Acoustic treatment for my HT room

[sunith]

All:

Need some expert advice on treating bad acoustics in my HT room.
I am (sadly) realising now that acoustics is so important in the HT design, which I overlooked until now.
My current setup is a Onkyo NR 609 using a Bose speaker set ( don't jump on me for using Bose - upgrade is around the corner ).
I have good amount of resonance in my room because of the plain untreated walls. Room size is 12 x 20.
So, I have to invest on acoustics as an immediate step.
I am not fancying a sound engineer to visit and suggest the solution, which will cost thousands ....
(A) DIY route using rock wool/glasswool and box panels as one option. A bit worried about the health aspect though.
(B) Spoke to MMT Acoustix who supplies foam panels at 165 per sft.
(C)I have some leftover carpet and foam from the floor installation, which can be a cheap option to try. Not sure of the effectiveness.
(D) Other suppliers ( I am in Bangalore) who supply acoustic panels. Spoke to one today. One single panel (4*2 I think) was quoted at 8K. Seems expensive

FMs, pls suggest best route for me.
I promise I will upgrade my speakers soon after this . The what HiFi show in Sep. in Bangalore , I plan to visit

Thanks in advance.

 

[elangoas]

I have no hands-on experience with room acoustics other than reading abt them, in the verge of attempting sooner..

advice on treating bad acoustics in my HT room.

Without knowing how bad is the listening position in you room, how would you approach treatment?..

Getting an Acoustic measurement Microphone like UMIK-1 and REW software tool (free) should help you evaluate the room..

I promise I will upgrade my speakers soon after this

Don't think speakers have to wait for a near perfect room.. You can get the speakers positioned ideally according to your room, measure the response at your listening position and approach treatment accordingly.. Since it is your dedicated HT room, positioning speakers (incl subwoofers) shouldn't be a problem..

Some generic info based on reading..

1) Handling room modes upto 250Hz.. This would be the most challenging.. Placing subwoofer on ideal locations should help this to greater extent up to 100Hz .. Between 100Hz - 250Hz, i think only main speaker positioning can help..

2) Beyond 300Hz, broadband absorbers are said to help, panel thickness depends on the target freq (no idea on this)..

If any of the above info is incorrect, will stand corrected..

 

[tuff]

@sunith Here is a thread of an FM who made the panels himself recently. https://www.hifivision.com/threads/diy-acoustic-panels.71048/
You may contact him and get additional information. Also here, https://www.hifivision.com/threads/my-success-stories-with-acoustics-treatment.69413/ Those thread might jump start getting room acoustics fixed. I am sure other will chime in. Could you post pictures of the room? That helps big time.

 

[sdurani]

IF you can find rigid rockwool/glasswool, then you can make your own absorbers. Make them at least 4-6 inches thick so that they absorb broadband. If they're too thin, they absorb only the higher frequencies and end up being a form of tone control. Folks try to save money by making thin panels. Those people could save even more money by simply turning down the treble knob (same result).

Cover as much of the front wall as possible; at least the area between the L/R speakers. This will make the front soundstage as clear as possible, without having reflections from the surround speakers coming from the same direction and muddying up the soundstage. Cover the middle half of the back wall, for the same reason.

Absorption on the side walls comes down to personal preference. Lateral (sideways moving) sound aids in the sense of spaciousness. Those reflections are outside the front soundstage so they don't interfere with clarity; just end up widening the soundstage. So, placing absorption on the side walls is up to you. Not a question of good or bad, just whatever you prefer.

 

[Naturelover]

My current setup is a Onkyo NR 609 using a Bose speaker set (don't jump on me for using Bose - upgrade is around the corner).

Slightly OT. It's not that Bose isn't good. It's only that it's overpriced for what it offers in terms of sound. It's USP is speaker size. So don't "upgrade" just because you have Bose.
In fact, Bose is definitely good for home theatre. Of course, it will also depend to some extent upon what model you have.

 

[hifitoaster]

I like how Bose for one thing. It is small enough to integrate to a designer appartment well. Most great sounding speakers in one way or the other kills simplicity of the living space. Also it sounds decent in living rooms with limited space- It depends on what you really want, a cool living which sound decent, or an ugly audiophile den. Most hi end audiophiles rooms look more like a lab more than a room.

 

[tuff]

I like how Bose for one thing. It is small enough to integrate to a designer appartment well. Most great sounding speakers in one way or the other kills simplicity of the living space. Also it sounds decent in living rooms with limited space- It depends on what you really want, a cool living which sound decent, or an ugly audiophile den. Most hi end audiophiles rooms look more like a lab more than a room.

Beauty is in the eye of the beholder...

 

[sunith]

Slightly OT. It's not that Bose isn't good. It's only that it's overpriced for what it offers in terms of sound. It's USP is speaker size. So don't "upgrade" just because you have Bose.
In fact, Bose is definitely good for home theatre. Of course, it will also depend to some extent upon what model you have.

I have Bose AM-15. For my room size, I feel it needs more 'filling' sound, which is somewhat lacking. Center channel clarity is a bit lower.
Bose will go back to my living room, eventually - I love them, owning it since 1998.

 

[sunith]

So, these guys from Elite Home Cinemas visited my place, and said there is to much reflection all over the place.
He suggested a full panel for my room, at a whopping 2+ Lakhs (400 sft @ 500 Rs approx.). Not sure, if its worth that much - but I am no expert. !!
Earlier - ProFx guy suggested I should be better sounding with doing absorbers in the 1/3rd part of the room only.. Again, I am no expert !!

 

[Indranil Sen]

sanity- I am glad that you are thinking about room acoustics because it's really the core foundation of any good listening environment, 2 channel or multi channel. Like anything in audio it needs a bit of experimentation and patience to get it correct for your room. Here is a quick starting guide for you.
1. You would need bass traps, broadband absorbers and diffusors to create a reflection free zone at the listening position. You can either build these products by yourself or buy it from the market. There are many DIY videos available online showing you how to build bass traps/broadband absorbers at an affordable price. Here are few DIY links for bass traps.
https://www.readyacoustics.com/DIY-BASS-TRAPS-MADE-EASY.pdf
https://sonicscoop.com/2016/11/10/d...ild-cost-effective-bass-traps/2/?singlepage=1
Diffusors are generally more complex to build and I would advise to buy it from a vendor if you plan to use it in your room

2. Placement of these products in a room is very important because the goal here is to achieve a balance output i.e balance across absorption, reflection and diffusion using these products. Without this balance you run the risk of the room sounding too dead i.e too much high frequency absorption, too live i.e too much high frequency reflection or have uneven bass response i.e too many peaks and nulls in the low frequency region. This is where you need to experiment in your room as every room is different. Again there are so many online documents on this topic to help you on this set-up process

3. Here is a very basic set-up steps that you might consider as a starting point
- Use at-least 4" gap between the panel and the wall when you want to use it as a bass trap
- Place bass traps in all three wall corners where the bass build up is the maximum
- Place bass traps in the wall ceiling corners
- Use broadband absorption panel on side walls, ceiling and floor to handle early reflections. Here s a video which will show you how to find early reflection points on any wall.

- Use diffusors on the back wall if that is 10ft or more away from the listening position
- If you are building bass traps, use a very thin plastic and bond it to the insulation for those traps which would be placed away from the listening position. This would prevent over absorption of high frequency in the room

4. As others mentioned invest into a good USB microphone like UMIK2 and use it with REW (a free room response analyzer) software to measure room response as you are experimenting with different acoustics products and its position in yo0ur room

Hope this helps.
Thanks.