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DIY Sound Diffusers—Free Blueprints—Slim, Optimized DIY Diffuser Designs (+Fractals)
Old 10th December 2013 | Show parent
  #391
Gear Addict
 
🎧 10 years
Quote:
There is still a place for products because not everyone has the desire to build treatments
+1
Old 11th December 2013 | Show parent
  #392
Lives for gear
 
AwwDeOhh's Avatar
 
🎧 10 years
Quote:
There is still a place for products because not everyone has the desire to build treatments
Quote:
Originally Posted by hsal ➡️
+1
+2,
and add to that:
those of us who had the desire to build, but after the first few started seeing the wisdom of having someone else build it...
Old 11th December 2013
  #393
Here for the gear
 
🎧 5 years
My first post here, so Hello to You all
I am newbie in acoustics, and need some advice. I've read most of this thread and found your design Tim very atractive in both: time and wallet friendly aspects. My concern is treatment to my listening room.
I already ordered UMIK-1 microphone from minidsp, so I should be ready to measure in next 10-20 days.
My room dimensions:
7.92 L x 5.95 W x 2.74-2.78 H in meters, but sloping ceiling, starting from 0.85 m to 2.74 m 45 degrees.
Two problems, both on axis of the lenght - window on one end, and door on the other, so symmetrically wall mounted panels are a problem, if possible at all. I think rather of standalone diffusers. What You say guys.
Material is not a problem: 4,6,10,12,18,22 mm plywood available, 6,10,12,18,22,28 MDF also available in Poland, some EPS too.
Old 11th December 2013 | Show parent
  #394
Gear Addict
 
Arqen's Avatar
 
🎧 5 years
Quote:
Originally Posted by Sound of silence ➡️
My first post here, so Hello to You all
I am newbie in acoustics, and need some advice. I've read most of this thread and found your design Tim very atractive in both: time and wallet friendly aspects. My concern is treatment to my listening room.
I already ordered UMIK-1 microphone from minidsp, so I should be ready to measure in next 10-20 days.
My room dimensions:
7.92 L x 5.95 W x 2.74-2.78 H in meters, but sloping ceiling, starting from 0.85 m to 2.74 m 45 degrees.
Two problems, both on axis of the lenght - window on one end, and door on the other, so symmetrically wall mounted panels are a problem, if possible at all. I think rather of standalone diffusers. What You say guys.
Material is not a problem: 4,6,10,12,18,22 mm plywood available, 6,10,12,18,22,28 MDF also available in Poland, some EPS too.
Hey welcome to the forum!

Stand alone diffusers sound like a good approach here. They would also give you the ability to test the acoustics of your room using different configurations.

As for the material thickness, you can use 12 mm as the base step size instead of 10 mm. 12 mm performs just as well, if not better (and you can keep the well widths the same as mentioned in the blueprints: 60mm).

I hope this helps!
Old 12th December 2013 | Show parent
  #395
Here for the gear
 
🎧 5 years
Thank You Tim
Yes, I noticed 12 mm is alright too or even better. Actually I don't mind a deep or very deep diffuser, but I must think of access to the window ( occasionally ). Please correct me, if I'm wrong, but diffuser - if not mounted to the wall - shouldn't be to far from it. Is it ? I mean the one behind the speakers. I was really considering 20-25 deep, decent N (41-53) 1D, until I found your design, which seems to me much more elegant. The weight also matters... yeah access to the window. In Poland we used to say: The need is a mother of invention, so maybe I can do that too. We'll see.
Does anyone know how much it weighs? 1 module, 5, 7 of plywood, mdf, xps ?
Thanks again. Great thread.
Old 17th December 2013 | Show parent
  #396
Here for the gear
 
🎧 5 years
Hello again,
I wanted to share a sample of A1-LF "fractalized". It took one hour of ... waiting.
I have to wait a few more days for the rest, they're busy before christmas. Very nice lady prepared a corel file and cut a sample for me this morning. I will upload it, when I get it.
There's bonus of some kind inverted panel. Do You think I can make use of it?.
When I get the rest, I,ll start painting and let You know.

Tim Please forgive. I've noticed You're not a fan of xps, but i really need a lightweight construction.
Attached Thumbnails
DIY Sound Diffusers—Free Blueprints—Slim, Optimized DIY Diffuser Designs (+Fractals)-image_4373.jpg   DIY Sound Diffusers—Free Blueprints—Slim, Optimized DIY Diffuser Designs (+Fractals)-image_9310.jpg  
Old 18th December 2013 | Show parent
  #397
Gear Addict
 
Arqen's Avatar
 
🎧 5 years
Quote:
Originally Posted by Sound of silence ➡️
Hello again,
I wanted to share a sample of A1-LF "fractalized". It took one hour of ... waiting.
I have to wait a few more days for the rest, they're busy before christmas. Very nice lady prepared a corel file and cut a sample for me this morning. I will upload it, when I get it.
There's bonus of some kind inverted panel. Do You think I can make use of it?.
When I get the rest, I,ll start painting and let You know.

Tim Please forgive. I've noticed You're not a fan of xps, but i really need a lightweight construction.
Looks great and no worries about the material choice. I know these fractal diffusers are time consuming to make if you use wood products.

My main concern is people mass producing them out of xps and shipping hundreds of them around the world, as it completely goes against the philosophy and turns these into a cheap, fragile, waste-producing product rather than a low impact product. Someone was doing this with the fractal designs and selling them on eBay (and apparently also trying to patent them to claim exclusive commercial rights to them), but fortunately a forum reader brought that to my attention and we're shutting him down.

In my mind if you're going to mass produce something and ship it around the world, you should ensure quality manufacturing and build it using the right materials. But if you're only building a small number of units, the scale is dramatically reduced so material choice is not as critical .

I would not use the inverted panel anywhere where you need controlled diffusion, because at close range it looks like they will have a focussing effect. However, over longer distances I expect they will still redirect / scatter sound in a sloppy way. If you want to maximize the diffuse field in your room, you could try placing these quazi-randomly around your room on reflective walls in places where controlled diffusive treatment is not needed. For example, you could potentially use these in locations far away from where you sit, or in places where you are not in the direct line of fire (e.g., they could be placed on the sidewalls near the ceiling). I don't know what the overall effect will be as it depends on many things, so view this as a concept you can explore rather than a recommendation.
Old 25th December 2013
  #398
Reviews Editor
 
Diogo C's Avatar
Quote:
Originally Posted by Arqen ➡️
Also, I’d like to know:

Do you think the stepped diffusers look easy to build?
Where do you live?
Do you have access to 1cm thick construction material? Or do you only have access to lumber with imperial dimensions?
Do you have access to affordable bamboo lumber?
What’s the most likely material you’d use for building them?
What tools are available to you? Do you have access to woodworking equipment? CNC?
Bumping.

1 - Yes, they look easy to DIY.
2 - Brazil
3 - Yes, we use metric here.
4 - My brother-in-law is an enthusiast of bamboo-based stuff.
5 - I'd probably eucalyptus and "pinus" (not sure how to translate that), because they're cheaper around here.
6 - Refer to #4 - he's got the tools and is willing to do it!
7 - CNC?

I'm just a bit unsure about building them right away because my room is very small (3.30x2.95m, ceiling is 2.80 meters). Since it will be rather easy and inexpensive to make them I'm thinking about having one (or three, right?) on the ceiling - in the back part, not at the listening spot. Would it hurt? There are 13 pannels planned for the room, so I wanted something else for variety's sake, and that spot doesn't have anything so it will be that or more broadband pannels...

Regards
Old 31st December 2013 | Show parent
  #399
Gear Head
 
🎧 10 years
Quote:
Originally Posted by diogo_c ➡️
7 - CNC?
Computer Numerical Control. It's one of those automated systems that cuts materials for you instead of doing it by hand (i.e. CNC router). It's a lot more precise and fast. It's also very expensive for a hobbyist.

I'm getting myself a router table!
Old 1st January 2014
  #400
Here for the gear
 
🎧 5 years
Happy New Year to everybody!

Here's a pic of the leanfusers installed in my studio.

What do you all think about putting another 5 half-module array behind the piano, near the ceiling?

I would like to have some diffusion on the rear wall behind the piano, as it is presently all absorption. However this would put the diffusers 3 feet from the piano player's head and sometimes the microphones...

As you can see in the photo the right wall currently has a huge broadband absorber covering most of it. I could always move this and/or add diffusion to that wall as well...

Any expert advice would be very appreciated!
Attached Thumbnails
DIY Sound Diffusers—Free Blueprints—Slim, Optimized DIY Diffuser Designs (+Fractals)-img_1105.jpg  

Last edited by theloniousgong; 3rd January 2014 at 02:40 AM.. Reason: sp
Old 1st January 2014
  #401
Gear Head
 
🎧 10 years
Quote:
Originally Posted by Arqen ➡️
  1. Do you think the stepped diffusers look easy to build?
  2. Where do you live?
  3. Do you have access to 1cm thick construction material? Or do you only have access to lumber with imperial dimensions?
  4. Do you have access to affordable bamboo lumber?
  5. What’s the most likely material you’d use for building them?
  6. What tools are available to you? Do you have access to woodworking equipment? CNC?
1. Yes. IF you have the right tools for the job. And patience. For efficiency, I recommend Festool's track saw (for the fractal diffuser) and router (for the stepped diffuser) equipped with parallel guides and guide rails. Festool uses the metric system (native), but can use imperial.

2. USA

3. Lumber and engineered wood (i.e. MDF, LDF, HDF, MDO, plywood), all in imperial, is ubiquitous here than any other construction material. However, bear in mind your design's maximum dimensions will mean special custom-order; they can be very expensive. 4+ in. thickness and >12" widths is not common here. Most likely there will be stacking and joining involved, which I hate.

4. Affordable? No. Accessible? Yes.

5. Whatever is cheapest, lightest, and strong. I'll have to do some research.

6. Circular saw and router. Looking to get some Festool stuff in there.
Old 3rd January 2014 | Show parent
  #402
Gear Addict
 
Arqen's Avatar
 
🎧 5 years
DIY Diffusers FAQ

Quote:
Originally Posted by diogo_c ➡️
Bumping.

1 - Yes, they look easy to DIY.
2 - Brazil
3 - Yes, we use metric here.
4 - My brother-in-law is an enthusiast of bamboo-based stuff.
5 - I'd probably eucalyptus and "pinus" (not sure how to translate that), because they're cheaper around here.
6 - Refer to #4 - he's got the tools and is willing to do it!
7 - CNC?

I'm just a bit unsure about building them right away because my room is very small (3.30x2.95m, ceiling is 2.80 meters). Since it will be rather easy and inexpensive to make them I'm thinking about having one (or three, right?) on the ceiling - in the back part, not at the listening spot. Would it hurt? There are 13 pannels planned for the room, so I wanted something else for variety's sake, and that spot doesn't have anything so it will be that or more broadband pannels...

Regards
Happy New Year and sorry for the delayed reply!

I recently posed an FAQ here that tells you a good way to mount 3 diffuser modules. Depending how you arrange these modules the minimum recommended listening distance is 7 - 10' (details given in the FAQ).

Given the size of your room I would not post diffusers in the direct line of fire of your listening spot, but yes you could post them in the back of the room on your ceiling. In that location they may improve the overall ambience in your room, but I'm not sure how audible the effects will be. It depends on many factors.
Old 4th January 2014 | Show parent
  #403
Gear Addict
 
Arqen's Avatar
 
🎧 5 years
Quote:
Originally Posted by theloniousgong ➡️
Happy New Year to everybody!

Here's a pic of the leanfusers installed in my studio.

What do you all think about putting another 5 half-module array behind the piano, near the ceiling?

I would like to have some diffusion on the rear wall behind the piano, as it is presently all absorption. However this would put the diffusers 3 feet from the piano player's head and sometimes the microphones...

As you can see in the photo the right wall currently has a huge broadband absorber covering most of it. I could always move this and/or add diffusion to that wall as well...

Any expert advice would be very appreciated!

I think you'' be alight since the diffusers are mounted high up, but since you're putting them that close to the mic location a safer way to do it is to use diffusers that only diffuse high frequencies. Like the flutterfree from RPG, or DIY QRD diffusers designed for higher frequencies.

You could also scale this design down in size so that it works as a high frequency diffuser. If you do this it's a good idea to simulate it in Reflex before committing to the build.
Old 4th January 2014 | Show parent
  #404
Gear Addict
 
Arqen's Avatar
 
🎧 5 years
Quote:
Originally Posted by brncao ➡️
1. Yes. IF you have the right tools for the job. And patience. For efficiency, I recommend Festool's track saw (for the fractal diffuser) and router (for the stepped diffuser) equipped with parallel guides and guide rails. Festool uses the metric system (native), but can use imperial.

2. USA

3. Lumber and engineered wood (i.e. MDF, LDF, HDF, MDO, plywood), all in imperial, is ubiquitous here than any other construction material. However, bear in mind your design's maximum dimensions will mean special custom-order; they can be very expensive. 4+ in. thickness and >12" widths is not common here. Most likely there will be stacking and joining involved, which I hate.

4. Affordable? No. Accessible? Yes.

5. Whatever is cheapest, lightest, and strong. I'll have to do some research.

6. Circular saw and router. Looking to get some Festool stuff in there.
Great feedback! Thanks for taking the time to answer these questions. I appreciate it.
Old 21st January 2014
  #405
Gear Head
 
🎧 10 years
are there any negative effects if you add absorption by cutting slats or perforating holes (B.A.D. design) into the panel? I'm wondering if it's better to perforate holes into the leanfractal if it helps improve the low frequency.

From RPG's website: "The Diffractal® can be further customized to extend into lower frequencies by either perforating the wells to add low frequency absorption"
Old 22nd January 2014 | Show parent
  #406
Gear Nut
 
🎧 15 years
Hi . . . I plan to put a five panel array arranged with profiled modulation against the back wall of my writing/mix room. my listening position will be approximately 9-11 feet away. However, I plan to record drums in the back coner of the room as well (between 1-3 feet away from the diffuser) . . . my question, would the diffuser effect my drum recording in a negative manner?

Thanks!
Old 22nd January 2014 | Show parent
  #407
Gear Addict
 
Arqen's Avatar
 
🎧 5 years
Perforated sound diffusers

Quote:
Originally Posted by brncao ➡️
are there any negative effects if you add absorption by cutting slats or perforating holes (B.A.D. design) into the panel? I'm wondering if it's better to perforate holes into the leanfractal if it helps improve the low frequency.

From RPG's website: "The Diffractal® can be further customized to extend into lower frequencies by either perforating the wells to add low frequency absorption"
That's an idea I've been thinking of too and I'd love to see someone do it. The effects would depend on the size of the holes, the spacing and the pattern, but in general I don't expect it will hurt the diffusion performance.
Old 22nd January 2014 | Show parent
  #408
Gear Addict
 
Arqen's Avatar
 
🎧 5 years
Quote:
Originally Posted by Drzayuss ➡️
Hi . . . I plan to put a five panel array arranged with profiled modulation against the back wall of my writing/mix room. my listening position will be approximately 9-11 feet away. However, I plan to record drums in the back coner of the room as well (between 1-3 feet away from the diffuser) . . . my question, would the diffuser effect my drum recording in a negative manner?

Thanks!
It may effect the drum recording if your microphones are close to the diffusers. The recommended minimum operational distance for these diffusers is 8’-6”. (more details here: DIY Sound Diffusers FAQ)

My feeling is that you would be okay putting mics closer than that (e.g. 6’), but to be honest I can't recommend that because those are just feelings, and I don't know what anomalies might be happening at that distance. I would not worry about close mics, but you don't want your overhead mics and any ambient mics to be too close to the wall.

People break the minimum distance guidelines all the time with diffusers (look at all the RPG diffractals positioned directly behind the couch in many control rooms). Whether you choose to or not may depend on how critical the application is.

If you have other places that would benefit from diffusion you can build these, test them out near your drums, and if you notice any anomalies you can use the diffusers elsewhere.

Hope this helps.

-Tim
Old 23rd January 2014 | Show parent
  #409
Here for the gear
 
🎧 5 years
I am considering a 7 section A1LF with modulation 2 and I am wondering how other builders have dealt with implementation of the different depths, especially with regard to minimizing materials. I would like to attach the 7 sections directly to the wall using a french cleat approach. But I haven't come up with a solution as to the best way the achieve the 8cm, 10cm, 6cm depths. Any recommendations? Thanks

gab
Old 25th January 2014
  #410
Gear Maniac
 
🎧 5 years
start building 5 A1LF with Different staining methods,pic will come soon
thanks Arqen!!!
Old 26th January 2014 | Show parent
  #411
Gear Addict
 
Arqen's Avatar
 
🎧 5 years
Quote:
Originally Posted by gabkw ➡️
I am considering a 7 section A1LF with modulation 2 and I am wondering how other builders have dealt with implementation of the different depths, especially with regard to minimizing materials. I would like to attach the 7 sections directly to the wall using a french cleat approach. But I haven't come up with a solution as to the best way the achieve the 8cm, 10cm, 6cm depths. Any recommendations? Thanks

gab
Hi Gab,

I'm not sure how other people have done it, but one way to do it is build a frame like this where
  • || represents a vertical brace
  • pppp represents a piece of wood, plywood or mdf cut to the shape of the profiled modulation.
  • You can ignore the "....." horizontal parts in the drawing. That simply represents white space so just pretend those parts are invisible.

The frame would need vertical braces at the wall surface (aligned with the wall studs to mount the frame on the wall). It would also need braces at the diffuser panel mount surface.

Here is a rough top view of the concept, where only the braces on the surface of the structure are shown (there would be a separate set of brace at the base of the structure for attaching it to the wall studs).


ppppppppppppppppppppppppp
||.......||.......||.......||.......||.......||
||.......||.......||.......||.......||.......||
||.......||.......||.......||.......||.......||
ppppppppppppppppppppppppp
||.......||.......||.......||.......||.......||
||.......||.......||.......||.......||.......||
||.......||.......||.......||.......||.......||
ppppppppppppppppppppppppp

It may also be necessary to add some cross bracing for structural integrity.

The pppp profiled modulation pieces would define the shape of the modulation, while the | braces would be responsible for 4 things:
  1. Holding the frame together.
  2. Providing structural support for the mass of diffuser panels which will be mounted on the frame.
  3. Providing anchor points to attach the frame to the wall.
  4. Providing anchor points to attach the diffuser panels to the frame.


I would attach the frame to the wall, then attach the diffuser panels to the frame.

Hope this helps,
Tim
Old 26th January 2014 | Show parent
  #412
Gear Addict
 
Arqen's Avatar
 
🎧 5 years
Quote:
Originally Posted by dor baruch ➡️
start building 5 A1LF with Different staining methods,pic will come soon
thanks Arqen!!!
Awesome. Good luck and I look forward to seeing photos!

-Tim
Old 1st February 2014 | Show parent
  #413
Gear Maniac
 
🎧 5 years
my a1-lf and Staining methods

hi all:
i used pine for my first "leanfuser" and asked by People to Explain some simple! different methods of Staining them

Just for clarification for my pro works i use only Arti Articidol Water-Soluble Dyes or Something similar and pro Epoxy "lacquer" with pro spray gun compressor.


this pine woods is example of the three options


*first (From left to right) is the good spray can "rust-oleum" (black)
ultra cover paint +primer gloss...you have to sand all the woods with 180-220 sanding paper then 360-450 sanding paper and then clean it and use some cloth, spray one or two Uniform layers of paint. no need for extra lacquer


**second is Varnish Mahogany(tint) lacquer one layer, you can use Brush but i love to work with Cotton cloth and then 3-5 layers of "rust-oleum" gloss clear spray can lacquer, first layers are Very thin and then more Thick layers
30-60Minutes from one layer to Other

***Third is black Water-Soluble Dye you need to sand the wood you can use sealer lacquer if you want and only one layer of color and then 1-2 of "rust-oleum" gloss lacquer

i didnt do it this time but after the lacquer Dry you can sand it with 400-500 sanding paper and Polish it with some "Polish" (i use car "Fine"! wax polish turtle wax)









Old 2nd February 2014 | Show parent
  #414
Gear Maniac
 
🎧 5 years
the a1-LF













Old 3rd February 2014 | Show parent
  #415
Gear Addict
 
Arqen's Avatar
 
🎧 5 years
Quote:
Originally Posted by dor baruch ➡️
hi all:
i used pine for my first "leanfuser" and asked by People to Explain some simple! different methods of Staining them

Just for clarification for my pro works i use only Arti Articidol Water-Soluble Dyes or Something similar and pro Epoxy "lacquer" with pro spray gun compressor.


this pine woods is example of the three options


*first (From left to right) is the good spray can "rust-oleum" (black)
ultra cover paint +primer gloss...you have to sand all the woods with 180-220 sanding paper then 360-450 sanding paper and then clean it and use some cloth, spray one or two Uniform layers of paint. no need for extra lacquer


**second is Varnish Mahogany(tint) lacquer one layer, you can use Brush but i love to work with Cotton cloth and then 3-5 layers of "rust-oleum" gloss clear spray can lacquer, first layers are Very thin and then more Thick layers
30-60Minutes from one layer to Other

***Third is black Water-Soluble Dye you need to sand the wood you can use sealer lacquer if you want and only one layer of color and then 1-2 of "rust-oleum" gloss lacquer

i didnt do it this time but after the lacquer Dry you can sand it with 400-500 sanding paper and Polish it with some "Polish" (i use car "Fine"! wax polish turtle wax)

Awesome. Thanks for sharing these finishing details!

-Tim
Old 7th March 2014
  #416
Here for the gear
 
AbreMuertos's Avatar
 
🎧 5 years
Hi Tim.
Thanks for all the info you provided.
I´m building a A1-LF (frac) diffuser using the exact dimensions of blueprints, but I´m kind of confused about the dimensions of the fractal cells.
I will use de array of 5 modules with profiled modulation 1.
I´m not good with numbers. I understand the fractal cells are 55mm wide; 20 cm tall; and 6mm fractal depth -after milling.-
¿Is that ok?
Also, I would like to follow your idea for making the diffuser/absorber you suggested.
I´m using the Helmoltz resonator calculator you suggested.
¿Which frequencies should I work with?
¿Should I mesure my room first or there is a standard recommended frequency I can choose to absorb for rear wall?
¿Should all modules have to absorb the same frequency or may I alternate them with different absorption coefficients on each module?
Mi room is irregular with an oblique ceiling, openings for the next room and a very short hallway entrance -More or less 3 mt x 3mt x 4mts.
The room is already treated with bass traps, panels at early reflections, dead wall in front of speakers (everything how is supposed to be). I just need diffusion in my rear wall (got room for the 5 module array)
Thank you very much.
Old 8th March 2014 | Show parent
  #417
Lives for gear
 
Miiko's Avatar
 
🎧 10 years
Quote:
Originally Posted by dor baruch ➡️

First, nicely done.

Second, don't ever use postimg.org... it is a spam filled virus trap full of pop up porn ads. I made a mistake clicking your pictures at work.

USE IMGUR BRO PLS
Old 10th March 2014 | Show parent
  #418
Gear Addict
 
Arqen's Avatar
 
🎧 5 years
Helmholtz resonator / diffuser

Quote:
Originally Posted by AbreMuertos ➡️
Hi Tim.
Thanks for all the info you provided.
I´m building a A1-LF (frac) diffuser using the exact dimensions of blueprints, but I´m kind of confused about the dimensions of the fractal cells.
I will use de array of 5 modules with profiled modulation 1.
I´m not good with numbers. I understand the fractal cells are 55mm wide; 20 cm tall; and 6mm fractal depth -after milling.-
¿Is that ok?
Also, I would like to follow your idea for making the diffuser/absorber you suggested.
I´m using the Helmoltz resonator calculator you suggested.
¿Which frequencies should I work with?
¿Should I mesure my room first or there is a standard recommended frequency I can choose to absorb for rear wall?
¿Should all modules have to absorb the same frequency or may I alternate them with different absorption coefficients on each module?
Mi room is irregular with an oblique ceiling, openings for the next room and a very short hallway entrance -More or less 3 mt x 3mt x 4mts.
The room is already treated with bass traps, panels at early reflections, dead wall in front of speakers (everything how is supposed to be). I just need diffusion in my rear wall (got room for the 5 module array)
Thank you very much.
Glad to hear you want to build a fractal diffuser / Helmholtz resonator hybrid.

If you use my standard dimensions, each well in the fractal is about 60 mm/7 = 8.6 mm wide. The two outside wells have a depth of zero, so we can ignore them. When you multiply the 8.6 mm fractal well width by 5 you get a total width of 43 mm for the fractal cell. You then glue these fractal cells on top of the 60 mm wide stepped diffuser wells.

However, if instead you use Schaap's dimensions here, each stepped diffuser well is 60 mm wide, and each each well in the fractal is 56 mm/7 = 8mm wide.

This part is flexible but I recommend a fractal depth sequence of about [0, 22, 28, 17, 28, 22, 0] mm deep. In other words, the total height of each fractal cell would be 22 mm deep (or "tall").

Bear in mind that Helmholtz resonators are hard to tune and they are not a replacement for broadband bass trapping in small rooms. I can't guarantee whether or not the effects of the Helmholtz resonator will be noticeable in your room, but I encourage you to try it. It's a neat idea to explore.

In general for the Helmholtz resonator you could try aiming for a center frequency between 80 - 120 Hz, and use some medium density fibrous absorption in the cavity to widen the bandwidth. I would try various center frequencies for the different modules. Maybe 80 Hz, 100 Hz, 120 Hz, 100 Hz and 80 Hz (if you're doing 5 modules) or 80 Hz, 95 Hz, 110 Hz, 125 Hz, 110 Hz, 95 Hz, 80 Hz (if you're doing 7 modules).

Does that make sense?
Old 11th March 2014
  #419
Gear Head
 
🎧 5 years

Last edited by hornguy; 11th March 2014 at 12:36 PM.. Reason: already asked
Old 11th March 2014
  #420
Gear Head
 
🎧 5 years

Last edited by hornguy; 11th March 2014 at 12:36 PM.. Reason: already asked
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