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How To Tune A Sound System In 15 Minutes

By Nathan Lively

sound-design-live-professional-sound-system-setup-15-minutes-MAPP-8k

Even professionals often skip sound system setup and go straight to mixing because there just isn’t enough time. Unfortunately, you can’t go directly to your artistic place without first passing through science. The good news is that even the smallest amounts of time can be put to good use. 

How? With a plan.

Simple Sound System Goals

The goal for tuning a sound system is very simple: manage interactions to reduce variance across the listening plane. Put another way: provide the same sound in every seat. Setting the master EQ for perfect sound at the mix position does not meet this goal. Instead, we need an order of operations to help us make changes that will benefit the entire listening area, or at least mitigate damage. The order of operations is:

  1. Verification
  2. Placement
  3. Aim
  4. EQ
  5. Crossover alignment

It might seem like you don’t have 15 minutes to spare to check all of this, but the most important items are listed first. Completing a few is better than nothing.

You will need a dual channel analyzer like Smaart, SATlive, SysTune, Tuning Capture, RiTA, Open Sound Meter, etc..

Here are the speakers we need to set up: (2) CQ-1 (wide coverage main), (2) 650-P (2x 18-inch sub) in an uncoupled symmetrical point destination array. It’s your standard left/right mains situation (see diagram below). This is the most common professional sound system setup that I run into; it is not good or bad, just common. 

Our job as a waveform delivery service is to minimize phase distortion that causes comb filtering. Comb filtering makes a swooshing sound in the high frequencies as you move your head and should never be fed after midnight. Unfortunately, any array with speakers facing in towards a destination will produce some amount of combing. We would prefer a single CQ-1 and 650-P flown above downstage center to match the room. This design often doesn’t happen because of hardware and time limitations. I could complain about it and waste your time, but those speakers will still be sitting there, bored as hell.

Download the MAPP XT project if you would like to follow along with each step.

Disclaimer: This is a highly simplified example with minimum microphone positions to give you an idea of the structure for verifying and calibrating a professional sound system. There are many factors at play and details that I do not cover, like how to operate an analyzer. For a more in-depth analysis of this subject listen to my interview with Bob McCarthy.

Minutes 0-4: Verification

Do you think a lighting technician starts running a show without making sure that each instrument responds at the correct address? No! Better make sure all of your speakers play what they are supposed to play.

  1. Set all outputs to unity.
  2. Play pink noise and isolate one speaker at a time. In this setup we are unable to solo individual drivers, but do it if you can.
  3. Is the left output playing from the left speaker? If not, track it down. Many times it’s just a case of faulty patching. If you’ve got lines wrong inside of a closed box, you’re going to need more than 15 minutes, so I hope you have a backup. Repeat for each speaker/driver.
  4. Listen. Are there any obvious problems like noise, distortion, or Left and Right sounding different?
  5. Measure phase response on your audio analyzer at on-axis of each speaker/driver. Confirm matching relative phase. A phase offset of 180° indicates a polarity inversion. Any point in the signal chain could cause a polarity inversion so either track it down or simply invert phase anywhere else so that they all match in the end.

This step is the most important. It will be a sad dance party if your subs aren’t working.

Placement

In this situation there’s not much we can do with placement. We would like to move each speaker closer to the center of its coverage area, but we have a stage in the way and no rigging hardware or points.

Minutes 4-8: Aim

We only have a single measurement microphone, so we’ll need more time on this step to move it between positions. If I were running late and needed to cut one step from this process, I would cut this one and instead estimate the aim with a laser.

  1. Compare Main Left solo at OFFAXL and OFFAXR.
  2. Adjust aim until OFFAXL = OFFAXR in the HF (high frequencies).
  3. Repeat for Main Right.

Minutes 8-12: EQ

  1. Measure Main Left solo at ONAX and set output EQ filters to match your target trace.
  2. Listen to the filters in and out while playing your reference tracks. Are you going in the right direction?
  3. Copy the Main Left output EQ to Main Right output EQ.
  4. Measure Main L+R at ONAX and set EQ filters to return system response to your target trace. 
  5. Listen.

Minutes 12-15: Crossover Alignment

  1. Measure Sub Left solo at ONAX.
  2. Compare to Main Left solo. Are phase measurements within 60º through the crossover region? If so, move to step 7. If not, fix it. (for more, see How to verify main+sub alignment in Smaart)
  3. Measure MainL+SubL and check the combined response to make sure you have summation throughout the spectral crossover.
  4. Apply any necessary combined EQ.
  5. Listen to the result with your changes in and out. 

This is a stripped-down example of one of the most common sound system setups that I have encountered in the field. It skips steps and makes assumptions, so use it at your own risk. There is a lot more to do to be thorough, but I wanted to demonstrate that even a small amount of time can be put to good use.

Bob McCarthy: Where do I place my delay towers?

By Nathan Lively

sound-design-live-bob-mccarthy-delay-towers-roskilde-featured

Subscribe on iTunes, SoundCloud, Google Play or Stitcher.

Support Sound Design Live on Patreon.

In this episode of Sound Design Live I talk with the director of system optimization at Meyer Sound and the author of Sound Systems: Design and Optimization, Bob McCarthy, about how to decide where to place your delay towers and how many boxes they should have.

Notes

  1. Movie: WW1 doc They Shall Not Grow Old
  2. Roskilde Festival
  3. Sub arrays: End-fire, Gradient inverted stack
  4. MAPP XT
  5. Design files for Jockey Plaza
  6. Do I have enough boxes in my delay towers?
    1. Compare the ratio of boxes in your Main array vs your Delay array to the ratio of distances they are covering.
  7. Quotes
    1. One of the big lessons of this experience was how important it was to not just extend 100Hz and above, but to extend the whole show. If you want it to stay impactful, you have to bring it down to 30Hz.
    2. If you’re in an outdoor environment, I prefer over covered to under covered.
Trump Wall at the Roskilde Festival

Audio Calculators for Sound System Tuning

By Nathan Lively

sound-design-live-audio-calculators-system-tuning-merlijn-van-veen-featured-image

[Originally publish by Merlijn van Veen here.]

Subscribe on iTunes, SoundCloud, Google Play or Stitcher.

Support Sound Design Live on Patreon.

In this episode of the Sound Design Live podcast I talk to Bob McCarthy, Mauricio Ramirez, Merlijn Van Veen and Daniel Lundberg about the best audio calculators for sound system design and optimization in the categories of desert island, design work, field work, and education.

Download the Audio Calculators Toolbox

Show notes:

  1. All music in this episode by DJ More SA.
  2. Bob McCarthy is currently head of the System Design and Optimization department at Meyer Sound.
  3. Mauricio Ramirez is currently senior seminar instructor at Meyer Sound.
  4. Merlijn Van Veen is an independent seminar instructor, designer, and tech.
  5. Daniel Lundberg is currently Head of Sound with the national tour of American in Paris.
  6. TSDCA: Theatrical Sound Designers and Composers Association

 

This Is Why You Are Over EQing

By Nathan Lively

this-is-why-you-are-over-eqing-merlijn-van-veen-featured

Subscribe on iTunes, SoundCloud, Google Play or Stitcher.

Support Sound Design Live on Patreon.

In this episode of Sound Design Live, I speak with sound consultant and educator Merlijn van Veen while attending his Calibration and Design Techniques for Modern Sound Systems workshop at the Banff Centre for the Arts in Canada. We talk about the way that audio analyzers used in sound system tuning can easily be abused for micromanagement and over EQing, my learnings from the workshop, and your questions on line array vs point source. I ask:

  • What manly songs can I play at soundcheck to make sure everyone knows what a big deal I am?
  • What’s one of the best decisions you made to get more of the work that you really love?
  • What is one concept or idea you wish everyone understood better before attending your workshops?
  • What is the main benefit or transformation you’ve observed for your students?
  • What are some of the biggest mistakes you see people make when they are new to sound system optimization?
  • Describe a loudspeaker crime scene investigation, and how can we try it at home.
  • True or false:
    • A doubling of distance results in a halving of sound pressure level.
    • A doubling of distance results in a 6 dB reduction in SPL.
    • A doubling of distance sounds twice as quiet.
  • What’s in your work bag?
  • Ajax or PSV?
  • Why is the stereo image so much better with point source systems comparing to line array systems?
  • Why are so many people using line array system, when single source system is better, cheaper, and easier to set up?

sound-design-live-touring-foh-sound-engineer-job-Merlijn_van_VeenThe modern line array speaker is 25 years old. It’s been around just as long as the point source, maybe even longer. It’s just another tool. Don’t obsess about it.

Notes

  1. All music in this episode by Young Link.
  2. Check Merlijn’s FB page for the most up-to-date information on seminars.
  3. My first interview with Merlijn – Understandable Misunderstandings
  4. Merlijn’s calculators, including Subwoofer Array Designer.
  5. Crime scene investigation:
    • Measure On-axis
    • Move off-axis (while keeping the delay locator unchanged so that you are equidistant) until you observe 6 dB of angular attenuation.
  6. Merlijn’s box of toys: Genelec Acoustic Tape, iSEMcon EMX7150, piston calibrator, protractor, laser range finder, Ampro humidistat hydrometer, transformer-based DI to handle up to 200V.
  7. The popularity of line array loudspeakers: less real estate, better range ratio.
  8. Quotes
    1. The FOH position is self-calibrating. If you don’t like what you hear, your brain will instruct your hands to start pushing buttons until you like what you hear. But there’s no guarantee that what you perceive in that square foot is the same art that the rest of the audience is perceiving.
    2. As much as I like to do art, ultimately, it’s a physics class.
    3. Luck is what happens when preparation meets opportunity. -Seneca
    4. Acknowledging that there is room for improvement is half the battle.
    5. You have this X-ray photo of your sound system, and it’s very tempting to start addressing every minor deviation. I did this in the beginning. It sets the table for micromanagement.
    6. Every new technological development, by definition, in the beginning, is used too often and in the wrong way. -George Lucas.
    7. If what we hear does not correlate with what we measure, we lose confidence in the measurement platform. And then most people will rely on their ears. But if you can connect the two, then you gain confidence in the things you are doing and you will feel more secure in approaching a new situation.
    8. The modern line array speaker is 25 years old. It’s been around just as long as the point source, maybe even longer. It’s just another tool. Don’t obsess about it.
    9. What I like about point source [speakers] is that afterward, I suffer less from listening fatigue.

sound-design-live-podcast-episode-98-this-is-why-you-are-over-eqing-merlijn-van-veen-crime-scene-1

sound-design-live-podcast-episode-98-this-is-why-you-are-over-eqing-merlijn-van-veen-crime-scene-2

sound-design-live-podcast-episode-98-this-is-why-you-are-over-eqing-merlijn-van-veen-main-sub-alignment

sound-design-live-podcast-episode-98-this-is-why-you-are-over-eqing-merlijn-van-veen-nathan-lively

 

Mauricio Ramirez: Trust your ears, not just the audio analyzer

By Nathan Lively

mauricio-ramirez-trust-ears-not-audio-analyzer-featured

Subscribe on iTunes, SoundCloud, Google Play or Stitcher.

Support Sound Design Live on Patreon.

In this episode of the Sound Design Live podcast I talk to Mauricio Ramirez, senior seminar instructor at Meyer Sound. We discuss some of the biggest mistakes he sees made by people who are new to sound system tuning. We also cover:

  • Most popular test tracks.
  • Which country has the most audio engineers who smoke?
  • How did you get your first job in audio?
  • What is the best choice you made to get more of the work that you love? (Hint: It rhymes with dedication.)
  • Why parents shouldn’t teach their kids that they are special and why it’s good to be normal.

mauricio-ramirez-trust-ears-not-audio-analyzer-headshotPeople want to see a beautiful graphic, but what people forget is that we are working with sound. We are not video guys or lighting guys. We are sound guys.

Show notes:

  1. All music in this episode by jACE the Caveat.
  2. Books: Don Davis Audio Encyclopedia, Yamaha Sound Reinforcement Handbook, Modern Recording Techniques
  3. Software: Smaart, SATlive, Systune
  4. The most common sound system tuning mistakes you might be making:
    1. You have an older, cracked version of Smaart without all of the latest features. Buy a license and update.
    2. You are using smoothing. Turn it off (use 1/48 or 1/24 octave smoothing).
    3. You are trying to equalize comb filtering. Move the microphone 1m away. Don’t make decisions based on a single microphone position.
    4. You don’t have enough practice. Watch Jiro Dreams of Sushi.
    5. You trust what you see on the graphic more than what you hear. Trust your ears.
  5. Jiro Dreams of Sushi: “Nowadays, parents tell their children, ‘You can return if it doesn’t work out.’ When parents say stupid things like that, the kids turn out to be failures.”
  6. Wrecking Crew
  7.  Quotes
    1. The big problem is that people smooth the graphic of the analyzer to ⅓. That is the biggest mistake. Smooth is easier to read, but what you are reading is a lie!
    2. Only correct what is common to all measurements.
    3. You need to compare the graphic of the analyzer with something that will be played during the concert. Some people only test the sound system with pink noise and then the graphic looks beautiful and they say, “It’s ready!”
    4. Start to learn what part of the information you can see that you can trust and what part you can see that you can not trust.
    5. Concerts in an anechoic chamber would be horrible because our ears are expecting reflections.
    6. Forget about what you see on the screen. We are sound guys, not video guys.
    7. If you are special, maybe only only special people will enjoy your mixing. But if you are an average guy, 90% of the population will enjoy it.
    8. It’s not important that you are working for famous artists. If people are calling you, you’re doing your job correctly.
    9. I normally prepare two snapshots. One before and one after the EQ. Then play music or speech and change the snapshots. Most people prefer the sound without the filters. So do I.
    10. Listen first. If your brain tells you it’s good, don’t do anything.
    11. If your delay error is less than 20ms, you might not hear an echo, but you’ll have comb filtering.

mauricio-ramirez-trust-ears-not-audio-analyzer-seminar

mauricio-ramirez-trust-ears-not-audio-analyzer-band

Ramirez’s band, Opción Cero, 1997

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