From an electrical standpoint, shorter is better, but keep in mind that many cable manufacturers voice their cables to sound best in the most common length, which is 1 meter.
Of course, if you have a particular model in mind, perhaps the dealer would be willing to let you audition two different lengths to determine which works best in your system.
Of course, if you have a particular model in mind, perhaps the dealer would be willing to let you audition two different lengths to determine which works best in your system.