Diffusor rolling....with books

[amit11]

Hi Friends,

Just sharing some thoughts and little experimentation i was doing.

To improve the sound, i used to try with keeping some rugs, or pillows or even canvas paintings in between the speaker space. Yes they used to modify the sound to some extent based on the material of the item. A big canvas 5 X 4 feet was less better than 3-5 small square pillows spaced out in between the speaker space. I observed that the canvas used to rob-off the low end and the high-ends were more focussed. Regarding the square pillows, the material of the pillows also used to change the sound experience. After few trials lasting for few hours or couple of days, I used to finally remove them and realized that sound is better without them even though i lose some aspects in comparison to them.

Then I recently came across the word 'Diffusor'. I had heard it but very very less compared to above experimentation. Then I realized what i was doing in these few years was mainly using 'Absorbers'. Absorber makes sense to use since it will absorb extra bass and make the sound coherent.. right?.... But then something was not just right about those absorbers I was using.

Then on some sites I started exploring what are diffusors, of what material they are made. But confusion was still there that they are not absorbing then how will they make a positive impact, and that too they are made of hard materials like wood. Skyline diffusor, quadratic diffusor.. then words like quarter wave length theory, then 4 inches depths of well in the quadratic diffusor, then even more words like matching well depth with the quarter wave length, uneven well spacing based on prime number etc... aroused more curosity. I also saw on youtube where someone also suggested that normal books can also act as a diffusor.. thought it might not be perfect but still it can.

So that aroused even more curisoity to try out without burning the pockets. So i started first with some books keeping on the floor (in between the speakers and where the floor & wall edges run with each other). That was a relevation for me. No bad effects like the 'absorbers' i used to use. Based on how many books we keep, how we arrange them, some a bit towards outside, some a bitwards the inside etc.. this made slight-slight differences in the sound heard. Also the material of the book, especially the outer cover also could make a difference.

Then I thought if I can stake 2 layers (like 2nd floor, 1st floor) that would help even more. But the books used to fall down when i staked the 2nd floor). So an idea cam to buy some rack. But the rack shelves should not be solid else that itself would impact sound. So an idea came to buy a rack (we used to use as show rack in the past). It was made of metal wires and nothing like a solid shelf. So it was airy-airy in all 3 dimensions. I purchased from a local kitchen utensil shop and told i can return if i do not like it...


So with this new item, I dumped my books on 2nd floor and even 3rd floor... .. yes that made even more difference and i was happy.

The in couple of days as my ears got further tuned, i realized that dumping the books is not the way. If i keep some spacing in between them it helps....

Then i started researching on the quadratic diffusors... and especialy words like quarter wave length, well-depth etc. So i started to experiment on spacing the books based on gap between them... for example 4 inches, 6 inches etc... Yes.. that made the sound better (atleast to me)... In 1st floor and 2nd floor I kept the books in a triangle fashion with 6 inch (roughly) gap starting between them.. and then on 3rd floor i kept multiple books like a skyline with very less space between them. To my understanding the 1st and 2nd floor helps to diffuse low end and 3rd floor helps to diffuse the high end to some extent.


I know it may sound stupid but mixing some theory and practical helped me to get a better sound, if i may say so.... Now i keep on experimenting with the books position, spacing between them which influences the sound.... kind of tone changer... or diffusor rolling (like tube rolling).

Attaching one pic and one calculation working sheet which helped me to get a better understanding.

Thanks for reading...

Regards,
amit11.

 

[jenson]

I also see great improvement in mid to high range if you hang a jaipuri 125 gm razai in center, placement above the book shelf you have. Tames bass quite a bit.

You may also consider pulling the speaker atleast 1 feet from the back of speaker to back wall.

 

[Analogous]

Hi Friends,

Just sharing some thoughts and little experimentation i was doing.

To improve the sound, i used to try with keeping some rugs, or pillows or even canvas paintings in between the speaker space. Yes they used to modify the sound to some extent based on the material of the item. A big canvas 5 X 4 feet was less better than 3-5 small square pillows spaced out in between the speaker space. I observed that the canvas used to rob-off the low end and the high-ends were more focussed. Regarding the square pillows, the material of the pillows also used to change the sound experience. After few trials lasting for few hours or couple of days, I used to finally remove them and realized that sound is better without them even though i lose some aspects in comparison to them.

Then I recently came across the word 'Diffusor'. I had heard it but very very less compared to above experimentation. Then I realized what i was doing in these few years was mainly using 'Absorbers'. Absorber makes sense to use since it will absorb extra bass and make the sound coherent.. right?.... But then something was not just right about those absorbers I was using.

Then on some sites I started exploring what are diffusors, of what material they are made. But confusion was still there that they are not absorbing then how will they make a positive impact, and that too they are made of hard materials like wood. Skyline diffusor, quadratic diffusor.. then words like quarter wave length theory, then 4 inches depths of well in the quadratic diffusor, then even more words like matching well depth with the quarter wave length, uneven well spacing based on prime number etc... aroused more curosity. I also saw on youtube where someone also suggested that normal books can also act as a diffusor.. thought it might not be perfect but still it can.

So that aroused even more curisoity to try out without burning the pockets. So i started first with some books keeping on the floor (in between the speakers and where the floor & wall edges run with each other). That was a relevation for me. No bad effects like the 'absorbers' i used to use. Based on how many books we keep, how we arrange them, some a bit towards outside, some a bitwards the inside etc.. this made slight-slight differences in the sound heard. Also the material of the book, especially the outer cover also could make a difference.

Then I thought if I can stake 2 layers (like 2nd floor, 1st floor) that would help even more. But the books used to fall down when i staked the 2nd floor). So an idea cam to buy some rack. But the rack shelves should not be solid else that itself would impact sound. So an idea came to buy a rack (we used to use as show rack in the past). It was made of metal wires and nothing like a solid shelf. So it was airy-airy in all 3 dimensions. I purchased from a local kitchen utensil shop and told i can return if i do not like it...


So with this new item, I dumped my books on 2nd floor and even 3rd floor... .. yes that made even more difference and i was happy.

The in couple of days as my ears got further tuned, i realized that dumping the books is not the way. If i keep some spacing in between them it helps....

Then i started researching on the quadratic diffusors... and especialy words like quarter wave length, well-depth etc. So i started to experiment on spacing the books based on gap between them... for example 4 inches, 6 inches etc... Yes.. that made the sound better (atleast to me)... In 1st floor and 2nd floor I kept the books in a triangle fashion with 6 inch (roughly) gap starting between them.. and then on 3rd floor i kept multiple books like a skyline with very less space between them. To my understanding the 1st and 2nd floor helps to diffuse low end and 3rd floor helps to diffuse the high end to some extent.


I know it may sound stupid but mixing some theory and practical helped me to get a better sound, if i may say so.... Now i keep on experimenting with the books position, spacing between them which influences the sound.... kind of tone changer... or diffusor rolling (like tube rolling).

Attaching one pic and one calculation working sheet which helped me to get a better understanding.

Thanks for reading...

Regards,
amit11.

Interesting experiments @amit11
I too have been using books as diffusers (or partial absorbers?) of sound to treat uncontrolled reflections from the side walls (areas of first reflection)
I love having my books around (old friends) and aesthetically they are to me better than panels.
Hopefully we will see more acoustic treatment panels with good art work coming to the market.

 

[Subbu68]

Interesting finds @amit11

Knowingly or unknowingly I had been having book shelves with random books on the sides of speakers a little behind them and that impact was felt when we emptied the shelves for cleaning. Now I have a sofa to one side and some heavy plants to the other side and a heavy sofa facing the speakers. Things seem to be under control but haven't done any study like you.

Keep educating us ...

 

[Subbu68]

Maybe a refinement with something like this (IKEA) instead of kitchen racks? It can serve as A/V rack also. Your books can go in too.

Buy FJALLBO TV Bench, Black,150x36x54 cm Online UAE - IKEA

Buy FJALLBO TV bench, black, 150x36x54 cm at IKEA UAE. The storage unit stands steady also on uneven floors since it has adjustable feet.

www.ikea.com

 

[gurujee]

I didn’t know a shelf between the speakers can impact the sound so much. I recently replaced my tv unit to a taller one to accommodate new equipments. But to my surprise, it spoiled the soundstage and imaging to a great extent. Is there anything I can do to use the unit without spoiling the sound.

 

[Analogous]

I didn’t know a shelf between the speakers can impact the sound so much. I recently replaced my tv unit to a taller one to accommodate new equipments. But to my surprise, it spoiled the soundstage and imaging to a great extent. Is there anything I can do to use the unit without spoiling the sound.

Try pulling the speakers out more towards you (inch by inch)
Also ensure there is at least three feet distance between the speakers and sidewalls. Symmetry is good.
Sometimes for better SQ you may need to sacrifice visual aesthetics a bit. This is surprisingly hard at first

 

[gurujee]

Try pulling the speakers out more towards you (inch by inch)
Also ensure there is at least three feet distance between the speakers and sidewalls. Symmetry is good.
Sometimes for better SQ you may need to sacrifice visual aesthetics a bit. This is surprisingly hard at first

Thank so much . Will try and update

 

[Analogous]

Another thing to try while moving the speakers is to shift the angle/ toe in. Generally more toe in means more focused imaging. However the stage may become a bit narrower. Once you have found a good position pulling the speakers away from the wall in front of you, you can experiment with toe in and out (little by little) till you find a position where you like it the best.
It’s a bit of labour but probably the best half hour you will spend to get the maximum performance out of your set up.
Use two or three tracks of different genres and styles that you are familiar with and use these to listen and decide.
A piece of chalk or a marker or some sticky tape would help to mark good sounding spots to return to during the process.
Your new TV unit should not be a deal breaker. All objects in the room will have some effect on the acoustics; experimenting with different placement of speakers will help discover new and sometimes a “hallelujah” position where you will be surprised how good your set up sounds. This has been my personal experience with every speaker I have had. Be bold and experiment with speaker positions.

 

[ajuvignesh]

Hi Friends,

Just sharing some thoughts and little experimentation i was doing.

To improve the sound, i used to try with keeping some rugs, or pillows or even canvas paintings in between the speaker space. Yes they used to modify the sound to some extent based on the material of the item. A big canvas 5 X 4 feet was less better than 3-5 small square pillows spaced out in between the speaker space. I observed that the canvas used to rob-off the low end and the high-ends were more focussed. Regarding the square pillows, the material of the pillows also used to change the sound experience. After few trials lasting for few hours or couple of days, I used to finally remove them and realized that sound is better without them even though i lose some aspects in comparison to them.

Then I recently came across the word 'Diffusor'. I had heard it but very very less compared to above experimentation. Then I realized what i was doing in these few years was mainly using 'Absorbers'. Absorber makes sense to use since it will absorb extra bass and make the sound coherent.. right?.... But then something was not just right about those absorbers I was using.

Then on some sites I started exploring what are diffusors, of what material they are made. But confusion was still there that they are not absorbing then how will they make a positive impact, and that too they are made of hard materials like wood. Skyline diffusor, quadratic diffusor.. then words like quarter wave length theory, then 4 inches depths of well in the quadratic diffusor, then even more words like matching well depth with the quarter wave length, uneven well spacing based on prime number etc... aroused more curosity. I also saw on youtube where someone also suggested that normal books can also act as a diffusor.. thought it might not be perfect but still it can.

So that aroused even more curisoity to try out without burning the pockets. So i started first with some books keeping on the floor (in between the speakers and where the floor & wall edges run with each other). That was a relevation for me. No bad effects like the 'absorbers' i used to use. Based on how many books we keep, how we arrange them, some a bit towards outside, some a bitwards the inside etc.. this made slight-slight differences in the sound heard. Also the material of the book, especially the outer cover also could make a difference.

Then I thought if I can stake 2 layers (like 2nd floor, 1st floor) that would help even more. But the books used to fall down when i staked the 2nd floor). So an idea cam to buy some rack. But the rack shelves should not be solid else that itself would impact sound. So an idea came to buy a rack (we used to use as show rack in the past). It was made of metal wires and nothing like a solid shelf. So it was airy-airy in all 3 dimensions. I purchased from a local kitchen utensil shop and told i can return if i do not like it...


So with this new item, I dumped my books on 2nd floor and even 3rd floor... .. yes that made even more difference and i was happy.

The in couple of days as my ears got further tuned, i realized that dumping the books is not the way. If i keep some spacing in between them it helps....

Then i started researching on the quadratic diffusors... and especialy words like quarter wave length, well-depth etc. So i started to experiment on spacing the books based on gap between them... for example 4 inches, 6 inches etc... Yes.. that made the sound better (atleast to me)... In 1st floor and 2nd floor I kept the books in a triangle fashion with 6 inch (roughly) gap starting between them.. and then on 3rd floor i kept multiple books like a skyline with very less space between them. To my understanding the 1st and 2nd floor helps to diffuse low end and 3rd floor helps to diffuse the high end to some extent.


I know it may sound stupid but mixing some theory and practical helped me to get a better sound, if i may say so.... Now i keep on experimenting with the books position, spacing between them which influences the sound.... kind of tone changer... or diffusor rolling (like tube rolling).

Attaching one pic and one calculation working sheet which helped me to get a better understanding.

Thanks for reading...

Regards,
amit11.

Try to bring the shelf up to the plane of speakers. Let the center of the bookshelf align with the tweeter height. It will bring definite improvement in sound.
In current setup, you're only diffusing the sounds near the floor. Most of the sound still bounces off the front wall. It you bring up the height of the stand to speaker level, it will diffuse most of the wall reflected sound and it not only improves the clarity but also improves the soundstage depth.
Also, what is the distance between the speakers and the wall? Keep the space atleast 3 feet for better soundstage depth.
All the best.

 

[mbhangui]

I didn’t know a shelf between the speakers can impact the sound so much. I recently replaced my tv unit to a taller one to accommodate new equipments. But to my surprise, it spoiled the soundstage and imaging to a great extent. Is there anything I can do to use the unit without spoiling the sound.

I have the same problem. I cover the tv with a thick quilt on certain days when I do critical listening

 

[keith_correa]

I didn’t know a shelf between the speakers can impact the sound so much. I recently replaced my tv unit to a taller one to accommodate new equipments. But to my surprise, it spoiled the soundstage and imaging to a great extent. Is there anything I can do to use the unit without spoiling the sound.

Can you post a picture? You will get better, relevant and practically possible suggestions if you do.

 

[gurujee]

Can you post a picture? You will get better, relevant and practically possible suggestions if you do.

Thank you. Here they are. There is a concrete shelf just to the side of right speaker, forming a passage that lead to attached bathroom. I guess, sound from speaker must be hitting on the wall there (reflection?).


@Analogous Thank you very much. As you can see, i can not move the speakers much as there is a bed in front of the tv unit, the space in between is a passage to attached bathroomon the right side and infront of that a concrete shelf at the right side of speaker. for experiment I moved the speakers to different positions, but the issue persisted. Previously, I had an enjoyable wider soundstage which was slightly beyond the speakers.

 

[keith_correa]

With the door at the back left of the left speaker kept open do this:

1. Drape a quilt over the unit and listen.
2. With unit draped, drape the TV too and listen.
3. Remove the drape only from the unit, leave the TV draped and listen.

Now repeat 1, 2 and 3 with the door kept closed.

What changes do you hear in both sets of 1, 2 and 3?

 

[gurujee]

With the door at the back left of the left speaker kept open do this:

1. Drape a quilt over the unit and listen.
2. With unit draped, drape the TV too and listen.
3. Remove the drape only from the unit, leave the TV draped and listen.

Now repeat 1, 2 and 3 with the door kept closed.

What changes do you hear in both sets of 1, 2 and 3?

Thanks so much for the tips.
Finally had some time and tested extensively.

Result-

Open door
1. Drape a quilt over the unit and listen. Ok.
2. With unit draped, drape the TV too and listen. Not ok
3. Remove the drape only from the unit, leave the TV draped and listen. Detail. Better.

Door closed
1. Drape a quilt over the unit and listen. No
2. With unit draped, drape the TV too and listen. Not ok
3. Remove the drape only from the unit, leave the TV draped and listen. Slightly detailed!

I had no idea TV can be a culprit as well. But still the wider soundstage before adding the to unit is not there now. If I have some time, I am planning to remove the unit and listen again in order to confirm my feelings.

 

[keith_correa]

Before you got the new unit, where was the TV mounted?

Also, many people talk about speaker toe-in. There is a thing called toe-out too (which affects soundstage) and might be worth looking into.

 

[gurujee]

Before you got the new unit, where was the TV mounted?

Also, many people talk about speaker toe-in. There is a thing called toe-out too (which affects soundstage) and might be worth looking into.

the tv was and is still mounted on the wall. the old unit however was of 1.5ft height compared to the present 2ft high.
thanks the speakers are currently toed in as suggested by the manual, will try and update on the toe out method to see any improvements