Back Wall Treatment for Home Theater

[CK.]

The advantage with sofa is that bass frequencies need deep absorbtion to actually have an effect due to their longer wavelenghts, the sofa adds to the thickness(depth). How much it helps is another matter, in theory it makes sense though often sofa's have foam or other materials that are not great absorbers however, the wavelenghts would travel through that then hit your panel hence why some panels plus the couch might not be so bad. So in this case the panel needs to be behind the sofa, hence why I suggested the whole back wall covered. The space behind the sofa wont play much of a role.

The rear wall is only a good pace for absorbtion if your sitting up on it, otherwise it is not a priority spot it all depends on the arrival of the reflection from the back wall and what you want to do with them and what you're trying to achieve overall.

I can try putting the panels behind the sofa just for testing and see the rt60/waterfall/impulse/fr response measurements to determine the impact.

Indeed the reason I am treating the backwall is because I am sitting right up against it. I wish I could do the ceiling as well.

 

[CK.]

Did you get any panels for the back wall? Would be interesting to hear any follow up on those.

Hi @HiMu just got my panels installed, took a little longer to be delivered. So as promised, first impressions: well I can hear the difference clearly no doubt about it. vocals sound softer, more focused and more defined, same goes for bass and treble. the soundstage is there but it is more discrete, i do not feel the sound coming from everywhere and overwhelming me. I feel like I want to increase the volume higher than i would normally listen.

But as with any change in the system I would need a few days for my ears and brain to adjust in order to have a clearer understanding of the impact but yeah I am excited with what I am hearing.

I will also be doing measurements and share the results

 

[Tio]

Hi @HiMu just got my panels installed, took a little longer to be delivered. So as promised, first impressions: well I can hear the difference clearly no doubt about it. vocals sound softer, more focused and more defined, same goes for bass and treble. the soundstage is there but it is more discrete, i do not feel the sound coming from everywhere and overwhelming me. I feel like I want to increase the volume higher than i would normally listen.

But as with any change in the system I would need a few days for my ears and brain to adjust in order to have a clearer understanding of the impact but yeah I am excited with what I am hearing.

I will also be doing measurements and share the results

Could you also post the photo after the panels installed? thanks.

 

[CK.]

Could you also post the photo after the panels installed? thanks.

 

[HiMu]

Looks good!
Have you or your companion noticed any non-hifi/HT related improvements or changes on how the room sounds/feels?

 

[CK.]

Hi, i cant recommend you any specific products, but about other questions.
I'm no expert or anything. First about panel depth. Here is absorption coefficient of some rockwool:View attachment 325507
As you can see, 5 cm will absorb frequencies about 300 hz and higher. 10 cm will absorb about 150 hz and higher. Will do very little to frequencies below that.

In my opinion, 3 60x60x10 panels wont provide much impact, if at all, audially. 3 120x60x5 will cover more area and, i suspect, will provide some minor differences audially.

That being said, i see in your rt60 and waterfall graphs that you have very lively room, about 800 ms of reverberation time. I see surround speakers, so this is your movie room. For movies recommended rt60 is about 200ms. For stereo music recommended rt60 is about 300ms.
At most 3 120x60x5 panels will reduce reverberations by, idk, few ms, but only in panel working frequencies, i.e. 300hz and above. This will align reverberations more to your high end frequencies, 10 khz and above. Since your high end have lower reverberations than the rest of spectrum. But low end, 200 hz and lower, will not change at all.
Something like that:View attachment 325512


So, in summary, adding panels will at most reduce some reverberations, but not in bass region, so it might emphasize bass, which is not a good thing. On the other hand, since your high frequencies rt is lower, panels will bring mid frequencies more close to high frequencies.
In reality though, i dont think so little quantity of panels will provide any meaningful difference in sound.

Looks good!
Have you or your companion noticed any non-hifi/HT related improvements or changes on how the room sounds/feels?

Thanks!
Yes I have noticed that talking while sitting on the sofa feels less reverberant and more relaxing. Not night and day but noticable.

I will be sharing my results also but I can confirm that while the treatment I added is limited it does offer an audible improvement but it is like 20 per cent of the way towards a fully treated room. I can only imagine how good a fully treated room with both absorption and diffusion will sound like but in a living room space it is impractical.

 

[Jack B]

Thanks!
Yes I have noticed that talking while sitting on the sofa feels less reverberant and more relaxing. Not night and day but noticable.

I will be sharing my results also but I can confirm that while the treatment I added is limited it does offer an audible improvement but it is like 20 per cent of the way towards a fully treated room. I can only imagine how good a fully treated room with both absorption and diffusion will sound like but in a living room space it is impractical.

For another point of view on this topic, you might want to read Dr. Floyd Toole's book SOUND REPRODUCTION. It is a wealth of information, mostly based on sound (forgive the pun!) acoustical research, and is also a fun read. Highly recommended!

 

[CK.]

For another point of view on this topic, you might want to read Dr. Floyd Toole's book SOUND REPRODUCTION. It is a wealth of information, mostly based on sound (forgive the pun!) acoustical research, and is also a fun read. Highly recommended!

Yeah I already bought the book a few weeks ago and started reading it albeit slowly