this guy says ... towels are better for cheap diy acoustic panels !!! check it people ...

[Naveenbnc]

some people in comments section disagreed with the way the test is done, ....
and some people said absorption is different from acoustic transparency (i didn't quite understood this ....)
But this video is worth watching ....

 

[diyaudio]

The video measures what sound is passed. if sound is passed less, it is either absorbed or reflected, its difficult to say whether its former or latter. We know that highs get reflected easily, this test will falsely come to conclusion that they are being absorbed. Its not a good test.

Directly measuring a reflection is a better test. Its not too difficult to do that with a dipole speaker and some gated measurement. But, a wide band absorber does not exist in my humble opinion. You will not find much independent data or measurement and there is a reason for it

BTW, instead of fighting the reflections why not use them to advantage.
And, youtube has a lot of fake content. They even tell you how to create energy from nothing

 

[Naveenbnc]

BTW, instead of fighting the reflections why not use them to advantage

it would be a great idea if we can figure out a way to use them as an advantage !!!!
each freq. has a different wavelength and they bounce back at different speeds, at different times etc etc is a complex thing to handle (im guessing)

And thank you for pointing out that we don't know if the sound is absorbed or reflected from the towels !!

may be this is a little off the topic, .... when talking about reflections... see the picture of my surrounds.
It is mounted high, and tilted down pointing towards listener. (of course the tilt angle is small)

Can we assume the the rear sound waves will hit the wall and bounce upwards in an angle ?
(instead of bouncing towards the listener directly)

 

[diyaudio]

it would be a great idea if we can figure out a way to use them as an advantage !!!!
each freq. has a different wavelength and they bounce back at different speeds, at different times etc etc is a complex thing to handle (im guessing)

And thank you for pointing out that we don't know if the sound is absorbed or reflected from the towels !!

Toe in a set of dipoles such that their axis meet a feet or two infront of you. Now you are listening to both speakers a bit off axis.
Notice that the left speaker will reflect the right wall and go past you into the room. It will add to reverberation behind you giving that subjective ambience, this together with the direct sound gives soundstage, clarity/intelligibility.

The left speaker null is on the left wall reflection and front wall reflection, means no treatment is needed. Place diffusers behind the speaker since thats a bright spot for the dipole.
See http://www.linkwitzlab.com/listening_room.htm
http://rtaylor.sites.tru.ca/2013/07/17/optimal-toe-in-angle-for-a-dipole-loudspeaker/

Can we assume the the rear sound waves will hit the wall and bounce upwards in an angle ?
(instead of bouncing towards the listener directly)

Its a sealed box (monopole), right?

 

[Naveenbnc]

Its a sealed box (monopole), right?

Its actually an OB

https://www.hifivision.com/threads/...om-cant-live-with-them-for-long-though.72404/