Need 25 foot interconnects

Belden? what kind of cheap monoblocks do you have to use that crappy cable? if you're going to use interconnects at least get the best, OCC single Crystal copper far superior to anything ofc on the market.

How about keeping your existing cables, but get a couple of AudioQuest (or similar) RCA female/female connector and then get a couple more RCA interconnects at 10 feet or so.  Then join them all together and you’ve got 25 feet. This gives you the flexibility if you ever need shorter ones again you can just take that apart and keep the interconnects for another purpose.

I would recommend a good cable company. My minimum is DHLabs. I have tried Blue Jeans and Belkin and found them to be equivalent to the quality that you get in boxes with inexpensive and mid-fi products.

Spoke too soon about no hum.  It got really quiet in the house tonight and had a good listening session and left the earlier comment where I said "No hum. No noise."  When I stopped playing music and stood up, I heard a slight hum.  I got closer to the speakers and they just have a monotone hum coming out of them.  Going to need to troubleshoot the hum this week and figure out the cause.  Lots of things going on that are different -- also switched from low level subwoofer connection (interconnect) to high level coming off the speaker binding posts, so not sure if it's the 15' interconnect or the high level subwoofer connect that is causing the hum.  Maybe the hum is making the soundstage better.  ;-)

+1 @ghdprentice . In my den I have a pair of Kef R11 being driven by PS Audio M700 monoblocks.  I took a pair of Audio Quest Rocket 44 cables cut them in half and am biwireing. The bass has improved so much I have turned off the sub. Big improvement over 8ft runs. I would also use RCA and an adapter to another pair of equivalent RCA of 10ft. Try to keep them clear of other cables. If it sounds good then spend the coin for a better pair.