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Discussion Starter · #1 ·
https://i.imgur.com/C0qEka2.png

Pardon the incorrect graph limits, this is just the screenshot i have on hand, but any further screenshots will abide by forum guidelines.

I am attempting to EQ my car's response after a new stereo install. I put in a head unit, amplifier, front and rear speakers, and a subwoofer.

To measure, i did the following:
  • DL/install REW, plug in Dayton UMM-6 mic, load calibration file for mic
  • plugged phone into head unit aux, max volume on phone, raised volume on head unit till it was decently loud as per the graph posted. Played PINK NOISE through phone.
  • Opened RTA window in REW, hit Record button
  • move mic around multiple places in the 2 listening positions I was concerned about, saved each measurement in the RTA window
  • Took average of all measurements
  • applied 1/24 smoothing

According to wikipedia, pink noise that was generated actually is supposed to look exactly like my graph. One person said that I should be using WHITE NOISE instead if i want a flat graph. Another post I read in my search said something about REW plotting transfer functions, and that is why pink noise doesnt show up flat.

I just need someone to validate this, my methodology, and perhaps give me an alternative way to do this. I'm not trying to get a super accurate lab-grade result, i just want to have an extremely basic idea of where the peaks and dips are without having to do it by ear.

If I were to do it by ear, i'd basically play sweeps in which a guy keeps saying what frequency was just played as the sweep progresses, and then increase/decrease whatever EQ band I needed to based on that, but that is extremely tedious.
 

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Discussion Starter · #3 ·
computer has an audio output but it is of far more questionable quality than my phone. i could use a test cd or use a usb flash drive to generate the tone as well.

im trying to get my usb DAC working because that actually does have a nice output, and would probably let me use REW's internal signals.

fwiw i did try the white noise and the result was still weird looking. not as drastic of a drop, but still a pretty big 30db differential along the frequency range and with huge peaks and valleys that are conveniently located where my 5 band EQ cant really do anything about them anyways.
 

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Discussion Starter · #5 · (Edited)
IT WAS DEFINITELY IN SPECTRUM MODE. YOU ARE THE WINNER!

In any case, i did end up hooking up my usb dac line out to my head unit. Set the sweep level to -35db, set my head unit volume so that the mic was also registering the same sweep level, and took a measurement.

https://imgur.com/m61DiWN

as for sorting out the sound in my car, the biggest problem was having audible bass frequencies when the windows were down, so i did a bass boost of +3 (i dunno what that translates to, its not +3db, its like a level setting) and now it seems to be pretty much perfect, if a bit too warm with the windows up.

EDIT: for educational purposes, what is the difference? or is it in the manual? if so i can just look it up there.
 
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