I'm trying to identify which frequencies my next HU would have to be able to adjust, as my current 3 band PEQ doesn't let me adjust all problem areas. I did a quick RTA scan in my car with my phone (haven't bought a proper mic yet) and it seems to be a big spike at 7-8k and some smaller peaks at 135, 235 and 315 (not sure if these are problematic). There is also a wide dip at 350-800hz. Other than that, I'm having trouble recognizing any problem areas from these graphs, but when I'm listening to music there seems to be something in the 2k-5k area that is way too loud. Am I missing something or is it just that the microphone on the phone is too inaccurate to give me any useful info?