Yes, up, down, behind information in recording is interesting and whether that can be reproduced in a room is a good test. I asked a question here https://www.diyaudio.com/forums/sol...ing-phase-differences-amps-2.html#post5674022 ...do you know?
Well the original question was about using absorption on walls when the main speakers are built into the front wall, in control room style. One wall has a door, the other doesn't.
From my experience and reading, I would say "Yes - use some absorption." But diffusion might be better. Given that the first reflections aren't going to be in the same range as a typical hi-fi setup, but much later, things will sound different than a typical setup. The door on one side will make the reflections asymmetric. How to deal with that?
Rooms with hard, flat surfaces rarely sound good for music playback. Putting absorbers in the room somewhere is going to help more than hurt. If it were my room, I'd try to add diffusion at the first reflection points (opposite walls) to scatter the sound. If the door is at the first reflection spot, it needs to be treated in the same way as the opposite wall. The rest of the room should get a mix of absorption and diffusion.
From my experience and reading, I would say "Yes - use some absorption." But diffusion might be better. Given that the first reflections aren't going to be in the same range as a typical hi-fi setup, but much later, things will sound different than a typical setup. The door on one side will make the reflections asymmetric. How to deal with that?
Rooms with hard, flat surfaces rarely sound good for music playback. Putting absorbers in the room somewhere is going to help more than hurt. If it were my room, I'd try to add diffusion at the first reflection points (opposite walls) to scatter the sound. If the door is at the first reflection spot, it needs to be treated in the same way as the opposite wall. The rest of the room should get a mix of absorption and diffusion.
That would be roughly the design I am contemplating except a little bit larger room dimensions.
One thing I was reading about absorption is that it is depending on the angle the sound waves hit the absorber and much less at below 45º (depending on the material only 30% from diffuse or 90º). The closer the drivers are to the corner the shallower the angle will be. So I think I have to come up with some design which is a partial diffusor and absorber
One thing I was reading about absorption is that it is depending on the angle the sound waves hit the absorber and much less at below 45º (depending on the material only 30% from diffuse or 90º). The closer the drivers are to the corner the shallower the angle will be. So I think I have to come up with some design which is a partial diffusor and absorber
In my experience any treatment helps. But of course you'd like to know what's going to work best.
The strange thing about Dave Moulton's paper is that he seems to advocate no treatment at all on the side walls. Since he's built dozens of rooms over the decades I respect his opinions, but I just don't understand how they would work and sound good. It goes against all my experiences. Maybe it's the built in speakers that change from the normal room.
The strange thing about Dave Moulton's paper is that he seems to advocate no treatment at all on the side walls. Since he's built dozens of rooms over the decades I respect his opinions, but I just don't understand how they would work and sound good. It goes against all my experiences. Maybe it's the built in speakers that change from the normal room.
3 Small Rooms
Hello,
Today, looking for some clarity I opened chapter 5 of “Handbook For Sound Engineers” Third Edition, Glen M. Ballou editor.
There are 3 types of Small Rooms discussed in this book.
Precision Listening Rooms
The purpose for Precision Listening Rooms is analysis.
Rooms to play back recordings exactly as recorded, if something is not in the recording nothing should not be audible in the Precision Listening Room. First / early reflections are evil and need be excluded. Early reflections are artifacts and not part of the recording. A Precision Listening Room is neutral and should never be audible.
Rooms for Microphones
Rooms for vocal recordings, conference rooms, not rooms primarily for playback. I am not going to address this type of room.
Rooms for entertainment
The purpose for Rooms for Entertainment is entertainment.
Things like intentional reflections add Comb Filtering are designed in the room to add space, imaging, and location shift that is not in the original recording. Also note that directed beamwidth and aimed reflections add or modify sound stage localization that is not in the recording. (To be avoided in the Precision Listening Room) There is a tradeoff between sharply focused sound stage and the sense of space. Lateral reflections should be emphasized to optimize these room effects.
So we have choices to make; Completely neutral playback rooms for clinical analysis or playback rooms for optimized room effects for our entertainment.
Thanks DT
Hello,
Today, looking for some clarity I opened chapter 5 of “Handbook For Sound Engineers” Third Edition, Glen M. Ballou editor.
There are 3 types of Small Rooms discussed in this book.
Precision Listening Rooms
The purpose for Precision Listening Rooms is analysis.
Rooms to play back recordings exactly as recorded, if something is not in the recording nothing should not be audible in the Precision Listening Room. First / early reflections are evil and need be excluded. Early reflections are artifacts and not part of the recording. A Precision Listening Room is neutral and should never be audible.
Rooms for Microphones
Rooms for vocal recordings, conference rooms, not rooms primarily for playback. I am not going to address this type of room.
Rooms for entertainment
The purpose for Rooms for Entertainment is entertainment.
Things like intentional reflections add Comb Filtering are designed in the room to add space, imaging, and location shift that is not in the original recording. Also note that directed beamwidth and aimed reflections add or modify sound stage localization that is not in the recording. (To be avoided in the Precision Listening Room) There is a tradeoff between sharply focused sound stage and the sense of space. Lateral reflections should be emphasized to optimize these room effects.
So we have choices to make; Completely neutral playback rooms for clinical analysis or playback rooms for optimized room effects for our entertainment.
Thanks DT
Nothing on normal living rooms, where humans actually listen to music?
http://www.mariobon.com/Articoli_storici_AES/Toole/Libro_bianco_Toole_123.pdf
http://www.mariobon.com/Articoli_storici_AES/Toole/Libro_bianco_Toole_123.pdf
Last edited:
Post #728
AVS Forum | Home Theater Discussions And Reviews
Edit: Dr Toole mentions his system and room on that forum and more important why he has that system and room, but I can't find it.
On page 290 fig 10.5 I see a picture of the room. Right are bookshelves, some curtains, glass window, chairs.
Typical living room.
AVS Forum | Home Theater Discussions And Reviews
Edit: Dr Toole mentions his system and room on that forum and more important why he has that system and room, but I can't find it.
On page 290 fig 10.5 I see a picture of the room. Right are bookshelves, some curtains, glass window, chairs.
Typical living room.
Last edited:
I was amazed seeing that in his book. Similar uneven rooms with asymmetric setup, big window(s) and open fireplaces I see in many audio reviewers rooms and then writing reviews of monstrous speakers (size and price wise). I guess it maters more how much one spends than the room acoustics.
Last edited:
https://s3-eu-west-1.amazonaws.com/s3-euw1-ap-pe-ws4-cws-documents.ri-prod/9781138921368/designing_a_home_theater_part_1.docx
This document describes Dr Toole's system (fig 1) and lots of stuff on reflections.
This document describes Dr Toole's system (fig 1) and lots of stuff on reflections.
If I where you I wouldn't incorporate any absorption in a fixed manner at this stage. I built myself a pair of corner line sources with 35 cm wide baffle. I tested different damping along the both sides of the lines at different distances. I ended up cutting one in half making the 15 cm wide and positioned more or less on the baffle, touching the drivers. This had an positive impact on the sound increasing resolution and sounded clearer. All other made the sound "dead" in some way.
So you will need to be able to try different things...
//
So you will need to be able to try different things...
//
Read with caution
Read this document with caution, it is major scope creep.
This thread started with 2 channel stereo.
This document brings in cinema with engineered movie sound effects with 5.1, 7.1 or 9.1 speaker systems. Plus Harman immersion electronics added sound processing effects.
Not that this stuff is bad, just that it is miles different than the illusion of sound stage and space using two channel stereo we were talking about to start with.
Thanks DT
Read this document with caution, it is major scope creep.
This thread started with 2 channel stereo.
This document brings in cinema with engineered movie sound effects with 5.1, 7.1 or 9.1 speaker systems. Plus Harman immersion electronics added sound processing effects.
Not that this stuff is bad, just that it is miles different than the illusion of sound stage and space using two channel stereo we were talking about to start with.
Thanks DT
I haven't come across info where the science guys differentiate between ht and stereo. Stereo being a subset of ht, logic dictates the demands must be the same.
But I haven't read all info.
Edit: Chapter 12 in Dr Toole's book is about home listening rooms, home theater and recording control rooms.
I read nowhere that the demands for these 3 different things are actually different.
But I haven't read all info.
Edit: Chapter 12 in Dr Toole's book is about home listening rooms, home theater and recording control rooms.
I read nowhere that the demands for these 3 different things are actually different.
Last edited:
I think you'll find some disagreement there.
Circular reasoning is indeed not correct.
But question remains, where do the scientists differentiate between the demands of ht, stereo and control rooms?
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.