Cables length ?

My speakers are at different distance form the amp, one is 14" and an other 4". Do I need to buy 28" cables (2 cable, each 14 ") or I can just buy 18" according to the distance of each speaker to the amp?
My understanding is that the length of the cables should be the same if possible. If not, the difference should be no greater than %10. If you must use a longer cable than needed on the closer speaker, wind the excess cable loosely.
I believe the cables should be the same. It is a timing issue. Also the length of the cables can slightly affect the sound itself, so you could end up where the two speakers sound different even in mono.
I have heard that it is not a timing issue, but an issue of impedance affecting the quality of the sound. The sound will not be the same due to different impedance in the two speakers. The timing is not really a factor because the signal travels through the cable at a significant factor of the speed of light, whereas it travels through the air (i.e. from the speaker to your ear)at the speed of sound. Thus, moving the speaker a few inches, or tilting your head, makes more of a timing difference than thousands of feet of cable. However, because impedance builds over length, the cables should be at least nearly equal for the two speakers to sound the same.
For all practical purposes, it would be best if your cables were appr. the same length. As mentioned above, impedance can play a part in this equation for sure. As such, "coiling" can increase inductance, so you best bet would be to loosely "snake" it back and forth if this is convenient. I don't know if "timing" (referred to as "velocity factor") is actually something to worry about at audio frequencies. While this can become quite critical in RF gear, i have never studied or checked into this with stereo equipment. As such, i'll see what i can find out and report back in a thread here. Sean
Timing is definitely not a problem, as Dbw1 notes. If you've got a really high-resistance cable, then impedance could be a factor. But if you've got a really high-resistance cable, you need to get a different cable.
One other reason to buy cables of equal length--resale value if you want to upgrade down the road. You won't find many buyers for different length cables--and if you do the price will probably be very low.
Do you mean inches (") or feet (')?? As Dbw and Jostler say, timing is not an issue. Try figuring out how long it would take a signal to travel 14 feet at say half the speed of light.

But the load seen by each side of your amplifier may differ if the lengths are too disparate. I'm not an engineer but I came away from a long explanation given to me at a show by a well known designer of very popular cables concluding that anything closer than 2:1 is probably ok, and 1.5:1 is definetely safe. So I wouldnt go with 14 ft and 4 ft. Id make the shorter one longer, say 10 feet at least. And then, if you're going to go that far, why not make them the same length so you can sell them if you need/want to. As Abstract says, unequal length cables are hard to sell.

There are several cable makers who say different lengths are fine. And one high volume dealer in Nordosts once told me that neither he nor any of his well-eared (and heeled) customers could tell the difference in sound between a one meter and a five meter length of Blue Heaven speaker cable paired with 5 meters on the other side.