Simulate and Create Your Own EQ Settings for Headphones and IEMs

This is a quick guide for any one to get started with creating your own EQ targets and understand how to view headphones and in-ear monitor measurements. I'll go over the process 

Simulation Software

An easy way to mess around with Parametric Equalizer tweaking is to download Room EQ Wizard, and then hopefully find a raw measurement file for your IEM or headphone. I highly recommend joining the forum and getting the BETA software which is more up to date than the current release version, by 3 years at this point.

Measurement Data

Next, you can download real measurements of headphones and IEMs from various sources. Some are available on GitHub publicly to download, including my own from Audio Discourse:

I have all my files open sourced here: 

Jakko Pasanen has open source files here too: 
In this measurement repository, I recommend sticking with Oratory1990's.

To download from GitHub, you can download the entire folder or if you want to download a specific file, you need to go to the file page, and then right click on RAW and click Save-As.

Importing Data in Room EQ Wizard

Setting up House Curves for EQ target

When you start the application, you will want to set up your House Curve. This is the curve you want to use as a basis for EQing later. You can always change this, but it's nice to get it going right off the bat.
First go to the application Preferences. Then you can select House Curve and load a target curve. For example, in my repository, there is a Harman Target you could use, or my own "Antdroid Target."

Importing a downloaded measurement

Now that you have your house curve set up, you can start importing data! Click FILE, IMPORT, and then choose IMPORT FREQUENCY RESPONSE.

The measurement will now load on the display and will look like this. By default, it'll be in the SPL & Phase screen.

You can choose the All SPL tab if you have multiple measurements loaded and want to view them side by side. In this example, I loaded the Koss Porta Pro. There are a lot of settings in each tab in the CONTROLS button on the right, and I won't go over them here, but play around and check out the REW Online Manual/Wiki for more information!

Equalizer Simulation Tool

Once this is setup, and you have the IEM/Headphone graph loaded, you can click the EQ button and you can play with EQ filters and it'll simulate the frequency response of the measurement with eq applied. Its a nice tool and is pretty accurate. It helps me determine my EQ settings quickly.

First set up the EQ settings on the new window pop-up. For Equalizer, just choose Generic for now. For Target Type, use Full Range Speakers, as show in my photo above.

You can then click Calculate Target Reference level from response and it'll move the House Curve target to closely normalize/match to your headphone measurement.

From here you can click the EQ Filters button in the center top of the window and mess around with EQ Filter settings to your heart's content. One thing I prefer to do is to open up the settings icon on the top right, and change the smoothing to PSYCHOACOUSTIC. This provides an easier measurement to play with that smooths out something closer to what humans can hear.

This REW Tool also has an auto-eq feature to try its best to match the target curve. This can be done by opening the FILTER TASK panel on the right side, and showing the various batch tools. MATCH RESPONSE TO TARGET will quickly do its best to match the curve given the limitations you provide in the settings. Sometimes this also won't do anything. It's kind of hit or miss! 

For this Porta Pro example, nothing happened when I used my Antdroid Target, but I swapped it out to the Harman Target and was able to get an auto-EQ:

If you're happy with this, you can stop here for a second. Otherwise, you can play with the filters until you're happy. In this case, I made two additional filters to reduce the spike and the mid-bass:

In reality, I do not like using Q-values higher than like 2. This EQ profile has pretty high Q values up to 7.5 and 10.0. The higher the Q value the sharper the peak filter is. Just be aware that some PEQ software/hardware may not allow you to have high Q values or large gains. For example, my Lotoo PAW 6000 Digital Audio Player limits gains to +/- 12.0 and Q value to 1.0. 

Exporting Data

Now that you're happy with the EQ Filter settings, you can write down your results, or you can go back to the main REW menu, and export the filter to a text file using FILE -> Export -> Export Filter Setting as Text.

This text file can actually be loaded into various EQ programs including Equalizer APO. Some unique filters like Shelf filters with Q values may not load correctly however, so you may have to manually add those in.

Anyway, this was a quick look at learning how to simulate equalizer settings using Room EQ Wizard. Hope this helps and happy EQing!