Corrective Room EQ

Monitor / Room Frequency Response Measurement

In some cases it absolutely makes sense to use an additional corrective room EQ even you have a well treated room from the audio perspective. A room EQ might be easier to set up than a very good acoustic treatment for your room but it also has it´s disadvantages.

How a room EQ works

A room EQ is set as the last peace in your output chain directly before the monitors. What the room EQ is than doing is to adjust the frequencies so that the result is an almost flat response. A corrective room EQ can not replace a good acoustic treatment in your room, but it should be seen as a additional supplement in some cases. To make it all possible you have to measure your room before to give the room EQ the proper information it needs to adjust the frequencies. For example it needs to know if you have any kind of standing waves in your room, the EQ can than disable by lowering the output for the specific frequency range.

So you need a measuring microphone and a software to measure the frequency response of your room. The software I use is “Sonarworks SoundID reference”. This is an all in one solution, depending on the package it also includes a measuring microphone. It also contains the measuring software as well as the final room EQ you can run as a standalone solution on your device but also as a VST Plugin within your DAW.


Sonarworks SoundID reference

If you want to check out Sonarworks SoundID reference software hit one of the following links depending on your location:

link for the USD offer

link for the EUR offer


Room Measuring

After you have installed the software you have to connect the microphone to your interface. Simply follow the instructions from the software for the proper setup for your system.

Is everything set up correctly the measurement can begin. The software will now send a click sound through your monitors which is caught by the microphone to locate the position of the microphone. Once the position is located the software runs a frequency sweep through the monitors. Now the microphone can measure the room response of the frequency sweep at a specific position. This progress will be repeated for about 30 locations in your room. This will bring enough data to the software to finally set up the room EQ.

Measuring Results

The picture above is the result of my latest room measurement. As you can see it is everything else than flat. As I have expected the is some trouble going on in the low end, as well as a build up in the top end. And even the mid range has it´s ups and downs.

This pictures shows you the calibration the EQ does with the data from the measurement to achieve an almost flat frequency resonse.

And this is the result of the measurement and the final room EQ. It´s almost completely flat from about 100 Hz up to the top. Everything below 80 Hz can´t be flat in my case because of the monitors. They can´t reproduce a solid low end and I´m not using an additional subwoofer. Something that isn´t there can´t be fixed with a room EQ.

Disadvantages from a room EQ

You have always to check back the room EQ. Because it can bring some problems in. For example phase problems. The more an EQ has to change frequencies, the more it can lead to phase cancellations.

The next thing is a small latency between the right and the left monitor for example. Sometimes there can be false information within the measurement process and when the room EQ tries to fix latency or delay problems, which hasn´t been a real problem before, can lead to problems with the stereo image and the perceived stereo center.

For example: to place a vocal directly into the middle between two speakers it´s necessary to reproduce the same signal at the same time on both speakers. When the room EQ tries to fix a delay problem, and delays a signal, even when it´s just a couple milliseconds, it will loose the perceived stereo center and it feels like the vocals appear more on the left and the right side.

Conclusion: Corrective Room EQ

All in all it really can help a lot and can make a huge difference in some circumstances. A room EQ can help to improve your monitor situation in your room and it can also identify some problems. But it also is very important to know your room and your monitors and to check back with reference tracks for example. When you have bad monitors in an untreated room, the room EQ can not hep you that much. The most important thing is the room treatment, the next important thing are the monitors itself and than afterwards you can bring the room EQ into the game.

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