Conclusion: This thing is small, powerfull, and very easy to take control of your speaker output. Very versitile amp that would clean up the sound on any system. Wide variety of crossover points and super easy to adjust. I power a set of jbl 608c and a gt5 in my 77 ford standard cab and it is so clear and loud that everyone has got to ask where its coming from.
Conclusion: The first one I received didn't have any output on all four channels. I sent it back and got another one and I am sure glad I did because this is a excellent amp for the sales price.I am using this amp to push a set of Focal 6.5'' components(70 RMS) and a set of Polk tweeters. The amp gives plenty of clean power to the components and tweeters.The sound quality is very good even with the 80db signal -to- noise ratio.
Conclusion: I have 3 of these up front and 2 of the matching 500s on subs. I've had to send a few back for exchanges for various quality control reasons (pass through on a couple...channels 3 and 4 on at least one). That has been a hassle, but Sonic is pretty good about returns. When you get one that works, it is great. The digital crossovers are sooooo much more convenient and precise than a dial. SQ is very good, especially compared to other full range class D's I've owned.
Conclusion: This amp replaced a Planet Audio amp that took up twice the footprint. Installation was simple and straight forward. The independent gain for input and output allowed for great flexibility. I'm using this amp without any of the crossover settings, just a straight pass through to 2 sets of Infinity Kappa component speakers. (Plus separate amp and 2 10" subs). My music has never sounded so alive. Everything is clean, clear, and extremely punchy and strong.
Conclusion: I have some issue with MS-A1004 amplifier. I used in a higher level audio system. And it makes whistling sound, even with the engine off, and even with radio off. I even unattached the input signal from it but the whistling still exist. And there is other thing that makes it even stranger for me. I have two other amplifiers in this system, which are working perfectly.