Not sure the bass is better with the M7. It is less abundant with the r2r 7, that for sure. I think you can say that the bass of the r2r 7 is fast however. It's the only point for which there is a contest between the two dacs. Otherwise, the r2r 7 is a clear winner. I had a lack of slam with the r2r 7 lately. I decided to upgrade some hook-up wire inside my amps (gauge 18 to gauge 16) and when i reinstalled the amps, it seems i might have had an inverted polarity on the right speaker for a while, seeing the way the speaker wires were bent. So i don't know if the problem was with the tiny hook-up wire or the partial polarity inversion, but things are fine now and as a bonus, the top end is now silky smooth whatever the recording i play. And i think the sound is a bit more laid back, not sure yet. But things are great really. I can only give the r2r 7 my very best recommendation.