Casaestudio Project

[Soundman2020]

... adding on to the last post:

You have clear issues at these frequencies:

36.5 *** 1.0.0
70.1 *** 2.0.0
75.9
83.0 * 2.1.0
89.8 * 0.1.1
103.0 *** 3.0.0
110.8 * 2.1.1
115.4 * 3.1.0
129 ** 1.2.1
137 *** 4.0.0
147 *** 0.0.2
175 *** 5.0.0

Most are modal. The numbers at the end show which mode I think each is associated with, and the number of stars shows how convinced I am that the number is correct. *=not so convinced, ****=100% positive.

So obviously the longitudinal axis is a big problem since almost all of the modes are associated with it. I would suggest a large thick absorber in the middle of one end wall, perhaps with large, thick wood planks or beams partially in front of it, and small superchunks in the corners of the opposite end wall. The first device I mentioned would be a good candidate for a variable device.

However, apart from that, I have no idea what I'm looking at! Please provide a diagram showing the exact location of the speaker and the mic for each of those measurements.

Your current decay time is around 1300-1400 ms, so you are going to need some small absorption panels on the side walls, and those could be variable as well, based on a basic "slot wedge" design.

The ceiling is low, so you could probably do several smallish, simple angled or curved panels with absorption on the other side, that can be flipped over or adjusted to be at different angles.

Also build a couple of gobos that can be moved around as needed.

- Stuart -

[casaestudio]

Thank you very, very, very much!

I'm going to update my sketchup file and mark the positioning of the speaker and mic of the meassurements. Also I'll work on the ideas I've got for the treatment and share them asap.

I'll be back soon.

[casaestudio]

Hello, this is the sketchup file. I positioned each meassurment position I used.

Still working on my treatment ideas. Oh, and never mind the control room, that's still a raw room.

https://www.dropbox.com/s/p25k09lki1208 ... s.skp?dl=0

[casaestudio]

Most are modal. The numbers at the end show which mode I think each is associated with, and the number of stars shows how convinced I am that the number is correct. *=not so convinced, ****=100% positive.

Thanks a lot for that input!!

I would suggest a large thick absorber in the middle of one end wall, perhaps with large, thick wood planks or beams partially in front of it, and small superchunks in the corners of the opposite end wall. The first device I mentioned would be a good candidate for a variable device.

Cool! I already built three superchunks in the corners where I could manage to build full floor to bottom ones. The superchunks are 45cm x 45cm x 68cm (more or less, don't remember exactly now). Those are going to be turned into slat-slot superchunks. So here's my first question: Is it worth to leave the top and bottom part of the superchunk with no slats? Will it increase the effect on bass absorbtion and flutter removal?

I have also built a 10cm thick (almost 4") treatment on one end wall. Lots of mineral wool there... I could actually make it 2.5cm thicker. Do u recomend it? My Idea was to leave it with the cloth cover but I could use planks of wood to make it more reflexive. I'm somewhere in between 400 and 500ms in RT30 by now and would like to bring back some life back to the room. The side wall where the window is also treated, this time with about 2" mineral wool. This side wall is meant to be covered with slats. I hope that contributes to give a bit more "air" too.
The mineral wool I use is of 70kg density.

so you are going to need some small absorption panels on the side walls, and those could be variable as well, based on a basic "slot wedge" design.

My Idea, for the wall in front of the window, was to build a full frame, from bottom to top, so I would build 10cm thick superchunks all along the wall on the top, right where the ceiling meets the wall. Under that I planned a 2 meter slat slot wedge (about half of that wall's length) so I'd brake the paralelism with the window.

The ceiling is low, so you could probably do several smallish, simple angled or curved panels with absorption on the other side, that can be flipped over or adjusted to be at different angles.

Going for angled panels that will be hanging... Do you think 2" mineral wool absorption would be enough? Instead I also have the possibility of building slot wood wedges on the ceiling which I think would also be more aesthetic.

Thanks a lot for all your input and advice.

[casaestudio]

Just realized the pics from the building process don't clarify the overall design. Let me take a few pics as the room is now and upload them.

Cheers!

[casaestudio]

One end of the room. With two superchunks on the corners and a 8cm thick absortion wall. I was thinking on leaving the walls with cloth and two or three planks of wood from where I could hang reflective devices in order to change the acoustics whenever I want. The superchunks will be both helmholtz resonators.

WhatsApp Image 2017-07-02 at 12.53.07 PM.jpeg.jpg

To the right of the last pic, where the mic is, is the side wall with a 8cm thick bottom to ceiling to the left of the door; right by the superchunk. Surrounding the window there's 4cm thick treatment tilting and growing to 8cm thick towards the end of the wall meeting the ceiling.

WhatsApp Image 2017-07-02 at 12.53.47 PM.jpeg.jpg

The other end of the room is untreated yet. Just 1 superchunk on the right. That wall is not parallel to the oposite end. I'm planning on building a bass trap just over the door and that upper corner.

WhatsApp Image 2017-07-02 at 1.00.24 PM.jpeg.jpg

The other side wall is still "naked". Just the two superchunks I built for the end walls. I'm planning on building slatted wedges on half of that wall, just in front of the window. Sorry for the pic, this is the only place from where I could make that wall fit in the pic.

WhatsApp Image 2017-07-02 at 1.13.48 PM.jpeg.jpg

Hope these pics clarify the room.

Hugs!

[casaestudio]

Well, quickly.

We are finishing one end of the room with a clearer design and finish. As for the design, the tests performed on the superchunks in the corners have led me to modify two of the traps I was building. A good move, I think. I removed all the mineral wool triangles and followed the design with two sheets of mineral wall and two air chambers.

resonadores.JPG

WhatsApp Image 2017-07-04 at 10.29.10 PM.jpeg.jpg

I'm sorry for the picture quality but I think you can appreciate ...
In black, the area of one of them with the empty room.
In light blue, with the superchunk filled with triangles of LR without air chamber (and without slats).
In fuxia, with the change of today, changing the triangles for two sheets of 4cm thick, one behind the other, leaving air gap between them and behind them. Still no slats yet.

WhatsApp Image 2017-07-04 at 10.58.45 PM.jpeg.jpg

As for the finishing, we have installed some frieze on the absorbent wall to give it a little more resistance. It might be that I add more frieze when I finish treating the walls to bring back mor mids and highs. We'll see.

And nothing more. Oh, well, I've also done a test hanging a panel on the ceiling ... I think I'll go that way, hanging 6 panels.

Cheers.

[casaestudio]

New set of meassurements.https://www.dropbox.com/s/unz4fbvqanueh ... mdat?dl=0

Mic locations map.

WhatsApp Image 2017-07-06 at 12.48.37 PM.jpeg.jpg

Still the window wall's treatment does not have the slats installed. I hope that will bring back some brightness and greater the decay time on his and mids.

Going to build the side angled slat resonator wall in front of the window now. That will be tuned to trap from 50 to 80hz

[casaestudio]

IMG_1629.JPG

IMG_1628.JPG

Good morning, some comments on the latest developments in the Live Room.

Superchunks with triangles Vs. Superchunks with two layers of mineral wool and air gaps.
Better performance with triangles. More expensive (about 10 times more mineral wool is used) although it does not have a 10 times higher performance, of course. I went for the triangles finally since I have lots of mineral wool.

Live room? Dead room? Dry room?
While I have been conditioning the room I have been testing diferent solutions and taking into considertaion both, measurements with REW and critical listening. Doing frequency sweeps in loop and playing music that I know well while walking through the room have been very helpful. In this way I have tried to locate the most critical frequencies and try to point to them in the slat slot resonator calculations.
My initial goal was to keep a tr of around 500ms but I soon realized that the size of the room required being very surgical to achieve something like while keeping a controlled sound (something hard to get with my little experience)... but I also realized that you can keep a live room still keeping it dry in terms of reverb and get good results in terms of sound. A low TR does not necessarily have to be bad in a Live Room. The slat-slot walls and traps absorb the bass well but still bring reflection in mids and highs that benefit the room a lot. I think drums, for example, will take advantage of that. This reflection keeps a much more vivid sound and there is a VERY appreciable difference between one end and another of the room: sound more dead at the end with absorbent walls and brighter at the other end of the room, where the window and slat wall are. I am happy with the results so far.

Low ceiling, a big problem?
Initial ceiling: 252cm high
After isolating: 236cm high (15mm drywall + MAD4 + 13mm drywall and 11cm air chamber)
After conditioning: 226cm high (system of hanging panels filled with 4cm thick mineral wool and air chamber of about 6cm over these)
These clouds have eliminated the annoying reflections between ceiling and floor and there is still a pleasant height, although a little to the limit, that if. I think the overhead drum miking will not be problematic. Before building the room I hoped to get a more characteristic room sound; Over time I have understood that the room is too small to achieve that and still use it for multiple purposes, so we must add that reverb artificially ...

I hope I'll finish the room this upcoming week. Very little left to do: Finish the slats in third superchunk, finish the bare wall as well as three ceiling panels and setting up electrics.

Until next post ... big hug!

[casaestudio]

Going ahead with my infinite baffle and soffit.

IMG-20171023-WA0009.jpg

Just one question: Do I need to box my monitors even though they are on an isoated stand?

Cheers!

[Eric Best]

That's what I did. I then made a bezel that fit over the speaker with about a 1/8" airspace all around the speaker. I haven't noticed any issues.

[casaestudio]

That's what I did. I then made a bezel that fit over the speaker with about a 1/8" airspace all around the speaker. I haven't noticed any issues.

Thanks for your answer, Eric Best.

What is the importance of boxing the monitors? I mean, what does actually happen when you box them?
I’ve always thought it was done to isolate the monitor from the soffit, that’s why i doubt if to box mine, because Of my stands..

[Eric Best]

I'm not really sure either, that is why I didn't spend the time doing it. I think that if the speaker cabinets are well damped and the front wall massive, I don't think there is an issue.

[casaestudio]

Thanks again, Eric. I've been following your posts also, and learnt a lot from them.
Since I know you like to mess around and work on speaker related stuff... I have a pair of Dynaudio BM6A that I want to mount on the soffit. I'd like to give it a try.
My plan is:
1. To extend the cabling and move the amp cover to the sidewalls right by the soffits.
2. To damp the inside of the speaker box with insulation
3. To dump the bass reflex port with insulation
4. To adjust the LF Trim

Is there any other thing to do that you would suggest?
Should I tie the speakers to the stands using straps?
Should I leave an air path to cool down the monitor even if I move the power amp out of the soffit?

Thanks a lot!!

[Soundman2020]

What is the importance of boxing the monitors? I mean, what does actually happen when you box them?

It adds mass and rigidity, if you do the "tight fit" mounting method, which makes it harder for the speaker itself to vibrate, lowers the resonant frequency of the entire thing, and makes it harder for the speaker to transmit vibrations into the structure.

I’ve always thought it was done to isolate the monitor from the soffit,

Only if you go with the "fully floated" mounting system, which is what I normally do.

2. To damp the inside of the speaker box with insulation

The interior of the speaker box is already damped properly by the manufacturer, at the factory, by careful design. I wouldn't mess with that.

3. To dump the bass reflex port with insulation

Definitely.

4. To adjust the LF Trim

Do that as part of the final room tuning, using REW, after you have everything mounted.

Should I tie the speakers to the stands using straps?

Definitely! Either rigidly (using the rigid "enclosure box" method), or floated properly on pads, but still tied down.

Should I leave an air path to cool down the monitor even if I move the power amp out of the soffit?

Definitely! Speaker drivers are extremely inefficient. Your amp might be pumping a hundred watts of electrical power into the driver, but you'll only be getting maybe one watt of acoustic power out of it. The rest has to go somewhere: it is mostly dissipated as heat, and that happens at the driver, not the amp. The reason that an amp has a heat sink on it is to dissipate the heat created by the amps own inefficiencies, not to deal with the highly inefficient conversion of electrical power into sound power. So you still need to ventilate the speaker box, even if the amp is elsewhere.

- Stuart -