20 foot long speaker cable: is it ok?


Hi guys I'm looking to move my speakers to the long wall of my room, the 14 foot one. In order to do this I'm going to need to acquire a 20 foot pair of speaker cables. I don't (can't) put my amp in the middle.

Based on my research it seems as long as the cable is well made, it shouldn't matter, at least 20 feet or under? I am worried that my sonics will suffer... 
d2girls
I have Blue Jean Cables (10 ga white) own a similar set up, except I ran mine in-wall one run is 45 feet long, one run is 22 feet long. I cannot move my amp to the middle due to my fireplace or anywhere other than it's current location, which has caused this install...They sound good with eh BJC cable but with the cable length there are issues.

I have Bryston Mini-T speakers and when connected directly to the amp (Anthem PVA-7) they sound incredible using a set of 15 foot Audioquest Rocket 88 cables. The clarity, they are sharp, crisp reproduction, the soundstage is incredible. However, with the Rocket88 cables the speaker placement is terrible, no stereo separation and right channel is much stronger due to having to relocate the left speaker to allow the cable to reach the back of the amp.
When I use the BJC 10 ga wire, there is a NOTICEABLE degradation in audio quality. I don't have all the audiophile verbs to describe the difference, but there are noticeable differences for the worse using this long of runs of speaker wire. 
If you never upgrade your speaker cables they will sound fine, but if you venture into higher grade cables you will notice the difference and want to find a way to replace the BJC cables...
I'm trying to find a way to buy a set of 22 foot long Rocket 88 cables, but without selling one of my kidneys, I just don't have $2,000 laying around for a set of speaker wires. 
14 gage copper wire is good for 15 amps. Sound will not change from one wire to another. Only be concerned with voltage drop from using too small of wire when drawing current through it.