# Would DIY acoustic panels reduce echo issues?



## alfa-74 (Aug 31, 2013)

Hello

I'm working on several different areas in order to put together a decent HT room with limited budget.

I have an issue with the room where I will be installing the HT equipment.

First, room is small, is around 21 ft lenght, 9 ft width and 10 ft height. The room is built with concrete blocks, ceiling is concrete as well, and the floor is also concrete covered with ceramic tiles. Walls and ceiling is covered with plaster (this is the typical construction where I live).

the problem is that this room is an echo chamber, and I need to reduce this problem in order to get a better performance of the HT equipment.

before finding this forum, I search in the web and found that acoustic panel would help me to reduce sound reflections.

I ordered some wood frames (2x4ft) see picture, and I will use Roxul HT80 2in thick panel and then I will cover with some grill cloth.

I'm planning to follow the "mirror" process in order to find the right spot for them.

would this help me to reduce the issue?

Thanks for any feedback

Regards


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## cavchameleon (Jan 7, 2008)

Yes, it would help the issue greatly to acoustically treat your room. What you're planning is a great start. I'd also suggest building some bass traps for the corners. With your planned treatments, you'll get the echos under control, but your bass will be very boomy and that will require bass traps (basically some deeper treatments in your corners).


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## cavchameleon (Jan 7, 2008)

HTS has a thread on the bass traps if interested:

http://www.hometheatershack.com/forums/home-audio-acoustics/3198-diy-bass-trap-will-work.html

Hopefully Bryan will chime in as he is the expert and can give you great ideas for your room.


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## alfa-74 (Aug 31, 2013)

cavchameleon said:


> HTS has a thread on the bass traps if interested:
> 
> http://www.hometheatershack.com/forums/home-audio-acoustics/3198-diy-bass-trap-will-work.html
> 
> Hopefully Bryan will chime in as he is the expert and can give you great ideas for your room.


Thanks a lot 

I will read the information in the link


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## bpape (Sep 14, 2006)

2" is OK for front wall and minmal side wall control. You will still need broadband bass control in the room. MINIMUM 4" thick straddling corners. 6" or chunks is better. 6-8"' on the rear wall.

Bryan


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## alfa-74 (Aug 31, 2013)

bpape said:


> 2" is OK for front wall and minmal side wall control. You will still need broadband bass control in the room. MINIMUM 4" thick straddling corners. 6" or chunks is better. 6-8"' on the rear wall.
> 
> Bryan


Thanks!

I will review those options


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## cavchameleon (Jan 7, 2008)

Bryan is the expert!

I did not have room for 6" in our room so ended up using 5" broadband traps. They created an amazing result as far as the sound in our room - very much some of the best $ ever spent on sound.

Click on the GIK Acoustics link under Bryan's signature - there is a LOT of information on their site, very informative!!! They also sell a lot of great products. I had to go DIY for most of my stuff due to a limited budget, but you can still learn a lot from such a well designed site.


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## Mikeythai (Aug 23, 2010)

I'm so happy to see this thread. I'm in the same exact boat. Cement walls and stone floor, and I haven't started acoustically treating the space. Unfortunately where I live in Asia, I can't seem to source rockwool insulation, just the fiberglass kind.

If I use the fiberglass for wall treatment panels and bass traps, will it be effective, or will I have to go with a greater thickness panel?


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## bpape (Sep 14, 2006)

Fiberglass is just fine and in my opinion better than mineral wool. Thickness is thickness once you have a decent absorbing material. Foam, no, you'd have to go MUCH thicker. 

Bryan


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## alfa-74 (Aug 31, 2013)

Thanks everybody

I have been reviewing some options, and also checking the space available, and I found that I don't have room for placing bass traps in the corners.

I found some bass traps with a triangular shape. I could place those in the upper 4 corners (where the 3 walls meet). Would this be enough for bass control?

If so, should they be 4 to 6 in thickness?


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## Mike0206 (Jul 14, 2013)

Great thread guys. By the way I reduced the echo in my room as well as the decay by a significant amount by doing some DIY panels. I used mostly r-30 insulation and that seemed to help the most. I did wrap some absorption material in batting and burlap and put that in the kitchen area above the cabinets and it definitely reduced the echo by quite a bit. I'm sure GIK panels would do much better but I'm happy with the results I got for literally $50 in material.


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## bpape (Sep 14, 2006)

YOu can't make bass traps smaller to fit the corners? You can do any size as long as the thickness is there. You just need cumulative surface area. Don't expect a few 12x12x12" triangles to fully do the job. The waves you're talking about are 10's of feet long.

Bryan


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## alfa-74 (Aug 31, 2013)

bpape said:


> YOu can't make bass traps smaller to fit the corners? You can do any size as long as the thickness is there. You just need cumulative surface area. Don't expect a few 12x12x12" triangles to fully do the job. The waves you're talking about are 10's of feet long.
> 
> Bryan


Thanks Brian

I could probably place some in the half upper position, i mean from the ceiling way down to half of the wall, would this work?

Another option is to place all around the upper corners between the ceiling and the walls, is this a good option?


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## bpape (Sep 14, 2006)

Both will work fine in terms of bringing the bottom end decay time into line

4" is OK - 6" is better.


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## alfa-74 (Aug 31, 2013)

Thanks a lot again Bryan

I think I still need to continue investigating about bass traps. But one question, is there a minimum surface or area for good result?


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## bpape (Sep 14, 2006)

It varies a lot by room, by frequency, whether you're trying to fix a frequency response issue or just tame decay time, etc. No 1 right answer - sorry.


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## alfa-74 (Aug 31, 2013)

Thanks, I understand that, every room and setup is different.

Well, here is my plan. I will continue with the DIY acoustic panels. Also, since I´m still building my system, I have not installed anything yet. So first I will install cabinet, speakers, projector, screens, etc, and then make some tests and see what´s the situation about bass response.

In the meantime, I will continue investigating about bass traps and REW.

Regards


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## rewjack (Aug 24, 2011)

I don't know if you want to make only absorbent panels and corner bass traps? 
I'm sure that many guys have experienced having killed the life and sparkling sounds in a room by applying to many acoustic panels and not enough diffusors or other reflectors of all sort (Schroeder 2D or quadratic).

I think it's better to break waves in as many pieces you can, avoiding echoes and by the way keeping more energy to provide a larger space feeling environment. This is true for high-end music fans like me. I understand that home video fans will prefer lower frequencies to be predominant. It's something else I suppose.

Like you said, every room and person has it's own solutions.


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## alfa-74 (Aug 31, 2013)

rewjack said:


> I don't know if you want to make only absorbent panels and corner bass traps?
> I'm sure that many guys have experienced having killed the life and sparkling sounds in a room by applying to many acoustic panels and not enough diffusors or other reflectors of all sort (Schroeder 2D or quadratic).
> 
> I think it's better to break waves in as many pieces you can, avoiding echoes and by the way keeping more energy to provide a larger space feeling environment. This is true for high-end music fans like me. I understand that home video fans will prefer lower frequencies to be predominant. It's something else I suppose.
> ...


Yes, i want this room for both movies but also music. So my first goal is to reduce echoes. So from you're point of view, its out better using difusors?


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## rewjack (Aug 24, 2011)

alfa-74 said:


> Yes, i want this room for both movies but also music. So my first goal is to reduce echoes. So from you're point of view, its out better using difusors?


Well, it's my personal experience and I found it in many specialized web sites. Most of them recommand panel and/or diffusors. They add what I told you about the room size emphasis with diffusors. There is a factor of taste-preference in music style to consider too.
I do my tests, after every setting, phase-delays and some EQ, are done, with my favorite acoustic guitar track (24/96 file). It is obvious that the addition to many acoustic absorbent panels cuts dramatically high frequencies and the beauty of very fine guitar picking. The high frequency harmonics are very important. It usualy shows on frequency response. 

Furthermore, if your system is set for loud rock music, you'll may not be happy with a flat response curve, including sub-frequencies. But if you like ECM label album style, I realy think that diffusors are needed to keep a clear sound without blurry sound from first réflexions, an this witout absorbent panels at miror location.

I've made several diffusor and reflectors, and soon I'll be adding some more for higher frequencies. 

It does not mean that you don't need absorbers, but keep it easy, one at the time, corners...


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## bpape (Sep 14, 2006)

I would agree not to absorb any more than needed if it is for music as much or more than home theater. That said, while breaking/scattering waves is good, trying to do that under 200-250Hz requires physical sizes while are basically unusable in a home room. 

As an example, our diffusers are 6" thick. They will perform down to approx 300Hz. Imagine trying to do 100Hz. Most people can't/won't give up multiple feet to try do diffuse bass. Plus diffusion does not address the excessive decay time component of the problem which is more prevalent in the bottom end.

Bass only absorbers like live and damped membrane types can function very well below a couple hundred Hz and do essentially zero above to leave all the 'life' in the room while controlling the bottom end. 

Bryan


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