are all inline converters the same? I feel that they are the cause of the "hiss" sound I get in the system. I have tried adusting the gain many times along with the gain on my amp and its built in crossover, but no success. My wife's Bose system in her Mazda Miata sounds so much better. In fact after spending so much money on this stereo, I feel that it doesn't sound that much better thta the original system. Is the HU wired form the LOC to the aftermarket amp or must it first go into the Bose EQ above the HU?