Sonolink Studio Project

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.

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

Soffit frames done and checked :mrgreen: 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

Alternatively, what about this option? Would the absorbent column be acceptable? Meantime, I'm going to get into the speaker stands and seal the central part form the corners. Cheers :)

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

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 :D 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 :)

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...

Something like this? 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

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.

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? Thanks alot for your time and help Cheers Sono

Sono - you aren't realising that a speaker's top end only projects in a 30 degree plane. Beyond that it tapers off. Draw a 15 degree angle either side of your speaker plane and you'll see how the side walls can direct all the important info away and behind you.

John, Thanks for chiming in. Your advice is much appreciated :mrgreen: Of course,.....you're right. It's not that I'm not realizing, I'm simply being an idiot and I apologize to Glenn for not paying attention and not catching what he was already pointing out with the Lenard Audio link. Back to Ray Tracing then :) Thanks again Cheers Sono

not a problem here... but it is interesting when your brain kicks in and finally "gets it" isn't it? :yahoo: one down, 9,984 more to go... :wink:

Sorry to use this thread to ask a question, John you mentioned that the high end only "projects" in a 30 degree angle (15 degree either side of the center axis). So when calculating your position (sweet spot), you want to place yourself inside that 30 degree angle? a picture to make my question clear. Does this apply to all/most speakers? Thanks

gullfo wrote:

but it is interesting when your brain kicks in and finally "gets it" isn't it?

I think in my case it was more like a kick in the face, really :lol: Soffit framing done. Need to add hangers and the absorbent part for console reflections. Yesterday I finished the speaker stands. I still gotta fine adjust their position and screw them to the concrete ground. I finally went for a column made of mdf that I'll fill with sand. The black speaker box made of mdf and drywall will be screwed on top of the column. I'm gigging all weekend so I'm taking a break until monday, when I'll tackle the hangers, slat walls, etc. Any comments about the ceiling on my sketchup file, please? I should be beginning that by mid next week....hopefully :D Thanks a lot or your help As promised, a couple pics :mrgreen: Cheers Sono

Nobody? Bump pretty bump, please....

just make sure the monitor base is nice and heavy to keep you monitors stable. otherwise it looks like good progress!

Glenn, Thanks for ur reply. I just screwed them to the concrete floor. Next I'll fill them with sand and then I'll screw the black box in. I doubt I can go more solid than that :) Can I ask for ur opinion on these, if you don't mind? 1-The central part between the soffits: reflectant or absorbent? 2-Any thoughts on the ceiling on my sketch up? Thanks a lot for your help Sono

for the space between the baffles, i tend toward solid over soft. it's a good spot for slots to add diffusion.

You mean in the center you'd build a slat wall like the ones on the sides (only not angled)? Cheers Sono

yes

Excellent!! :) Any thoughts on my ceiling? Cheers

use a series of clouds hung down and angled. in the case where you have the baffle mounted monitoring, build a cloud so you have about 12-16in (300mm-400mm) gap all around.

Glenn, thanks for your reply and for the pic :) To make sure I follow you properly, please allow me some questions: 1-The clouds are absorbent panels, right? If so, 500mm thickness and 40kg/m3 density mineral wool is ok? 2-Are the cloud angles important? If so, how do I determine them? 3-What about distance between clouds and ceiling? 4-The ceiling is presently bare drywall. Shouldn't I first place a layer of cloth covered rockwool (something like 50mm inside a wood frame) and then hang the clouds? 5-The gap you mention applies also to the other clouds and the side walls, correct? (meaning roughly the same gap runs all around the ceiling) Sorry if I'm being too inquisitive in a single post, I just want to make sure I understand everything properly...my initial idea was to make a 12º angled ceiling covering roughly the front half of the room, filled with either hangers or rockwool, like in John's "components.skp" file or the Da Silva project, but your suggestion opens plenty of creative and attractive doors to solutions for illumination!! :idea: :mrgreen: Thanks again for your time and help Cheers Sono

2x 2'x4'x4in (400mm x 1200mm x 100mm) side by side, they can have some hard surfaces as well like slats spaced widely. in the example i posted, i used 30 degrees for the first set and hung down so the point closest to the ceiling is 6in (150mm). the other clouds are 15 degrees. the ceiling can be as-is although you'll note the trapping in the front and rear top corners. the trapping could also be hanging absorbers behind a cloth false ceiling as well.