So what's the verdict, are they different or not ?
What's (exactly) the same:
the drivers appear to be similar in looks.
the plastic headband is similar with the difference of no name on the Samson and the Superlux's has it's name on it.
the general construction is the same (AKG look alike)
the cable and plug are exactly the same.
the ear pads are the same.
the dust filter is the same.
What's different:
the color scheme.
the clamping force.
the openings in the driver chamber on the rear.
the shape of the headband holders.
the shape of the rods (Superlux is bent outwards at a point and not running in parallel till it reaches the other side again, the Samson has 2 bends so the rods run parallel)
the isolator material of the rods (thicker on HD681)
the clamping force.
the name plate (obviously)
the box it came in.
brand and type number.
Now how about the most important thing ... the sound.
Well they are definitely not the same.
There are no piercing highs and the mids are better.
The bass is there but not as looowwww as HD681
the upper treble is not very present.
So the drivers, though from the same manufacturer do not sound similar (as Claus already established
).
because the clamping force was a bit high I bent the rods a bit.
Now the clamping is nicer but the bass extension isn't as deep anymore.
having owned the HD668B from Superlux I can say (without the room for much doubt) that the drivers from the samson are sounding (almost ?) exactly like the HD668B when the clamping force is as low as the HD668B is.
The 'almost ?' is due to the fact that I can't do a direct comparison but only from memory.
I can still remember the same differences with the HD681 and HD668B as I am hearing now though.
So I think the Samson SR850 is slightly different in appearance and has similar drivers like the HD668B but in 32 Ohm version instead of 56Ohm for the HD668B.
This makes even more sense when you compare the price point of the Samson SR850 which is similar to the HD668B.
I did sell my HD668B as I did not think it was as lively and engaging as the (modded) HD681 and sounded more like the K701 (which sounds accurate but aty the same time a bit dull and liveless to me)
The Samson has the same sound signature as the HD668B which I found too be a bit lean on the bass compared to a HD681.
Compared to the K701 the SR850 has more bass IMO.
The SR850 doesn't need the HD681 filter mods and sounds quite pleasant right out of the box after a few hours already.
With the higher clamping force you get more bass then the HD668B and only slightly less then HD681.
Whether this is caused by the ear pads making a better seal or the drivers being closer to the ear I don't know.
The mids from the Samson and HD668B are clearly better/fuller/warmer then HD681.
This has been established before by Mike and Chaz too.
The highs in the upper region of the filtered HD681 are way better and more sparkly then SR850 and HD668B which seem to be somewhat pinched off at this point.
The highs are there but simply less sparkly as the modded HD681.
More like the
Sennheiser HD650 in level but less 'velevetty'.
The deep lows of HD681 are slightly better, Samson is a bit more realistic though but because of this less 'fun' too.
All in all the same conclusion (for me) as with the HD668B:
SR850 and HD668B better for vocal and neutral listening without any fatigue.
The (modded) HD681 is more fun, lively-er, more dynamic.
I think I will keep the SR850 for a while and see if it goes out the door after some time like the K701 and HD668B (and many others) did.