Quick Tip: DIY Basic Room Acoustic Measurement

Quick Tip: DIY Basic Room Acoustic Measurement

on Mar 6th 2012 with 9 comments
Tutorial Details
  • Difficulty: Beginner-Intermediate
  • Time: 10 minutes to read
  • Requirements: See the list of gear and software below

If you are serious about your own career as a musician, DJ, or producer, or just like good sounding environment, here’s something worth learning. A room with good acoustics is essential for recording and mixing your music. If you make music in a room with great acoustics, it has the best chance of sounding good in other rooms too.

Step 1: Get the Basic Tools

In the past, a measurement setup would cost more than $1,000, but nowadays you can grab the tools to do the job for a couple hundred bucks.

Gear You Need

  1. Measurement microphone. I recommend a calibrated Behringer ECM8000 or Dayton Audio EMM-6 from Cross Spectrum Lab. Price is from $65-100 with different calibration data. Personally, I use Dayton Audio EMM-6.
  2. Small mixer with mic preamp and sound card which supports full duplex operation, or just an audio interface with integrated mic preamp. I use my audio interface MOTU Ultralight.
  3. Microphone stand ($30 or $40).
  4. Cables to connect everything together.

Software You Need

Freeware Room EQ Wizard (Win, Mac and Linux) or Fuzzmeasure (Mac, costing $150). There are many more options with a higher price for professional use.

Step 2: Connect Everything

Connect everything together, as you see in the diagram.

Important: Buy cables long enough to move around.

Step 3: Configure the Software

See the diagram below for some typical settings. Please check software manual for detailed instruction because every case is different.

Step 4: Make the Measurements

Frequency Response

Frequency response is usually measured within the range of human hearing, from a low of 20 Hz to a high of 20 kHz. This measurement shows how the room is responding to various frequencies. Peaks or troughs show reinforcement or cancellation at specific frequencies.

Reverberation Time

This is the time it takes for an initial sound to decay a certain number of decibels. For example, RT-60 is the time that it takes a sound to decay 60 dB. My measurement result makes it possible to see the RT-60 times across the frequencies and identify any frequencies that are problematic.

Cumulative Spectral Decay

This measurement shows the combination of the frequency responce along with the decay times for specific frequencies – ideal for understanding low frequency decay in a room and see effects of resonances.

Final Thoughts

Making the measurements is actually quite simple task, but being able to interpret the data in another matter. You will read about measurements interpretation, reality examples, myths and tricks in my next tutorials. All reality examples will be from our DIY small project studio measuring session.

 
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I am computer music and technology enthusiast. I have been learning and studying various production, sound design and recording techniques about ten years. Right now I am part of Juolab Audiovisual Studio. Our web still under construction but you will find some information at www.juolab.com.  

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  • http://www.deanfields.net Dean Fields

    Very timely! I’m just now beginning to build my own home studio and this is a really concise read to help make the best setup. I use a Mac. Do you recommend Fuzzmeasure over the higher priced alternatives?

    • http://www.juolab.com Mantas
      Author

      Hi Dean, thank you for reply. I recommend Fuzzmeasure for beginners. Very easy setup, good support from software developer. For example Smaart V7 ($895, mac) more complex solution for professional use. Also do not forget free alternative RoomEQ (cross platform mac win linux versions, documentation, tutorials and forum for questions). Do not hesitate to contact me if you have any further questions.

  • Steven Ketscher

    Try also iK Multimadias ARC. A package with mic and software included, super easy to set up, extremely detailed instructions (to be honest one of the best manuals I’ve ever read) and amazing results for 199$ !!!

    • http://www.juolab.com Mantas
      Author

      Hi Steve. Thank you for suggestion but it is other sort of application. It is digital room correction software. In other words it is digital eq combined with measuring tool. I think it is not as deep as Fuzzmeasure can be. Also it is easy solution for beginners (eq suggestedand you can tweaks it) but ARC is no substitute for proper acoustic treatment. It can maximise performance and reduce minor response irregularities with negligible quality degradation. In oher hand ARC price is very attractive against acoustic panels + Fuzzmeasure + mic.

      Three options for beginners:
      1. You can use simple solution like IK Multimedia ARC, JBL LSR 4300 and 6300 Series studio monitors ( studio monitors with room correction DSP built into) or KRK ERGO (hardware box designed to go between your audio interface and studio monitors).
      2. Second option is acoustic treatment with acoustic panels (measuring mic, audio interface, software, acoustic panels).
      3. Third is the same second but with DIY acoustic panels + free Room EQ sowtware. I made acoustic panels for our project studio myself and very happy with it. If you have enough free time you can DIY.

      Good reading why digital room correction isn’t better than acoustic treatment.
      http://www.prosoundweb.com/article/in_the_studio/P1/
      http://www.soundonsound.com/sos/mar08/articles/ikmultimediaarc.htm

  • drew

    what do guys think about the FOCUSRITE VRM?

    • http://www.juolab.com Mantas
      Author

      Hi drew. It doesn’t sound anything like as good as a real pair of good monitors in a treated room but still can be useful. You can’t replace monitors + good room with FOCUSRITE VRM but you can combine this tools with main studio setup. It is a very good tool to check how well mixes translate. If you are mixing on the road FOCUSRITE VRM is solution too.

  • http://www.juolab.com Mantas
    Author

    Also forgot to mention FOCUSRITE VRM sound depends on headphones quality. Not all headphones sound the same so try it with different headphone options.

  • http://www.toadspin.com Trunkdog

    Ah! The shear simplicity of it all… Good ears in a “good room” with “good” nearfields to measure. I can’t “fix” what I can’t analyze. I can’t analyze what I can’t measure. Do SPL movements evoke images of gentle breezes, rustling leaves or gale force winds?
    Thank you Mantas for the tip(s). I am somewhat like the late Dale Earnhardt who could see the wind at Daytona. Music can be a visual thing regardless what the purest say. Listening with one sensor deprives one of the total sensory fulfillment of the art form. Music by its nature is mathematical and math by its nature is visual. Certainly the sound (music) elicits a parasympathetic response(s). Our ears can and will deceive us in the mix room.

    These tools (Room EQ Wiz, FuzzMeasure, SMAART, etc) should be applied at the level of expertise for any given user or misapplied altogether. Bottom line: get your room right or as Mike Senior puts it: …spend good money on your nearfields then at least as much again on room acoustics.

    Happy Listening All!

  • bve

    This is great, but as a newcomer in room acoustics I’d like to know what do we have to aim, how does look the “perfect” graph?