Room Treatment Report from Frank (GIK)

[FrankGIK]

I took all the treatment out of my room and retreated it one section at a time, shooting the room and taking notes as I did. The point was to show everybody what could be done with even the worst rooms. I posted this over at Studio-Central and people seemed to think it was helpful, so I thought I'd do the same over here.

The Room:
- 13’7”Wx14’4”Lx8’H
- 12’Wx5’H windows on the back wall and left wall
- 6’Wx7’H sliding glass door on the front wall
- 6’Wx7’H French doors on the right wall
- One layer of 5/8” sheet rock over metal studs; all walls are filled with spray insulation. 3’ crawl space beneath the room.
- Wood floors

The Equipment:
- dBX RTA-M Measurement Microphone
- Soundcraft M12 mixer (nice, clean preamps)
- One Atlas Pro Sound mic stand
- Two JBL LSR4328 monitors
- SSL XLogic converters
- Room EQ Wizard (free download)

The Goal: The goal was simple: the take a bad room and turn it into a good one using a combination of good positioning and acoustic treatment. When I say, “bad”, I really mean “almost as bad as you can get”. As you can see by the dimensions listed above, the space is nearly square and while all the glass isn’t necessarily a bad thing from a low-end standpoint, it’s definitely a problem in the mid range and high end.

The Procedure: I took all the treatment out of my room then shot it for a baseline reading. After that I added acoustic treatment one area at a time, using well-established best practices and commercially available panels from GIK Acoustics. All panels utilized mineral wool with densities ranging from 48kg/m3-70kg/m3 depending on the thickness of the panel.

Room Shot 1:
No treatment. Note the 25dB null at 70Hz, the 14dB null at 100Hz, the resonance at 280Hz, and the 14dB trough from 700Hz to Decay times are too long across the board. That means that the low end ringing in the room is masking the high mids and high end and tricking you into cutting more bass than you should.





Room Shot 2:
Add GIK 244’s floor-to-ceiling in the back corners. The goal was to begin to stabilize the low end response in the room and to improve decay times in a general way.
All of the dips from 150Hz are improved by 2-4dB each. There is some smoothing in the 700Hz-1Khz trough and in the highs. Note the improvement in decay time.





Room Shot 3:
Add GIK 244’s floor to ceiling in the front corners and two GIK 242’s on the front wall to further soften the sub 250Hz range and to reduce decay times some more.
Got 1dB reduction in the 70Hz null and some more reduction in the 150-700Hz range. There is a good bit of smoothing from 1.2Khz to 4Khz. 6Khz to 20Khz is nearly flat. More broad improvement in decay time, but there is specific reduction at 80Hz. The high mids are starting to seriously clear up.





Room Shot 4:
Add five Monster Bass traps to the back wall. Moved the listening position back 12”; moved the speakers 7” further apart. The point on this step was to take a serious bite out of the sub 200Hz issues. I also suspected that covering much of that glass would result in a good bit of high end smoothing. The move back was a calculated risk to see if I could move out of (or partially out of) the 70-80Hz modal issues; it paid off.
This one took 8dB off the 70Hz peak, took 2dB off the 80Hz peak, evened out the low midrange more and evened out the 700Hz-1Khz valley. Unfortunately there’s a new dip at 1.7Khz. Testing indicated that this was comb filtering caused by the console. The highs are still pretty even. There is more improvement in decay time especially at 40Hz and 80Hz.





Room Shot 5 (PLEASE NOTE THE CHANGE OF SCALE):
Add four GIK 244’s at the first and second reflection points, two GIK 244’s above the mix position and two 242’s just ahead of the firs reflection point. Moved the listening position back 6” more. I knew that moving back had produced a dramatic reduction in the 70-80Hz problems, so I decided to try moving back a bit more to see if I could reduce it further.
Huge improvement. The 44Hz peak was reduced by 2dB or so; the dips in the 50-100Hz range have improved by 6-8dB each. The biggest change is the radical smoothing from 100Hz-3.4Khz, though there is still some comb filtering from reflections off the console and a 15Khz dip to work on. Though decay times are still much more even than they were to start with, the move back into the room results in a longer decay time at 80Hz. 40Hz is still better than the first three waterfall plots.





End Result: The room is within 10dB of flat from 50Hz to 22Khz at 1/12 octave smoothing. The highest peak (80hz) is 85dB and the lowest dip (15Khz) is at 75dB. The rest of the room is within 8dB and the majority of it is within 6dB of flat. Note the stead reduction in decay time between 40Hz and 200Hz throughout the process, with the exception of the last waterfall dispay (note the 80Hz area). While the move back 18” into the room reaped a significant benefit in terms of frequency response, there was a trade off with respect to decay time.


Frank Oesterheld, CTS
GIK Acoustics
Room Design/Customer Support
http://www.gikacoustics.com

[TrevCircleStudios]

Nice job frank. Just goes to show what is possible even in a home studio!

[modz1]

Thanks for this Frank.. Will be a solid reference for all, and tis stickied!

[sureno]

lovely job Big F

[Monarch]

Well done Frank! Thanks for sharing all that info!

[FrankGIK]

You know, I thought I should include some pictures of the room too...so you can see what I did. Please pardon the crappy picture quality...I am NOT a photographer.

Front of the room...three GIK 242's, Mackie 32.8, JBL LSR 4328's, dynamics and preamp racks.




Back left side of the room...GIK 244's floor to ceiling, five Monster Bass Traps, one D1 Diffuser


Back right side of the room...same thing as the left


Left Side...right side is a mirror image from a treatment standpoint...two GIK 244's, one GIK 242


Ceiling treatment...two GIK 244's and a 242 behind it.


Tracking rack...patchbays, SSL converters and a headphone amp


Dynamics rack...DBX 266, two RNLA's, a DBX 160, RNC, two ART Pro VLA's


Preamp rack...can't see the Great River ME-1NV and the RNP (on top), two ACMP-73's, two ART MPA Gold


This is my power management stuff, my Rev 5 reverb/delay unit, the MasterLink and the console power supply.



Frank

[sureno]

the way you have treated your room looks very simple and feasible for me, i like it very much, nothing looks too permanent. i got to ask how do the corner bass traps work for rooms with unorthodox corners, walk in wardrobes etc?

[FrankGIK]

Originally Posted by sureno

the way you have treated your room looks very simple and feasible for me, i like it very much, nothing looks too permanent. i got to ask how do the corner bass traps work for rooms with unorthodox corners, walk in wardrobes etc?

Inaccessible corners are...well, inaccessible. If you can't hit a corner, don't worry about it. Go on to the spaces you CAN treat in the room. I mean, if you can move some stuff around to make the corners, back wall, front wall and reflection points accessible, then you should...but then again, having a wardrobe in the middle of the back wall may not be a bad thing at all as it breaks up the acoustic signature.

Remember, you can always hit wall/ceiling or wall/floor corners as well so you should have plenty of places you can treat.

Frank

[sureno]

cool, iv got 2 top corners, will address acoustics in the new year
and nice pics dude, lets hear what comes out of there some time

[Monarch]

Lovely Pics Frank.

[Meander]

I have an ART VLA comp myself, great sound, great price. Congrats on the improvement too.

[FrankGIK]

Originally Posted by Meander

I have an ART VLA comp myself, great sound, great price. Congrats on the improvement too.

I LOVE that thing. It's either that or the 160 on almost every vocal...you can nuke a vocal for 10dB of reduction and never hear it working. Amazing...can't touch them for less than four times the price for a single channel.

Frank

[terminal3]

Originally Posted by FrankGIK

I LOVE that thing. It's either that or the 160 on almost every vocal...you can nuke a vocal for 10dB of reduction and never hear it working. Amazing...can't touch them for less than four times the price for a single channel.

Frank

Minorly OT - I'm a MASSIVE 160 fan... have a 160A that gets used on almost all vox and bass around here. It's got this slight bit of colour which I think is cool, but you're mentioning transparency with the VLA. Would a VLA complement the 160, in your opinion, or would it unnecessarily overlap?

Have you ever heard the Pro Channel? Any good? That thing's vari-mu which is pretty unusual for anything under, like, £2k. But I'm still worried that it's heavily compromised.

In addition to being a big fan of the 160 I'm also a big fan of mid-range value-for-money gear...

[FrankGIK]

Originally Posted by terminal3

Minorly OT - I'm a MASSIVE 160 fan... have a 160A that gets used on almost all vox and bass around here. It's got this slight bit of colour which I think is cool, but you're mentioning transparency with the VLA. Would a VLA complement the 160, in your opinion, or would it unnecessarily overlap?

Have you ever heard the Pro Channel? Any good? That thing's vari-mu which is pretty unusual for anything under, like, £2k. But I'm still worried that it's heavily compromised.

In addition to being a big fan of the 160 I'm also a big fan of mid-range value-for-money gear...

I have four channels of the VLA and I find very little overlap. The VLA is more transparent than the 160...it's absolutely fantastic on snare and kick, two tasks I *hate* the 160 for. The 160 is my hands down favorite on most vocals and bass, though the VLA usually gets the job on really close, intimate vocals.

Yeah, I'm a big, big fan of mid-range-value-for-money gear too. I sold off all the cheap stuff a few years ago and started collecting only mid-value stuff that is really, really good. I've mixed dozens and dozens of records on this stuff. Love it.

Frank

[terminal3]

Originally Posted by FrankGIK

I have four channels of the VLA and I find very little overlap. The VLA is more transparent than the 160...it's absolutely fantastic on snare and kick, two tasks I *hate* the 160 for. The 160 is my hands down favorite on most vocals and bass, though the VLA usually gets the job on really close, intimate vocals.

Yeah, I'm a big, big fan of mid-range-value-for-money gear too. I sold off all the cheap stuff a few years ago and started collecting only mid-value stuff that is really, really good. I've mixed dozens and dozens of records on this stuff. Love it.

Cool, cheers, a pint your way. Are the stock tubes OK or does it benefit from a swap?

Could be useful around here. I'm loving buying all these compressors... as far as EQ goes I'm happy with software (other than one 2-buss "mastering" EQ I have) but outboard comps just rock my world.