The Importance of Room Treatments

[shaizada]

I've been in this hobby for many many years now. Through the maniacal change of equipment we often overlook the most important part of the room...

the room itself.

Without a doubt, a properly treated room is probably the most important factor in true listening. We often judge equipment without actually hearing the full potential of the component or system because the room never let you fully realize the sound.

Every room has peaks and valleys in regards to its sound spectrum. Hence every room has a different resonant peaks and different bass response. What we hear in an untreated room is a summation of ALL those sound anomalies.

As an example, walk towards one of the corners of the room while the music is playing. You will notice an increase in the bass response and a very weird sound as compared to your (hopefully) centered listening position. All these sounds come together and muddy the true audio that we would be listening in a well treated environment. How we really listen to a stereo system is extremely important before we can pass judgement on what a speaker sounds like, what amplifier is doing and what wiring has what sound.

In a properly treated room, it will be black and white to a person what a single change in the system is doing.

Also, it is important to not overdo acoustic panels as they can totally rob the sound of all the liveliness and dynamics. There is a fine balance to this. I have been to showrooms in Delhi that have the whole listening room COMPLETELY covered with acoustic material. The equipment was B&W 800d and Classe amplifiers. Whats the point of demoing components like this if you can't let the listener actually hear what they are doing?

Anyhow, I've started this thread for an educationally enlightening perspective so that we ALL can understand and move forward in this hobby. It should be all about the music in the end ..... and this is all just a part of the journey.

Here is an example of how I've treated my room. My ceiling in front of the room starts at about 9ft. and slants upwards to the back to about 20ft at the back wall. This is a cathedral ceiling and was a perfect choice for a dedicated room in my house.

This should give you an idea of the BACK of the room (The black area in the top right is NOT any room treatment. Its just the program I used to stitch the photos together):

This is the front of the room:

Let's discuss if you like....this thread is purely for knowledge sharing.

~Gaurav

 

[vinay]

Gaurav,

I am pleased to see your informative writing.

If i would be in your shoes, i would book a flat in a under construction building, and get the dimensions of the room as per the acoustics need, etc, etc.

For me after the room acoustic, the room should look clean and ascetically good, otherwise it is half battle won.

I have come across many people who want to make a dedicated entertainment room, but they refuse to follow the depth in so many aspects.

There is a lot written in this forum on acoustics, with you also writing, it is very good.

Vinay.

 

[santhosh]

Gaurav,
Thats a nicely treated room and ofcourse fantastic equipment:clapping:. Could you please share pictures of your listening position a.k.a sweet spot in relation to your speakers.

Also, from the pictures, it looks like your speakers are not toed-in. Please throw some light on this placement.

Thanks in advance

 

[shaizada]

Hi,

Think of an equilateral triangle between the two speakers and the seating position. The third point that you imagine between the speakers, I sit right at the tip of that triangle. Just behind the tip.

You are absolutely right about the speakers facing flat out without any toe in. There are a few reasons for this.

1) Each room is different and you have to see what position of the speakers give you the best height, width and clarity of soundstage. That can only be done through listening and experimenting.

2) More importantly, my speakers are single driver coaxial speakers. They radiate sound from a point source (the driver) and disperse sound evenly in all direction. Think of the sound as a spherical wave with the wave getting bigger as the sound moves away from the speaker. With two single drivers emanating sound from a point source, I can keep the speakers flat out and still get the advantage of a large stage and presence. This driver style and cabinet are designed like this.

Other multi driver speakers (if the cabinet construction doesn't account for it) are phase incoherent. Meaning that a sound from a larger driver would reach to you later as it is slower in moving the air molecules compared to a tweeter. In a two way speaker, the tweeter puts out a sound wave at a given velocity and frequency. The mid driver/woofer puts out its own sound wave at another velocity and frequency. There are frequency overlaps between the driver AND the sound waves as well. The cabinet has to be constructed to allow sound waves to arrive at the listening position in phase with each other. Out of phase sound is perceived as a distorted sound to the ear.

My speakers have one driver that does 27Hz up to 40Khz. Below 27Hz is handled by two subwoofers (one for each channel, which you can see behind the speakers). That is how I get my deep base. It is a very unique listening experience.

Hope that helps explain the positioning of things.

 

[heliumflight]

Hello shaizada,

You seem to be very passionate in what you do, for you are those who believe in sharing rather than keeping and hence your wisdom extends...

I'm in the constant pursuit of upgrading speakers, interconnects, source, amplifiers and speaker wire to get just that 5%- 10% improvement in the sound I have spent lot of time, effort and money and still not satified.

When will I acheive Audio Nirvana?:indifferent14:

If I were to keep the same audio eqipment and if the room treatment is done, the golden question?-

• How much improvement in sound quality can I acheive?
• What will it cost me for a room size of 150 sqft?
• What are your recommendation to begin with?

Kindest regards

--
Bryston + B&W

 

[shaizada]

Thanks for the kind comments heliumflight. That was very nice of you.

I've been doing high end audio for about 15 and a half years...before people actually even cared about high end audio. I still don't know it all, but there are definitely a few things I've learnt along the way.

Spending money on equipment is well and good. But how does one judge the quality of the equipment or measure the improvement? Through your ears by listening right? Well, anything that influences the listening environment, will effect what what you listen to to pass that judgement.

Now if I tell you that you are missing close to 45 ~ 55% of the true sound of your system, how would you feel about the judgements you have made so far? That is what has been happening all along.

You MUST take care of the room to extract every bit performance from whatever you have and make a true judgement. It is the only way to really know if you are improving the listening experience or actually hurting it.

Room treatments are a one time investment that keeps on giving back. I strongly feel it is the the FIRST thing a person should invest in so that there is a clear direction of where the system is going.

That is the ONLY way to Audio Nirvana. Give your ears the chance to really do their job.

I've spent close to $3000 for room treatments, but that just because I bought panels that pass very strict quality control and testing in terms of their frequency absorption values.

One of the company's I used is GIK acoustics:
GIK Acoustics.
GIK Acoustics presents Acoustics Primer: Some Basics on Acoustics.

GIK Acoustic Panels are tested and certified by the Riverbank Acoustical Laboratories (RAL)TM Sound Absorption and Sound Absorption Coefficients by the Reverberation Room Method ASTM C 423-02/NVLAP 08/P03 GIK Acoustic Panels submitted to two standard acoustic test methods: ASTM "A" and "J" testing. For "A" testing the acoustic panels are placed all together flat against a surface and tested. "A" testing is the standardized testing method for the manufacturing industry. "J" testing simulates the recommended mounting of the product by the manufacturer. GIK tested two set-ups: 1) panels straddled in corners 2) panels spaced off the wall and mounted on stands. To our knowledge GIK Acoustics is the only company to provide data on both testing methods.

The other company I use is Real Traps:
RealTraps - Home

These traps were developed and then tested at the IBM Acoustics Lab.

Both products are properly tested. Read about the information there and educate yourself because it is one of the most important thing you can learn in audio.

Cost factor in India should be quite low actually. Basically you need to get a hold of some fiberglass and a given density and have a person build a wood frame. Labour is very cheap in India and I would take advantage of that. I can post links to building plans later on. You can do some DIY traps that way and get 80% to 90% of the way there compared to a professionally made product.

Now, to give yourself and Idea....just and IDEA...this is not the way to do it at all. But you can learn from the experience

Get a bunch of pillows and stack them up in the front corners of the room up as high as you can. Second, put a carpet dead-center on the wall in front of your listening position. Try this experiment and report back about what you hear. Again, this is not the proper way to do room treatments, but it will give you an idea of what all is happening

Good luck! And I hope to hear back from you guys.

 

[heliumflight]

missing close to 45 ~ 55%....Gaurav I feel wasted!

I really don't know why I never came up on a single thread on this article.

All are infact talking or using adjectives to describe the bigger unfullfilled promises.

I was trying to avoid taking this path as I believed that by spending big money and bigger brand names one feels he/she will eliminate or overcome the obstacles which will give immense pleasure but then in my shortsighteness missed on the laws of Physics.

What ever steps we take to improve sound quality we all hope for a postive outcome and may be sometimes biased if that equipment was expensive. So I never took on this path as I felt I have the power of the brand besides me.

To actually test what you've said, I'm infact going to take this test and report the findings. I know with realiztion only comes conviction and I believe this is why you are putting so much empahasis on room treatments.

1. stack a bunch of pillows and stack them up in the front corners of the
2. put a carpet dead-center on the wall in front of your listening position.

Thank you

 

[santhosh]

Hello shaizada,

You seem to be very passionate in what you do, for you are those who believe in sharing rather than keeping and hence your wisdom extends...

+1 to that. Gaurav has gone great lengths in selection of his equipment, sound treatment, cables, isolation etc. Must appreciate his passion

I'm in the constant pursuit of upgrading speakers, interconnects, source, amplifiers and speaker wire to get just that 5%- 10% improvement in the sound I have spent lot of time, effort and money and still not satified.

When will I acheive Audio Nirvana?:indifferent14:

If I were to keep the same audio eqipment and if the room treatment is done, the golden question?-

• How much improvement in sound quality can I acheive?
• What will it cost me for a room size of 150 sqft?
• What are your recommendation to begin with?

Kindest regards

--
Bryston + B&W

If you are the type who is in the constant pursuit for improvement, you must definitely treat your room. I have seen for myself the difference that sound treatment can do at a friend's place, everything else remaining the same. It is definitely worth it.

Have a look at my thread below where I have documented my Home Theatre\Listening Room Build. You'll find information about pricing too. I am in the final stages and should be able to put up a review soon. On thing though, I cannot do a before and after comparison as this room was built only recently and built specifically for the purpose.

http://www.hifivision.com/av-enhanc...ing-my-home-theatre-room-please-guide-me.html

 

[Sumit]

Hey Gaurav!!

I couldn't agree with more when it comes to room treatments. When I built my HT, the sound was more than Pathetic and I was flabbergasted. Then I consulted and expert and got the trap boxes made by my local carpenter.
The difference in sound quality was phenomenal.

Before, I got the treatment done, it occurred to me; ' Maybe my equipment is not good enough"- Back then I was using an entry level onkyo amp and speakers. Then after a few suggestions, I got on the road to room treatment. And, thank god I took the road less travelled- at least in our country.

Now, I swear by room treatment.

Anyways, I myself am going through a repair phase for my room...since sometime actually. I have a plyboard ceiling with fibre optics. As you already know that plyboard is a bad idea. The whole ceiling jars like there is no tomorrow. I took acoustic consultancy after I got my HT made. He had asked me to install a trap box on the ceiling as well. I did not do the same as it was spoiling the aesthetics.

Nevertheless, he gave me an alternative. He asked me to buy 'Tecsound 70', a product by texsa.TEXSA INDIA - Roofing , waterproofing, thermal and acoustic insulation.

I am suppose to install this sheet by screw and washer arrangement either on top of the ply or from the bottom. In the case of latter, I would have to cover the same with a parchment cloth or speaker cloth etc.

I have already bought the stuff and it is lying with me for a few months now. Due to shortage of time, I am unable to apply the same.

I just want to know your views on the same. You can view my HT http://www.hifivision.com/my-audio-video-setup/1167-showcase-your-audio-video-setup-here-16.html

Cheers!

Sumit

 

[santhosh]

Now, I swear by room treatment.

Anyways, I myself am going through a repair phase for my room...since sometime actually. I have a plyboard ceiling with fibre optics. As you already know that plyboard is a bad idea. The whole ceiling jars like there is no tomorrow. I took acoustic consultancy after I got my HT made. He had asked me to install a trap box on the ceiling as well. I did not do the same as it was spoiling the aesthetics.

Sumit, can you please share some more information as to why plyboard ceiling is a bad idea. Was it hollow inside?

I too have a false ceiling made of plywood. My Home Theater is currently work in progress so I do not know what problems I may face and am worried seeing your post. I have laid 4 inch layer of high-density fibre-glass wool. Do you expect that I would have this problem too? You can see pictures of my ceiling on Page 8. Link is:
http://www.hifivision.com/av-enhanc...g-my-home-theatre-room-please-guide-me-8.html

If you feel you are going Off-Topic on this thread, please post your suggestion/information on my HT Build Thread.

 

[Sumit]

Hi Santhosh!!

Perhaps, my choice of words was not good. Plyboard ceiling 'could' turn out to be bad option if not done properly.

For me it did not work out. From the linter, I have about 08"-12(approx) air gap where I have installed a network of wooden planks on which the ply is screwed from the bottom. In my case the air-gap was a bad...no, very bad idea. I did have help of this forum OR acoustic consultant then. I was naive then.

In your case, you have a high-density fibre wool installed on top of the plyboard. The fibrewool could stop the plyboard from jarring. Although, I am not sure as I have had bitter experience. You see with change in temperatures the wood expands and contracts. This enhances the jarring during low frequencies over a period of time. When my ceiling was new I had little problems. But, situation got out-of-hand as months went by.

The best solution that I have come across is 'Armstrong' acoustic tiles - Model 'Optra'. These are the same tiles that are used in Cinemas and work out to be around Rs. 100/sqft. Vinay has something similar installed and till date he has not mentioned any problems.

Santhosh, I want to help you. But, I am not qualified to advice w.r.t. your particular situation. I have narrated you my personal experience. Where did you get the idea of 4" fibrewool in plywood ceiling? Does that person have some experience?

Cheers!!

PS> I too have similar Stanley staple gun. Where do you source the staples in India? Thanks.

Sumit, can you please share some more information as to why plyboard ceiling is a bad idea. Was it hollow inside?

I too have a false ceiling made of plywood. My Home Theater is currently work in progress so I do not know what problems I may face and am worried seeing your post. I have laid 4 inch layer of high-density fibre-glass wool. Do you expect that I would have this problem too? You can see pictures of my ceiling on Page 8. Link is:
http://www.hifivision.com/av-enhanc...g-my-home-theatre-room-please-guide-me-8.html

If you feel you are going Off-Topic on this thread, please post your suggestion/information on my HT Build Thread.

 

[shaizada]

Hey Gaurav!!

I couldn't agree with more when it comes to room treatments. When I built my HT, the sound was more than Pathetic and I was flabbergasted. Then I consulted and expert and got the trap boxes made by my local carpenter.
The difference in sound quality was phenomenal.

Before, I got the treatment done, it occurred to me; ' Maybe my equipment is not good enough"- Back then I was using an entry level onkyo amp and speakers. Then after a few suggestions, I got on the road to room treatment. And, thank god I took the road less travelled- at least in our country.

Now, I swear by room treatment.

Anyways, I myself am going through a repair phase for my room...since sometime actually. I have a plyboard ceiling with fibre optics. As you already know that plyboard is a bad idea. The whole ceiling jars like there is no tomorrow. I took acoustic consultancy after I got my HT made. He had asked me to install a trap box on the ceiling as well. I did not do the same as it was spoiling the aesthetics.

Nevertheless, he gave me an alternative. He asked me to buy 'Tecsound 70', a product by texsa.TEXSA INDIA - Roofing , waterproofing, thermal and acoustic insulation.

I am suppose to install this sheet by screw and washer arrangement either on top of the ply or from the bottom. In the case of latter, I would have to cover the same with a parchment cloth or speaker cloth etc.

I have already bought the stuff and it is lying with me for a few months now. Due to shortage of time, I am unable to apply the same.

I just want to know your views on the same. You can view my HT http://www.hifivision.com/my-audio-video-setup/1167-showcase-your-audio-video-setup-here-16.html

Cheers!

Sumit

Hi Sumit,

Each room is very different so there isn't a one size fits all situation here. Having too much absorption also kills the sound. Having too little leaves too many reflection that distort the sound.

Here are some pictures of what people have done with sound panels:

Personally, looking at the size of your room, I would like to use ceiling diffraction if you can get it done. You won't be absorbing but breaking up the sound going to the ceiling so that sound waves don't directly reflect back to you. This keeps the room ambiance intact while providing a clearer picture into the sound.

This is an example of ceiling diffraction.

I hope you see my point.

 

[santhosh]

Hi Santhosh!!

Perhaps, my choice of words was not good. Plyboard ceiling 'could' turn out to be bad option if not done properly.

For me it did not work out. From the linter, I have about 08"-12(approx) air gap where I have installed a network of wooden planks on which the ply is screwed from the bottom. In my case the air-gap was a bad...no, very bad idea. I did have help of this forum OR acoustic consultant then. I was naive then.

In your case, you have a high-density fibre wool installed on top of the plyboard. The fibrewool could stop the plyboard from jarring. Although, I am not sure as I have had bitter experience. You see with change in temperatures the wood expands and contracts. This enhances the jarring during low frequencies over a period of time. When my ceiling was new I had little problems. But, situation got out-of-hand as months went by.

The best solution that I have come across is 'Armstrong' acoustic tiles - Model 'Optra'. These are the same tiles that are used in Cinemas and work out to be around Rs. 100/sqft. Vinay has something similar installed and till date he has not mentioned any problems.

Santhosh, I want to help you. But, I am not qualified to advice w.r.t. your particular situation. I have narrated you my personal experience. Where did you get the idea of 4" fibrewool in plywood ceiling? Does that person have some experience?

Thanks Sumit,
I wanted to do up my Home Theatre myself and hence did not engage a qualified sound engineer/acoustic consultant to help me. Everything I have done is based on what I have read online. My family feels I have never read/re-read anything so much in my life before - not even during my school or college days:lol:l . I may be wrong and may face problems too. I am kind of prepared for some amount of rework as it will help me understand these things better . So, here is the logic I have used based on my interpretation of various online resources.

My ceiling has two parts to it -
a)A border of around 2.5 feet on three sides of the room(except front). I have 4 inches of high density (48kg/cubic meter) fiber glass wool and an air gap of about 8 inches above it. This has been made like a bass trap as bass normally attacks the corners(where two walls meet). Bass traps don't need to be porous also.

b) Second part spans through the center of the room and this has been covered with perforated peg board(two layers stapled and glued together). Just above these peg-boards is two inches of low density glass wool and another 2 to 4 inches of high density glasswool. The low density glass wool absorbs high and mid frequencies through the pores in the pegboard. The high density glasswool absorbs the lower frequencies. There is also some amount of diffusion going on here and is called diffsorption. I have posted more info here. I too have used optic fiber lighting to achieve the star-light look.

There is some information about air gaps in the link below: Acoustic Treatment and Design for Recording Studios and Listening Rooms

In theory, what I have done should work, but I am atleast one week to ten days before my equipment is ready to play in this room. Will update this thread based on my experience.

Anutone also has good ceiling tiles (in black color). Have you considered them?

PS> I too have similar Stanley staple gun. Where do you source the staples in India? Thanks.

Stanley Staples are available in 8mm, 10mm and 12mm and cost around Rs.70 to Rs.90 for a box of 1000 staples. I always buy my tools from Goodwill Hardware Stores here in Bangalore. There are several other Stanley dealers in Bangalore, should be the same in your location. If you face any difficulty, don't hesitate to pm me your address I can send you some from here.

 

[Sumit]

Gaurav!!

I do see your point. But, at this time I am unsure as to how much of your 'diffraction" advice I can incorporate in my HT. You see, the height of my ceiling is only 8'. The only way, I can get diffraction panels installed is by taking the plyboard apart and raising the ceiling height!!!

I shall give it a thought....

Cheers!!

 

[shaizada]

Gaurav!!

I do see your point. But, at this time I am unsure as to how much of your 'diffraction" advice I can incorporate in my HT. You see, the height of my ceiling is only 8'. The only way, I can get diffraction panels installed is by taking the plyboard apart and raising the ceiling height!!!

I shall give it a thought....

Cheers!!

See what you can do...

In your situation, I would MUCH MUCH rather diffract sound off the ceiling that purely absorb it.

Why not have your kaarigar build you something like this.

Problem solved dost

You want to read about "acoustic diffusors"...just ask professor Google for the rest.

 

[Sumit]

In theory, what I have done should work, but I am atleast one week to ten days before my equipment is ready to play in this room. Will update this thread based on my experience.

Anutone also has good ceiling tiles (in black color). Have you considered them?


Stanley Staples are available in 8mm, 10mm and 12mm and cost around Rs.70 to Rs.90 for a box of 1000 staples. I always buy my tools from Goodwill Hardware Stores here in Bangalore. There are several other Stanley dealers in Bangalore, should be the same in your location. If you face any difficulty, don't hesitate to pm me your address I can send you some from here.

Santhosh!!

It seems you have read like crazy before you planned your room. I can see that your ceiling is nearly complete. I suggest you should go ahead as planned as maximum work has been done. It at all, it doesn't work well then we shall figure out a repair job. All the very best!!!

Many thanks for the Stanley offer. I appreciate it.
At present I have enough staples as I have just bought them from my recent trip to UK<>

Cheers!!

 

[Sumit]

See what you can do...

In your situation, I would MUCH MUCH rather diffract sound off the ceiling that purely absorb it.

You want to read about "acoustic diffusors"...just ask professor Google for the rest.

ha ha...Yes, I can get a kaarigar to build the same, sure why not!!!!
But, can please elaborate the size of the said diffusor.

Also, I am skeptical> won't the diffusor jar/rattle against each other? It is also made of wood?

Cheers!!

 

[Sumit]

Gaurav!!

Tecsound too does not have absortive properties. It is purely reflective!!!

Thought you shd know.

Cheers!

 

[shaizada]

What is the size of your ceiling. Basically you want to cover up the area where the sound is going to reflect of the ceiling. It is at an angle from the speaker to the listening position. If possible, have the kaarigar make it as one big piece....the beauty of doing a custom job.

Try doing that here...I'd end up paying more for that diffusor than my whole system (or almost!)

If it is built and secured properly, you should have absolutely no hum or rattle.

 

[Sumit]

The size of my HT is 21' X 15' X 8'.

What is the size of your ceiling. Basically you want to cover up the area where the sound is going to reflect of the ceiling. It is at an angle from the speaker to the listening position. If possible, have the kaarigar make it as one big piece....the beauty of doing a custom job.

Try doing that here...I'd end up paying more for that diffusor than my whole system (or almost!)

If it is built and secured properly, you should have absolutely no hum or rattle.