So i finally start treating my room tomorrow :D

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Yelamanchili manohar

Well-Known Member
Joined
Apr 27, 2021
Messages
181
Points
63
Location
Hyderabad
Hi all
:)


I guess I've been ranting for years about treating my room, and also going active. The going active journey might be a bit delayed as 2 of my tube amps are away for a regular service. And iam also undecided about the 3 way active crossover. So that will be for later, and will be a seperate post completely.

So I thought I'd just start with my room treatment plans and share my everyday progress. I will also be posting links of the material Iam using .

Iam no expert at acoustic treatment, thus I've talked to a reliable supplier, who also undertakes treatment projects. And I have highlighted the issues I've been facing. And he has suggested the materials to be used for my project. Besides I've done a fair bit of research over the last one year, so I guess I know my marbles when it comes to the voodoodo of acoustic treatment.

Room size - 11.5 x 15 feet

Speaker placement- along the longer 15 feet wall ( why along the longer wall, which is the unconventional way of placing speakers , please read below :D )

I have been very fortunate to be blessed with some great imaging in my small 11.5 x 15 feet room. Though I have severe bass issues low down, the imaging is somehow just great. I can list down the things that improved my imaging as I tried several different things :

1. Speaker placement: My speakers are not symmetrically placed, as I have a small extension, opening into the dresser behind the left speaker. Thus, when I played with positioning to get the best imaging I could, I ended up with the left speaker being about 2 inches farther from the seating position, than the right speaker. And the toe in on my right speaker ( there is a window just to the side ) is ever so slightly lesser than my left speaker. The visual disparity is visibly very evident. So I darken the room, and when playing music, the speakers just disappear.

2. Again speaker placement : In my small room I experimented placing the speakers along the long wall, as well as the short wall. And very surprisingly, I preferred the long wall placement. The speakers are now 11 feet apart, tweeter to tweeter. And the tweeter is around 130 cms from the wall behind the speakers. Almost 1 meter away from side walls. And my seating distance from the speakers is just about 8 feet. This wide placement of the speakers with a large toe-in ( I almost can only see the front baffles of the speakers and not their sides ), has reduced side wall reflections very well. And the sound stage is huge - 15 feet wide , with a very good perception of depth, and the imaging is as sharp as a pins head. On many many tracks, the side walls completely disappear, with no perception of the size of the room at all. Many instruments infact sound outside the plain of the speakers.

The tweeters are almost a foot above my ear height. Yes, that is right, the tweeters are not at my ear height when sitting down. This has given me an excellent sense of height to the sound stage. So all in all, my room will always trigger a big laugh from any friends who visit.

3. Vibration control : adding the isoacoustics gaia's under my previous pmc speakers, really improved the imaging. So iam a believer that these things work for me. However, my new speakers are really heavy at 120 kgs each, and I don't have the budget to buy something that can support that kind of weight. So Iam planning a short cut, and will report back once done.

But I can easily say that the biggest gain was with the placement of the speakers, though my setup goes against the established wisdom on the net
:)


Coming back on topic now :D

Biggest challenge : This is my daughters room, so will still have to be aesthetically pleasing with the end result. My daughters favourite colour is teal or turqouise. So the colour theme for the room is turquoise and navy blue. I have already dismantled my daughters queen bed today. And will be replacing with a sofa cum bed from IKEA, as my daughter never sleeps here, and is mostly used by my father in law on his visits. So comfort is not really a factor
:D


So here is the bed in navy blue :

https://www.ikea.com/in/en/p/friheten-3-seat-sofa-bed-skiftebo-blue-10431565/

Below are the biggest issues I have :

1. Bass suck outs from 65 to 110 hz : Due to quarter wave cancellations.

The center of the 10 inch bass driver is 130 cms from the back wall, 100 cms from side wall and 90 cms from the floor. I didn't measure from the ceiling though :D.

With all these three distances being between 90 to 130 cms, iam having severe quarter wave cancellations in the 65 to 105 hz bass range. And this is readily apparent with a sense of loss of dynamics, and one note bass.

THE FIX : i have been suggested to go for the heaviest density geo wool at 160 kgs / Cu.M. I will be building 2 corner traps from floor to ceiling, each 2x2 feet. And one 8 feet wide and one foot deep, floor to ceiling trap immediately behind my listening position. This higher density wool is apparently not suitable for making a broad band absorber ( I will revisit this topic below ). And is to be used only for bass traps. As it apparently only absorbs in the lower bass region, and starts loosing it's absorbing efficiency above 200hz, due to its gas flow rate. Thus, it acts as a reflector at higher frequencies and will not make my small room overdamped.

Below is the absorbing material :

https://www.auralexchange.com/product/nankarrow-geowool-6-pcs-1-2m-x-0-6m-mineral-wool-acoustic-insulation-board/?attribute_pa_density=160kg-m³

Below is the wrapping fabric to retain all the fibers in place:

https://www.auralexchange.com/produ...ttribute_pa_size=10m-x-1m-roll-10sqm-107-sqft

I've received the above already, and it is very breathable and close to being transparent. The bass traps will be covered with this first. With a finishing layer of the below in turquoise colour as planned :

https://www.auralexchange.com/produ...eilings-panels/?attribute_pa_colour=turquoise

Below are the sal wood frames on which the finishing fabric will be stapled :

https://www.auralexchange.com/produ..._size=3650mm-x-50mm-x-38mm-12ft-x-2in-x-1-5in

2. Room bass modes : Ive used a DSpeaker antimode 2.0 before, and it easily chopped off the bass peaks I was having due to room induced peaks. Though with bass treatment I expect to have smoother bass response, but these peaks might not be fully cancelled, thus will be using the either the DSpeaker antimode 2.0 or dirac live correction to cancel the peaks still left after bass treatment.

3. Too much echo and reverb: I've been suggested to use rocksul safe and silent 370 (80 kgs /Cu.M ) and with a panel depth of 4 inches as wide band absorbers at first reflection points including the ceiling clouds. Please bear in mind that the geowool of 160 kgs density that iam using for bass traps is not recommended here. A lot of small rooms apparently sound dampened, as the higher frequencies are absorbed first, and the bass and mids left on their own (I believe it happens when one uses foam based absorbers , which probably doesn't do much in the lower mid range and below ) Resulting in a completely skeweed room. Thus, I have been suggested to start with addressing the bass first with the geowool 160 and then start working up the frequency range from here with the rocksul safe and silent. ( I will eventually come to why iam not using much of diffusion to keep the room alive, which is a very important thing for me )

https://www.auralexchange.com/product/roxul-rockwool-safe-n-silent-pro-acoustic-insulation-boards/

However, I have read to do the ceiling clouds first, before even attempting to touch the side walls. And only once done with the ceiling clouds, I've been advised to very cautiously add these broad band panels to the side walls.

4. Improving imaging with diffusion/ absorption : My speakers are great at imaging already. And just want to improve it further. I've read that absorption helps more than diffusion in smal rooms, as diffusion needs distance from the listener to really work. And the usual minimal recommended distance is 10 feet. As I will probably have that distance only at the front wall, will experiment there first and see.

Below is the diffuser I have in my sights : ( will order 2 panels to make it 4 feet wide atleast )

https://www.amazon.in/gp/product/B08X6HDKG7/ref=ox_sc_saved_image_3?smid=A3SWZ8R1PUKMB&psc=1

So there is the start finally, I will be getting the 14 bags of geowool to start with tomorrow. Rest all materials are already here. And I have borrowed 4 nos of 4x2 feet broad band absorbers from a very good friend of this very same parish to experiment in different positions, and I plan on retaining them. Will keep updating with my daily progress from tomorrow onwards, though I really doubt if I could really make any sense of the measurements I get from REW. As I also intend to keep measuring ( Rta 30 reverb time ) as well a listening to see if iam not going in the right direction. Please wish me good luck :D
 
Last edited:

Vivek Batra

Well-Known Member
Joined
Mar 13, 2019
Messages
1,132
Points
113
Location
Chandigarh
Hi all
:)


I guess I've been ranting for years about treating my room, and also going active. The going active journey might be a bit delayed as 2 of my tube amps are away for a regular service. And iam also undecided about the 3 way active crossover. So that will be for later, and will be a seperate post completely.

So I thought I'd just start with my room treatment plans and share my everyday progress. I will also be posting links of the material Iam using .

Iam no expert at acoustic treatment, thus I've talked to a reliable supplier, who also undertakes treatment projects. And I have highlighted the issues I've been facing. And he has suggested the materials to be used for my project. Besides I've done a fair bit of research over the last one year, so I guess I know my marbles when it comes to the voodoodo of acoustic treatment.

Room size - 11.5 x 15 feet

Speaker placement- along the longer 15 feet wall ( why along the longer wall, which is the unconventional way of placing speakers , please read below :D )

I have been very fortunate to be blessed with some great imaging in my small 11.5 x 15 feet room. Though I have severe bass issues low down, the imaging is somehow just great. I can list down the things that improved my imaging as I tried several different things :

1. Speaker placement: My speakers are not symmetrically placed, as I have a small extension, opening into the dresser behind the left speaker. Thus, when I played with positioning to get the best imaging I could, I ended up with the left speaker being about 2 inches farther from the seating position, than the right speaker. And the toe in on my right speaker ( there is a window just to the side ) is ever so slightly lesser than my left speaker. The visual disparity is visibly very evident. So I darken the room, and when playing music, the speakers just disappear.

2. Again speaker placement : In my small room I experimented placing the speakers along the long wall, as well as the short wall. And very surprisingly, I preferred the long wall placement. The speakers are now 11 feet apart, tweeter to tweeter. And the tweeter is around 130 cms from the wall behind the speakers. Almost 1 meter away from side walls. And my seating distance from the speakers is just about 8 feet. This wide placement of the speakers with a large toe-in ( I almost can only see the front baffles of the speakers and not their sides ), has reduced side wall reflections very well. And the sound stage is huge - 15 feet wide , with a very good perception of depth, and the imaging is as sharp as a pins head. On many many tracks, the side walls completely disappear, with no perception of the size of the room at all. Many instruments infact sound outside the plain of the speakers.

The tweeters are almost a foot above my ear height. Yes, that is right, the tweeters are not at my ear height when sitting down. This has given me an excellent sense of height to the sound stage. So all in all, my room will always trigger a big laugh from any friends who visit.

3. Vibration control : adding the isoacoustics gaia's under my previous pmc speakers, really improved the imaging. So iam a believer that these things work for me. However, my new speakers are really heavy at 120 kgs each, and I don't have the budget to buy something that can support that kind of weight. So Iam planning a short cut, and will report back once done.

But I can easily say that the biggest gain was with the placement of the speakers, though my setup goes against the established wisdom on the net
:)


Coming back on topic now :D

Biggest challenge : This is my daughters room, so will still have to be aesthetically pleasing with the end result. My daughters favourite colour is teal or turqouise. So the colour theme for the room is turquoise and navy blue. I have already dismantled my daughters queen bed today. And will be replacing with a sofa cum bed from IKEA, as my daughter never sleeps here, and is mostly used by my father in law on his visits. So comfort is not really a factor
:D


So here is the bed in navy blue :

https://www.ikea.com/in/en/p/friheten-3-seat-sofa-bed-skiftebo-blue-10431565/

Below are the biggest issues I have :

1. Bass suck outs from 65 to 110 hz : Due to quarter wave cancellations.

The center of the 10 inch bass driver is 130 cms from the back wall, 100 cms from side wall and 90 cms from the floor. I didn't measure from the ceiling though :D.

With all these three distances being between 90 to 130 cms, iam having severe quarter wave cancellations in the 65 to 105 hz bass range. And this is readily apparent with a sense of loss of dynamics, and one note bass.

THE FIX : i have been suggested to go for the heaviest density geo wool at 160 kgs / Cu.M. I will be building 2 corner traps from floor to ceiling, each 2x2 feet. And one 8 feet wide and one foot deep, floor to ceiling trap immediately behind my listening position. This higher density wool is apparently not suitable for making a broad band absorber ( I will revisit this topic below ). And is to be used only for bass traps. As it apparently only absorbs in the lower bass region, and starts loosing it's absorbing efficiency above 200hz, due to its gas flow rate. Thus, it acts as a reflector at higher frequencies and will not make my small room overdamped.

Below is the absorbing material :

https://www.auralexchange.com/product/nankarrow-geowool-6-pcs-1-2m-x-0-6m-mineral-wool-acoustic-insulation-board/?attribute_pa_density=160kg-m³

Below is the wrapping fabric to retain all the fibers in place:

https://www.auralexchange.com/produ...ttribute_pa_size=10m-x-1m-roll-10sqm-107-sqft

I've received the above already, and it is very breathable and close to being transparent. The bass traps will be covered with this first. With a finishing layer of the below in turquoise colour as planned :

https://www.auralexchange.com/produ...eilings-panels/?attribute_pa_colour=turquoise

Below are the sal wood frames on which the finishing fabric will be stapled :

https://www.auralexchange.com/produ..._size=3650mm-x-50mm-x-38mm-12ft-x-2in-x-1-5in

2. Room bass modes : Ive used a DSpeaker antimode 2.0 before, and it easily chopped off the bass peaks I was having due to room induced peaks. Though with bass treatment I expect to have smoother bass response, but these peaks might not be fully cancelled, thus will be using the either the DSpeaker antimode 2.0 or dirac live correction to cancel the peaks still left after bass treatment.

3. Too much echo and reverb: I've been suggested to use rocksul safe and silent 370 (80 kgs /Cu.M ) and with a panel depth of 4 inches as wide band absorbers at first reflection points including the ceiling clouds. Please bear in mind that the geowool of 160 kgs density that iam using for bass traps is not recommended here. A lot of small rooms apparently sound dampened, as the higher frequencies are absorbed first, and the bass and mids left on their own (I believe it happens when one uses foam based absorbers , which probably doesn't do much in the lower mid range and below ) Resulting in a completely skeweed room. Thus, I have been suggested to start with addressing the bass first with the geowool 160 and then start working up the frequency range from here with the rocksul safe and silent. ( I will eventually come to why iam not using much of diffusion to keep the room alive, which is a very important thing for me )

https://www.auralexchange.com/product/roxul-rockwool-safe-n-silent-pro-acoustic-insulation-boards/

However, I have read to do the ceiling clouds first, before even attempting to touch the side walls. And only once done with the ceiling clouds, I've been advised to very cautiously add these broad band panels to the side walls.

4. Improving imaging with diffusion/ absorption : My speakers are great at imaging already. And just want to improve it further. I've read that absorption helps more than diffusion in smal rooms, as diffusion needs distance from the listener to really work. And the usual minimal recommended distance is 10 feet. As I will probably have that distance only at the front wall, will experiment there first and see.

Below is the diffuser I have in my sights : ( will order 2 panels to make it 4 feet wide atleast )

https://www.amazon.in/gp/product/B08X6HDKG7/ref=ox_sc_saved_image_3?smid=A3SWZ8R1PUKMB&psc=1

So there is the start finally, I will be getting the 14 bags of geowool to start with tomorrow. Rest all materials are already here. And I have borrowed 4 nos of 4x2 feet broad band absorbers from a very good friend of this very same parish to experiment in different positions, and I plan on retaining them. Will keep updating with my daily progress from tomorrow onwards, though I really doubt if I could really make any sense of the measurements I get from REW. As I also intend to keep measuring ( Rta 30 reverb time ) as well a listening to see if iam not going in the right direction. Please wish me good luck :D
Hi Manu

Very informative post, Good luck with the project. I guess we all would be very eager to see the end product and your impressions after its done
 

fLUX

Well-Known Member
Joined
Jun 13, 2012
Messages
1,262
Points
113
Location
Bangalore
Hi all
:)


I guess I've been ranting for years about treating my room, and also going active. The going active journey might be a bit delayed as 2 of my tube amps are away for a regular service. And iam also undecided about the 3 way active crossover. So that will be for later, and will be a seperate post completely.

So I thought I'd just start with my room treatment plans and share my everyday progress. I will also be posting links of the material Iam using .

Iam no expert at acoustic treatment, thus I've talked to a reliable supplier, who also undertakes treatment projects. And I have highlighted the issues I've been facing. And he has suggested the materials to be used for my project. Besides I've done a fair bit of research over the last one year, so I guess I know my marbles when it comes to the voodoodo of acoustic treatment.

Room size - 11.5 x 15 feet

Speaker placement- along the longer 15 feet wall ( why along the longer wall, which is the unconventional way of placing speakers , please read below :D )

I have been very fortunate to be blessed with some great imaging in my small 11.5 x 15 feet room. Though I have severe bass issues low down, the imaging is somehow just great. I can list down the things that improved my imaging as I tried several different things :

1. Speaker placement: My speakers are not symmetrically placed, as I have a small extension, opening into the dresser behind the left speaker. Thus, when I played with positioning to get the best imaging I could, I ended up with the left speaker being about 2 inches farther from the seating position, than the right speaker. And the toe in on my right speaker ( there is a window just to the side ) is ever so slightly lesser than my left speaker. The visual disparity is visibly very evident. So I darken the room, and when playing music, the speakers just disappear.

2. Again speaker placement : In my small room I experimented placing the speakers along the long wall, as well as the short wall. And very surprisingly, I preferred the long wall placement. The speakers are now 11 feet apart, tweeter to tweeter. And the tweeter is around 130 cms from the wall behind the speakers. Almost 1 meter away from side walls. And my seating distance from the speakers is just about 8 feet. This wide placement of the speakers with a large toe-in ( I almost can only see the front baffles of the speakers and not their sides ), has reduced side wall reflections very well. And the sound stage is huge - 15 feet wide , with a very good perception of depth, and the imaging is as sharp as a pins head. On many many tracks, the side walls completely disappear, with no perception of the size of the room at all. Many instruments infact sound outside the plain of the speakers.

The tweeters are almost a foot above my ear height. Yes, that is right, the tweeters are not at my ear height when sitting down. This has given me an excellent sense of height to the sound stage. So all in all, my room will always trigger a big laugh from any friends who visit.

3. Vibration control : adding the isoacoustics gaia's under my previous pmc speakers, really improved the imaging. So iam a believer that these things work for me. However, my new speakers are really heavy at 120 kgs each, and I don't have the budget to buy something that can support that kind of weight. So Iam planning a short cut, and will report back once done.

But I can easily say that the biggest gain was with the placement of the speakers, though my setup goes against the established wisdom on the net
:)


Coming back on topic now :D

Biggest challenge : This is my daughters room, so will still have to be aesthetically pleasing with the end result. My daughters favourite colour is teal or turqouise. So the colour theme for the room is turquoise and navy blue. I have already dismantled my daughters queen bed today. And will be replacing with a sofa cum bed from IKEA, as my daughter never sleeps here, and is mostly used by my father in law on his visits. So comfort is not really a factor
:D


So here is the bed in navy blue :

https://www.ikea.com/in/en/p/friheten-3-seat-sofa-bed-skiftebo-blue-10431565/

Below are the biggest issues I have :

1. Bass suck outs from 65 to 110 hz : Due to quarter wave cancellations.

The center of the 10 inch bass driver is 130 cms from the back wall, 100 cms from side wall and 90 cms from the floor. I didn't measure from the ceiling though :D.

With all these three distances being between 90 to 130 cms, iam having severe quarter wave cancellations in the 65 to 105 hz bass range. And this is readily apparent with a sense of loss of dynamics, and one note bass.

THE FIX : i have been suggested to go for the heaviest density geo wool at 160 kgs / Cu.M. I will be building 2 corner traps from floor to ceiling, each 2x2 feet. And one 8 feet wide and one foot deep, floor to ceiling trap immediately behind my listening position. This higher density wool is apparently not suitable for making a broad band absorber ( I will revisit this topic below ). And is to be used only for bass traps. As it apparently only absorbs in the lower bass region, and starts loosing it's absorbing efficiency above 200hz, due to its gas flow rate. Thus, it acts as a reflector at higher frequencies and will not make my small room overdamped.

Below is the absorbing material :

https://www.auralexchange.com/product/nankarrow-geowool-6-pcs-1-2m-x-0-6m-mineral-wool-acoustic-insulation-board/?attribute_pa_density=160kg-m³

Below is the wrapping fabric to retain all the fibers in place:

https://www.auralexchange.com/produ...ttribute_pa_size=10m-x-1m-roll-10sqm-107-sqft

I've received the above already, and it is very breathable and close to being transparent. The bass traps will be covered with this first. With a finishing layer of the below in turquoise colour as planned :

https://www.auralexchange.com/produ...eilings-panels/?attribute_pa_colour=turquoise

Below are the sal wood frames on which the finishing fabric will be stapled :

https://www.auralexchange.com/produ..._size=3650mm-x-50mm-x-38mm-12ft-x-2in-x-1-5in

2. Room bass modes : Ive used a DSpeaker antimode 2.0 before, and it easily chopped off the bass peaks I was having due to room induced peaks. Though with bass treatment I expect to have smoother bass response, but these peaks might not be fully cancelled, thus will be using the either the DSpeaker antimode 2.0 or dirac live correction to cancel the peaks still left after bass treatment.

3. Too much echo and reverb: I've been suggested to use rocksul safe and silent 370 (80 kgs /Cu.M ) and with a panel depth of 4 inches as wide band absorbers at first reflection points including the ceiling clouds. Please bear in mind that the geowool of 160 kgs density that iam using for bass traps is not recommended here. A lot of small rooms apparently sound dampened, as the higher frequencies are absorbed first, and the bass and mids left on their own (I believe it happens when one uses foam based absorbers , which probably doesn't do much in the lower mid range and below ) Resulting in a completely skeweed room. Thus, I have been suggested to start with addressing the bass first with the geowool 160 and then start working up the frequency range from here with the rocksul safe and silent. ( I will eventually come to why iam not using much of diffusion to keep the room alive, which is a very important thing for me )

https://www.auralexchange.com/product/roxul-rockwool-safe-n-silent-pro-acoustic-insulation-boards/

However, I have read to do the ceiling clouds first, before even attempting to touch the side walls. And only once done with the ceiling clouds, I've been advised to very cautiously add these broad band panels to the side walls.

4. Improving imaging with diffusion/ absorption : My speakers are great at imaging already. And just want to improve it further. I've read that absorption helps more than diffusion in smal rooms, as diffusion needs distance from the listener to really work. And the usual minimal recommended distance is 10 feet. As I will probably have that distance only at the front wall, will experiment there first and see.

Below is the diffuser I have in my sights : ( will order 2 panels to make it 4 feet wide atleast )

https://www.amazon.in/gp/product/B08X6HDKG7/ref=ox_sc_saved_image_3?smid=A3SWZ8R1PUKMB&psc=1

So there is the start finally, I will be getting the 14 bags of geowool to start with tomorrow. Rest all materials are already here. And I have borrowed 4 nos of 4x2 feet broad band absorbers from a very good friend of this very same parish to experiment in different positions, and I plan on retaining them. Will keep updating with my daily progress from tomorrow onwards, though I really doubt if I could really make any sense of the measurements I get from REW. As I also intend to keep measuring ( Rta 30 reverb time ) as well a listening to see if iam not going in the right direction. Please wish me good luck :D

Manohar ji , curiously awaiting for you to finish your setup. All the best
 

Smadhu

Member
Joined
Jun 24, 2020
Messages
70
Points
18
Location
Bangalore
That is some planning and elaborate detailing of the plan.

I would definitely await for the final outcome and the result. I am sure a lot of folks will benefit from the exercise being undertaken.

Hoping you attain the musical nirvana post this. Good luck!
 

sud98

Well-Known Member
Joined
Nov 13, 2008
Messages
2,392
Points
113
Location
bangalore,india
THE FIX : i have been suggested to go for the heaviest density geo wool at 160 kgs / Cu.M. I will be building 2 corner traps from floor to ceiling, each 2x2 feet. And one 8 feet wide and one foot deep, floor to ceiling trap immediately behind my listening position. This higher density wool is apparently not suitable for making a broad band absorber ( I will revisit this topic below ). And is to be used only for bass traps. As it apparently only absorbs in the lower bass region, and starts loosing it's absorbing efficiency above 200hz, due to its gas flow rate. Thus, it acts as a reflector at higher frequencies and will not make my small room overdamped.

Best of luck on your exercise. It will good to measure a solution of each problem and see if it worked. Its very difficult to assess if you solve multiple issues at the same time.

The highlighted part I am not sure is correct. AFAIK, for waves below 100Hz to be absorbed you need a lot of depth to absorb quarter wavelength. 1/4*(speed of sound/frequency) = 1100/4/100 ~ 3 feet deep. If you want 65Hz it will be around 4 feet of depth.

Having a very high density of absorber will make it difficult for absorbing bass as the flow resistivity will be very high. Please do consider the same when you build the bass trap. Rest of the ideas look very good. Just my thoughts.
 

Love4sound

Well-Known Member
Joined
Nov 23, 2018
Messages
3,815
Points
113
Location
Chennai
Hi all
:)


I guess I've been ranting for years about treating my room, and also going active. The going active journey might be a bit delayed as 2 of my tube amps are away for a regular service. And iam also undecided about the 3 way active crossover. So that will be for later, and will be a seperate post completely.

So I thought I'd just start with my room treatment plans and share my everyday progress. I will also be posting links of the material Iam using .

Iam no expert at acoustic treatment, thus I've talked to a reliable supplier, who also undertakes treatment projects. And I have highlighted the issues I've been facing. And he has suggested the materials to be used for my project. Besides I've done a fair bit of research over the last one year, so I guess I know my marbles when it comes to the voodoodo of acoustic treatment.

Room size - 11.5 x 15 feet

Speaker placement- along the longer 15 feet wall ( why along the longer wall, which is the unconventional way of placing speakers , please read below :D )

I have been very fortunate to be blessed with some great imaging in my small 11.5 x 15 feet room. Though I have severe bass issues low down, the imaging is somehow just great. I can list down the things that improved my imaging as I tried several different things :

1. Speaker placement: My speakers are not symmetrically placed, as I have a small extension, opening into the dresser behind the left speaker. Thus, when I played with positioning to get the best imaging I could, I ended up with the left speaker being about 2 inches farther from the seating position, than the right speaker. And the toe in on my right speaker ( there is a window just to the side ) is ever so slightly lesser than my left speaker. The visual disparity is visibly very evident. So I darken the room, and when playing music, the speakers just disappear.

2. Again speaker placement : In my small room I experimented placing the speakers along the long wall, as well as the short wall. And very surprisingly, I preferred the long wall placement. The speakers are now 11 feet apart, tweeter to tweeter. And the tweeter is around 130 cms from the wall behind the speakers. Almost 1 meter away from side walls. And my seating distance from the speakers is just about 8 feet. This wide placement of the speakers with a large toe-in ( I almost can only see the front baffles of the speakers and not their sides ), has reduced side wall reflections very well. And the sound stage is huge - 15 feet wide , with a very good perception of depth, and the imaging is as sharp as a pins head. On many many tracks, the side walls completely disappear, with no perception of the size of the room at all. Many instruments infact sound outside the plain of the speakers.

The tweeters are almost a foot above my ear height. Yes, that is right, the tweeters are not at my ear height when sitting down. This has given me an excellent sense of height to the sound stage. So all in all, my room will always trigger a big laugh from any friends who visit.

3. Vibration control : adding the isoacoustics gaia's under my previous pmc speakers, really improved the imaging. So iam a believer that these things work for me. However, my new speakers are really heavy at 120 kgs each, and I don't have the budget to buy something that can support that kind of weight. So Iam planning a short cut, and will report back once done.

But I can easily say that the biggest gain was with the placement of the speakers, though my setup goes against the established wisdom on the net
:)


Coming back on topic now :D

Biggest challenge : This is my daughters room, so will still have to be aesthetically pleasing with the end result. My daughters favourite colour is teal or turqouise. So the colour theme for the room is turquoise and navy blue. I have already dismantled my daughters queen bed today. And will be replacing with a sofa cum bed from IKEA, as my daughter never sleeps here, and is mostly used by my father in law on his visits. So comfort is not really a factor
:D


So here is the bed in navy blue :

https://www.ikea.com/in/en/p/friheten-3-seat-sofa-bed-skiftebo-blue-10431565/

Below are the biggest issues I have :

1. Bass suck outs from 65 to 110 hz : Due to quarter wave cancellations.

The center of the 10 inch bass driver is 130 cms from the back wall, 100 cms from side wall and 90 cms from the floor. I didn't measure from the ceiling though :D.

With all these three distances being between 90 to 130 cms, iam having severe quarter wave cancellations in the 65 to 105 hz bass range. And this is readily apparent with a sense of loss of dynamics, and one note bass.

THE FIX : i have been suggested to go for the heaviest density geo wool at 160 kgs / Cu.M. I will be building 2 corner traps from floor to ceiling, each 2x2 feet. And one 8 feet wide and one foot deep, floor to ceiling trap immediately behind my listening position. This higher density wool is apparently not suitable for making a broad band absorber ( I will revisit this topic below ). And is to be used only for bass traps. As it apparently only absorbs in the lower bass region, and starts loosing it's absorbing efficiency above 200hz, due to its gas flow rate. Thus, it acts as a reflector at higher frequencies and will not make my small room overdamped.

Below is the absorbing material :

https://www.auralexchange.com/product/nankarrow-geowool-6-pcs-1-2m-x-0-6m-mineral-wool-acoustic-insulation-board/?attribute_pa_density=160kg-m³

Below is the wrapping fabric to retain all the fibers in place:

https://www.auralexchange.com/produ...ttribute_pa_size=10m-x-1m-roll-10sqm-107-sqft

I've received the above already, and it is very breathable and close to being transparent. The bass traps will be covered with this first. With a finishing layer of the below in turquoise colour as planned :

https://www.auralexchange.com/produ...eilings-panels/?attribute_pa_colour=turquoise

Below are the sal wood frames on which the finishing fabric will be stapled :

https://www.auralexchange.com/produ..._size=3650mm-x-50mm-x-38mm-12ft-x-2in-x-1-5in

2. Room bass modes : Ive used a DSpeaker antimode 2.0 before, and it easily chopped off the bass peaks I was having due to room induced peaks. Though with bass treatment I expect to have smoother bass response, but these peaks might not be fully cancelled, thus will be using the either the DSpeaker antimode 2.0 or dirac live correction to cancel the peaks still left after bass treatment.

3. Too much echo and reverb: I've been suggested to use rocksul safe and silent 370 (80 kgs /Cu.M ) and with a panel depth of 4 inches as wide band absorbers at first reflection points including the ceiling clouds. Please bear in mind that the geowool of 160 kgs density that iam using for bass traps is not recommended here. A lot of small rooms apparently sound dampened, as the higher frequencies are absorbed first, and the bass and mids left on their own (I believe it happens when one uses foam based absorbers , which probably doesn't do much in the lower mid range and below ) Resulting in a completely skeweed room. Thus, I have been suggested to start with addressing the bass first with the geowool 160 and then start working up the frequency range from here with the rocksul safe and silent. ( I will eventually come to why iam not using much of diffusion to keep the room alive, which is a very important thing for me )

https://www.auralexchange.com/product/roxul-rockwool-safe-n-silent-pro-acoustic-insulation-boards/

However, I have read to do the ceiling clouds first, before even attempting to touch the side walls. And only once done with the ceiling clouds, I've been advised to very cautiously add these broad band panels to the side walls.

4. Improving imaging with diffusion/ absorption : My speakers are great at imaging already. And just want to improve it further. I've read that absorption helps more than diffusion in smal rooms, as diffusion needs distance from the listener to really work. And the usual minimal recommended distance is 10 feet. As I will probably have that distance only at the front wall, will experiment there first and see.

Below is the diffuser I have in my sights : ( will order 2 panels to make it 4 feet wide atleast )

https://www.amazon.in/gp/product/B08X6HDKG7/ref=ox_sc_saved_image_3?smid=A3SWZ8R1PUKMB&psc=1

So there is the start finally, I will be getting the 14 bags of geowool to start with tomorrow. Rest all materials are already here. And I have borrowed 4 nos of 4x2 feet broad band absorbers from a very good friend of this very same parish to experiment in different positions, and I plan on retaining them. Will keep updating with my daily progress from tomorrow onwards, though I really doubt if I could really make any sense of the measurements I get from REW. As I also intend to keep measuring ( Rta 30 reverb time ) as well a listening to see if iam not going in the right direction. Please wish me good luck :D
Great I was just planning to do some basic room treatment and hoping to learn few things. If possible please do share clear images of the products and room in each stages of installation.
 

Yelamanchili manohar

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Best of luck on your exercise. It will good to measure a solution of each problem and see if it worked. Its very difficult to assess if you solve multiple issues at the same time.

The highlighted part I am not sure is correct. AFAIK, for waves below 100Hz to be absorbed you need a lot of depth to absorb quarter wavelength. 1/4*(speed of sound/frequency) = 1100/4/100 ~ 3 feet deep. If you want 65Hz it will be around 4 feet of depth.

Having a very high density of absorber will make it difficult for absorbing bass as the flow resistivity will be very high. Please do consider the same when you build the bass trap. Rest of the ideas look very good. Just my thoughts.
Hi sud :)

As you rightly mentioned, it will be impossible to effectively tame bass down to 65 hz in my small room. So the only thing being attempted is to reduce the cancellation to the extent possible. And usually for deeper bass traps, lower density between 48 to 80 kgs wool is recommended. However the danger with this approach is the possibility of absorbing over the entire frequency band and there by making the room sound over damped. I have been reliably told that using very high density wool for smaller rooms has been tried before, with great results. While still keeping the room alive. Thus, thought I'd give it a shot and see. And I admit this is something iam attempting with my own doubts, as using between 48 to 60 kgs for bass would have been a fool proof approach. Maybe I will be the guinea pig for this experiment :D
 

Yelamanchili manohar

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Great I was just planning to do some basic room treatment and hoping to learn few things. If possible please do share clear images of the products and room in each stages of installation.
Hi :)

Will definitely do so. I also wanted to take a room measurement before starting the project. But unfortunately while I was away yesterday evening, the geowool arrived. And my wife got it dumped into the very room iam treating :D

And honestly the packs are too heavy to move. So taking a measurement with 14 boxes of absorption sitting in the room, might not be an indicator of how the original rooms acoustics are.

Hence I guess I will take my first measurement after the bass traps have been installed. And then will keep taking subsequent measurements when adding brand band absorbers at first reflection points.
 

Yelamanchili manohar

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So day -1 ( 6th Oct 2021 )

Got up at 3 AM. Took a hot shower, and started on the project. Now at 5 AM iam already hiding in the balcony, huffing and puffing. Anyone planning on starting with a similar project, please wait till the onset of peak winters :D

So some pics to follow : IMG-20211006-WA0007.jpg This is the breathable fabric that is first stapled to the backing cupboard to prevent the loose fibers from escaping. IMG-20211006-WA0009.jpg IMG-20211006-WA0005.jpg IMG-20211006-WA0004.jpg


This insulation material is a real b****h to cut. God knows if it will reduce my bass gremlins or not. But will definitely reduce my weight first :D
 

Yelamanchili manohar

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Finally winded up for today at 0930 hrs. Have to attend to other daily chores now :(

The progress so far in 6 hrs :D

1. Almost finished one corner trap. Got the retaining frame mounted on the right side easily as it is screwed to the wooden cupboard. Now stuck at the left one, as the wall is solid cast concrete, and none of my different drill bits are able to penetrate the same.

2. That white fabric is too brittle. Absolutely no chance of it retaining the fibers in the longer term. Even though there is a outer fabric that will be covering the trap, I will definitely add another interim layer of fabric to make sure those fibers don't escape.

I would have definitely finished this corner trap today in straight 6 hrs, had it not been for that concrete wall :(

IMG-20211006-WA0017.jpg IMG-20211006-WA0018.jpg IMG-20211006-WA0019.jpg IMG-20211006-WA0020.jpg
 

Yelamanchili manohar

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Curious.. Was this economical than going for corner traps.. https://www.auralexchange.com/product/aural-exchange-propanel-b-custom-built-corner-bass-traps/
Read that space behind bass traps further helps breaking down resonance

are you entirely going diy for this..?
Also, assuming due consultations were done with respect to placement...
I honestly am not sure jenson :)

The total cost of raw material for me was around 70k. I could have got around 12 bass traps with the same geowool stuffing for this money. However, I found that these type of panels are used more in the ceiling corners, and full depth traps are used behind speakers, and whichever other corners are available. Hence I thought that these might be more effective. But honestly, I could be entirely wrong here.
 

Yelamanchili manohar

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So finally got a hammer drill to penetrate the concrete and fixed the left retaining wooden frame.

IMG-20211006-WA0066.jpg
As can be seen, I have a power socket in the upper section of the left retaining frame, so had to fix the frame in 2 sections. Will be gluing up some wood with silicone sealant to make it a tight seal.
IMG-20211006-WA0065.jpg

I had wrapped the retaining fabric to pass behind the left frame. So the left frame holds it on the left side. While it has been stapled to the wooden cupboard on the right.

Then I fixed top and bottom wooden frames. Iam still learning how to make angled cuts with a jigsaw, so cut the angles with a hacksaw by hand. Didn't get the angles spot on, to get a flush fit as can be seen. But will serve the purpose for now.
IMG-20211006-WA0075.jpg

Lastly I passed a central vertical wooden bar to act as an additional retaining frame. The geowool is almost 3 feet wide at the corner, and more than 2 feet deep. And as it is dense, it is actually staying in placing all by its own weight. So the retaining frame, was more for covering the trap with acoustic fabric, than to hold the geowool in place. But iam happy I could improvise along the way to accomplish both.

IMG-20211006-WA0077.jpg

Iam still waiting for the top acoustic fabric. Otherwise would have finished the left trap today.

IMG-20211006-WA0078.jpg

New challenges : The white breathable fabric that is presently covering the trap is too fragile. And is unlikely to hold on for long. So will probably seal all the sides of the retaining frame with silicon sealant before I wrap the top acoustic fabric.

Things I should have done differently : I think I made a mistake by placing the geowool first, and then building a frame around it. In most of the youtube videos, they showed similar. But I should have first built the wooden frame. Then sealed the small gaps between the frame and the wall with silicon sealant. And then placed the geowool inside. This would have made sure, that the wool fibers would not escape through these gaps. But I will be building the frames first when I resume work tomorrow.

Okay off to sip some chilled beer now :)

Will resume work in the morning again.
 
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