# Baseline measurements from my home recording studio control room



## bsconz (Jul 29, 2013)

I joined this forum after deciding to get some measuring equipment and software in order to make my home recording studio control room a more ideal monitoring situation. I spent the last 6 months or so mixing a solo album and found it very difficult in terms of having the mixes translate nicely to other listening environments (car, home stereo, headphones, computers, etc.). By the time I start my next project, I would like to build and install some treatments to the room. 

The room is not ideal but it is what I have to work with:

Width = 10' 4"
Length = 11' 2"
Height = 8' 4"

Floor is carpeted. Walls are 5/8" sheet rock. Ceiling is popcorn. There is no treatment in the room at all. There is one heavy drape that covers a large window on the wall behind the monitors.

Monitors and console are arranged on the width of room. Center of monitor woofers are 28" from the back wall, 32" from the side walls, and 44" from the floor (right and ear level). Monitors are set up to form an equilateral triangle with 30-degree angle from the centerline of the mixing/listening position. Distance from the mixing/listening position "sweet spot" to either the left or right monitors is 58". That puts my head in the mixing/listening position at 72" from the back wall, centered from left to right side walls, and about 44" from the floor (level with the monitors).

I used REW 5.01 and a miniDSP UMIK-1 to record 3 measurements. All measurements were sine wave sweeps from 20-20kHz taking 5.9 seconds to complete. The sine wave signal was sent at -12dBFS through my recording interface and console to my monitors. I observed signal loss through these components but mainly due to output trim settings on the interface. Input levels for the measurement purposes were sufficient according to the criteria specified by REW.

I analyzed the data according to the recommendations and methods presented in the "Acoustical Measurement Standards for Stereo Listening Rooms" paper by Nyal Mellor and Jeff Hedback. Some of the standards seem to be specific for listening rather than recording studio mixing but it was a good starting point. Here are some plots showing the results.

Hopefully you guys can help me come up with a treatment plan for this room to get it closer to acceptable for mixing music. I open to all suggestions!

This is the left versus right speaker Energy Time Curve with no filtering and 1ms smoothing. 








This is the left versus right speaker ETC with 500Hz filtering and 1ms smoothing.








This is the left versus right speaker ETC with 1000Hz filtering and 1ms smoothing.








This is the left versus right speaker ETC with 2000Hz filtering and 1ms smoothing.








This is the left versus right speaker ETC with 4000Hz filtering and 1ms smoothing.








This spectrogram shows the low frequency decay times. The noise floor in my control room is about 40dB SPL.








This is the left speaker T60.








This is the right speaker T60.








This is the left speaker T20 and T30 to assess deviation by frequency band.








This is the right speaker T20 and T30 to assess deviation by frequency band.








This shows the midrange consistnecy.








This shows the low frequency response with 1/3 octave smoothing.








This shows the low frequency response with 1/24 octave smoothing.


----------



## dougc (Dec 19, 2009)

A call to GIK Acoustics would be a great place to start since the mixing studio application might be out of the comfort zone for most folks to offer advise. It is a pretty small room, so some room treatments would be in order to get better results with your recording playback.


----------



## FOH (Aug 27, 2012)

bsconz said:


> Width = 10' 4"
> Length = 11' 2"
> Height = 8' 4"
> 
> There is no treatment in the room at all.


Just my take, however a small room such as this can really benefit from an aggressive, brute force absorption approach. If an all out and very ambitious exercise is a consideration, I'd implement a NE approach, ... whereby you build a simple baffle wall, flush mount the monitors and entirely and effectively absorb every surface except the front, monitor wall. 

But, oftentimes there's a myriad of realistic reasons why that may be a bit much. I think I'd be remiss if I didn't offer up the theoretical ideal, regardless how difficult or un-realistic. The above really wouldn't be that tough to pull off, fwiw. 

So, some middle ground approach may be better suited to this situation. First question for either approach; is this a DIY or ready made/purchased solution? The smaller the room, the more one can benefit from absorption; as much LF treatment as you can manage, every possible corner, ceiling panels, sidewalls, and of course the rear wall behind you. 

There's much to get to regarding your measurements, but it'll all need to be re-visited post treatment of the acoustic "low hanging fruit". This would include the bass trapping, effective (thick/spaced) rear wall treatment, side-wall, and then ceiling treatment, front wall and SBIR issues. Just guessing based on your description, that'd be the order of importance and how_ I'd _proceed. 

As you know, measurements rule the day, and typically one does nothing without a quantifiable/measureable reason. However, with the small room, there's some best practices that can be followed for a treatment baseline. Also, dougc offered up good advice regarding contacting GIK, and allow them to help as well, they're great. 



So, buying or DIY'ing?
Any images you could share of the space?


----------

