Bass Trap help

Are you placing them flat on the wall? You may get better results putting them across the corner. If you can get a little space behind the panel (placing thick batting between the wall and the panels) the lower the frequency it will affect, my guess it that your panels are working on higher frequencies. Just a hunch.

Acoustic panels have very little effect below 100Hz a few dB is about all you can expect. Meanwhile room modes can easily be 15 dB or more. Straddle the panels across the corners. However you should hear a big improvement in the lower midrange.

For those frequencies google "super chunk corner bass traps". These work extremey well and are easily DIY'd

You might try moving your chair forward in small increments and check readings.

Even DIY sealed membrane traps, using 1/4" hardboard as the membrane would have to be at least 4'X4' or 4'X6' to be effective for 63 Hz.

I found the "super chunk" article. Thanks for that. Since I already have the OC 703, ill build it from that and hope it works as well as the mineral wool material.

Thanks.

Good advice. I have tried various locations for the listening position. Going further forward makes the peak greater at 63hz, where moving back creates one at 100hz. Perhaps going back will help some given 100hz is a bit easier to manage than 63hz.

Thanks.

Jim,
Your resistive-type bass traps made from OC703 work best when placed out from the wall a distance equal to 25% of the offending wavelength. So, for 100, 80, and 63Hz peaks, you should experiment with an air space of 33.9", 42.4", and 53.8" respectively. Obviously this really intrudes into the room physically and visualy but it wouldn't hurt to try a little experimentation.

Try placing the traps in the 4 room corners with the air spaces as indicated above. Try a bass trap in the middle of the front and rear walls, again with the same air spaces. I found the front/rear wall absorption seemed more effective than side wall absorption for bass but that could just be my room.

If you can't tinker your way to sonic bliss with the bass traps then you'll need a parametric EQ to tame the peaks.

For what it's worth, my room dimensions are multiples of one another (a bad thing indeed) which compounded my 80Hz peak making it a 19dB peak. I reduced the 19dB peak to 2.5dB by using very thick (i.e. 27" thick including an 8" air space) bass traps of OC701 in the four room corners and some in the middle of the front and back walls. (See my System for pictures of the DIY bass traps that double as Mid/High frequency hemi-cylindrical diffusers, for what it's worth.)

You can also use 2 or 4 subwoofers to constructively reduce the peaks but is much more complicated.

Good luck and be sure to let us know how it turns out.

Go to a store that sells rugs. Ask them for the core they use to roll the rugs on. This tall hollow cylinder will form a bass trap. Paint it and use adhesive to stick in corner.

Orpheus, you're kidding. Right?

Dan_ed, I have two of them in the corners behind the left and right speakers. There was all kinds of bass reverberation before I installed them.

i agree with orpheus 10. i got good results using cardboard concrete forms from lowes. i filled mine with some pink[corning] stuff and made legs to get them elevated so both ends were open. very inexpensive and if you don,t like them hang em in the garage for fishing rod storage.

The cores are very easy to decorate in order to make them invisible.

Orpheus10 wrote "The cores are very easy to decorate in order to make them invisible"

. . . or you can dress them up and make them look like architectural columns. I bought a 12foot long 48" diameter Sonotube to fill with OC701 fiberglass for a bass trap and covered the curved exterior with a red oak veneer and polyurethaned it. It's a hemi-cylindrical diffuser+bass trap in one. I'm using 5 of them: 160degree arc, two 130 acrs and a 100degree arc in the room's 4 corners and middle of the front wall. (Pics are in my System for what it's worth.)

Sounds beautiful, and functional at the same time.

Just to update things......Ive moved both the speakers and listening position back about 3ft. This made both the peak less. My room (if you look at my crude drawing) is untypical in that its not a rectangle. So moving the listening postion back into the more open area that flags right into my kitchen helped with my problem. Im now closer to the back wall which isnt great, but the extra space behind the speakers has made more a deeper soundstage (which is good!). The sacrifice was minimum in that the detail in middle suffered mildly, but barely noticeable.

Ive come to the firm conclusion that the bass below 100hz or so just cant be tamed unless you are willing to spend a great deal and a few feet of absorption material in every direction and corner.

While all the OC 703 I bought did little for the deeper bass, it did help a bit to clean up the upper bass and lower midrange.

i agree. this bass boom in my room was awful. but with the tubes, 4 cathedral panels and the room tune upper corner pillows[4] i have made a lot of progress. and it is somewhat uniform. before i made the additions the bass changed in many different regions of the room, for the worse. unlisteneable

This is a different slant. I had standing waves that correlated very well with the room dimensions. I installed a lot of absorbers which helped somewhat but Physics is phsics and I still had standing waves, I opted for a subwoofer and a crossover for it (Velodyne SMS-1 but there are cheaper units see The absoute Sound article by Greene). This enabled me to move the subwoofer for best bass response without messing with the main speakers. It is more expensive than panels but will give you very good results.