BroadBand Bass Trap's Build

**cinema mad** · **12-28-08, 09:27 PM**

Hi Prof Merry Xmas and happy new year...
My biggest concern is being surrounded with posinous Fiberglass

As far as the Diffusion Tiles I can make them as long as I want but the well sequance is 4" wide total, so I can make them 4" /8' /12" and so on but you have to stay within the mathamatical formula..
They are Diffusors disigned to deal with fluter Echo in the higher frequency's but I can also mount with an air gap & add fiberglass behined them to absorb the lower frequencys....

So they will reflect in the lower frequencys if I dont design them to absorb the lower frequency's and they Diffuse not reflect in the higher frequencys...

The 2'x4' BroadBand nested diffusors are the most complexed ones I will be building

but also the best performance....
Retail they are over $2000AU each in Australia for simlar design performance But you should'nt be seated any closer than 6ft from them for Best performance because of the Well depth I will be using....

Cheers....

**Prof.** · **12-29-08, 05:37 PM**

Thanks Jason and all the best for the new year..

Quote:

cinema mad wrote:

The 2'x4' BroadBand nested diffusors are the most complexed ones I will be building

but also the best performance....
Retail they are over $2000AU each in Australia for simlar design performance But you should'nt be seated any closer than 6ft from them for Best performance because of the Well depth I will be using....

Cheers....

I'll be very interested to hear your results on all these panels..and some pics during the build would be great..

**cinema mad** · **01-12-09, 09:20 AM**

I Made up some Acoustic Diffusing Tiles for the control of Flutter Echo, The design of these Tiles are Built using the quadratic residue sequence and based on A Prime 7 well 1-Dimention QRD Reflection phase grating principle....with the seventh well being formed when two tiles are placed beside each other....

As mentioned above I tried MDF but it kept splitting so I went with A hard wood "Tasman Oak" and had success...They are not that easy to make very very time consuming and A router bench with high quality router bits is A must for A clean precise finnish....
I am not sure wether to stain them to bring out the beautiful grain or paint them black

...

So far I have only made around 10 tiles as A trial run the next lot I will make will be 3ft long made from Tasman Oak hard wood....

More to come, Let me know what you think so far....

Cheers...

**Prof.** · **01-12-09, 05:23 PM**

Very nice job Jason..

That looks like an awful lot of work!!..How many tiles did you say you're making?
I think they would look great stained and providing that it's fairly dark stain, you should have minimal light reflection from them..

**cinema mad** · **01-12-09, 09:57 PM**

Hi Prof, Yes your right that it is A lot of work in making these tiles But the main thing is that because the well depth is only small you are able to be seated closer to them unlike the primitive-root & nested QRD type Diffusors.... These tiles are the less complexed to make compared to the other Diffusors I will be making....

At this stage I am unsure exactly how many of the tiles I will make/need but most will be 3ft long as to cut down on the layout of each tile.... Once I do some more in room analysis with the "future" ETF acoustic mesurement software I will have more of an idea...

No work today to hot ment to be"37deg" here let alone where you are in SA "41deg", some places in SA are upto '43deg" today

.....

Cheers....

**cinema mad** · **01-18-09, 12:09 PM**

I finnished some of my flutter echo tiles today, I built some 3ft long tiles and stained them black with A gloss clear coat, these ones will be hung from the very top of the side walls but slightly angled down & placed near the side surround speaker position as A starting point....further room analysis with Acoustisoft R+D will help determine there final position...

If any one is looking for some good info on room Acoustics & Treatment the Forth Edition MASTER HANDBOOK OF ACOUSTICS is A must and where I have sourced much of my Ideas such as these Flutter Echo Diffusors.. But it should be Noted that this book does not give you the exact messurments of well depth and well width for IE: Flutter Echo Diffusors but does provide the mathamatical tools to help work it all out....

In the near future I will build some nested BroadBand Diffusors but they will have to wait untill I have finnished the rest of my Flutter Echo Diffusors

....

The well sequence and depth to make your own Flutter Echo Diffusors are as follows

The width of each well is 10mm with A 3-4mm wide fin...(quadratic residue sequence 0,1,4,2,2,4,1 prime number of 7)
1. The first is 0mm
2. Then 5mm deep well..
3. Then 3-4mm fin followed by A 20mm deep well
4. Then 3-4mm fin followed by A 10mm deep well
5. Then 3-4mm fin followed by A 10mm deep well
6. Then 3-4mm fin followed by A 20mm deep well
7. Then 3-4mm fin followed by A 5mm deep well
8. Then last is 0mm...

See the Picture I have Attached for the layout Dimentions...

I should menton that you MUST route groves in the back of the hard wood to releave the tention in the hard wood coursed by routing the Wells in the Front in order to stop warping....
Also To make these Diffusers Takes wood working skill and is very labour intensive

...

Cheers.....

**Prof.** · **01-18-09, 06:12 PM**

They're much smaller than I imagined..
How many of those strips do you place in each position?

**cinema mad** · **01-18-09, 09:17 PM**

To Diffuse horizontaly they are hung verticaly so as A starting point mine will be hung verticaly, In most case's the first row of Diffusors at the top are hung verticaly and then underneath that they are hung horizontaly..

The total width of the Flutter echo tile is 4", But if you wanted you could repeat the Quadratic Residue Sequence but this would need to inclued the seventh well that is formed when the Tile is placed together......

What do you think of the Finnish on the Tasman Oak ?, I am happy with it....
Cheers....

**Prof.** · **01-19-09, 05:40 PM**

Yeah..looks good..
What did you use to get that colour?

**cinema mad** · **01-19-09, 09:27 PM**

Thanks Prof,

To stain the Tasman Oak hard wood I used 500ml Wattyl professional stain "Black" and the clear Gloss was 1lt Wattyl Estapol Gloss, Polyurethane Based... Purchased from Bunnings

I loved the red wood stains but wouldnt go with my Black walls, I dont want the Diffusors to stand out to much...

Cheers....

**cinema mad** · **01-20-09, 02:12 AM**

Here is A picture of the V cut into the back of the Flutter Echo Diffusor tiles to help stop warping caused by the wells in the front of the Diffusors...

Cheers....

**cinema mad** · **01-20-09, 02:48 AM**

Couple of Pictures of A ROUGH setup to give you an idea of where and how they will be placed, In the Final setup The Diffusors will all be custom cut to fit the exact hight/length needed for A perfect fit...

It is important to note that The Flutter Echo tiles will be placed at Ceiling hight and one 4" wide continuous Diffusor will be hung horizontaly at the top where the ceiling and side walls meet and slightly tilted down all the way along the left and right side walls in the room, underneath them the diffusors will be hung Verticaly in carefully chosen places.....

IMO Diffusion is often overlooked by most & is just as important as Absorbtion, and can be as affective if applyed correctly....
QUOTE "Its Application converts small rooms with flat parellel sufaces into functional spaces with good SPEECH INTELLIGIBILITY, SOUND QUALITY,AND A NATURAL,COMFORTABLE AMBIANCE....

The down side of Diffuson is that it is much more complexed to design build and apply than Absorbtion and it costs more to manfacture....

Cheers....

**Mike P.** · **01-20-09, 05:00 AM**

Looking good, Jason! Do you notice an improvement in the sound with the tiles in place?

**cinema mad** · **01-20-09, 06:52 AM**

Hi Mike And thanks for your complement...

I only put them up today Roughly so I could post pictures, so I have'nt put them through there paces But I left them in place for now because I Have Eagle EYE on Blu-Ray so I will let you know what I think....

I have to make heaps more to the required length before I can install them permanetly and
so they hopefully look like they belong, unlike the above picture of the Diffusors placed around the surround speakers ... I got another 20mt of Tasman oak today and have already used around 15mt

I would say I will end up using 40-50mt of the stuff

....

Cheers....

**robbo266317** · **01-20-09, 01:56 PM**

I bought some Tassie Oak before Christmas, it's not cheap...

Did you keep the shavings to do some home smoking? My local sawmill used to put a 20kg bag of sawdust aside for me in return for a couple of smoked trout!

**Prof.** · **01-20-09, 05:56 PM**

Quote:

cinema mad wrote:

Couple of Pictures of A ROUGH setup to give you an idea of where and how they will be placed, In the Final setup The Diffusors will all be custom cut to fit the exact hight/length needed for A perfect fit...

It is important to note that The Flutter Echo tiles will be placed at Ceiling hight and one 4" wide continuous Diffusor will be hung horizontaly at the top where the ceiling and side walls meet and slightly tilted down all the way along the left and right side walls in the room, underneath them the diffusors will be hung Verticaly in carefully chosen places.....

IMO Diffusion is often overlooked by most & is just as important as Absorbtion, and can be as affective if applyed correctly....
QUOTE "Its Application converts small rooms with flat parellel sufaces into functional spaces with good SPEECH INTELLIGIBILITY, SOUND QUALITY,AND A NATURAL,COMFORTABLE AMBIANCE....

The down side of Diffuson is that it is much more complexed to design build and apply than Absorbtion and it costs more to manfacture....

Cheers....

Very interesting Jason..
So these tiles are placed beyond the first reflection point..somewhere near the second reflection point?

Any particular reason for coating them with gloss Estapol?..I think they will look distractingly shiney when you're projecting..

**Prof.** · **01-20-09, 05:59 PM**

Quote:

robbo266317 wrote:

I bought some Tassie Oak before Christmas, it's not cheap...

Did you keep the shavings to do some home smoking? My local sawmill used to put a 20kg bag of sawdust aside for me in return for a couple of smoked trout!

Good point about the shavings..

I could do with some myself for smoking Carp

..

**cinema mad** · **01-20-09, 07:40 PM**

Hi Prof, & thanks for your post...

I have A two stage riser with two rows of seating, so I set up first reflection absorbtion for both... The idea is that between the 2 reflection points you can have Diffusion this is one place where my Advanced BroadBand QRD nested Diffusors will be placed for the higher performance once built...With this type of Diffusor the seating position should not be any closer than around 6ft Due to Well depth....

For the picture I put the flutter Echo diffusors in this position to show where they can be placed But as pictured above they will be placed mainly around the surround speakers with A small amount of absorbtion and where the side wall and ceiling meet. So that is why I whent gloss but I totaly agree with you Prof that if they were permanatly placed between the first reflection points that flat black is more appropriate...

Cheers....

**cinema mad** · **01-20-09, 07:49 PM**

Quote:

robbo266317 wrote:

I bought some Tassie Oak before Christmas, it's not cheap...

Did you keep the shavings to do some home smoking? My local sawmill used to put a 20kg bag of sawdust aside for me in return for a couple of smoked trout!

Hi Robbo,Thanks for your post..

Yes I have heaps of the Tasman oak sawdust, so far from all the routing I would have around A 80lt bin full.
Did'nt know they use that to smoke trout, I was going to use it for the kids Guinea pig beding

....

FWIW I am paying around $5.80au per meter for 140mm x 35mm F17 tasman oak hardwood... One I run it through my thicknesser to dress it it comes up nice...

Cheers....

**robbo266317** · **01-20-09, 07:59 PM**

I've smoked quite a few over the years with Tassie Oak and the only complaint was from the old bloke at the sawmill who saved me the sawdust missed out one time as the others had an early lunch and found them in the fridge first.

**raZorTT** · **01-20-09, 09:54 PM**

Jason,

Which facing did you get the ultratel with? Would they make much difference?

Cheers,
Simon

**cinema mad** · **01-21-09, 03:06 AM**

You need the ultratel with no facing for BroadBand Bass traps, If you want to block out high frequencies you can just use A Brown paper membrain like the Tuned bass trap on the first page check it out .....

**raZorTT** · **01-21-09, 06:33 PM**

Thanks Jason

**cinema mad** · **01-24-09, 08:53 AM**

Once I Dress the 140x35 f17 Tassie oak through my Surface Planer down to 25mm thick it comes out like the more Expensive pre Dressed 32mm Tasman Oak

......

Where would we be without power tools.....

Cheers.....

**Prof.** · **01-24-09, 06:28 PM**

Very nice bit of gear...Man would I love to have one of those in my workshop..

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