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-   -   New control room challenge : 800 square feet with floor absorption and weird windows (

Jpastor 12th June 2020 08:57 PM

My new studio : full build, and measurements.
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Hey guys, i've finally moved into the new house, so after spending 2 years getting an outstanding sound from my old studio (300 square feet), i've got to redo it all over again !

-room is 75m2 (806ft2)
-ceiling height is 2.9m (9.5ft)
-ceiling will be filled with broadband absorption.
-floor is tiles but it will be wood, with special absorbing deck under the console area.
-i'm going to fully treat the room with basstrap, hh resonators and finally diffusors.
- i'll do the same process as in my other room : when i get the acoustic under full control (especially waterfall), i'll apply a thin layer of XTA DSP to tune the speakers and crossovers.

This time i think it will be easier because the volume of the room is huge (to me, european). i'm not too worried about controling the energy, but i've have a few specific questions :

- in my old studio, i fought for a long time a dip at 100hz, caused by the floor (even considered the 2sub technic on the floor under each speaker). i did manage to kill it with a ton of HH resonators placed under and around the console, but it was really a pain. i thought about making some kind of deck, with broad band absorption inside, in order to minimize this 100hz dip, and have a "floor trap", what do you think ?

- is the window going to be a problem ? (other than leaks, i'm already not putting the console right under it to avoid any problems)

- i'm thinking of extending the wall on the left side, and moving the bar, in order to block reflections on my left side, any thought on that ?

-i think i'll start with a sort of LEDE room, but i'm afraid that i'll have to cover the back wall at least (it's nice stones too).

Jpastor 21st June 2020 06:46 PM

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well, i went on with my idea, i'm almost done with the floor.
there is 200mm of floor broad absorption under the console with a rockwool i've successfully used before.

i'll use this thread as a journal, like with my current studio, i'll post all designs and measures as i go on

JayPee 22nd June 2020 09:49 AM

Why didn't you just buy (or DIY) 2 subwoofers? It would have been more "safe"...and more predictable as Jens suggested in your thread :
Should i consider a sub ? (REW data included)

"Two subs on the floor, positioned close to the mains (in the width dimension, not depth: close to front wall is often the best place in depth dimension) and integrated properly (X-over, alignment, correction etc.) with a DSP is in my opinion the best solution. One reason being that it´s often (almost always) a good thing to be able to cross over fairly high (150 Hz or even higher, assuming you can position the subs in a way so that works) since it´s then possible to get rid of the often otherwise problematic dip due to SBIR related to floor bounce (often showing up at around 100-150 Hz (depending on position of source and receiver)." Jens Eklund.

I would never treat my room based on my ideas, but only on very solid referenced papers. You're brave! rockout

Worth reading IMO :

By Northward : Greatest studio designs

By Jens : Flooring question

spirit 23rd June 2020 07:59 PM

Do you mean a 'peak' at 100Hz?
Adding Helmholtz absorption would only make a "dip" worse.

It sounds like you are trying to address a specific problem with your console platform. But if it is built as a broadband absorber, it's not really a specific solution. Do you know that you have a 100 Hz issue again in this room?
If it is a 100 Hz peak, I wonder if it is more of a resonance issue from a poorly supported floor. In that case, you need to either:
A) re-enforce the floor joists below (for example, it may be too long of a span, with relatively undersized joists)
B) add mass to your deck - preferably something with high density and good dampening - like sand, for example. But you may need to provide additional support to the floor joists before loading the floor with sand (e.g.. jack posts)

Other than poor isolation, the windows shouldn't be problematic. But, I would be surprised if they have an STC rating of more than about 20. So, just as long as you recognize they will be the weak point in your room, as far as isolation is concerned. Depending upon what/ who is on the other side, that may/ may not be okay.

Good luck. Very exciting for you, I'm sure.


Jpastor 26th June 2020 11:42 PM

Hey guys, thanks for answering on that thread, i'm not moving much on the building atm but still doing bits at the time. just finished the entire floor.

from my experience with my previous control room, a dip or a peak is the same, it means that a particular frequency needs absorption : too much energy. whether it's a peak or a dip just means that your mic is in the bottom or the top of the wave (to simplify). the goal is to reduce the amplitude of that wave (which you can hear if you put only one frequency and walk into the room, you can actually hear the fluctuation especially in mids).

In my precedent studio, i had great results when i tried to put broadband absorption under and around the floor of the listenning area, so that's why i wanted to try this giant basstracp absorber on the floor.
i even kept dampenning in the previous room, wich left me not a lot of space for me feet but helped me achieve great results (within 2DB of range on FR without curve smoothing from 40 to 500hz, taking average of 7 points in the sweet spot).

i'm confident this floortrap will be effective.
maybe i'll be wrong thought, but i had to try it freshflowe

i'll post more pictures in the next days, can't wait to start measuring :)

Jpastor 26th June 2020 11:43 PM


Originally Posted by JayPee (Post 14814168)
Why didn't you just buy (or DIY) 2 subwoofers? It would have been more "safe"...and more predictable as Jens suggested in your thread :
Should i consider a sub ? (REW data included)

post0.html"]Flooring question[/URL]

Hey, well the two sub method is a way to fix a problem. i'm hoping that the floor trap will take care of that problem prior to that.
i believe that even if it doesn't work 100%, i cant still do the 2 sub method later.

JayPee 27th June 2020 09:04 AM

Did you calculate the resonance frequency of your floor?

spirit 28th June 2020 05:41 AM

I believe what you are measuring is a null (or at least a non-peak amplitude) of a particular frequency.

If you locate at 2 positions in the room relative to the peak and trough of a resonant frequency, the amplitudes, on your SPL meter/ software, will be the same and maximal at both locations- but not opposite in magnitude. The measurement device rectifies the input and averages it over time.

If you are located at a node, the amplitude will be minimal, appearing as a ‘dip’ relative to other positions or frequencies. The important point is that, at a node there is an absence of amplitude/ sound pressure. You need to determine why you have this behaviour at that location.

If it is a result of normal modal resonance, the solution is to re-locate your mix position, not add absorption (note, I’m not talking about the situation of coincident modes, causing increased amplitude, in which case, tuned absorption would be appropriate)

If the issue is a result of reflected bass frequencies and destructive interference, the solution is to apply broadband absorption to the reflecting surface(s).

A reasonable first step is to determine if the problematic frequency is one of your room modes. There are online calculators for this. I would look at axial modes first. But beware, most calculators assume a rectangular room. If you have parallel boundaries though, the math could be valid.

Reflections will cause constructive and destructive interference, meaning that you will see boosting and attenuation of different frequencies at different locations - far from a flat line. So, using broadband absorption is common.

I prefer membrane absorbers (limp mass type), rather than porous absorption.

Reflected bass frequencies are actually a very common problem, and the reason why the rear wall is usually loaded with broadband bass absorption.

Ethan Weiner has a lot of great information about this problem on his Realtraps website.



Jpastor 8th August 2020 10:00 PM

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Hey everyone !

So i've been working hard on the studio, i'm at a point where i can work, and the sound is already superb, really happy with the results, and the measures are promising IMHO.

i still need to work on HH resonators (i may do some test with subs, so i do not want to start working on HH resonators now, as i'm not sure where the sub will be placed and where the high pressure area will be). it also needs some last finishing touches.

here a small fraction of the steps :

- i made a huge absorber in the hidden section of the studio, on top of the speaker, next to the glass. It is filled with about 25kg/m3 rockwool.

Jpastor 8th August 2020 10:04 PM

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i made structures for the sides, i wanted to have something thicker in the corners, and absorption all the way. i left space for 3D diffusers, but it still has some absorption behind.

the front wall itself will stay the way it is, it does act as a "natural" diffuser, even thought the higher frequencies are not omnidirectionnal.

i will put HH resonators on the bottom of it, behind the console, in order to control basses better.

ps : i don't know why some pictures are tilted, on my computer they are straight, can't seem to work around it.

Jpastor 8th August 2020 10:06 PM

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- here i was working on the fabric and the diffuser. The diffuser was calculated with software, i made 5 60*60cm squares that i put together on the wall.

it took me 5 days to cut it all, sand everything and glue everything properly so it looks nice. what a pain.

Jpastor 8th August 2020 10:12 PM

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- here i was working on the ceiling : it was drywall squares, pretty heavy, with about 25cm depth and no insulation. i used the ceiling to get all my wires and light through, then i proceeded with removing ALL the drywall squares, as they were bringing the average weigh at 9kg/m2, wich was the theorical maximum that the structure could take.
i replaced them all with compressed mineral wool, super light squares., and so i could place my glass fiber inside the entire ceiling, for absorption.

i did find these interesting grills, so i decided to paint the structure black, and to attached a piece of black fabric behind each grill, so that the sound couldn't bounce and reflect on the entire section above the console (even thought the compressed mineral wool squares arent really reflective). Plus it looks great.

Jpastor 8th August 2020 10:18 PM

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more pictures of the ceiling and the grill, this one was just a test.

ps : really annoying that thing with tilted pictures :)

Jpastor 8th August 2020 10:20 PM

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here i was starting the finishing touches on the right. i was done with the diffuser and done with the cool LED strips.

Jpastor 8th August 2020 10:24 PM

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There i had brought back my Studer 903 from my other studio. what a pain, it took 2 days. i'm going to redo the sides because they are a bit damaged on some parts and i want them to match the new furniture that i made for the racks

you can also see the light i made right on top of the console, they are dimmable old school type bulbs, and the bream i used is the same as the material i cut for diffusers.

Jpastor 8th August 2020 10:29 PM

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i wanted to go back to smaller, tilted racks, compared to the previous studio, especially as i have more space now.
i did a design on a conception software called solidworks and instead of marking the whole furniture myself, i went to my local wood factory were they have industrial machines, they cut all the pieces, with the type of wood and decore i needed. They also do the milling to have perfect alignement and locking mechanisme to make the racks easily dismantlable (if that's a word)

i just had to do some of the edges decor myself with neoprene glue.

i have 10U on the top part and 3U on the bottom.
i may add wheels to them but i'm not sure.

Jpastor 8th August 2020 10:52 PM

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unfortunately i didn't take many pictures of the build. i did storys on my instagram everyday, showing day to day work (i kept 100 stories in highlight).

here are some screenshots from these :
-You can see the studio at night.
-You can also see a super cool effect, when the sun is at a certain angle, it make amazing lights on the stone wall.
-There is also a picture from the back wall as i was making it. it's covered now with the black fabric + wood.
- i welded some metal that was laying around here to make a tv stand. i may go for a bigger TV, and i need to do the finish on the stand, we will see. it's a bit temporary but still does the job properly.

Jpastor 8th August 2020 10:58 PM

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These are the measurements at the moment.
on the SPL curves, which have NO smoothing, you can see my old studio in red, and the green curve the an average of 6 points at the sweet spot (but they are actually really homogeneous).
The old studio had a perfect harmann curve, with 4dB range from 45 to 200 cycles, with no smoothing. It took me a real long time and effort and trial to get to that results, in a room 4 times smaller thatn this one. i'm confident i'll easily get to a similar result with the new room.

On the waterfall, the man problem is a 32cycles and 80cycles.

The 80Hz "power zone" is located behind the console, i'm sure i'll kill this probleme easy with effective Helmholtz traps.

The 32Hz will be harder but i've already located several spots where i could place resonators.

i may try to get some subs and differents placements in the room before going on the resonators.

djmogovan 11th August 2020 05:34 PM

Looks sweet!