Improving my controlroom. Soffit mount monitors

[hugo_inside]

Hi everybody,

Tomorrow I'll start the changes in my control room. This is the layout of my studio:



The hole front and rear wall are ABSORVENT. It's made of soft metal frame with rockwool 8 cm thick, and a red cloth covering.

The hole ceiling are ABSORVENT too. And the side walls are REFLECTANT.



I want to soffit the monitors and put some shelves in the rear wall. And maybe a closet to store guitars.

The first step I must made is to make a new wall in right angle with the center line of the control room to make it symmetrical.

I'll start building it of particle board 19 mm thick (6/8 ") over a metal/wood frame.

Then I'll leave a port about 30 cm (1 ft) over the wall and below it to use is as a big bass trap.





What is your opinion or advices about that? May I bulid the hole straight wall? Are that gaps dangerous?

[Scott R. Foster]

Nice!

My concern is it might be more absorbing surfaces than is helpful - but I suppose that is easy to adjust as you go along. I would not worry about the gaps.

[hugo_inside]

Thanks for answering.

Today I've been building the front frame. The back wall has been made from the floor (no port below) to 2,44 meters height.

I have a question about the top. May I let a gap and fill it will rockwool? Then I want to cover it with an acoustical transparent cloth.

Here you have the current work done until today.



Tomorrow I'll close the sides baffles top at the particle board line to seal the boxes and made a shelf at the middle heigh stud line to lay down the box where the monitor will be in. Then I'll caulk all the joints.

The bottom will be filled with some hangers made of 5 mm plywood core and 30Kg/m3 rockwool on the sides.

All the perimeter of the middle box will be filled with 70 Kg/m3 rockwool.

What do you think about it?

[bert stoltenborg]

Why hangers?

And why caulcing?

[hugo_inside]

Hangers are the best way for low frequencies absorption I think.

The boxes need to be sealed with caulk to avoid rear/side reflexions of the monitor comes out of the box.

The basic idea is to ear only the sound of the front of the monitor and avoid back reflexions.

[bert stoltenborg]

Hangers seem to work, but I'm not aware of any proof they are better than plain old mineral wool, which is an easier and cheaper way to go, I guess.

I'm not sure I understand you, but caulking small gaps to avoid diffraction from the speaker in a flush mounted or absorptive situation is moot, IMHO.

[hugo_inside]

I'll filled the back wall with rockwool the next day. Should I filled it with sand or something heavier than rockwool?

Today we've been building the box top and bottom plates and caulking all the joints. We've made a lot of hangers but they are not hanged, yet.

Center box is caulked and rockwool filled.

The next day (Monday I think) we'll fill the perimeter boxes with insulation and try to do the monitor boxes. Then I try to get some boards to made the front box lid. What about 2 layers of MDF 1 cm think and another layer of timber?

Here some pictures about the job until now.













I don't know if I need to decoulple de monitor MDF box from the bottom plate.I think monitor will be decoupled with high density particle foam (I don't know the name in english).Will It work?



Regards.

[hugo_inside]

Hangers seem to work, but I'm not aware of any proof they are better than plain old mineral wool, which is an easier and cheaper way to go, I guess.

I'm not sure I understand you, but caulking small gaps to avoid diffraction from the speaker in a flush mounted or absorptive situation is moot, IMHO.

Hi again,

I'm not an expert and I cannot tell you the reason of caulking the boxes.

On the other hand, hangers are very cheap to do. 5 mm plywood, soft insulation (maybe 15 kg/m3 density) and staples.

[hugo_inside]

Here you have the monitors specs:

The main features of the Adam P22A include:

- Designed for applications where deeper bass and louder volumes are needed, ideally suited for project studios as well as professional recording and broadcast facilities
- 2-way active bass reflex speaker
- Woofer: 220 mm / 8 inch coated paper cone
- A.R.T. tweeter
- Frequency response: (+/- 3 dB): 38 Hz - 35 kHz
- Max SPL in 1m: 109dB or Greater
- Panel (rear-mounted): Input/HF gain, Hi/Lo EQ
- Power: 100W (sin) 150W (rms)
- Inputs: Balanced XLR
- W x H x D: 260mm (10 inches) x 430mm (17 inches) x 340mm (13.5 inches)
- Weight: 13 kg (28.5 lbs)

[bert stoltenborg]

It's all very nice, but you really should forget about those hangers.
This ain't gonna come near to a super chunk absorption-wise.
And perforate the top and bottom of those big speaker boxes and fill 'm with absorption.
You'll get way more benefit of absorption if the sound "sees" the whole absoption without dividers.
Sound is, as Eric said lately about a situation like this, not just something moving in one direction (in this case from front to back of the room).
If the sound sees one absorbing volume from floor to ceiling you'll get that extra absorption peak. With all these boxes you diminish the possibilities you could have with this setup.

[hugo_inside]

I'm following this plan:



As you can see there will be more insulation, not only hangers, at the bottom. I must drill 2 holes in the monitor small box and let a space open at the top and another open space at the bottom for air flow, because monitors are active, and the power amp need could be overheated.

[Scott R. Foster]

You do very nice work - it is a shame you are following a plan of pointless complexity. The time and money you will waste on hangers and separate boxes for your absorptive elements would be better spent building a custom mix desk with built-in equipment racks, mixing gold records, or taking a nap. I marvel that these design concepts persist absent any support from the physical sciences to justify the cost and trouble.

Secret chambers hidden behind the walls filled with magical devices - just to absorb sound - a job that can be accomplished with a stack of cheap building insulation - the internet is an amazing place init?

[Bob]

hugo_inside:

What's above the false ceiling?

[hugo_inside]

Subject: Improving my controlroom. Soffit mount monitors

You do very nice work - it is a shame you are following a plan of pointless complexity. The time and money you will waste on hangers and separate boxes for your absorptive elements would be better spent building a custom mix desk with built-in equipment racks, mixing gold records, or taking a nap. I marvel that these design concepts persist absent any support from the physical sciences to justify the cost and trouble.

Secret chambers hidden behind the walls filled with magical devices - just to absorb sound - a job that can be accomplished with a stack of cheap building insulation - the internet is an amazing place init?

Make hangers is very cheap and fast. I don't know if it will work. but I think is not a waste of money and time. Cost per 14 hangers 50€.
Time spent doing them: 1 hour.

Anyway, next week I would do some tests: hangers vs full of rock-wool corner.

[hugo_inside]

hugo_inside:

What's above the false ceiling?

About 20 cm Air space and this:



I'm planning to do a cloud over the listening point. Or maybe some of them:

[Scott R. Foster]

God bless you Hugo - I am sure it will work out - I am metaphysically certain that what you are doing is more complex than needed - but that is not really important. Given the tremendous overall effort you are expending on these rooms a few extra moments here or there don't amount to much. It seems to me that the room treatments you plan to will work and that is all that matters. I wonder if perhaps it all might add up to a bit much but that is an easy fix.... consider a few measurements as you go along and prepare your mind to maybe do some patches of paneling or maybe some spaced slats [like Rod G does] over some of the large areas of mineral fiber wall covering on areas which are not critical early reflection spots. These ideas may come in handy and it certainly won't hurt to have them in mind.

On a side issue, I think it is worth your time to detail the speaker installation and get Bert's advice. He sometimes plays the fool but the truth is he is the most clever white man I know [besides Bob who knows everything but is forgetful - this is why he makes so many lists - sad really, but a boon to us lost in the Google looking for...].

Bert could help you make sure to get the critical speaker mounting element right. You could spend a lot of money and get worse advice than he might provide for the cost of answering a few impertinent questions, listening to a couple stupid jokes, and worst case taking a slice off your ego.

My $0.02 [in devalued US currency]

[bert stoltenborg]

http://www.johnlsayers.com/phpBB2/viewt ... 4&start=15

Normally these Aussies keep things so simple: drink beer till they hardly can stand so when the bar fight begins they don't harm themselves and their opponents to much. But when designing studio's it's complexety all over the place.

Is this Philip Newell dude by any chance an Aussie?

[hugo_inside]

I've found good information in johnsayer site since a few years ago. I realized that all the "experts" in John's site are in all the acoustic forums, but not here (I think).
Ethan, Gullfo, xSpace, Soundman, Sharward, etc. Is like a masonic band all over the world who control the acoustics in the web... with John directing them to advice the more complex the better.

Jokes aside, I'd been recording next to 10 years (6 of them in this studio) http://www.lanauestudi.com , and I've been planing some improvements. I think soffit mount monitor will improve the sound, and the aesthetics (the more visual impact in customers the better, IMHO)

I bought Phillip Newell's book and Handbook of acoustic a few years ago and read them, but when I need some advanced specific advices, John's site is my first choice. So this has been until now. Now I know here you have a opossite opinion than there, I'll ask here too.

[Scott R. Foster]

Why bother? Seems you already have answers that satisfy.

[hugo_inside]

New pictures:

Removing the ADAMs poweramp:



Wires must be cut to add a longer ones, and then soldered again.

Monitors are made of 16 mm MDF...



The power amp is attached on the below frame and the monitor in its box.



Slat resonator between the monitors.



Covering with slats till the top for aesthetics and bottom cloth stappled.

Second layer over the monitors: