Sonolink Studio Project

[Soundman2020]

Updated design.

OK, better! Your soffits and room geometry are making more sense now, but you still seem to be missing the point on a couple of things.

The hangers in the front corners are pointless. They are behind the speaker soffit, and behind the slot walls. Room sound has no way of getting to them, and therefore they will have no effect on the room. You don't need them, and they aren't doing anything useful.

Related to that is the large "box" on the back of your speaker soffit panels: It also isn't doing anything for you. Yes, one approach to a speaker soffit is to have a box around the speaker itself, but if you do that then it needs to be a tight fit. In your case, you have a large empty air gap around the speaker, inside the box. So you can either tighten up the box, or lose it.

Once you have done that, then fill the entire space behind the soffit panel with insulation: it acts as a damper inside the soffit, much like the insulation inside your speaker itself. You do not want that cavity to resonate! It needs to be damped, but with insulation, not hangers.

Yes, you can use hangers as part of your soffit, but do it like John does: Below the speaker, behind the soffit panel, in a sealed box that is only open to the room, through a large opening down near the floor.

Two more points on the soffits: the area between the soffits is fine for mounting a flat panel. No problem with that! But you should also decide whether you are going to make that front center panel hard or soft: reflective or absorptive. Personally, I think absorption makes more sense in a small room, but if you want to make it reflective, think carefully about how to do that without causing yourself reflections of the front wall, and comb filtering...

Next, your slot walls: need to get rid of part of that slot wall, right where the first reflection points are, since those need to be treated with deep insulation.

Regarding your question on the shelves: I don't think it would be a problem to have shelves in front of the rear side absorbers, as long as you don't clutter them and stack them with too much stuff! Shelves with small items on the, like mics and headphones, should not be a problem, I reckon. But I wouldn't store large boxes and things like that on them!

- Stuart -

[sonolink]

Stuart,
Thanks a lot for checking out my plan and for your comments

Related to that is the large "box" on the back of your speaker soffit panels: It also isn't doing anything for you. Yes, one approach to a speaker soffit is to have a box around the speaker itself, but if you do that then it needs to be a tight fit. In your case, you have a large empty air gap around the speaker, inside the box. So you can either tighten up the box, or lose it.

The "box" is a copy of John's "speaker unit" in his components.skp sketchup file. My speakers are inside an MDF box covered with a layer of 15mm drywall. The fit is so tight the only way I can extract the speakers is by tilting the box. So much so that I'm now trying to find an easy system to pull the speakers out for when I'll need to i.e. adjust parameters on their back (as I won't be able to tilt the soffits:)).
If you hide the soffit to see the "box" you will see the mdf and the drywall boxes. the speaker is represented by the 2 white circles (that correspond to where the woofer and tweeter are placed on the HS80Ms). Btw, inside the box there is no insulation depicted.

Once you have done that, then fill the entire space behind the soffit panel with insulation: it acts as a damper inside the soffit, much like the insulation inside your speaker itself. You do not want that cavity to resonate! It needs to be damped, but with insulation, not hangers.

I will fill the boxes with insulation and the cavity between the drywall and the soffits too (loosely)

Yes, you can use hangers as part of your soffit, but do it like John does: Below the speaker, behind the soffit panel, in a sealed box that is only open to the room, through a large opening down near the floor.

Actually, that's another mistake on my sketch. I intented to do exactly that, following John's pic on what to do with amped speakers, and the bass port and trap are drawn behind the soffit, but I forgot to draw the cloth bit Sorry about that
So in reality the soffit part under the speakers to the floor is cloth and absorbent to avoid the console reflections. Also, the speaker bass trap hangers are not depicted. I will correct that asap on the sketch.

Two more points on the soffits: the area between the soffits is fine for mounting a flat panel. No problem with that! But you should also decide whether you are going to make that front center panel hard or soft: reflective or absorptive. Personally, I think absorption makes more sense in a small room, but if you want to make it reflective, think carefully about how to do that without causing yourself reflections of the front wall, and comb filtering...

You are once again right. It will be absorbent, from ceiling to floor. The flat screen will be bright enough.

Next, your slot walls: need to get rid of part of that slot wall, right where the first reflection points are, since those need to be treated with deep insulation.

I thought the point of soffits and slot walls was precisely to eliminate reflections That's why I didn't put any first reflection point absorbers, because I thought the slot wall would absorb low mids and reflect the rest to the back of the room, not the mixing position (because of the splay).
So I need to calculate the mirrors of the speakers on the side walls and place absorbents there?

ONE little question (only ONE.... ):

-The ceiling, made of a timber frame and cloth: shall I fill it with hangers or rockwool/fibreglass? If it's rockwool/fibreglass should I fill the space inside the frame or everything between the drywall ceiling and the frame?

Thanks again for saving my life. I can't even imagine what I would have built without your help

[sonolink]

My first attempt at Ray Tracing...
I have erased most elements in the sketch to keep the file size down. The dotted lines represent the speakers sound (duh!). I drawed one line every 5º, covering a horizontal dispersion of 120º. I know it gets much more complex but I'm trying for now to get an idea about what angle should the slat walls have. The diagonal lines along the side walls represent the slat walls. The black lines coming back at the rear wall are the first reflections from the slat walls. The slat walls are angled at 25º.
The rest of the room (including ceiling and door) is absorbent. Am I correct in thinking this angle should be ok?

StudioSonolink RayTrace1.zip

Please don't forget my question about the ceiling
Cheers
Sono

[carsten_d]

sono,

1st:
if there's enough place between your real ceiling and your cloud you could use hangers.
but it isn't that easy. it's not just hanging sth somewhere in some manner under your ceiling...
somewhere is a more or less detailed thread in which john explains how he arranges the hangers
but I can't find the bookmark...must be on my main machine (which only works for five minutes due to
tons of gyprock- and mdf-dust on and in everything)

2nd:
you want to fill only your frames. air between your cloud and ceiling is good!

quote taken from f. alton everest - the master handbook of acoustics, 4th edition, page 191:
"Low-frequency absorption can also be improved by spacing the absorbent out from the wall.
This is an inexpensive way to get improved performance—within limits."

greetings,
carsten

[sonolink]

Carsten,

thanks for your tips and for chiming in (not that I get bored with Stu )
I read that thread about John's hangers some weeks ago (or was it months?) and now I can't find it either
Anyway, I think I'll go with insulation and pass on the hangers because A) my ceiling is 2.35 after soundproofing and B) I need to get ready to mix asap. So I'll do something like the Da Silva Studio, only my ceiling will have 12º tilt at the front (instead of 6º front and rear like Da Silva).

The reason why I was wondering about filling the frames or the entire fake ceiling, was because I was comparing it to the difference between a Superchunk and a corner panel (i.e. like Ethan's). Filling the ceiling would be like building a massive Superchunk. Filling only the frames would be like building a massive corner panel. Isn't this so? And if it is, money aside, I guess the Superchunk should be a go, am I wrong?

Best
Sono

[carsten_d]

yeah.
you're right.
sorry, I haven't read between the lines. I thought it was more like a "how to" question...

cheers,
carsten

[sonolink]

yeah.
you're right.
sorry, I haven't read between the lines. I thought it was more like a "how to" question...

cheers,
carsten

Of course not, dear friend, keine probleme
Actually all your input is very welcome indeed (and probably well needed...)

Now for a "how to" question, I am worried about the first reflection points that Stuart mentions earlier. In my previous mixing room (in a flat, free standing monitors, treated following essentially Ethan's guidelines) I used to have absorbents at the mirror points, but after reading John's Recording Manual, I liked the idea of slat walls, not only because (in his own words) it looks nice, but because I'm sure it'll sound more natural.
So when faced with designing this new room, I assumed I wouldn't need absorbents if I had slat walls...
By trying to Ray Trace the room (assuming I did it right), I can't find problems with reflections with a 25º slat wall...but of course, I am no acoustics expert, hehe.
Anyway, if you (or anyone else) could shed any light on this matter, I would be very interested and grateful

btw, your doors are impressive. I made mine as well, following a modified design by Ro and they weigh about 120kg each, but the union hinges/door, hinges/frame looks lousy compared to yours I used a teakwood spine for the screws. And also, I'd like to say, very nice music you make, reminds me of so many things I love

Cheers
Sono

[Soundman2020]

I thought the point of soffits and slot walls was precisely to eliminate reflections That's why I didn't put any first reflection point absorbers, because I thought the slot wall would absorb low mids and reflect the rest to the back of the room, not the mixing position (because of the splay).

Slot walls don't eliminate reflections: they have large hard reflective surfaces. Paradoxically, they are broadband absorbers, too, but that doesn't mean that they don't reflect anything. They absorb certain frequency ranges since they are tuned traps (Helmholtz resonators, basically), but they only really absorb in the slots and the areas right around them, while the slats themselves are reflective. Yes, from one point of view you could say that the entire slot wall acts as one giant broadband absorber, but it is a selective absorber, in that it treats only a range of frequencies in the middle of the spectrum. But it still reflects, diffuses or diffracts all of the other frequencies.

So you still need absorption on your first reflection points.

So I need to calculate the mirrors of the speakers on the side walls and place absorbents there?

Yup!

My speakers are inside an MDF box covered with a layer of 15mm drywall.

That's the only box you need. You don't need the second, larger outer box shown on your diagram. Just the one that holds your speakers themselves is fine.

Actually, that's another mistake on my sketch. I intented to do exactly that, following John's pic on what to do with amped speakers, and the bass port and trap are drawn behind the soffit,

But your plan is nothing like John's plan! John only has hangers in a sealed cavity below the speakers, so that the hangers are not in the same air space as the cavity behind the soffit wall. But your hangers are way distant, tucked into the room corner behind the slot wall, and are part of the soffit cavity. That won't do much for you! How are you going to direct sound from the lower soffits to the hidden hangers?

So in reality the soffit part under the speakers to the floor is cloth and absorbent to avoid the console reflections.

That's not what John shows, either! John has a panel there, with absorption on the front and the hangers in the cavity behind and below the speakers. That cavity is sealed off from the actual soffit cavity, and is open to the room ONLY through a slot at the bottom, at floor level. Also, the absorption should NOT start right under the speakers: You need it ONLY on the part of the soffit panel where you will actually get reflections from the rear of the console or desk. As I explained before, the soffit panel needs to be as large as possible, so don't cover any part of it with absorption unless it really needs it. This is why you need to show your real console and real desk accurately in your SketchUp model, in order to determine exactly where you will be getting reflections off the back of it, so you can work out what parts of the soffit front panel need absorption, and what parts can be left reflective, to do the job properly.

Also, the speaker bass trap hangers are not depicted.

OK, so then what ARE those hangers for in the front corners, behind the slot wall modules??? If those aren't the hangers behind the soffit panel, then what are they? What is their purpose?

-The ceiling, made of a timber frame and cloth: shall I fill it with hangers or rockwool/fibreglass? If it's rockwool/fibreglass should I fill the space inside the frame or everything between the drywall ceiling and the frame?

I'm not really sure why you even need that "angled frame and cloth" ceiling at all. I'm thinking that a simple cloud would probably be just as effective, and would be easier to build. That cloth-covered frame isn't really doing much for you. If you think you might need more bass trapping in the room then you could do something like that across the front wall/ceiling corner for sure, but I don't think it needs to be that big, or extend that far back into the room. I think I'd drop that idea for now, build the room, put up a cloud, measure the room, and if you still have issues then you have that space up there where you can install additional treatment. I'd keep it in reserve, and my guess is that you probably won't need to use it.

Thanks again for saving my life. I can't even imagine what I would have built without your help

You are welcome! Folks here saved mine the same way: maybe you can return the favor down the line, and help out someone else...


- Stuart -

[sonolink]

Any chance someone would comment on my Ray Tracing file, please?
Cheers

[carsten_d]

sono,

first let me say that you made my day!
thank you very much for your nice words!

your ray tracing looks fine. but you can see that with your angle you will have
a first reflection ray in front of your listening position. if your slatsangle will be 5 degrees more
you can see (in my sketch) that the first reflection will be behind your head. and thats def better!
your slat will become shorter...so less money for slats, too


hope that helps.
cheers,
carsten

[sonolink]

You just did mine mate!!
Thanks for the tip. I never considered tilting the slat wall from the soffit side!! Great idea! Thanks!
I have recalculated everything and trying to fine tune it I reckon 17º is fine. (15º was on my previous sketch, you suggested 20º). Or maybe is that going too near?
Anyway, if you have a minute, please take a look at my new plan. The slat walls are now corrected (although they are just tilted on the file, I will build them properly. I couldn't be asked to redraw the whole thing...).

StudioSonolinkF8.zip

I hope to be finishing electric lines today so that I can begin building the soffit/slat walls frames
Thanks again for your tips Carsten.


EDIT: photos added...

IMG_2638.jpg

IMG_2661.jpg

IMG_2678.jpg

IMG_2681.jpg

IMG_2693.jpg

IMG_2695.jpg

IMG_2701.jpg

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IMG_2746.jpg

IMG_2750.jpg

Next step: finish cabling behind soffit space and begin soffit frames.
Cheers
Sono

[sonolink]

I realized my speakers are not centered on my soffits. They are aprox 10 cm nearer the sides than the center of the soffits.
Is this a problem?
I drawed a new sketch, extending the shortest side of the soffits to match the largest one. BUT the problem is I can't place the slat wall now because of the left pillar (and I really would like to use slat resonators).
So I'm left with 2 options:
1) shorten the longest side by 10 cm (that would also shorten the distance between center panel and mix position and widen the center panel). That would still leave me with a 1m wide soffit.
2) leave them like that...

Any ideas/suggestions?
Thanks

[sonolink]

Nobody?
Please, pretty please.....

[gullfo]

are the soffits larger than your cabinet? it looks like the speaker box is centered.

[Soundman2020]

I think I already asked this several times, but you never noticed, and now you have already built the soffits without taking this into account:

1) What is the purpose of the OUTER box, surrounding the INNER box into which your speaker fits? I do not see the acoustic purpose of that box. Please explain what it is supposed to accomplish.

2) You have not extended your soffit panel down below the speaker, and have instead installed absorbent material underneath it. What is the purpose of that? Yes, you said it was supposed to deal with reflections off the back of the console, but you never did show the geometry that you used to calculate where it belongs and in any case you seem to have misunderstood the purpose, and John's design.