Ok so im going to start off by saying i was open minded when i was buying this unit really didnt know what to expect. It helps you set your gains on your amp so you dont have dirty signal, distortion which would lead to clipping your equipment(no bueno). The way i used to set my gains at first was by the 3/4 rule, then i went to the dmm setting guild, then i switched to the dd-1 my first impressions of this new toy would have to be very ridged the silicon boot feels like good quality. It doesnt come with a 9volt battery but thats not that big of a deal. My highs and mids alot clearer and louder.. also the subs sound alot deeper to my and my gf ears. i would never go back lol. The amps i have set so far with this unit are alpine kicker and planet audio will be a jl 1000/1 monday.
Also i dont have a head unit in my car so i had to rip the cd in itunes but you have to use the loss less format option when you import it or just use the cd if you have that option
Bottom line yes i would recommend for a friend and would purchase another
heres the web site i found it on ordered Friday was delivered Tuesday
West Coast Car Audio .: The Official SMD Product Webstore
if any one lives near las vegas and needs there gains set pm me and we can work something out