Room treatments
It's pretty common on the AVS forum to do the bottom 5'(approx) of your walls in 1" thick rigid fibregass (owens corning 703 ottomh) The back wall behind your mains is completely covered.
This is then covered in acoustic fabric (usually Guildford of Maine - GOM )
This is said to reduce all early reflections as they're not needed for HT - the surrounds provide the ambiance needed.
Leads to a room too dead for stereo but excellent for 5.1 stuff apparently.
Huge thread on room acoustics
Back on topic - hurrah !
Rob.
It's pretty common on the AVS forum to do the bottom 5'(approx) of your walls in 1" thick rigid fibregass (owens corning 703 ottomh) The back wall behind your mains is completely covered.
This is then covered in acoustic fabric (usually Guildford of Maine - GOM )
This is said to reduce all early reflections as they're not needed for HT - the surrounds provide the ambiance needed.
Leads to a room too dead for stereo but excellent for 5.1 stuff apparently.
Huge thread on room acoustics
Back on topic - hurrah !
Rob.
Hi Rob,
you are saying that we should actually work on deadening the early reflections almost completly for surround setup ?
so a room designed for HT won't work for stereo music listening .. that is what i thought also
Do you believe that everybody in the audience should be in the nearfield of the drivers ??
you are saying that we should actually work on deadening the early reflections almost completly for surround setup ?
so a room designed for HT won't work for stereo music listening .. that is what i thought also
Do you believe that everybody in the audience should be in the nearfield of the drivers ??
i also ask myself if phase difference between all the loudpseakers will affect listening quality for ht setup ?
should we be concerned about that ?
should we be concerned about that ?
Hi Jin,
I'm only really quoting from AVS wrt room treatments. I can say that I feel my own room is too 'live' for home cinema right now, and that I'm going to build some large panels with 2" thick rigid fibreglass to deaden it down a little.
If I was building an ultimate room I'd definitely do some big reading on acoustics before parting with any money. Room shape is the 1st big and major hurdle.
Speaker phase - I don't feel there's any major problems with the 5.1 setup. You adjust delays for the rears to make them match your mains. Obviously this will be for one seat, but I don't think its worth worrying about.
Rob.
I'm only really quoting from AVS wrt room treatments. I can say that I feel my own room is too 'live' for home cinema right now, and that I'm going to build some large panels with 2" thick rigid fibreglass to deaden it down a little.
If I was building an ultimate room I'd definitely do some big reading on acoustics before parting with any money. Room shape is the 1st big and major hurdle.
Speaker phase - I don't feel there's any major problems with the 5.1 setup. You adjust delays for the rears to make them match your mains. Obviously this will be for one seat, but I don't think its worth worrying about.
Rob.
ULTIMATE = worrry about everything 😀
else it can't be called ultimate right ? 😛
I have difficulty to imagine all the different sound waves mixing all together at different seating positions ..
Room shape won't be a problem since i can decide that almost right now ...and i have space and possibility
i only need to reread my accoustic master handbook
and corroborate with other papers ..
The same questions still remain though,
should i completly remove early reflections ?
problem is that i can't find alot of information on the "goals" of a home theater room ( not commercial craps)
else it can't be called ultimate right ? 😛
I have difficulty to imagine all the different sound waves mixing all together at different seating positions ..
Room shape won't be a problem since i can decide that almost right now ...and i have space and possibility
i only need to reread my accoustic master handbook
and corroborate with other papers ..
The same questions still remain though,
should i completly remove early reflections ?
problem is that i can't find alot of information on the "goals" of a home theater room ( not commercial craps)
The way I interpret it is that all seats must have the left / right wall reflections damped. Then you need to get the rooms RT60 down to a reasonable level (can't remember the figure ottomh ) In a lot of top home theaters this seems to be done by damping all walls from the floor up to ear height. That gets all 1st reflection points to all seats done, and the rest gets the reverberation down.
Front wall should be completely covered in absorption.
Thats how I see it, others may disagree.
There seems to be some merit in having diffusers on the back wall to heighten ambiance, but thats something to experiment with I guess - I've never seen it written that it works all the time, or indeed none of the time. I think it helps when a room doesn't need a lot of absorbers, but needs to lose noticable reflections but keep the 'liveliness' of the room.
Sorry if this doesn't help much.
A good book to read through is 'the master handbook of acoustics' by Everest. I've also found the 'handbook for sound engineers' good too. (Ballou) EDIT - just realised you said you had the master handbook of acoustics.
Rob.
Front wall should be completely covered in absorption.
Thats how I see it, others may disagree.
There seems to be some merit in having diffusers on the back wall to heighten ambiance, but thats something to experiment with I guess - I've never seen it written that it works all the time, or indeed none of the time. I think it helps when a room doesn't need a lot of absorbers, but needs to lose noticable reflections but keep the 'liveliness' of the room.
Sorry if this doesn't help much.
A good book to read through is 'the master handbook of acoustics' by Everest. I've also found the 'handbook for sound engineers' good too. (Ballou) EDIT - just realised you said you had the master handbook of acoustics.
Rob.
RobWells said:
thanks neway! it does help 🙂
Yes i do have it, but i will need to reread it soon as it is now pretty far to my mind
The use of diffuser at the back could be a very good idea tokeep the ambiance alive instead of deadening it all to zero ...
i have already designed phase grating diffusors with absorptive properties in the past, it could work pretty well there i believe!
modeling room acoustics
Jin,
You may want to consider using CARA software to model your room acoustics. This will give you a better idea of what you have and what you need.
You can learn about this by going to this web page:
http://www.audioroundtable.com/StudioRoom/messages/67.html
There is a lot os discussion completely appropo to your needs on the Studio Room of the AudioRound Table discussion group.
Zarathu
Jin,
You may want to consider using CARA software to model your room acoustics. This will give you a better idea of what you have and what you need.
You can learn about this by going to this web page:
http://www.audioroundtable.com/StudioRoom/messages/67.html
There is a lot os discussion completely appropo to your needs on the Studio Room of the AudioRound Table discussion group.
Zarathu
thanks much i will have a look into that asap 🙂
edited :
i have just used a few minutes to look at that nice piece of software, wich for once took into account dipole and OB loudspeaker system .
Have you used it before Zara ??
what is your experience with that software?
at 75$, it sure seems like a steal!!
edited :
i have just used a few minutes to look at that nice piece of software, wich for once took into account dipole and OB loudspeaker system .
Have you used it before Zara ??
what is your experience with that software?
at 75$, it sure seems like a steal!!
CARA software
JIN,
I'VE NOT USED IT. It was recommended by Wayne Parnham. Since I'm within the nearfield in my line array, I have no need to adjust the room. Anything that reaches me as a reflection comes too late for brain/ear combination the perceive it as part of the music, so it is discarded by the brain. A benefit of Nearfield listening.
Zarathu
JIN,
I'VE NOT USED IT. It was recommended by Wayne Parnham. Since I'm within the nearfield in my line array, I have no need to adjust the room. Anything that reaches me as a reflection comes too late for brain/ear combination the perceive it as part of the music, so it is discarded by the brain. A benefit of Nearfield listening.
Zarathu
I would like if possible to have link to professional
documents/papers on surround mixing and studio stuff 🙂
thanks
documents/papers on surround mixing and studio stuff 🙂
thanks
"Has there been any other discussion on nearfield listening for HT applications ?"
When we were talking about line arrays, that was nearfield listening.
Its not possible to be in the nearfiled for point source speakers unless you are sitting within about 2 feet of them.
Zarathu
When we were talking about line arrays, that was nearfield listening.
Its not possible to be in the nearfiled for point source speakers unless you are sitting within about 2 feet of them.
Zarathu
Unless ofcourse if the point source speakers are horn loaded. Like a cinema system, duel concentric ect. Where you dont sacrifice the point sourced basis of the mix with a defused effect of a line array.
Bose are the only to try arrays in cinemas and quite simply failed due to the poor quality of the sound produced compared with the horn based systems found in 99.9% of the 150 000 cinemas worldwide. The tiny market they did have was only because they gave them away for free !
Sound mixing suites are acoustically dead rooms, with 3+ channels of point sourced sound plus very defused surround channels and big subwoofers. Films are recorded & mixed differently than classical music CDs.
Cameron: could you point out to high quality dual concentric drivers
( other than Tannoy on ebay wich are $$$ )
i'd like to give them a try asap ..
i've seen 2 models from JBLpro.com
but only 1 featured a horn ( the other one as a dome tweeter on top of it ..so i don't believe that the drivers are phase aligned )
( other than Tannoy on ebay wich are $$$ )
i'd like to give them a try asap ..
i've seen 2 models from JBLpro.com
but only 1 featured a horn ( the other one as a dome tweeter on top of it ..so i don't believe that the drivers are phase aligned )
post 17
I had a link earlier
Selenium Emenence and Carvin Vaga also make them.
I have tried the P. Audio and its a very nice for its price. I used them for an outdoor cinema here in Australia, The owner loves them. The Altec made by Great Plains Audio, like the Tannoy is considered a classic (and costs aprox 3 x as much as the p.audio.)
I believe it is the same speaker that was used by JBL for many years. Altec Lansing and James B Lansing (JBL) have historical ties.
I had a link earlier
Selenium Emenence and Carvin Vaga also make them.
I have tried the P. Audio and its a very nice for its price. I used them for an outdoor cinema here in Australia, The owner loves them. The Altec made by Great Plains Audio, like the Tannoy is considered a classic (and costs aprox 3 x as much as the p.audio.)
I believe it is the same speaker that was used by JBL for many years. Altec Lansing and James B Lansing (JBL) have historical ties.
thanks much for the info ..
do you know the approximate retail price on the PA and altec units ?
have you ever seen distortion plots for those drivers?
do you know the approximate retail price on the PA and altec units ?
have you ever seen distortion plots for those drivers?
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