Help with apartment home studio build in Brazil

[diogodasilva]

Response from Event regarding soffit mounting the opals:

Hi Diogo,

Thanks for getting in contact.

Technically speaking as the speakers are front ported, it is possible to soffit mount them. That said however, they are designed as free standing monitors and as that is the case, soffit mounting is untested. We would not recommend sofft mounting the speakers.

I'm afraid most of our users simply use these free standing as intended so I am unable to offer up any prior experience with the speakers having been soffit mounted.

Sorry we can't be more assistance.

Regards,
Matt Springall

Service & Support - Australia
RODE Microphones / EVENT Electronics

[Soundman2020]

Adam said the same thing about the A7X... On the other hand... :

A7X-soffit-mounted.jpg

A7X-soffit-mounted-2.jpg

I could show you the final acoustic response graphs for the first case above, if you want. The outcome is nothing short of spectacular.

It is also not true that only front-ported speakers can be soffit mounted: in reality, rear-ported speakers can also be soffit mounted.... It's just a bit more complicated to do that. I'm working with one of my customers and also with the chief engineer of the speaker manufacturer to do soffit mount a pair of rear-ported speakers. It will work just fine...

The only speakers that most definitely should not be soffit mounted, are the strange ones that have additional drivers poking out the sides, bottom, or top (some Barefoot models, for example). Apart from that, it is possible to soffit-mount pretty much any speaker, provided that the soffit is designed correctly. I bet I could even soffit-mount your Eggs... it would be very complicated to do that, but I it could be done. The key is correct design, then correct tuning....

As long as you know what you are doing, and think it through carefully, there's no problem.

There's no reason why your Opals can't be soffit mounted, except that a service guy at their Australian operation doesn't want the liability of saying it would work. ( Even though he DID say it would work... )


- Stuart -

[diogodasilva]

Yeah! I could imagine. I just posted it here for the history.
Did you have a chance to look at the post before that regarding the Soffit mounting distances between speakers?
If I was to keep them 132cm apart as advised on the measurement setup, I would lose almost 70% of the front room and would cover my window which I wouldn't be able to do that extremely. How bad would be to increase the spacing of speakers to clear more room for the window ?

[diogodasilva]

Stuart.

I am digging the idea of removing the dry wall ceiling and stuffing the combs with insulation.
as for to cover it with fabric I hd an idea to use a thin PVC membrane called Barrisol.
They say It is acoustically transparent almost but it has a nice property that allows for light diffusion so I can plase LED lighting on top of it and have all of the ceiling light up uniformely.

Here is some date on it:

Snap 2016-01-27 at 15.36.29.png

I can choose either from the perforated or the non perforated version.
Is this suitable for this project?

[Soundman2020]

Did you have a chance to look at the post before that regarding the Soffit mounting distances between speakers?

If I was to obey your guidelines for the monitor placement, the soffits would take a huge amout of space as seen in the pics below. What do you think?

That looks about right, yes. I would suggest that you make the soffit panels even wider. The concept of soffit mounting is to create an "infinite baffle", that extends the front baffle of the speaker cabinet itself, over a much larger area. That eliminates all of the ugly artifacts that arise from having a speaker inside the room, such as comb filtering, SBIR, phase cancellations, edge diffraction, and many others. With a soffit mount, technically the speaker is not really in the room at all! If it isn't in the room, then it cannot create those artifacts...

If I was to keep them 132cm apart as advised on the measurement setup, I would lose almost 70% of the front room and would cover my window ...

We can probably adjust things to uncover the window a bit. I have developed a method for doing that while also not shrinking the soffit. It is possible.

How bad would be to increase the spacing of speakers to clear more room for the window ?

It is possible, yes, but you will need to recalculate the geometry, and change the angle of the speakers, as well as perhaps the location of the mix position. This is what studio design is all about: compromising some things to make other things better. That's what I do all the time when I'm designing a studio! It's a continuous process of adjusting one thing to make some aspect better, then adjusting a bunch of other things to compensate for that, then adjusting even more things to compensate for those changes... Sometimes I feel like a dog chasing his own tail around in circles, and never quite catching it!

as for to cover it with fabric I hd an idea to use a thin PVC membrane called Barrisol.
They say It is acoustically transparent almost but it has a nice property that allows for light diffusion so I can plase LED lighting on top of it and have all of the ceiling light up uniformely. Here is some date on it:

Looks interesting, but hold of on that idea for a bit: you do not yet know what frequencies you will need to treat on your ceiling, so what it is showing there in the data sheets might be good, or it might be bad! You'll have to wait until the design is more advanced and you have some projections of what the ceiling is going to be doing, then you can decide on that. It's too early to make that decision.

By the way, there is something badly wrong with the way you are setting the camera parameters in SketchUp: it is causing terrible distortion of some of the views. Make sure that the "field of view" is set to no more than about 45 degrees, and no less than about 30 degrees. Anything outside that range will exaggerate and distort perspective too much. Try something around 42 degrees.


- Stuart -

[diogodasilva]

It is possible, yes, but you will need to recalculate the geometry, and change the angle of the speakers, as well as perhaps the location of the mix position.

Soundman,
Does the speaker need to seat in the horizontal center of the baffle on the soffit? Or can it be offset to either side?

[diogodasilva]

There's no reason why your Opals can't be soffit mounted,-

The Opal has a somewhat rounded design, not only on the 2d plane but also 3d plane.the shape is curved both on the X, Y, and Z axis it should be difficult to match the front bezel considering all the planes.

Should I make the front baffle flush with the woofer and tweeter part? or flush with the end of the front ports?
you can see what I mean on the pictures attached.

opal.jpg

[diogodasilva]

Here is a new study of the soffits considering the 45 degree angle and keeping the 38% mixing position with a larger baffle.
Still need to decide how to position the baffle in relation with the Opals considering their Odd shape and different z planes on the front.

room.jpg

[diogodasilva]

Here is a new REW file with panels I made just seating on the walls.
Nothing too fancy.
50mm rockwool.
12 panels

The panels are not finished I think I need to increase the thickness to help with reverberation times on lower octaves.
What do you guys think?

Download REW

[diogodasilva]

Here is the before and after of Spectrogram

[diogodasilva]

So when you measure the room height, please give the measurement form the floor to the BOTTOM edge of the concrete webs, and also all the way up to the top of the wells between the webs.

Hello there!
Just another quick update, I've emptied the room and begun the construction adjustments.

First take off the drop ceiling to measure the cob webs.

From floor to bottom edge 2,60m
From floor to top edge 2,90m

Next step will fill those cavities with 32kg/m3 RockWool and hold them in place with with a thin wire mesh I had lying around.

After that I will have to deal with the gaps between the existing walls and the ceiling which you can see on this image:

After the combs are filled then I need to decide if will leave as it is and just create a frame to cover with fabric or Barrisol and have all the ceiling be like a huge trap.
or put some resilient channels and 2 sheets of drywall glued with green glue to help with isolation?
I guess not since it won't matter doing this to the ceiling if the walls are not isolated vibration will be transmitted inevitably ?

So many questions!

[diogodasilva]

Update on progress.
Partition wall for the closet.
Begin double layer insulation (50+50mm rock wool) on the combs .

[Soundman2020]

Next step will fill those cavities with 32kg/m3 RockWool and hold them in place with with a thin wire mesh I had lying around.

Excellent! That's a great bass trap / diffuser up there. It should work well. Fill in those cavities with as much insulation as you can.

After the combs are filled then I need to decide if will leave as it is and just create a frame to cover with fabric or Barrisol and have all the ceiling be like a huge trap.

Yes! definitely! if you are already getting enough isolation for your room, then make the most of that "grid" up there for treatment. Keep your acoustic ceiling high, with good bass trapping and diffusion.

or put some resilient channels and 2 sheets of drywall glued with green glue to help with isolation?

I would try to avoid that. What you have up there is obviously some pretty sturdy concrete structure, so it should be giving you good isolation up there already. I would only hang a decoupled ceiling from it if it turns out that there is flanking noise in the concrete itself. Hopefully there isn't.

I guess not since it won't matter doing this to the ceiling if the walls are not isolated vibration will be transmitted inevitably ?

So make sure your walls are well isolated!

- Stuart -

[connextionproperty]

[SPAMMER BANNED AND BLOCKED]
Thanks for sharing this information:)
[SPAMMER BANNED AND BLOCKED]

[Soundman2020]

Thanks for getting yourself banned forever!