Hi Amirm,
I have just joined your forum after finding your previous tests of various equipment very useful, some of which I have purchased, so thanks for that.
I have joined the Massdrop drop for the SMSL SU-8 DAC (US$199), which I will use to feed a pair of Behringer 15" powered speakers that I bought cheaply second hand. I intend using this system for parties as the SU-8's remote and balanced outputs makes it perfect. My source will most likely be Spotify playlists on a Mac book pro.
The only real negative I can see in your test results above is your comment that in balanced mode ... "Distortion climbs unfortunately reducing SINAD to 86 dB. As you see in this IMD graph, this is due to the output stage saturating". A couple of questions:
Would actually hear this "distortion" in a party situation?
Would keeping the volume down on the SU-8's remote, while increasing the volume on the Behringers, minimise the effect?
Would the addition of a better power supply for the SU-8 help reduce the distortion and if so what would be the required voltage? Is the answer is "Yes" is there an inexpensive power supply you would recommend?
Many thanks in advance and keep up the good work - it is great to have an independent resource such as Audio Science Review.
Regards,
Ajax
There's no chance you'd hear any of that distortion in a party situation IMO, even maxing the balanced outputs from the SU-8 won't be an audible problem at all.
Keeping the volume at -6dB on SU-8 would minimise this effect slightly on peaks higher in level than -6dBfs (which are rare), but it's all academic - the effect just won't be audible in the first place.
I'm not sure about the power supply question. All I can say is that the speakers will be producing exponentially more distortion than the DAC at party levels, and there is no chance that even the worst case scenario 0.008% distortion at 0dBfs produced by the DAC will be anywhere near audibility thresholds.
To give some context, a top line pair of two-way PA speakers might produce around 1% distortion at 100dB, or 10%+ distortion when driven towards their maximum RMS levels, and those Behringers will be producing more distortion than that.
Even on a pair of excellent studio monitors in a properly-designed studio, it would be very unlikely the SU-8's level of distortion (at any volume) would be audible IMO. But this would be the only context where I might try to take steps to mitigate the issue.