Acoustic diffusers at First Reflection

sidvee

Well-Known Member
Joined
May 14, 2007
Messages
3,311
Points
113
Location
Hyderabad
I recently tried out a combination that I have been planning. In my smallish 14' x 12' room, I replaced GIK 244 absorption panels at the first reflection point on the sidewalls with their new evolution Polyfusor diffuser panel which acts as a bass trap upto 80hz and a diffuser from 600hz on. I felt that the soundstage widened more beyond the speaker location - imaging sharpness remained more or less the same - and I hear more resolution in the stage and more airy treble especially on cymbal strikes and better overall decay. I am liking this now and will keep the current configuration. There is a lot of debate on having diffusion at first reflection points on the side walls, with a lot of recommendations for broadband absorption at this point, but I think this type of a hybrid absorption/diffusion panel might be better.
Overall now my room has a mixture of broadband absorption in the corners, diffusion/absorption at first reflection on sidewalls and wall behind speakers and QRD diffusers at the ceiling reflection point and I feel it is sounding excellent. I am mostly using GIK panels except the wall behind the speakers where I am using 4 vicoustic wavewood panels.
Cheers,
Sid
 
Last edited:
Hi Sidvee, in a small room, i always prefer a diffuser with minimal absorption to an absorber at the first reflection point. I have experienced this in mastering studios too.
 
Hi,

Anyone here on hfv tried these out ? Has anyone tried making a QRD panel, diy. Did search for threads with no luck.

ciao
gr

Some of the youtube videos on QRD panel look deceptively simple. But the quality of carpenters make it tough. All that you need is a hand lathe and steady hands but was afraid to trust my carpenter.
 
Some of the youtube videos on QRD panel look deceptively simple. But the quality of carpenters make it tough. All that you need is a hand lathe and steady hands but was afraid to trust my carpenter.
They do make it look easy :)

There are many who have used high density styrofoam instead of wood but I am no entirely sure if that will absorb or reflect/ diffuse. There is a lot of labor that goes into the sanding and finishing which kind of vanishes with the styrofoam, it would also be lighter to hang (than a wooden one) on the ceiling

Moot point really ATM i neither have a source for styrofoam/ wood nor know someone who will cut and assemble for me.

Guess I will start by looking for a carpenter and also research designs. I cannot do a well depth of more than 4" so that one decision is done :rolleyes:

ciao
gr
 
I can help you the references, there are local dealers who have these things in Stock and will match the price on the website you've mentioned.

meanwhile how about taking the four absorber panels from my room, which are movable ; and see how it changes the sound?

The diffusers can be worked out accordingly if the end result doesnt satisfy either of us.


Sent from my iPhone using Tapatalk
 
I can help you the references<snip>
meanwhile how about taking the four absorber panels from my room, which are movable ; and see how it changes the sound?

Hi,

Thanks a pile. :)

I have BBA on the back/front/ (1) side wall and ceiling cloud. I think I have overdone it somewhat :eek:

I've liked the sound, so far. Then this worm of a thought started gnawing on my brain - upgrading speakers that is. I know I have to do something about it before it becomes python sized and eats me.

So, I now want to get diffusers for the side. It should (will ! ) change the sound.

ciao
gr
 
Hey guys do look at the stillpoints aperture acoustic panels which are 1.5 feet x 1.5 feet panels which can be wall mounted or placed on a flat surge.. .they are amazing and you can sort your acoustics with as little as 3 panels in the room. I can vouch for it cos I use them. You needn't go in for any extensive wall cladding or any other expensive and extensive methods for good sound imaging .
cheers!
Anand

STEREO: Transrotor zet 1 TT, Transrotor 8.2 MC reference phono stage, Ortofon rondo red cartridge,MSB Platinum iv DAC, MSB Platinum DATA CD transport iv, Electrocompaniet PC -1 CD player, mola mola Kaluga power amplifiers, Transparent audio Ultra cables and interconnects, Transparent audio premium USB cable , Synology D 415 play 12 TB RAID NAS drive ,Mac book air with Roon, Joseph Audio Perspectives Floor standers , Stillpoints Aperture Acoustic panels, Stillpoints ultra mini isolators , Blue jeans CAT6a cables. Apple airport extreme router and D link switcher.

HT1: Optoma HD 82 projector, Ibox media player, Synology D 415 play 12 TB RAID NAS drive, Anthem MRX 500 AV receiver , B & W centres & surrounds , REL T5 subwoofer.

HT2: Panasonic 42' Plasma, Monitor audio Radius R250 centre and front speakers, Radius R90 rears and radius R360 subwoofer. Dune media player and pioneer BDP 140 blu ray player.
 
Hey guys do look at the stillpoints aperture acoustic panels which are 1.5 feet x 1.5 feet panels which can be wall mounted or placed on a flat surge.. .they are amazing and you can sort your acoustics with as little as 3 panels in the room. I can vouch for it cos I use them. You needn't go in for any extensive wall cladding or any other expensive and extensive methods for good sound imaging .
cheers!
Anand.

Is there a link to these? Do post pictures of the panels you are using.

Also, could you please avoid posting your entire equipment in every post?

MaSh

Sent from my Redmi Note 3 using Tapatalk
 
Is there a link to these? Do post pictures of the panels you are using.

Also, could you please avoid posting your entire equipment in every post?

MaSh

Sent from my Redmi Note 3 using Tapatalk

Hey Mash , will send u pics of the panels I'm using on whatsapp if you care to share your mobile number. As for the link you can look up Official Site of Stillpoints - Home online
And apologies for posting my setup didn't know it was such an eyesore
 
I recently tried out a combination that I have been planning. In my smallish 14' x 12' room, I replaced GIK 244 absorption panels at the first reflection point on the sidewalls with their new evolution Polyfusor diffuser panel which acts as a bass trap upto 80hz and a diffuser from 600hz on. I felt that the soundstage widened more beyond the speaker location - imaging sharpness remained more or less the same - and I hear more resolution in the stage and more airy treble especially on cymbal strikes and better overall decay. I am liking this now and will keep the current configuration. There is a lot of debate on having diffusion at first reflection points on the side walls, with a lot of recommendations for broadband absorption at this point, but I think this type of a hybrid absorption/diffusion panel might be better.
Overall now my room has a mixture of broadband absorption in the corners, diffusion/absorption at first reflection on sidewalls and wall behind speakers and QRD diffusers at the ceiling reflection point and I feel it is sounding excellent. I am mostly using GIK panels except the wall behind the speakers where I am using 4 vicoustic wavewood panels.
Cheers,
Sid
Imo, using a diffuser at the first reflection point should reduce HF energy due to less reflected waves. I shall be trying my parabolic diffuser today at the first reflection point at my sweet spot. This is a 100% solid diffuser with no absorption.
 
l
Imo, using a diffuser at the first reflection point should reduce HF energy due to less reflected waves. I shall be trying my parabolic diffuser today at the first reflection point at my sweet spot. This is a 100% solid diffuser with no absorption.
do let us know how it goes
regds

I recently tried out a combination that I have been planning. In my smallish 14' x 12' room, I replaced GIK 244 absorption panels at the first reflection point on the sidewalls with their new evolution Polyfusor diffuser panel which acts as a bass trap upto 80hz and a diffuser from 600hz on. I felt that the soundstage widened more beyond the speaker location - imaging sharpness remained more or less the same - and I hear more resolution in the stage and more airy treble especially on cymbal strikes and better overall decay. I am liking this now and will keep the current configuration. There is a lot of debate on having diffusion at first reflection points on the side walls, with a lot of recommendations for broadband absorption at this point, but I think this type of a hybrid absorption/diffusion panel might be better.
Overall now my room has a mixture of broadband absorption in the corners, diffusion/absorption at first reflection on sidewalls and wall behind speakers and QRD diffusers at the ceiling reflection point and I feel it is sounding excellent. I am mostly using GIK panels except the wall behind the speakers where I am using 4 vicoustic wavewood panels.
Cheers,
Sid
Hey Sid,
Just realised it is an years-old post.
How has your subsequent experience been?
Regards
 
Hey Sid,
Just realised it is an years-old post.
How has your subsequent experience been?
Regards
I am now using QRD - diffusers at the first reflection, and I prefer this to any type of absorption.
Cheers,
Sid
 
Last edited:
I am now using QRD - diffusers at the first reflection, and I prefer this to any type of absorption.
Cheers,
Sid
Thanks, mate!
 
do let us know how it goes
I have installed he parabolic diffuser at the first reflection point from m sweet spot which is around 5 feet from the speaker.

I listened for an hour and found better focus of the centre image and balanced mids and highs anywhere in the room - not only the sweet spot. The shrillness in the music has compltely vanished
 

Attachments

  • 1659414086318-2036678330.jpg
    1659414086318-2036678330.jpg
    141.1 KB · Views: 44
  • 1659414139566-1562860274.jpg
    1659414139566-1562860274.jpg
    136.2 KB · Views: 44
Purchase the Audiolab 6000A Integrated Amplifier at a special offer price.
Back
Top