Tuning is the hardest part of stereo installation, in my opinion. I've always been one to use a DMM to get stuff within the right level, then use my ears to 'spot' out any distortion. Tone CDs are great for sub tuning, but when it comes to tuning your mids and highs, get familiar with a song that has alot of different instruments and/or tone ranges. I listen to alot of jazz, and there are several songs I am familiar with that I've listened to for years on my Sennheiser HD600s(HiFi headphones). These are the songs I use to tune stereos. When tuning, try to use an audio CD(not an MP3 CD) that has been burned with high quality files or preferably an original CD.