rocket 88

Short answer: "No. There won't be an audibile difference"  Premium cables have gotten quite expensive and you have a chance to buy a pair of 10' factory-terminated Rocket 88's at the right price, you should go for it.

fyi- I upgraded the internal cabling of my speakers with Rocket 88 year ago.  It was well worth the time, and money.  Also, I have decades of experience with Audiopquest (semi-retired, but still a dealer on the books) and have been a fan of DBS since it's introduction.  I'm sure there are situations where the DBS difference isn't perceptable.  I just haven't come across one, yet.

@guitarlenn55

"Bi-wiring" the 802s:

There is much debate on this subject. Justifiably so.

I think it can be argued that "all things being equal" there may be little benefit to "bi-wiring." But, given the fact that the 802’s (as are many premium speakers) are factory configured for bi-wire. So, the options are: bi-wire or not bi-wire?

If you run full range cables to a speaker set for bi-wire, you have 2 cables running to a speaker with 4 input terminals. This requires a jumper, of some kind to "feed" all 4 terminals. This can be accomplished via a factory-supplied "jumper bar" to get the job done. Not the best material, or geometry for best SQ. Or, you get high quality jumpers (from AQ, or others) to do the job. Better, but there’s still an extra set of connection points and cabling, in the signal path.

SBW (single bi-wire) is a neat, simple solution for bi-wiring. One cable, one jacket, split out into 4 leads at the speaker end. However, this does take part of the cable’s total AWG and divide it between "lows" and "highs" with debatable (by some) SQ benefits. This is your current configuration, it appears. DBW (double bi-wire) uses dedicated cables for "lows" and "highs" meaning, of course, that 100% of the cable is used for each, with no compromises in the AWG to feed signal to each. So, essentially, you’re doubling the gauge of your speakers, which is a good thing.

Given the fact that the 802’s are factory configured for bi-wire, running an additional set of Rocket 88’s is a no-brainer, in my view. Especially, if the price of admission is at a reasonable price.

thankyou for all your input.

I change one thing a time over a few days so I digest and see if I can hear a difference. There's no doubt, not placebo, that cables do matter! Power matters 

also.

I once used some speakers, one a couple feet from the amp and the other was 8 feet away.  From bulk cable, I cut a 5 foot length to wire the closest one, and a longer one for the other [to keep excess wire from the floor].  Didn't seem to bother the sound to me, but when my pal [who thinks a lot] said it would bother him to have things set up that way, it started in on my head, too. A few days later, I changed out the shorter one for an equal length one.  Didn't seem to make a difference, but mentally I felt much better. 

Most (if not all) professional audiophile equipment reviewers do not believe bi-wiring amounts to anything.  If you hunt around the web, you'll find a few fair & objective A/B shoot-outs or comparisons out there where some folks have tested single vs. bi-wire to evaluate the difference(s).  The results are largely inconclusive and, essentially, in the ears of the beholders.  It's like the age-old debates of whether $5,000 speaker cables are better than $500 cables; super expensive connecters are better than less expensive ones; digital sound is better than vinyl; etc., etc. etc.  The standing joke is that "bi-wiring" is just another ploy for "buy wiring".

I had a pair of Paradigm Monitor 9 (original versions) single-wired with 14-gauge Monster speaker cable and then bi-wired them with some 12-gauge AudioQuest Type 4, similar in construction to Rocket 88.  Sound was noticeably improved with the AudioQuest.  However, I believe this was a function of thicker gauge wire; not bi-wiring.

If I were you, I'd hunt around for a shop that would loan me a pair of 12' Rocket 88 with the dbs (or some other suitable length) and try bi-wiring for yourself before spending that kind of cash.  Personally, I'm inclined to agree with those who believe this dbs thing is a marketing ploy.  All of the reading and research I've done on this from impartial sources points in that direction.

With respect to the lengths of wire involved, I would keep the lengths identical.  I'm not sure you'd hear a dramatic difference, comparatively speaking, in phase response by using different lengths.  However, this is a theoretical possibility.  Try it.  See/hear what you think.