Sonolink Studio Project

[sonolink]

Glenn,
I am sincerely grateful for all your comments, especially for your clarity
I am now building the soffit and slat walls frame. I'll seal between center and corners, and corners and slat walls. I'll fill the center part with rockwool.
Could it be an option to replace the corner hangers with rockwool/fibreglass? I'm asking just cos it seems easier than building the hangers (although I'm ready to build them if it makes a real difference).
I'll post some pics soon
Thanks again for your support

[gullfo]

the hangers are less expensive to make and you could then use that rigid insulation elsewhere in the room...

[sonolink]

mmm...good point I guess

[gullfo]

make sure you spend some time in the construction section looking at how the hanger and soffit assemblies are put together. it will help you a lot and prevent a lot of those "oh darn" moments later...

[sonolink]

Finished the right soffit and slat wall frame. Gotta calculate the hangers different sizes now. I cant seem to find homosote around here. Stuart, or anyone, do you know what it's called in spanish? Alternatively can I use 12mm MDF?
Thanks.
Cheers

EDIT:
Ok, this is what I came up with for the hangers: full size hangers would be in the square zone between the speakers and the slat walls, measuring aprox W500xL700mmxH2350
They'd be made of 12mm MDF (if that's ok) and 50mm mineral wool (40kg/m3). Wool is glued to MDF with contact glue (unless there's a better system. I have seen some people taping it but it looks like that could squash the wool?). Total hanger size would be L2100 x W600 x D112mm.
They'd hang in the sense of the Length of the room, the first one 50mm from the side wall, the others at 50mm distance from each other. So there would be room for three full size hangers in the square zone between the speaker and the slat wall. I still have to calculate the others around the speaker. Does this sound ok so far? While a wait for a confirmation, I'm going to build the left soffit/slat wall frame.

Yesterday was a really good day. Confusion, fatigue and depression have disappeared (:mrgreen:) and all that thanks to you guys.
So, thanks again for your help.
And now, back to work!!
Cheers
Sono

[gullfo]

Homasote SoundBoard has a number of analogs: softboard, cellulose fiber board, etc. search the construction and materials section as this has been discussed numerous times and there are definitely equiv products in Europe.

[sonolink]

Glenn,
Thanks for the advice. The thing is, I already searched for it in that section but couldn't find anything. So I looked for alternatives and IIRC, John says somewhere that alternatives are OSB or MDF.
Cheers

[sonolink]

Soffit frames done and checked
I need to build the slat walls now but I have a doubt all of a sudden. My slats need to be at a 20 degrees angle minimum to avoid getting reflections on my face. Is this normal, considering that John's slats are usually at 12 degrees? (unless I'm wrong on that).
Cheers

[sonolink]

Alternatively, what about this option? Would the absorbent column be acceptable?

FPR1.jpg

Meantime, I'm going to get into the speaker stands and seal the central part form the corners.
Cheers

[gullfo]

are you accounting for the surface angle when you ray trace? I see a lot of folks ray tracing and they don't account for the surface angle to determine possible reflection angles. secondly, the axis of the frequencies most like to actually "bounce" with enough energy is usually 90 degrees or less (check your speaker specs, if not on the manufacturer site, in a proper speaker review, to identify the polar response) (although some speakers are designed for a full 180 degrees...)

here's a link that explains it rather simply... http://www.lenardaudio.com/education/05_speakers.html

[sonolink]

Glenn,
Thanks for ur reply and link. By "surface angle" do you mean angle of incidence/reflection? The way I Ray traced is as follows:
1-Draw a line from the speaker's tweeter to the mix position. This line is at 90 degrees from the soffit wall.
2-From the same spot draw lines 5 degrees apart, covering a total horizontal surface of 120 degrees.
3-check where each line hits the slats, and measure the smallest angle between the slat and the line (on the front wall side). When measuring angles between two crossed lines there are always two complementary angles that added give 180. So let's call the smallest we just measured "A".
4-we now wanna draw a line from where the initial line hits the slat back into the room at the same angle "A"

Sorry if this may sound a bit unclear, I'm not very good at describing this kinda stuff
There's a couple pics a few posts earlier in this thread.
I calculate like that cos I thought angle of incidence = angle of reflection.
Isn't that right?
Cheers

[gullfo]

if i'm not mistaken, you need to find the nominal (normal) angle relative to the surface to accurately compute the reflection and that then influences the incident angle and the reflection angle...

[sonolink]

Something like this?

Angle.png

If that is correct, I need a minimum of 20º to avoid having reflections in my face, like on the pic.
Meantime, I'm going to try to find my speakers specs. They're Yamaha HS80M.
Cheers
Sono

[gullfo]

i think there are other considerations as well - your monitor's on/off axis response (directivity) will also determine if the angles and distance will suffice. the absorption characteristics of slats etc all contribute to this as well. but, if you have the option for wider angles, why not? in your case if could reduce the depth of the treatments and you can use the "saw" pattern to add multiple 20 degree slats.

[sonolink]

Mmmm....that's very interesting. I guess then that putting that absorbent column I draw a couple posts earlier is not a good idea?

I have no real competence to talk about this (hence so many questions ), as I'm not an acoustics engineer. What I really did when designing my room was to use John's "components.skp" file and read as much as I could on this forum. So when I drawed my Ray Trace pattern I only found (actually, Carsten kindly found that for me) reflection problems in the first bit of the slat (soffit side), forcing me to angle the slat up to 20º.

I don't know for sure if I will have those problems as I still couldn't find my HS80M's dispersion specs, (all I could find is this:
http://www.yamahaproaudio.com/downloads ... asheet.pdf), so when ray tracing, I followed Stuart's advice to calculate 120º horizontal x 60º vertical and be on the safe side.

Now, the thing is I have to be practical and find a solution or choose one from the available ones, because I really need to be able to mix in a couple weeks (the last finishing touches such as painting, lights, etc, can be left for later). If I build a 20º slat wall it will be much shorter than if it has a smaller angle, so the slat wall will finish more or less a bit before the mix position, meaning I will have absorbers in front of my ears. The idea of the absorbent column between the soffit and the slat therefore is an attempt at maintaining the slat down to its original length. But as I said before, I have no idea if what I'm saying is actually a waste of time, if it's of any use, or even if it's worth it (as I might be just complicating things out of my ignorance in this matter).

Considering my last sketchup file (attached) with the soffits and speaker units corrected, may I ask you what would your advice be regarding the slat walls angle/location/size?

StudioSonolinkF11.zip

Thanks alot for your time and help
Cheers
Sono