acquired a pair of ProAc Response D2 via an Audiogon member. Am thinking about bi-wire... I wanted to tap into the experience of this forum, even to hear whether you think bi-wiring is necessaryBi-wiring is absolutely not necessary. Whether it's beneficial or not is a separate question. You'll likely get differing opinions on that, so you'll have to decide for yourself.
I ran Response 2.5's both ways, and didn't notice any real difference. Just be sure to replace the metal jumper bars with some quality jumper leads. The same brand/model as the speaker wire is of course ideal.
All other things being equal, I think it's more cost-effective to put the $$ you would spend on two runs of wire towards a better grade of single run.
Of course, there are speakers that more or less demand bi-wiring; this isn't one of them.
This is a well-travelled off-repeating question dissected in AGON and just about every other audio forum.
Here is one on AGON worthy of prior research that is readily available in your journey
(1) It is always system dependent as best evidence ,
(2) Without prejudice of the above, an increasing number of major manufacturers are advocating a best-of-breed single run and jumpers array.
CHORD even stopped making dedicated bi-wires.
Some makes/models just use the same number of wires/strands inside the cable, and wire them differently. So with those, on the bi-wire model, half the number of strands is being used to transmit treble and half for the bass. I don't know whether this is the case with the Kimber, but the similarity in price certainly suggests it.