What stands out about these is the sub-bass performance: there's more sub-bass than I know what to do with, I actually have to tone it down a good 4-6 dB and I still get plenty of satisfaction out of what's left.
By contrast with this and with the overly pronounced treble, the upper bass and all of the mids sound lost, pushed into the background somewhere. So overall if you care about fidelity there is no way to use these without EQ. (You will have better chances with the 662 or 662-Evo if you're still after a closed set.)
Dynamics/resolution seems on par with what I've heard from Superlux in the 668B and the 662-Evo, meaning excellent for the price.
Comfort is typical for Superlux - a disaster out of the box - with the clamping force too high (but you can adjust it by stretching them out) and the pads both too thin and too stiff. I have no idea what the other reviewers were talking about calling these good isolators but I found them to be anything but. The pads need to be far softer / more spongy to make good contact all around the ear and isolate well. The way I solved it was to get AKG K240 pleather pads and glue them on top of the stock pads, to achieve at the same time better depth and comfort and isolation (the AKG pads are also too thin to work well on their own).
Bottom line, if you have multiple Superlux options, get these only if you care a lot about sub-bass performance. Otherwise, if EQ is going to be a problem, maybe go for the 662-Evo, which is closer to neutral and also comes with velour pads.
By contrast with this and with the overly pronounced treble, the upper bass and all of the mids sound lost, pushed into the background somewhere. So overall if you care about fidelity there is no way to use these without EQ. (You will have better chances with the 662 or 662-Evo if you're still after a closed set.)
Dynamics/resolution seems on par with what I've heard from Superlux in the 668B and the 662-Evo, meaning excellent for the price.
Comfort is typical for Superlux - a disaster out of the box - with the clamping force too high (but you can adjust it by stretching them out) and the pads both too thin and too stiff. I have no idea what the other reviewers were talking about calling these good isolators but I found them to be anything but. The pads need to be far softer / more spongy to make good contact all around the ear and isolate well. The way I solved it was to get AKG K240 pleather pads and glue them on top of the stock pads, to achieve at the same time better depth and comfort and isolation (the AKG pads are also too thin to work well on their own).
Bottom line, if you have multiple Superlux options, get these only if you care a lot about sub-bass performance. Otherwise, if EQ is going to be a problem, maybe go for the 662-Evo, which is closer to neutral and also comes with velour pads.
As for coupling a good DAC with (sub)mediocre headphones, I guess I'll find out how far that can go when my Oppo HA-2 arrives. If the Oppo also turns out not to sound much better than integrated audio through the HD668Bs I'll consider updating this review.