Testing Frequency Response (Using Room EQ Wizard)

[ghetto3jon]

i'm attempting to measure the frequency response of the preamp kits i built. i developed a method, and i'm wondering if it's at all accurate. here's what i'm doing...

i created 5 seconds of white noise with a piece of software, then i play that white noise through one of my preamps and record the result. i then open the free application called Room EQ Wizard, and import both versions of white noise as "impulse responses", and visually compare the two in the "spectrum" view.

i know the white noise goes through a direct box before it hits the preamp, and an additional DA/AD on the way as well...so it's not perfect.

can anyone share their DIY method of testing the frequency responses of their preamps? anyone else use Room EQ Wizard? i know it's typically used to analyze a room, but does anyone know if it's accurate in this application?