I was going through my menu on my head unit and one of the options to adjust is the sum. I checked my book and it just says its adjustable from 0 to 30 and nothing else. So I was wondering if any of you guys know what that is. Its a Rockford Fosgate MP3 player if that helps

Toney
'97 RS 5 Speed (totaled)
15.4606@88.42 Mph
96 Toyota Celica GT
88 Toyota Supra NA-T (w/ sports package)
Got Boost?? Hell yeah I-6 turbo powah baby!

SUM FLAT <80HZ> (Model 9210 only) — Means third pair of RCA pre-outs is full-range while
80Hz means that the pre-outs are crossed-over 80Hz low-pass for subwoofer use.

That's all I could find in the manual, I'll ask my boy and find out for sure since yours seems to have a different value setting.