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How to Set EQ with iPhone Sound Frequency Analyzer

Kade Young
Kade Young
Chief Audio Guru

When you get EQ right, the end result is amazing. You no longer have problems with feedback and you can run your sound at a higher volume without irritating people's ears.

Actually, when someone says that the sound is too loud, it is generally just one part of the frequency spectrum that is too loud, not the overall sound.

By using the following tools, you will be able to analyze sound, find bothersome frequencies, and cut them so they fit with the rest of the sound spectrum.

Note: If you are using the X32, follow this post instead.

Step 1: Download Octave RTA for iPhone.

You will be so glad that you spent $5 on this app. It will save you hours of headache and help you reach your goal of the best sound possible.

Keep in mind, there are other software and hardware solutions for RTA sound frequency analyzers, but at $300+ the cost is significantly more. On the plus side, they are more accurate than the iPhone app, but with a little tweaking, the iPhone app will work just fine.


or search 'Octave RTA' in the app store.

Step 2: Check the settings.

Open up the Octave RTA app. On the bottom of the screen, use the following settings:

  • Octave: 1/3
  • FFT Size: 8192
  • Average: Medium
  • Graph: Line
  • Peaks: Auto

Step 3: Determine your baseline measurement.

Before you start analyzing the sound at your church, I recommend going to another church or venue where you like the overall sound. Then, pull out your iPhone and analyze the sound. This will give you an idea of what you need work towards.

In my opinion, Church on the Move in Tulsa has the best sound of any venue I have ever been in. So, I went to one of their events, pulled out my iPhone during worship and examined what was going on. I also took a few screen shots to help me remember (see below).

COTM Frequency Chart

The two screen shots were taken during two different songs. The main thing to notice is where the higher frequencies begin to fall of, which would explain why their sound is so warm and powerful, but still plenty of clarity.

Step 4: Using pink noise, find the room's troublesome frequencies.

Every room has its problems, some more than others.

In our current venue, there are lots of problems. The room is long and narrow, we have concrete floors, plastic chairs and hardly any sound absorbing surfaces. We have since installed a significant amount of sound absorbing panels, which helped tremendously, but a good amount of EQ is still necessary to achieve a good sound.

I could tell you the frequencies we have to cut in our room, but it wouldn't help you as every room is different. So you will need to run a test for your room using the following steps.

  1. Use something other than your iPhone to play pink noise through your sound system. Play it loud enough to fill the room with sound.
  2. Open the Octave iPhone app and analyze the sound from the middle of the room while pink noise is playing.
  3. The peaks show you what frequencies are sticking out above the rest. Tip: you can hold your thumb down to highlight specific frequencies.
  4. Now, use EQ to cut these frequencies. Continue adjusting EQ until you have successfully cut all those that are sticking out.

Keep in mind, the goal is not to get every frequency the same level. You are only looking for those that stick way out from those around it.

Also, there should be a gradual drop off after about 800Hz. Refer back to step 3 for a reference on what you are trying to achieve.

Step 5: Bring in the band and make necessary adjustments.

After EQing with pink noise, you will have a great starting point. But, once you bring in the band, you may find that you have cut too much somewhere, leaving a hole in the sound.

So, pull out your iPhone and analyze the sound as the band plays and fine tune as necessary.

It took me about 3 weeks to get the sound I wanted, but it was well worth the effort. Now, we can run the vocals where they need to be without fear of feedback. And, our sound is full of energy, fills the room, but no longer hurts your ears.

One Final Tip

The biggest tip I can give you when it comes to EQ is to cut frequencies, not boost them. When you cut out frequencies you don't want, it allows the right frequencies to shine.

There are cases where you will boost frequencies (i.e. getting more 'thunder' out of the floor tom), but make this should be the exception rather than the rule.

You might also be interested in: The Most Important EQ Techniques for Church Sound


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25 comments on “How to Set EQ with iPhone Sound Frequency Analyzer”

  1. When you talk about adjusting the EQ, are you talking about the EQ on individual channels on the sound board, or the overall room EQ? Or both?

    1. Hey Barry. In this post, I am talking about setting the overall room EQ to give you a good foundation for everything else. In other words, 'tuning the room'.

    2. OK, so that's a one time thing, not an every week thing?

      Once you fix "the room", you shouldn't have to check this each week?

    3. Tuning the room is a one time thing, yes. But I often find myself bringing out the frequency analyzer app during rehears to help diagnose problem areas. For example, I will have the vocal sing by themselves so I can find what part of the voice is not working well with the room. Then, use EQ to fix the problem.

    4. Why iPhone?
      I don't understand why the manufacturers design everything to work with apple products and then MAYBE later add Android or windows apps?
      I personally don't like apple products!
      And not everyone can afford iPhones and or iPads.
      The manufacturers need to take this into consideration when installing/programing. software

    5. Hey Donnie - They have the same kind of app for Android devices as well. I just don't use Android and therefor don't have one to recommend.

  2. Hey Kade!

    Great resources here! I was wondering if you could help me with the new version of this app. There's no gear anymore, but all the settings are on the bottom. It gives an "octave" option with 1/3, 1/6, and full as the options, an FFT size, at 2048, 4096, 8192, and 16384. I believe I have the other right options set. Average is set to medium as opposed to slow, infinite, and fast and I have my graph set to bars instead of line, and my peaks are set on hold as opposed to off and auto. Also, I guess I just need to know what frequency range instruments and vocals need to be between so I can cut the necessary frequencies on that specific channel. Thanks for any help you can give!

    1. Hey Jonathan. For the 'octave', I'd use the 1/6 option so you can really dial in the frequency that is sticking out above the rest. I am unsure on the FFT size...this is a new feature that I have never heard of.

      There really is no specific 'range' you are looking for. This app should simply be used to help your ear learn how to diagnose frequencies that stick out above the rest. So, when you know something doesn't sound quite right, pull out this app and find where the peaking frequencies are and use that as a starting point for setting your EQ.

      Of course, your ear trumps and digital tool you can use. This is just a tool that will help you diagnose faster, but in the end, trust your ear.

  3. To follow up on that question that Barry asked a couple of years ago, do digital boards have an EQ for the main outs or something? I am working with an analog board and can only adjust channel EQ. If I find troublesome frequencies, is it a matter of finding out what instruments/vocals may be in that frequency and trying to work with the individual channels? Feel like I am missing something obvious here.

    1. Hey Dan - thanks for the comment. Yes, digital boards have EQ for the main output, which is where the 'overall EQ' can be dialed in. On an analog mixer, you'll need an external graphic equalizer connected to your Main Out's 'Insert' to control EQ for the main mix.

      Although this post is geared towards the X32, it should help you further understand how to EQ the main mix:

  4. This app is currently listed as not operating in iOS 11. It has not been updated in 5yrs. Can you confirm that we can still operate this app? Can you recommend an alternative which is being actively updated?

  5. The App Store says it will not work with iOS 11.
    So, sounds like a great idea, but...,,
    Now what?

    1. Hey Paul - I didn't realize that version of the app didn't work with iOS 11. Here is a link to the updated version. (The link has also been updated within the post.)

  6. I have Octave on my I phone. ( 7plus) it says the developer need to update it to work with iso11. has this been done yet. no sense paying for a app that don't work


    1. Hey John - there is now a new, updated version of the app called Octave RTA (the previous version was Octave - RTA app for iPhone). The icon is blue with white bars.

  7. Good tips.
    Re: Step 5, why not use a commercial CD (not compressed MP3) with good quality songs instead of a live band? You’ll have a constant variable. I’ve read of touring pros having several songs they always play in fine tuning. Each for different reasons. Highs, lows, m/f vocals, drums, etc. Be sure the input channel EQ is flat.

    1. I haven't tried it on an iPad, but it should work. You can generally download iPhone apps on an iPad, they just don't fill the entire screen. Give it a shot and let us know what you find out!

    1. I am not familiar with this type of mic, Joel. But looks pretty cool! Didn't know it was available.

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