I currently have Buchardt S400s
Spinorama:
Dash line = Buchardt S400
Continuous line = Kef R3
Preference Score (if goes up to 10):
Kef R3:
Without EQ: Preference Score is 6.5 and would be 8.2 with a perfect subwoofer.
With EQ: Preference Score is 7.0 and would be 8.6 with a perfect subwoofer and the same EQ.
Buchardt S400:
Without EQ: Preference Score is 5.6 and would be 7.6 with a perfect subwoofer.
With EQ: Preference Score is 6.5 and would be 8.5 with a perfect subwoofer and the same EQ.
So if you EQ the S400's, and add the perfect sub, it will match EQ'd Kef R3's with a perfect sub.
Bass extension:
Kef R3: 35Hz at -6dB (winner)
Buchardt S400: 43Hz at -6dB
Distortion:
Seems R3 is a bit cleaner...but not by much.
Plus, they both have similar horizontal directivity....so not much difference there.
update: r3 has a smaller horizontal directivity than S400.
So overall, not a major upgrade, but still an upgrade to get the R3's.