Unequal length interconnects?

I recently acquired a second Monarchy SM-70 Pro, and with the power distribution in my room it made sense to move both amps out of my rack to under the speakers. I got upgraded power cords (Volex 17604s) and a pair of 4ft Speltz Anti-cables to my Von Schweikert VR-1s, both of which made an audible improvement.

The last piece of the puzzle is the interconnects from my Wright WLA12A to the Monarchys. In my current room the rack needs to be in the corner rather than between the speakers. The distance to the far amp is about 12 feet, with the near amp at about 4 feet. I had two 6 foot mid-level Calrad pairs (http://www.electroniccity.com/shopping/pricelist.asp?prid=498&brandinc=42)
so I split them up and used a decent quality F-to-F joiner to make a 12 footer. I tried it with 12 footers on both channels and with a 12 footer to the far amp and a 6 footer to the near one and could hear no difference.

My questions are:

1) Would there be a big improvement using one solid 12 footer versus using the joined 6 footers? Right now I have no way to test that, so I was looking for someone who may have tried it.

2) Is there any downside to using unequal length cables? If I get two 12 footers I'd have to do something with the excess on the near amp.

In either case, if I have to replace the Calrads I'd probably go with something like Signal Cables, which would probably be a step up anyway.

Thanks for your help.

Avoid the audio nervosa and go for same-length cables. Do not coil the excess, better to figure-eight it to avoid an inductive loop. Joining cables isn't necessarily a bad thing but I'd avoid another junction point if possible. BTW, those Calrads appear to be of decent quality. One of my favorite tube gurus uses Belden mic wire with excellent results, and he recommends the same for his customer's systems. I like Signal and Blue Jeans Cables, and LAT Int'l, too. Let us know how it works out for you.
if your preamp has low output impedance and your power amp has high input impedance (typical of SS gear) then cable length should make very little difference. The difference should be inaudible in the majority of cases. The only worry might be noise or ground loops....in which case a longer cable is more likely to be at a slight disadvantage compared to a relatively short one.

I have made 75' runs of line level succesfully in the past. Studios use long runs of line level cabling with few problems (although they tend to use XLR cables for better noise protection)
Unless you`re using balanced ICs, I wouldn`t use 2-6ft. RCAs to make 12ft. Since the signal is traveling @ roughly the speed of light, different length ICs are no problem. If you were running miles of cable, it MIGHT be a concern.
In theory you want them equal length but assuming a difference of say 10 feet, you will hear a time difference of 1/27000 of a second, not significant, however the difference in capacitance, impedance and inductance may filter the sound in the longer channel ever so slightlt.

Of bigger concern would be the joint, I would not worry too much about unequal lengths but I would use on continuous cable.

You could put the 12 footers on both, but the surplus could cause bigger problems than it solves as they will have to cross each other or snake around to take up the excess and this could cause worse problems.

Let your ears be your guide.

Today I ordered Analog Twos from Frank at Signal Cable. He was very helpful in helping me determine the right cable and his opinion is that using two different cables lengths won't be a problem, especially with the lower capacitance of the Analog Two.

I found one problem with my current Calrads - they don't really have any strain relief, and with all the switching and trying different lengths and combinations, one of the ends has become intermittent. Time for new cables anyway!

Thanks for everyone's help.

After having my wife's son sleeping in my listening room for two weeks, I was finally able to install my new Signal Cables today. Right out the box they're a big improvement over the Calrads - much less noise, and much better high frequency extension. Can't wait to hear what they sound like after some break-in.

After being able to A/B, it's clear that using the two 6 footers with the F-to-F joiner was introducing some noise in that channel, so Loontoon and Porziob, you were exactly right.

Thanks again for all your help.