How I built my bass traps...

[Adlen]

Originally Posted by chezballs

Ya, got it... but any idea if the canvas printing you can have done at say Costco would do the same thing?

Probably, I have never felt one though so I'm not certain.

[Mister Fox]

A question regarding most builds from the last 10 pages or so...

Most of these pictures look like you built 20cm (or 8") deep panels, or are these just 15cm (6") and 10cm (4") panels?

[trafficarte]

Originally Posted by Mister Fox

A question regarding most builds from the last 10 pages or so...

Most of these pictures look like you built 20cm (or 8") deep panels, or are these just 15cm (6") and 10cm (4") panels?

Mine are 5cm and 12cm deep, the smaller are removable from the walls so I can use them as gobos.

[Mister Fox]

So you put 6-8cm holes into the 12cm frame, am I getting this right?

Personally I'm interested in the sizes of the absorber from Nervrem (I do like the design) and Jason Baliban since they look more like 20cm frames (8") rather than 10cm ones (4").

[trafficarte]

Originally Posted by Mister Fox

So you put 6-8cm holes into the 12cm frame, am I getting this right?

I've done the holes to make the structure lighter and to improve the total exposed surface, but after some calculation i discovered that the latter is minimal ( less than 10%...)
I've also found some spots in the studio with impressive bumps in the bass range, one of them in a niche behind a pillar. With some experiments I've found the right quantity of absorbent material to be put there.
Voilà! All major issues in the bass range almost resolved with a minimal effort.

[mtbdudex]

Been reading gearslutz for almost 1 year, kinda new at posting here.
I made these movable SSC for the rear of my Home Theatre, sharing here.
(I need access to the rear so these can't be built into place)
This was before I knew that for these big/deep ones pink fluffy was better than the OC705 I used.

removable lower corner superchunk bass trap made with 1/2-13 thd rod and OC705


Each stack is (6) sheets of 2" thick 2' x 4' OC705 panels, cut 24" x 24" x 34".
The 24 triangles stack just over 48" high, I've decided to make them removable "corner tables".

fwiw: I have some Star Trek stuff to display, the 3D chess set, some ST:TOS replica phaser and tricorder, etc, collected over 20+ years.
So, the top will be nice wood, while the bottom possible mdf or even some leftover OSB I have. The 1/2 thd rod comes in 72" size.

Now, above that display zone, which will get light w/o shadows via the sconces, will either be a 17" x 17" x 24" superchunk as shown on LH side, or a more visually pleasing triangular patch as shown on RH side, tbd.

(the boys and I watched a movie last night, sorry for the clutter)

Regarding cutting the superchunks out of the 2' x 4' sheets, I started with the big bread knife, did 4, then tried the electric turkey knife.
My experience, the manual knife was MUCH easier to get dead straight and perpendicular lines cut, the electric knife seemed to walk on its own slightly, giving a wavy edge, not style points.


Here you can see what I'm talking about.
The bottom 4 were cut by hand/bread knife, the next 4 by electric knife.
It's not that much more time for hand/bread knife, 1st pass with edge guide sets the line, then 4 more passes holding the knife at a low 15-20 degrees gives perfect straight and perpendicular edge.
I suppose a jig could be made to ensure the electric knife is straight and perpendicular, but this manual method worked for me easily.


in the garage, via makeshift paint/infra red warm booth I'm painting the thd rods......and the attach nuts/washers


-final cut/paint the OSB base.
I added a 1 1/4 perimeter of 3/4 OSB so the thd rod/nuts won't be resting on the floor directly. Painted green, same as walls.


-Final cut/sand/stain the birch top board


Maybe tomorrow these "Mikes Mondo Corner Bass traps" might get assembled and put into the room.
Each will weigh 50+ lbs, looking back at my original plan of 1 huge removal bass trap.....nope that's 100+ lbs of weight, glad I went "1/2 size" then an additional trap in the top corners

Good progress made today on these beasts, they are huge, big, and sturdy
(YouTube video clip will show that)

Layout the cut big triangles, cut back corner 3" x 3" 45 deg for clearance to rear thd rod


Stack 'em, trying to keep the leaning tower straight/aligned as it gets higher...


Me next to my the 4' stack, showing size of this beast.
However, mistake I made was NOT putting the rods in 1st before loading the triangles, so I had a PIA to get the rods in...lesson for #2
After fiddling here are the rods installed



I did NOT pre-cut the thd rod in the garage, had no way of knowing how much the OC705 would compress.
I actually can compress easily 1", more than 2", but the 1/2" birch ply top flexes too much at 2", I settled on 1" of compression, it felt very sturdy and solid.
Green tape for cutting spot, my wife held the rod top while I used a Dewalt 18v buzzsaw.
Load in room, check for ingress/egress of loading the trap etc.
No other issues appeared to prep for fabric covering time


Cut the mid-hi freq blocker (kraft paper here) for the front face, install and hold with simple 1 3/4" craft pins


Cut the 56" wide fabric (roll size), for this first one I cut just 3/4" extra top/bottom (to 50", compress size is 48.5 "), it worked but for the 2nd one I increased that to 1" top/bottom extra for wrapping safety.
I should say this is a GLUE-LESS/PIN-LESS build for the fabric, I just use pins for the top to start, put the top birch ply board down and compress/tighten, keeping fabric not attached, and tuck the fabric in at the bottom.


1st one "done", front face side


cont....

Backside looks good, needs covering


Now, the 2nd one went much quicker and smoother!
Make a 3 rod frame with base and top, gave 5" extra for loading.
This worked best for aligning the loose big triangles for flatness.


Kraft paper installed on 2nd bass trap:


Close-up showing 1" of extra material on the top before clamping down the birch ply.


2nd one done, and backside covered


Loaded into the HT room, RH side one is the 2nd one made, it came out a little better.


YouTube video showing how these can be moved around.

[Al Nutrition]

Ive done 6 pcs of 60cmx120cm panels out of 10cm rock wool that has density of about 100kg/m3 .

I was wondering, if i stack Rockwool Flexi Batts-bales in their wrappings to the corners of my room (floor to seiling) will they work ok as a bass trap? The density is about 31kg/m3



Flexi-Batts vuorivilla 570x1170x100 4m2/pkt - Rautakauppa Taloon.com

[mtbdudex]

Part II Upper corner superchunk bass trap using 1/2-13 thd rod.
Note: Made these 1 year ago, this was before I knew that for these big/deep ones pink fluffy was better than the material I used.
Still, this 1/2-13 thd rod method could easily work with pink fluffy.


Starting from here:


Plan out the cuts to maximize material usage....I had an image on how to do this and just sketched it out like this.
Each sheet I used as fully as possible.


Using newly made templates for the 23 1/8" x 47 1/8" sheets I have, start cutting and stacking, cut in reverse order, ie, the big one first and smallest last.
This is big template........................Smallest template showing placement


This cotton product is much harder to cut thru than OC703/705, so I bring out the turkey knife. Still cuts came out not nicely, determined my blades were dull and sharpened them, much better after sharp blades.



2 traps cut and stacked! I will use those "extra" pieces shown, part of my material usage plan.


I was not 100% satisfied with how the lower corner bass traps edges looked, so decided to tryout using drywall edging. I picked the white paper covered ones to minimize any issue with shiny reflection being seen thru the fabric. If need be, I would have painted them green, but that was not needed.


I used fishing line to secure the the bottom side and screws the top side.


1 done with material stacking, added loose pieces with sticky spray, worked great.


Putting on the Kraft paper to block mid-hi frequencies:


1st one wrapped and done!
Those drywall edges made all the difference, I'm going to add those as lesson learned to lower bass trap post. Much crisper look.




Installing into the HT room.
I used a 30+ year old hydraulic bottle jack as 3rd hand...


The upper bass traps are just sitting on (2) L brackets each, gotten from Lowes in the outside deck building area, painted them green.
By simple geometry they are trapped up there, not even attached screws to lower wood piece.
I did put 3/4" round felt on the top/ceiling piece to space it off the ceiling and ensure no vibrations.
Also on the wood edge to space it off the back/side walls, no issue with vibrations at all.




Both installed


Detail LH side....................................RH side


That completes the Rear wall broadband bass treatments.

[kasmira]

Uh, that looks freakin' AMAZING Mike! Good work!!

More importantly...how does it sound?

And if you did test the room, you should post the results up!

Again, congrats on the build. The drywall definitely helps give a sharp, great looking edge. Also love the odd shape of the ceiling/wall/wall corner traps.

[djtrailmixxx]

Sorry, not allot of detailed pics for you. I built these after lurking on these forums. Frames are 1"x8" pine, 83" tall and 23" wide, stained. 6" (2 layers) of Roxul Safe n' sound. Lots of pricey black fabric that breathes, held down by 5/8" quarter round molding.

[IMG]******//i28.photobucket.com/albums/c249/djtrailmixxx/Audio-Video/meboxes.jpg[/IMG]

[IMG]******//i28.photobucket.com/albums/c249/djtrailmixxx/Audio-Video/installed.jpg[/IMG]

Thanks to EVERYONE in this excellent community, I swear my mixes are slowly improving/translating better.

[nquit]

Mike - beautiful room!

Is the kraft paper on your bass traps your "limp membrane" to reflect some highs and increase low freq absorption a little?

[mtbdudex]

Originally Posted by kasmira

Uh, that looks freakin' AMAZING Mike! Good work!!

More importantly...how does it sound?

And if you did test the room, you should post the results up!

Again, congrats on the build. The drywall definitely helps give a sharp, great looking edge. Also love the odd shape of the ceiling/wall/wall corner traps.

Thx kasmira - I had to dig for some before charts, taken so many measurements over the years, start/stop, some uploaded to picasa web, some in folders......

How does it "Sound"? - subjectively night and day, truly I can feel a pressue wave come over me, when guest come over love to demo some LFE movie clips. (Kung Fu Panda Ska-doosh is favorite)
The 2nd row now has consistent seat-seat response - and room gains clearly shows, the 1st row still some nulls to work out.

The problem with taking data - or maybe just my problem, when I get data/analysis, then I know the issues in my HT. Nobody else, I mean nobody else hears them.
Everyone is overwhelmed because it is so much better than what they have in their home.
Anyway, guess OCD comes with the HT hobby.


For reference, here is the HT layout/other info:


Before, these are from Jan-2009 timeframe, 2nd row seat #6 only shown here.
There was seat-seat variation in 2nd row back in 2009.
These are from when I was trying different PEQ filters.
The purple is before any filters, the middle green is after 2 PEQ filters.




after, these are from July-2011 time frame:
These are all via the Ext In, no Audyssey EQ applied,no PEQ applied either, raw IB sub <> room response.
1st row has seat-seat variation, yet the modal ringing is decent and bass sounds very clear.




Here is 2nd row, these are the "money seats" for LFE!
Room gain shows itself clearly.




Hopefully not TMI....if so I can edit out some charts.....
For fun, heres a video clip of KFP "skadoosh" made back in 2009....be kind to me

[mtbdudex]

Originally Posted by nquit

Mike - beautiful room!

Is the kraft paper on your bass traps your "limp membrane" to reflect some highs and increase low freq absorption a little?

Exactly, advice from Ethan W is thick kraft paper works fine for mid/hi freq reflection, and you should adhere it to the porus material via spray ashesive for some limp membrane effect.
Others have said use 6mil plastic, my wife has lots of the 3' wide thick kraft paper, so I used that.

[Shilla]

i am NOT really capable of making these myself; i'm sure I'd end up messing them up and wasting money!

you guys are driving me crazy with these awesome bass traps.

anyone want to build 4 for me????? just kidding .. no seriously????

[Metatron One]

Originally Posted by Shilla

i am NOT really capable of making these myself; i'm sure I'd end up messing them up and wasting money!

How to make rockwool acoustic panels - YouTube



Above is a two minute youtube video that will walk you through the construction of something that is basically like what you find in this thread. The extra holes in the sides of some of the models endorsed by members here represent a "next level" that you don't have to hit in order to benefit.

The standard panels will still help you out and can be made with

cheap lumber

cheap fabric

relatively cheap rockwool insulation

Staples, screws and you're done.

Very little for you to mess up.

[kasmira]

Hello slutz,

I really wanted to post a new thread because this is awesome, but I decided it'd be better to just post this in a general thread instead.

So yesterday I was at work, and had to go above some of the offices (some of our rooms are built into our warehouse, so we store stuff above the rooms) to put some boxes up there. While I was up there, I found a goldmine. An almost full 100' x 47" roll of Johns Manville Linacoustic RC, as well as a 4' x 8' sheet of CertainTeed rigid fiberglass. As we are renting the place, we obviously didn't leave it up there, so my boss let me take it home. In the process of cutting it up now.

Unfortunately, both are faced and are only 1" thick, so I'll have to spend some time ripping off the facing. But, looks like my panels will be finished by this weekend! I'll be quadrupling the JM up to make 4" thick panels. It doesn't look like much of it at all was used, so I should be able to build around 10 panels with the insulation. **** yeah, life is good.

[FoxMulderFBI]

Guys, one noob question. I want to build bass traps, but I wanted to know, if I put fiberglass or rockwool in a thin plastic bag and than some fabric around to make it look nicer, will this work regarding absorbing lower freq's? I asked that because everywhere I see and hear that fiberglass is not good for health and I plan to spend a lot of time in that room, so....

[natureloop]

Hi there and thumbs up for the great contructions!

I am looking for alternatives to rockwool/fiberglass and came up with the acoustical cotton solution while surfing. Then I thought, would it be possible to construct a 4'' width frame and fill it in will unwated clothes made of cotton/various fabrics etc?!

Would that work? About how many kgs would a 4'x2'x4'' trap need to weight?

Thanks
Costas

[Jens Eklund]

Originally Posted by FoxMulderFBI

I asked that because everywhere I see and hear that fiberglass is not good for health and I plan to spend a lot of time in that room, so....

******//www.gearslutz.com/board/bass-...ml#post6519664

******//www.gearslutz.com/board/bass-...ml#post6519627

[rowlow]

Hi,


I have a question regarding to the normal panels. The normal measurements of a panel is about 47 to 21 inch, is this the standard? Will a smaller panel placed on the reflecting-point work or is it in the measurement?

Thanks!

[rowlow]

I have a question regarding to the normal panels. The normal measurements of a panel is about 47 to 21 inch, is this the standard? Will a smaller panel placed on the reflecting-point work or is it in the measurement?

Thanks!

Please stop sending me inbox-messages. My account can't handle the amount of reactions that you all provided me with. Pffffff you are so helpfull, slutz!

[Zownd]

Originally Posted by rowlow

Please stop sending me inbox-messages. My account can't handle the amount of reactions that you all provided me with. Pffffff you are so helpfull, slutz!

there is no standard. so smaller or bigger could be fine either way.
I guess most people stick to the size of the rockwool.

The biggest panels in my studio are 1.40 x 1.00 x 0.17 (in meters)
The smallest 0.85 x 0.25 x 0.08.

not sure if this helps.... but as anything else in audio, there is no standard.

cheers,
Mark

[rowlow]

Dankje!

[mtbdudex]

Use ETC as a tool for size and placement of your RFZ panels. Threads here, search.

[natureloop]

Hi there guys,

I will be using rockwool and would like to know what is more preferable choice for bass traps. I can have the following choices:
1) 6cm 75kg/m3 rockwool
2) 10cm 50kg/m3 rockwool
3) 10cm 75kg/m3 rockwool

Which one would have the most prerefable absorption for bass trap use?

Cheers
Costas

[Zownd]

Originally Posted by natureloop

Hi there guys,

I will be using rockwool and would like to know what is more preferable choice for bass traps. I can have the following choices:
1) 6cm 75kg/m3 rockwool
2) 10cm 50kg/m3 rockwool
3) 10cm 75kg/m3 rockwool

Which one would have the most prerefable absorption for bass trap use?

Cheers
Costas

Is this purely meant for bass, or for all frequencies?

[natureloop]

Originally Posted by Zownd

Is this purely meant for bass, or for all frequencies?

Hi Zownd!
I could call this "Zero latency in responding"! Thanks!

I would mostly go for the low end but I guess the rest of the spectrum is also affected. The room is about 50m^3 and I am planning to DIY and install
1) about 10 absrorbers diagonally at where pairs of walls or wall-ceilling meet.
2) about 3-4 panels (half the size) at first reflection points.

Hope that helps.
Thanks again!

[Zownd]

Originally Posted by natureloop

Hi Zownd!
I could call this "Zero latency in responding"! Thanks!

I would mostly go for the low end but I guess the rest of the spectrum is also affected. The room is about 50m^3 and I am planning to DIY and install
1) about 10 absrorbers diagonally at where pairs of walls or wall-ceilling meet.
2) about 3-4 panels (half the size) at first reflection points.

Hope that helps.
Thanks again!

I am not saying that I will no it all!
but just did my own room with the help of "Jelle van der Voet" of "Mutrox" here in the Netherlands and it is turning out fine.

I used multiboard rockwool which I believe is 55kg/m3
this is great for first reflections.

I used 15 cm for the sidewalls as they are very near and 10 cm for the ceiling.
I made basstraps with the same stuff. the bass traps are 90 cm deep. and work great.

If you want the basstraps to handle the whole spectrum I would not go above the 55kg
If it's only bass, theoretically you could go a bit further.

I am sure you'll get better replies from more experienced guru's in this forum

Cheers,
Mark

[cybernaux]

Hello,

I built 4 bass traps - that I'll soon post the pictures - with rockwool. But now that the job is done I'm thinking to make a little change..

Would it be, sonically speaking, bad to add one layer of styrofoam? (Just to insure that any fiber gets out) Some of the HF would not be absorbed, but could it degrade to much the bass trap function?

0.4 inches a panel of styrofoam?

Bests regards,
Dias

[J.S.Vega III]

Originally Posted by cybernaux

Hello,

I built 4 bass traps - that I'll soon post the pictures - with rockwool. But now that the job is done I'm thinking to make a little change..

Would it be, sonically speaking, bad to add one layer of styrofoam? (Just to insure that any fiber gets out) Some of the HF would not be absorbed, but could it degrade to much the bass trap function?

0.4 inches a panel of styrofoam?

Bests regards,
Dias

If you covered the panel with material that will stop any fibers from escaping perfectly well. Don't worry about it!