ktraughb 10+ year member
CarAudio.com Elite
ive been using an eq with an 8 v line driver. i was never sure if it actually produced a measurable spl difference. well, my head unit has had noise issues ever since i bought it used (improper rca ground internal), so i decided to remove the eq to see if the problem would get better worrying that i was actually only creating more noise with the increase in signal. it did help to eliminate the noise a little bit. its not completely gone, even with the rcas grounded, however it also dropped my spl score. i basically tested this for reference to find out. single dd 3512 on a 2k rms amp. score with the eq/line driver was an even 143 sealed on the dash. score after removing and setting eq on head unit only, 141.5 sealed on the dash. (term lab tests) i couldnt repeat the 143 to save my life with all factors the same. heres the kicker---my ear meter actually thought that this was louder without the eq/line driver. i mean i thought there was a HUGE difference in my bass output without the eq/line driver. i guess thats why we use the term lab instead of the ear. just found this interesting, thought id post it up.