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Posted: Mon Jan 08, 2007 4:40 am
by Ro
very beautiful and fast work. Yes, the red/black turned out better than I initially thought it would. In combo with the wood it makes good contrasts. I hope it at least sounds as good as it looks.

I'm still not sure on those ceiling panels. Although they're convex styled it would still leave an amount of energy scattered through the room (at least there's some diffusion going on) But we'll know for sure when your back with "hearing" tests/results, eh!

good job so far!

Posted: Mon Jan 08, 2007 5:17 am
by sharward
At least they're not concave... :roll: ...Even this* acoustical embicile knows that would suck. 8)

--Keith :mrgreen:

*So that there's no misunderstanding, "this" is referring to myself! :lol:

I´m eager too

Posted: Mon Jan 08, 2007 5:22 am
by Kaj
Thanks Ro,
We will see how it works, it will take some time before I will measure the room, but thats because I want to play music, and in March when I'm back from offshore work, then its time to measure it, this is taking time as I have to plot the room and put markers for the standing waves on floor/walls and see if trapping is doing the job, I will drop the ceiling boards as the pic attached to verify if flutter reduces with them, so I have a pretty detailed plan on what I want to check. If you or anyone else think I should measure more than Room mode trapping, RT60, frequency response, plotted in the room let me know. If I have to move around the speakers in the room, than I have to spend many many hours before I can find the best listening/speaker position, I have planned to place the speakers with an equal distance to the coach I will have in the room, but the stereo image will not be right, but I might find a way around that problem as well, still having a few options in my test procedure. So at that time it will not be updates in this thread as frequently as I have get you used to. >To evaluate before posting will be very important!

And to the pics,
I got the wireing done for the spot lights today and started with the wireing for the power sockets I still waiting for material for floor/wall trims, I have a trim template I use to measure the hight where I fix the clips for the cable, easy to slide in the trim under later, I might put the sockets 90cm above the floor on the Yellow wall and on the lower slats on the oposit absorber wall (three section absorber), I find it convinient to have the power sockets elevated for easy access, but it would look bad on the Helmholtz absorbers, where I go for more traditional hight. We will have 4x4socket, 3x2socket earthed sockets and 1x2socket standard socket on the wooden beam.

Cheers

Posted: Mon Jan 08, 2007 6:01 am
by VSpaceBoy
WOW..

Talk about coming together nicely!!

Your clouds brings a question to mind so I'll just ask it here. Flutter echo is created from having two parallel walls and your convex cloud sill reduce that. My question is, is the flutter only a problem from perpendicular to both parallel walls from the original sound source?

Reply

Posted: Mon Jan 08, 2007 7:23 am
by Kaj
Hi Spaceboy, long time since last?
I will try to clarify again in a bit more depth, reasons behind decisions about design, I have qouted similar questions about these boards and will not only answer your question, but Ro as well and any other that want to know why???

Here are a qoute from my earlier posts on this thread;
What is the bad thing(s) to use Soundboard for what I intend to use it for , (anything good with Soundboards VS polys at all?). I have seen One of the legend Bruce Swedien's personal friend in Sweden (Björn Asplind) design of a studio with this sound board as deflecting/diffusion devices suspended from the ceiling . Background of Björn;

Björn wrote an Sound engineering book for the Swedish musicians/sound engineers in the 80ies , and I had him as a mentor and we used Michael Jacksons Thriller, in Multi track version (thanks to Bruce giving a copy away ) during my Sound engineer training, It might be the old school from 80's that used soundboards and not plywood??
Background Note:
Björn was having the designer of Vivaldi Studios and Bohus studio as instructor/trainer during his start in the acoustic/recording swamp. Åke Eldsäter was involved in this training as well as far as i have been able to find out on other forums. One of the most famous groups ABBA used Studio Bohus and Åke Eldsäter are to be found on some of their records as well as the cream of the Swedish musicians as sound engineer, he is one of the best in Sweden. He recorded our first record in Studio Bohus 1982 so I have an Idea of his skill. I can not for sure say where the slanted soft boards used in the studio Björn was leading the project came from, but the studio sounded fine, not dead as the previous at the same location. He used the same system for floating the floor as for Vivaldi studios, so I can only guess he got the idea from Vivali Studios.

Your question;
Your clouds brings a question to mind so I'll just ask it here. Flutter echo is created from having two parallel walls and your convex cloud sill reduce that. My question is, is the flutter only a problem from perpendicular to both parallel walls from the original sound source?
And from Ro as well.
I'm still not sure on those ceiling panels. Although they're convex styled it would still leave an amount of energy scattered through the room (at least there's some diffusion going on) But we'll know for sure when your back with "hearing" tests/results, eh!
Ok, I poured up a single malt and getting ready for reply to you. All at the same time I would assume.

The design of these soft boards in the ceiling, are only there to deflect the sound to stop flutter between perpendicular Floor and Ceiling, nothing more nothing less. I have designed them to be adjustible in view of angle and pack some insulation on top of them. I will during the fine tuning try with different amount and type of insulation on top of them, currently only 4 are filled to 50% with similar to OC703 95mm thick. I can hear clearly that the very high end are more damped, and the reverbation increased after installing them. But the flutter around 210 Hz allmost dissapeared after installation, need to adjust my helmholtz to more around 210Hz will be verified during measurement, we can only wait until that day, and I will not keep them if they are doing bad to the sound. We can in 5 minutes remove them and test acoustics and re install with different configurations i.e. angle and type of filling test again, but I will not do this if all is ok from start. I might do this test just to verify (Not prove) if they are doing anything good or bad.
I understand that building helmholtz or other kind of traps around the whole building will absorbing problem frequences, might be a good way to go, but if I say that my trausers stays up with belt only, why put suspenders as well?
The room we have treated have very thin wall construction and are not showing any big problem soo far in the LF.
Note.
There are noise leaking in from the traffic outside approx 150m away. If I would go for taking care of that would I have to build a room in the room, but the joist would not cope.

To add more mass to the walls, was not practical as the studs where OC600mm and some of the walls built on 2x3 studs, would be much weight with three layers of gypsum board as there are only a 12mm MDF on walls and ceiling. Floor MDF 28mm. End Note

So with this given starting point, I had no other options as I can see than try to get the room as it was to sound as good as possible with a reasonable amount of work and material to be used, a bit driven by budget and a bit driven by common sence. To not add more mass reduced the need of Low range trapping, a cost save. I used all frequencies for the room modes to decide the two first helmholtz absorbers and the 200-230hz as target for the last two absorbers on north wall, I might slope the Ceiling panels to defect more sound towards those absorbers in hope that they will take care of some of it.

Hope I have not bored you with my logic and plan behind decisions made in the past? I have not exhausted my my memory of ideas and plans behind this design but, think I have give you enough to start to ask more if any clarifying are required.

Thanks for your questions, I do enjoy discussions about this subject and other music/acoustic/construction topics as well, and I'm NOT an expert in acoustics, but have picked up little here and there. Please keep asking, question or comment as you feel approriate, I learn from that as well.

Cheers



[/quote]

Posted: Tue Jan 09, 2007 11:42 pm
by VSpaceBoy
Thanks Kaj for your reply. Heres more what what I mean though.


~cloud~

...8)

_______


This illustrates the sound being created directly inbetween the cloud and floor. In the picture, I can see how the cloud would stop/help flutter echo.

My question is.

~cloud~ ~cloud~ ~cloud~ ~cloud~

....8)

______________________________

The clouds directly about the the sound source, same thing. But my question is, do the other clouds help flutter echo since they are receiving the sound on an angle from the source.

Posted: Wed Jan 10, 2007 12:11 am
by Kaj
Spaceboy,
The panels (clouds) are curved as you know and will deflect any sound hitting the surface and its not paralell with any surfaces in the room, hence it will reduce flutter ceiling/floor. Independent on the source location. (we will have speakers in many locations and can angle clouds above the source as required).

I also expect panels to partly deflect room modes Ceiling/floor, trapping would do this better (more efficient for sure), but I cant hang anything that heavy in the ceiling.
(I expect to deflect sound towards excisting helmholtz traps, north and south walls are tuned for ceiling/floor modal frequencies).

I have made those panels adjustible to change the angle if I need to experiment with them, during tuning and measurment of acoustics.

The real need for the curved panels for me are to reduce the paralell surfaces, floor / Ceiling, and ceiling are the only practical one to do.
I like to have some reverb left in the room, but can put more insulation on top of the panels to change (little) the acoustic properties of the room.

Hope this is what you was asking for, 8) drawing, hehe!

Cheers

Posted: Wed Jan 10, 2007 7:42 am
by VSpaceBoy
Thanks for the clarification, it was a help!
Ron

Posted: Wed Jan 10, 2007 7:48 am
by Kaj
Ron!
You are welcome!!!

Posted: Thu Jan 11, 2007 12:14 pm
by knightfly
Ron, flutter is caused by any two parallel surfaces - the larger the surfaces, the more evident the flutter. The actual frequency of the flutter is predominantly controlled by the distance between the two parallel surfaces.

IF you make some changes in the area of parallel surfaces in a room, you may lower the flutter amount to a point where you can't hear it by simple means (such as hand claps) but that doesn't mean it's GONE - just reduced.

If such a "partially de-fluttered" room is to be used for recording ("live room") then every track you record in there will have some small, not-quite audible flutter component inherent in the recording - if you then mix several tracks that were recorded in that room, at some point the flutter will build up in the final mix until it is once again audible, and this has driven more than one mix engineer nuts trying to figure out where it came from...

This, and having a variety of acoustic "fingerprints" available, is why a live room should have no parallel walls, preferably not a parallel ceiling, and a mix of absorption and diffusion devices chosen to reach the desired RT60 overall - Any less "malice aforethought" and your room's sound will be more luck than plan... Steve

Construction completed

Posted: Sat Jan 13, 2007 7:05 am
by Kaj
Finally, after 1-1/2 month of hard work are the construction of the rehearsal room completed, and all trims installed electrical in place, only the electrical inspection remain to be done. Its planned for comming Monday, we have finally moved in the music equipment. And now we going into the fine tuning phase. I think I run that thread here, to make it easier to follow the progress, if the Moderator think I should run it in acoustic section, than I'll start a tuning and tweakin' thread there.

Here are the last construction pictures.

Thanks for your support and encourage we have received from you.

Cheers

Moving in

Posted: Sat Jan 13, 2007 7:08 am
by Kaj
And we have not moved in before you see the pic's :lol: :lol:

Cheers

Posted: Sat Jan 13, 2007 9:41 pm
by Ro
Very cool and hard work Kaj. no let's start rocking!
let us know how it "sounds", ok?!

Posted: Sun Jan 14, 2007 6:29 am
by knightfly
Kaj, I think the Acoustics forum would be the best place for your "tuning agonies" :wink:

Please be sure to post a link to THIS thread at the beginning, though - that way others can see the space you're working with and get a better idea of what's going on - thanks... Steve

Posted: Sun Jan 14, 2007 10:08 am
by infiniteposse
Great work! Thanks for taking the time to create such a nicely documented project.