There is a fireplace at this point in the room which is 90 inches wide (not the firebox but the whole assembly is brick which has been covered with plaster. Behind this fireplace is an extension of this room that goes back another 14.4 feet. There are two opening on each side of the fireplace of 39 inches each. The listening chairs are about a foot in front of the fireplace. The firebox is never used and is stuffed with fiberglass.
I have read that one should not have the diffuser behind the listening chair. I have found this position to sound better than sitting any closer. Everything seems to converge well here. Moving the chairs out into the room, at this point, does not make the system sound better. I am using horn loudspeakers.
I am wondering if I mount three of these panels (the ones discussed in this thread) about eight feet above the floor would I eliminate the problems mentioned from sitting too close? There is not another practical place I could put them. I am hoping that placing them there would also be good way to break up reflections from the angled ceiling along with back wall reflections. Is height of the diffuser placement a substitute for depth behind the listening position?
Sorry for all of the details. Any opinions would be appreciated.
Thanks,
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I don't think that is actually true, behind the listening chair seems very good in my (admittedly limited) experience. But the diffuser has to be sufficiently far behind the chair, 4 or more feet, otherwise it behaves much like just having a wall right behind your head (which was about as bad as it gets when I've tried that). Having the diffusers up high would get you the distance from them, but I'm not so sure they would be in a position there to help with room ambience. Maybe set to the sides? (particularly if the horns are arranged with toe-in).
I have tried it with good and not so good results. If the rear wall is too close to listening position you may do better with absorption (that has worked best for my different situations.) With a diffuser sound waves will bounce but not have a chance to scatter effectively before reaching the listener. Try it you never really know until you know.
Thanks Mr. Waslo and SS4927 for your comments.
I see I was not emphatic enough about the chair being around 18 inches from this fireplace/wall.
AS much as I would like to introduce diffusion into the room I may not have a way to do it without blocking windows and access to a staircase!
I have been using old ROOM TUNE absorbers to tune out a strange little upper midrange squeal - you could really hear when you aimed your ear at the back wall but were not consciously aware of it when facing the speakers. Other than that the wall seems to not cause problems, which is surprising. Nonetheless, one is never sure how good a setup is until they try something.
One of these days I will try placing three panels on the wall as I mentioned and hope the effort is not wasted, which I cannot imagine it being. Breaking up the stuff bouncing off of that big wall would have to improve things. Would it change anything if you re-consider this: the fact the ceiling is at close to a 45 degrees angle which reflects what is coming off of that wall? Would a diffused reflection be better or could it be worse?
I know all this is ridiculously hypothetical. So feel free to respond in kind!
I see I was not emphatic enough about the chair being around 18 inches from this fireplace/wall.
AS much as I would like to introduce diffusion into the room I may not have a way to do it without blocking windows and access to a staircase!
I have been using old ROOM TUNE absorbers to tune out a strange little upper midrange squeal - you could really hear when you aimed your ear at the back wall but were not consciously aware of it when facing the speakers. Other than that the wall seems to not cause problems, which is surprising. Nonetheless, one is never sure how good a setup is until they try something.
One of these days I will try placing three panels on the wall as I mentioned and hope the effort is not wasted, which I cannot imagine it being. Breaking up the stuff bouncing off of that big wall would have to improve things. Would it change anything if you re-consider this: the fact the ceiling is at close to a 45 degrees angle which reflects what is coming off of that wall? Would a diffused reflection be better or could it be worse?
I know all this is ridiculously hypothetical. So feel free to respond in kind!
If you have front speakers with broad depth and open space in between with a span of flat bare wall it can use work. I could picture sound waves travelling back leaving the baffles then bouncing off the wall then again off the side of each speaker forming a continuous "X" smearing the main image from the speakers.
I got so close to finishing this panel. I dont know when I will but I had to try it. Results are positive and immediately noticeable. I still plan to build a second one with deeper wells to try.
I had a hell of a time getting it on the wall partially. The block underneath and one screw are all thats holding it until Im able to line it in proper. But sound is more important than looks for now.
I got so close to finishing this panel. I dont know when I will but I had to try it. Results are positive and immediately noticeable. I still plan to build a second one with deeper wells to try.
I had a hell of a time getting it on the wall partially. The block underneath and one screw are all thats holding it until Im able to line it in proper. But sound is more important than looks for now.
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Hi Rick
With the wall that close, I suspect your only good option is a heavy absorber between you and the wall. Diffusers far above may help with ambience but the need to reduce that specular reflection from behind you would seem much more important to deal with first.
With the wall that close, I suspect your only good option is a heavy absorber between you and the wall. Diffusers far above may help with ambience but the need to reduce that specular reflection from behind you would seem much more important to deal with first.
For my next try instead of using a flimsy piece of .25 mdf backer I have a larger piece of multi layer birch ply approx .75" thick. covering that is fine veneer with grains cascading through half the 48" span that reminds me of a waterfall. that with the birds eye looking details speckled throughout should make a nice front piece along wall. I might arch the vertical ends slightly in search of more eye appeal.
then instead of hardwood runners I will use a finished birch ply for the runners to create the channels. I will also miter the backboard .75w x .25d" this time to lock them in place opposed to gluing strips in between them, that along with glue.
then instead of hardwood runners I will use a finished birch ply for the runners to create the channels. I will also miter the backboard .75w x .25d" this time to lock them in place opposed to gluing strips in between them, that along with glue.
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I was wondering about making a diffusor stacking a 2inch on a 3inch on a 4 inch board, and am asking if this might be better than uniform widths....or even variations like 4 on 3 on 2 (or whatever)....and then I was also thinking about using various molding shapes, and I also was wondering about scoring the outermost pieces with kerf cuts on a table saw at various depths....any feedback on these ideas? I would be willing to add a small bit of complexity and extra work, if it resulted in a reasonable improvement.
I'd strongly suggest you download the (free for 1month eval) of AFMG Reflex. Not just any old shape makes a good diffuser, and most aren't at all very good over much bandwidth. On the Reflex simulator you can enter your shape and see how it will (or won't) diffuse.
Before simulators like Reflex, the only way to reliably design a diffusor was with one of the mathematically-derived types like QRD. But with a simulator like Reflex you can develop and analyze other shapes that are as good or better (and easier to make). Don't just take a random stab with wood, you'll probably get only decoration or firewood. Take your random stab(s) with software.
Before simulators like Reflex, the only way to reliably design a diffusor was with one of the mathematically-derived types like QRD. But with a simulator like Reflex you can develop and analyze other shapes that are as good or better (and easier to make). Don't just take a random stab with wood, you'll probably get only decoration or firewood. Take your random stab(s) with software.
Is this the right choice diffuser to lessen slap echo between two parallel walls 13' apart in my theater room. I understand i would need two of these, one on either wall facing each other. Height is pefect as is width, crossing my fingers.
I have a few area's that can benefit from energy scattered not absorbed. I've dealt with bass absorbers and first reflection points already in my room.
I have a few area's that can benefit from energy scattered not absorbed. I've dealt with bass absorbers and first reflection points already in my room.
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It should help break up mid-high echos, but directly across from each other may not be as effective as staggered to more broadly break up reflections throughout the room. I know they're heavy, but I'd expect you'll find improvements from experimenting with placement (unless other forces decide where exactly you can place them, then alls you can do is alls you can do and it will certainly help)
They should do pretty well for that. Just make sure that the listening position is about 4ft or more away from them. They will stand up on the floor temporarily if you want to move them around to play with placement, but I don't think they'll be very fussy.
Try having one about 5ft behind the listening chair if you can, while you're at it -- I really like the effect that gives.
Try having one about 5ft behind the listening chair if you can, while you're at it -- I really like the effect that gives.