The No.1 Website for Pro Audio
 Search This Thread  Search This Forum  Search Reviews  Search Gear Database  Search Gear for sale  Search Gearslutz Go Advanced
New CR from the ground up. Measurements + timelapse included. Need some advice Dynamics Processors (HW)
Old 4 days ago
  #1
Here for the gear
 

Thread Starter
New CR from the ground up. Measurements + timelapse included. Need some advice

Hello guys, i’m in the process of building a new studio, i’ve started 6 months ago building a two floor extension to our house, which the first floor will be my new control room. it’s been a massive project, i’ve done 100% of the work myself, from digging the fondations to the dry wall, all concrete construction. Actually i’ve included a quick draft of the time-lapse video in the dropbox file that includes pics of the room + measurements for those who might be interested. i’ve been reading books about room building and acoustic, and i’ve been reading this forum for years, but this time i need some guidance, to help me take the best decision for the rest of the adventure.

i’m musician and producer (i make my own music and i’ve been touring for about 4 years on the week ends, mostly in europe, i produce mostly electronic music but also rap or pop music for other artists) and i really needed to fulfill that dream of having an actual real studio, with a nice console, and most importantly, a place which i feel excited to work in, and that i can trust (plus i’m originally a geek engineer with OCD, so the sound response is quite a big deal for me).

This room will be mostly a control room : a Studer 903, my converters, two side racks of gear (bantam patch bays, thermionic culture phoenix, pultec eq, ssl compressors, elysia things, distressors, mostly dynamics fun things).
i only have a single pair of near field monitors (focal twin 6) due to the volume of the room.

i’m not looking for isolation at all, this room isn’t used at all for recording, and i don’t have neighbors (plus i always work at low level). i wanted to tame the bass as much as possible (cause this room isn’t big), so my game plan was to use the heavy rock wool to make integrated super chunk plus broadband absorption on every wall to tame the bass, then cover about 75% of the surface with spaced wooden slats, in order to «*revive*» the higher frequencies.

I plan to put 3 diffusors, on in the front for reflexion, on in the back for reflexion, one on the ceiling for reflexions. the side reflexions will be treated by absorption (no slats).

i wanted to do the whole bass thing, then measure the room, in order to know which frequencies i need to control with diffusions, then to measurement in order to add a few tuned traps for the last improvements.


Now here are the dimensions :
Concrete blocks hard walls :
Lenght : 5.8 meters /
widht : 4.5 meters /
height : 2.85 meters /
structural ceiling : concrete poorer on steel beams + polystyrene «*mold*» in between.

-The walls are covered with 10cm of fluffy thermic insulation + 13mm drywall, mounted on steel structure.
-The ceiling is a whole structure with dense rock wool, slanted in the from corner with 6 inches rock wool to cover this angle on the bass side.
-The walls : 2 inches air gap and 5.5 inches very dense rock wool on the walls
-The 4 corners are integrated basstrap (5.5 inches + fluffy in the 2 fronts and 11inches + fluffy in the 2 back ones).

The rock wool is the most dense thing i've seen in my entire life, i've gotten it in an older studio (video dubbing place) they used it under the screen for basstraping, there was a least 4m3 of it, to me it weight at least 200kg/m3, it's incredibly dense and heavy, and i got it for free, i still can't believe it .

i left an empty space on the front and back in order to integrate a diffusor for higher frequencies.
a diffusor cloud will be added on top of the console. The sides which receive reflexions and treated with less dense rock wool, so sound wouldn’t bounce on it.

i placed the monitors on concrete blocks for now, i’m going to make wood+sand stands very soon, i use the concrete to to the tests for now. i’ve placed them as an equilateral triangle with the listening position.



at the moment, i’m at the stage where i’ve put all the first bass treatment, but it seems like i’m right in a null at the 38% listening position. my console is a magnificent Studer 903, but in this room it takes some space, i don’t have a lot of margin to move it forward, but i seem to get a better response when i place the mic closer to monitors, on top of the console (at the normal listening position, i’ve a bump on 60hz and a dip at 100hz).

here is a link to :
picture of the room
screenshots of the measurements
.mdat file for measurements
construction timelapse videos

https://www.dropbox.com/sh/ptb8ytbp3...Q8eBevlVa?dl=0



Here are my interrogations :

- am i going to have to move my listening position ? i though the first bass treatment would make my sweet spot bigger, it seems like just moving the microphone 15 inches corrects the low dips and bumps, but then it means my sweet spot is really small ?

- Are tuned traps (helmholtz for example) able to tame the peak between 110hz and 400hz ? what are my options with this ?

- Is my method of putting wooden slats in the wall to revive the room (other than bass) a good idea ? i thought i could actually measure the room as i go and calculate the spacing between slats, to «*tune*» them.

- any advice i will take in consideration and use for the rest of my quest.


thank you for reading, sorry if my phrasing isn’t adequate sometimes, english isn’t my primary langage, really looking forward to read you guys.
Old 4 days ago
  #2
Gear Nut
 

Can't be of any help I'm afraid but it's amazing all that work you've done! I enjoyed the time-lapse videos very much. In fact, I watched them in half-speed
Where did you gain all that construction knowledge?
Old 4 days ago
  #3
Here for the gear
 

Thread Starter
Quote:
Originally Posted by tkmin View Post
Can't be of any help I'm afraid but it's amazing all that work you've done! I enjoyed the time-lapse videos very much. In fact, I watched them in half-speed
Where did you gain all that construction knowledge?
Thank you very much tkmin ! Actually i wanted to expand the house, so i read constructions forums and the internet for about a year, made a big synthesis of everything, and started the adventure.

i'm always eager to learn new things, doing this was not easy, and very physical, but it's a great pleasure to it myself, and most importantly, total cost 32.000 euros against 140.000 average requested by contractors
Old 3 days ago
  #4
Lives for gear
Quote:
Originally Posted by Jpastor View Post
-
- am i going to have to move my listening position ? i though the first bass treatment would make my sweet spot bigger, it seems like just moving the microphone 15 inches corrects the low dips and bumps, but then it means my sweet spot is really small ?

- Are tuned traps (helmholtz for example) able to tame the peak between 110hz and 400hz ? what are my options with this ?

- Is my method of putting wooden slats in the wall to revive the room (other than bass) a good idea ? i thought i could actually measure the room as i go and calculate the spacing between slats, to «*tune*» them.

- any advice i will take in consideration and use for the rest of my quest.


thank you for reading, sorry if my phrasing isn’t adequate sometimes, english isn’t my primary langage, really looking forward to read you guys.
Great work!

It looks to me like some of that may be from your console, the measurement itself seems odd, what's with the dip at 1-2k in the green? Possibly the solution is to move your speakers more so than your listening position. Can you post the mdat? It would be telling to look at the spectrogram. Also did you measure the L and R speakers together here or just one or the other?

How hard would it be to move the console to the back of the room and measure without it?

The slats will be a good idea, the best is to use the spectrogram to measure what they are doing. You want to ensure you have as few reflections (and diffractions) as possible inside the 20ms window, so if you are 2M from your speakers make sure no reflection path is shorter than ~8M. Once you learn to use the spectrogram function in REW you can measure this.

Are you going to be adding a sub(s)?

Also some of your rockwool may be too dense, you want fluffy insulation where it is thicker than ~20cm.

I don't think helmholtz would work here for 110hz-400hz very well, it would seem this is above your schroeder frequency. As that bump is in both, corrective eq may actually work well here. You might try the demo for sonarworks or dirac and see if you can implement that. Minidsp makes hardware Dirac, but it does have latency when it's on.

What speakers are you using?
Old 2 days ago
  #5
Here for the gear
 

Thread Starter
Hello RyanC, first off, thank you for taking time to answer my post. the pictures and MDAT files are in the dropbox file i posted the link to.

Quote:
Originally Posted by RyanC View Post
Great work!

It looks to me like some of that may be from your console, the measurement itself seems odd, what's with the dip at 1-2k in the green? Possibly the solution is to move your speakers more so than your listening position. Can you post the mdat? It would be telling to look at the spectrogram. Also did you measure the L and R speakers together here or just one or the other?
the green line is the measurement from the listening position, the blue one is from above the console. i have been taking the measurements in stereo, cause the mic was perfectly placed in the middle of the triangle, maybe it comes from that ? i thought i wouldn't mind too much with everything above 500hz, because without the slats the highs would be dead, but i'm not so convinced now...

Quote:
Originally Posted by RyanC View Post
Great work!
How hard would it be to move the console to the back of the room and measure without it?
?
it would be pretty hard, but i'm going to have to move the console to move my listenning position and the speakers. i've ordered stands with height adjustement so i can play as much as possible with the placements. i'll receive them tomorrow. i'll put the console on wheels in order to find the best position. it's very heavy but i'm sure i can do it without damaging the floor.

Quote:
Originally Posted by RyanC View Post
Great work!
Are you going to be adding a sub(s)?
?
it's a possibility, if the acoustic requires it. otherwise i dont think i'm in a room big enough to get clear response under 50hz, and what's under 40hz usually i filter it.

Quote:
Originally Posted by RyanC View Post
Great work!
Also some of your rockwool may be too dense, you want fluffy insulation where it is thicker than ~20cm.
?
i thought that the more mass = the best for basstraps ? i read in books that it was best to leave the airgap (or fluffy) behind the more dense product, because when the waves "bounces" on the wall the speed is zero. my 2 front corner traps are 10 cm (4inches) and fluffy behind, and the 2 back corners are 20cm (8inches) and fluffy behind, could this cause the problem ?



Quote:
Originally Posted by RyanC View Post
Great work!
I don't think helmholtz would work here for 110hz-400hz very well, it would seem this is above your schroeder frequency. As that bump is in both, corrective eq may actually work well here. You might try the demo for sonarworks or dirac and see if you can implement that. Minidsp makes hardware Dirac, but it does have latency when it's on.

What speakers are you using?
?
i'm using a pair of Focal Twin6. i tought about corrective EQ in order to correct the bumps, and i also own the ARCII from IK, the pahe correction room thing. it actually worked pretty good on my previous room, but i really would like to treat the room itself as good as it is possibly doable, and maybe then, use some +/- 1.5 DBs line EQ to correct bumps, as icing on the cake (also it could create phase problems no ? the studios i used in the past had some minor graphic EQ on their system thought).

i was also wondering if the fact that i havent filled yet the front and back (visible on the pic), to leave room for the integrated diffusor could be a problem ? i checks the ETC graph, and i do have some reflection, if someoine can check it in the .MDAT ? i will conduct a lot more tests tomorrow, as i can move the console and speakers more freely.
Old 2 days ago
  #6
Lives for gear
Well a couple quick things-

If you go here and play with the calculator, you will see that deep traps benefit from lower density (pa.s/m2). There is a thread here with figures, but around 5000 is fluffy, and 20,000 is your typical 703. As you increase the depth, they are more efficient with less gas flow resistivity.

Porous Absorber Calculator

Your mdat is kinda weird. I've never seen one where the peaks were negative dB. There is a good chance that something isn't setup right, ultimately REW will show relative dB, so the absolute values don't matter much, but I'm curious what your gain staging was to get this. Were the sweeps relatively loud in the room? If you have a spl meter it's not a bad idea to calibrate it and test around 90dB. It doesn't look like the noise floor is very high...not sure whats going on there.

Also do test one speaker at a time, but here again it's strange that your left to right nulls are showing so much ringing.

In any case, if your Schroder frequency is around 100hz, you do seem to have some decay here from 100-200. It would be good idea to test one speaker and move it up and down to see what changes.
Attached Thumbnails
New CR from the ground up. Measurements + timelapse included. Need some advice-screen-shot-2017-11-17-12.10.58-am.jpg  
Old 1 day ago
  #7
Here for the gear
 

Thread Starter
very interesting the link for the calculator. Unfortunately i havent received the stands for the monitors, hence i cant perform and test regarding the speaker position. But i'm going to experiment with the traps, i'm going to measure with the dense and with the fluffy corners.
Old 1 day ago
  #8
Here for the gear
 

Thread Starter
so i removed the super dense stuff from 3 corners, and replaced it with 15Kg/m3 fluffy thing, results are almost the same as before, maybe the null is a bit bigger at 90hz. the corner traps are 35 inches large, filled completely, frk removed.

it's starting to be a bit depressing, i'll leave the corners with the fluffy and do more experiments when i can move the speakers and console.
Old 1 day ago
  #9
Lives for gear
Quote:
Originally Posted by Jpastor View Post
it's starting to be a bit depressing, i'll leave the corners with the fluffy and do more experiments when i can move the speakers and console.
Well don't freak out yet, even the best built rooms are going to take some time and effort to get the most out of them- especially when you go to put gear in them. On some level a desk (console or computer), gear etc are all going to hurt the acoustics- but certainly many great records have been mixed that way.

With either variable smoothing, or smoothing turned off all together your purple one is the best. +/- 7dB is actually good for a real world room and it shows no major nulls.

Looking over the spectrogram of that one, it looks like there is something causing reflections with a 13ms difference in time in the 100-250 range.

So this is a about a 4.3 meter difference in flight path. There is a good chance this could be floor bounce. It seems too long to be coming off your console. Can you try to put some insulation on the floor? You have the ceiling covered already right?

From the graph it seems like there is some sort of resonance around 150hz. By any chance do you have some other speakers to test? It would be good to rule out as many things as you can.

When you look at the spectrogram from the speakers, the fact that the bass is late below ~90hz is normal. This is typical group delay for the bass range of a speaker, especially one that is ported. It can often be corrected in a dsp crossover, at the cost of a system latency of around 15ms or more.

How does the room sound?
Attached Thumbnails
New CR from the ground up. Measurements + timelapse included. Need some advice-var-smooth.jpg   New CR from the ground up. Measurements + timelapse included. Need some advice-spec-20db.jpg  
Post Reply

Welcome to the Gearslutz Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Forum Jump