DIY Bass Trap

[tecmo04]

http://www.diy-home-theater-design.com/bass-trap-build.html

Im thinking about trying to build a bass trap. Anyone ever try this? Opinions as to if it will work?

[GV#27]

According to some acoustics experts that design will have no effect and is a waste of material.For a bass trap to work it must be absorbative ,that sonotube is just a reflector.However their are several inexpensive and easy to build bass traps designs.I will dig up the links and post them for you when I get a few minutes.

[GV#27]

http://webpages.charter.net/jdgeisen/BassTraps/BassTrap1.htm

[unc2701]

Yep, that sonotube won't do crap. The design GV links to is way better, but probably won't hit the standing wave frequencies most people have in their rooms.

Look into slat helmholtz resonators, panel resonators, and if you can afford to lose about 3'-4' in your corners, the design as above.

Of course the first step is an SPL meter and some test tones to see how bad your room is and where the problems are.

[RuSsMaN]

I wish it was that easy. (link in orig post)

[GV#27]

If you can afford to give up the corners of your room (this is were bass traps are most effective) Super Chunks are the Queen Mom of bass traps.http://www.bobgolds.com/TrapHarder/home.htm
http://forum.studiotips.com/viewtopic.php?t=535

[tryrrthg]

This page is pretty much the standard for bass traps that I've seen around the forums. The cylinder trap is probably one of the most effective traps.

http://www.geocities.com/jonrisch/basstrap.htm

more details:

http://www.geocities.com/jonrisch/a.htm

[jm1]

I think that 'bass trap' would function more as a diffuser than a bass trap. An empty tube would only diffuse higher frequencies. Loading the tube with sand will increase the mass and make it full range diffuser. I imagine this should provide some benefit as it would break up standing waves by diffusing (scattering) the reflected sound. It will not provide any absorption of bass energy within your room.

I found some of my posts on what I have completed for my room:

DIY Tube Traps (http://www.polkaudio.com/forums/showthread.php?t=23371)

jmierzur & bass traps (http://www.polkaudio.com/forums/showthread.php?t=25565)

If you are not handy, try the quick and dirty corner traps on the Risch site to see what benefits this provides. You can also place DIY or purchased panels across the room corners to create a 'bass trap'.

[tecmo04]

ive seen those. Is there any way to do this with out using insulation. Im not to thrilled on having isolation exposed in my house. Any thoughts?

[jm1]

ive seen those. Is there any way to do this with out using insulation. Im not to thrilled on having isolation exposed in my house. Any thoughts?
Are you referring to the quick and dirty traps? If so, you do not open the bundle to expose the insulation. Look for bundles without any rips or tears. If this is not possible, seal the bundle with tape. Clean the exterior and place in the desired location to determine if they provide any benefits. If you decide to keep the bundles, cover with some type of fabric to compliment the room decor or build a container for the bundle.

[SLOCOOKN]

Just more info and a good article.

HTTP:www.ethanwiner.com/acoustics.html

[SLOCOOKN]

I have had it. Other than SVS I don't think anyone out there can agree on anything collectively as a group..hd vs. blue ray, sacd vs. redbook, Dlp vs. plasma vs. lcd, seperate dac vs. no seperate dac...NOW even on bass traps 705 vs. 703....AHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH

MAKE UP YOUR FLIPPIN" MINDS!!!!!!!!!!!!!..

This is just amusing to me..I guess the old adage goes...Try it if ya like it that is just fine..

[Midnite Mick]

Yeah, there is just no hope for us that don't know what the hell we are doing. I suggest flipping a coin.:)

Mike

[SLOCOOKN]

Yeah, there is just no hope for us that don't know what the hell we are doing. I suggest flipping a coin.:)

Mike

You would need to find out what the right coin would be! :)
and no one would agree on that either.

[Midnite Mick]

lol

Would need a 3 sided coin for your display example as well.

Mike

[GV#27]

I just finished these corner traps.They are cheap and easy to build and they are very effective.

[Midnite Mick]

What are they stuffed with?

Mike

[GV#27]

What are they stuffed with?

Mike3" thick mineral wool.I cut pieces in a triangular shape and stacked them into the plywood frame.
http://www.roxul.com/graphics/rx-na/canada_us/products/AFB/AFB-English-5-16-06.pdf

[Midnite Mick]

Interesting.

And you have a little corner shelf. Is there an optimal size...etc. Did you get that idea online or did you do this on your own.

Thanks,
Mike

[GV#27]

Mike, That pic with the plywood is not a shelf but the bare frame before the wedges of mineral wool were added then it was covered with material.It just supports the insulation.
As far as size goes the bigger the better.I got the idea from a commercial product but I made mine a bit smaller for WAF reasons.Mine are 40" tall and it spans 16" across.

[Midnite Mick]

The stuffing though is only on the inside is it not? One could still put something atop if one desired couldn't they?

Just curious what kind of transparent material did you use?

Thanks,
Mike

[GV#27]

Yes Mike, the stuffing is only on the inside.Sure you could place something on the top and use it like an end table.Is that what you mean?I may put a solid wood top piece on mine at some point.I am not sure what the material I used is made of (possibly nylon or polyester),but it is easily stretched without bunching up and it is acoustically transparent.Any material that you can see light through or breathe through is fine.
Fred

[tecmo04]

interesting. was that hard to build? total cost?

[GV#27]

Hi tecmo04,these are very easy to build.
As far as costs ,I already had the insulation and the material left over from another acoustic panel project so I only needed to buy the 1/4 inch plywood for a total of $15 for two bass traps.I think the insulation was about $25 and that was enough for several units.The cover material was inexpensive.

[SLOCOOKN]

One thing you might consider as well. Flat panel may absorb more LF than a corner wedge placed directly in the corner. You may not need as much wood and lower the cost.

That said, GV#27 your traps look great!

I am going to build mine over the next 2 months. I am going to use white fabric and have them airbrushed with pictures or designs...not sure yet.

My plan is as follows...so far....1x6 frames that are 2' wide at the top and 4' tall...if I can find mineral wool great....if not 705 or 703...6 panels I think..

[GV#27]

Thanks SLOCOOKN, According to the experts I consulted ,the wedge shape with its increased insulation thickness will actually be more effective at lower frequencies than a flat panel with an air space behind it.The thicker the insulation the better.As far as cost it was cheaper and easier to build these corner traps than it was to build my regular panels.

[SLOCOOKN]

Thanks SLOCOOKN, According to the experts I consulted ,the wedge shape with its increased insulation thickness will actually be more effective at lower frequencies than a flat panel with an air space behind it.The thicker the insulation the better.As far as cost it was cheaper and easier to build these corner traps than it was to build my regular panels.

Would you suggest that I am on the right construction path with my panels?

[GV#27]

Yes that type of trap can work very well also.Most build them 2'x4' and at least 4" thick.The OC 703 or 705 is excellent for this purpose. I used mineral wool because the OC 703 is not sold in Canada.
Here is how I did mine.

[SLOCOOKN]

Yes that type of trap can work very well also.Most build them 2'x4' and at least 4" thick.The OC 703 or 705 is excellent for this purpose. I used mineral wool because the OC 703 is not sold in Canada.
Here is how I did mine.

They look like maggies... :)
Thanks for the pics! They look very nice..The end caps are a nice touch.
I was thinking of using "chicken wire" to hep support the insulation...What do you think.

[GV#27]

The OC stuff is semi rigid so it may not need any more support than the wooden frame and the material holding the front.But you could use chicken wire across the back for support.I added strips of 1/4'' hard board running from top to bottom to hold the insulation in.