# Bass Traps no success, frustrating



## sweetsounds (Feb 13, 2010)

So after some time of my original conquest, I tried to optimize my living room to be get better audio (5,5m x 4m x 2,5m, speakers firing in long direction, seating slightly forward from the middle of the room, quite some furniture in the room).

My original measurements are here: http://www.hometheatershack.com/forums/rew-forum/25900-oscillations-rew-measurement.html

I struggled with plenty of echoes and long decays.

I added heavy cotton curtains, a 2.5m x 4m rug in the back of the room and most important added two absorbin panels of 1.2m x 0,6m x 0,08m to the back wall filled with Homatherm flexCL (when sitting next to them, they really silence down. No more zing when clapping my hands, atmosphere really improved.

Now for the measurements: the waterfall graph looks improved -40dB within 300ms quite uniform across the spectrum except for the room modes. Your opinion?:dontknow:

The SPL is still very wavy and I certainly did not put the mic exactly at the same location as last time. My perception of the music tonality and stage still improved substantially.

Now I moved in two large Hofa cylindric bass traps (46cm/18" in diameter, 40" high) and tried several corners. From the measurements bass eveness in 3 out of 4 configurations became worse:foottap:, especially when I placed them on the front wall (pink graph). Best position would be to stack them in the back right corner (blue graph), but to me not a major step compared to no bass traps (green graph).

Any recommendations from the experts? 

Adding more accoustic treatment has no WAF. Only possibility would be to add skyline diffusors (aesthetically wife approved), would that help? 

Thanks!


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## Wayne A. Pflughaupt (Apr 13, 2006)

Do you really have an ambient noise floor below 25 dB, or did you just not do a SPL calibration?

For starters, waterfalls aren’t terribly relevant above ~300 Hz, IIR. Also, if you engage 1/6- or 1/3-octave smoothing for your response graph, it’ll look more like what you’re actually hearing. What smoothing setting did you use?

For advice on bass-trap placement, you’re better off posting your question on our Acoustics Forum.

Regards, 
Wayne


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