That's an excellent point, Neil, and one which certainly has merit. However, define "big"...? What's 'big' to you, may be small or insignificant for someone else (and no, I'm not talking about *THAT*, har, har
). It's an entirely subjective matter.
The other thing to consider is the
nature of the sonic improvement gained by upgrading cables, or anything else in a hi-fi system, and most importantly, how the listener perceives said improvement and how important that is to him or her, in terms of their enjoyment of listening to their favourite music. Upgrading speakers will always cause a 'bigger' change in the sound of a system than that effected by any cable, but only in the most 'obvious' hi-fi sense (deeper bass, crisper treble, wider soundstage, etc, etc).
However, judiciously upgrading cables,
in an already well-sorted system (that last part is important), can bring about subtle improvements in other areas (in terms of revealing nuances and details in recordings that increase the 'emotional connection' of the listener in the music he or she playing), which is difficult to achieve by other means. Therefore, to said listener, the improvements effected by a cable upgrade can sometimes be more fundamental/important and thus, to him or her, 'bigger' than the rather obvious (and expected) sonic improvements brought about by something like a speaker upgrade.
That's half the problem... Those who define a 'big' difference/improvement in audio as being that achieved through a component or system simply excelling more in what I would call 'prosaic hi-fi considerations', will never
GET what the right cables (and these needn't be hugely expensive) can do for the MUSICAL, as well as
sonic performance of a hi-fi system. The two are very different entities.
Quite simply, in order to truly 'get' what the right cables can do for a hi-fi system (note that I said 'right', rather than 'best', as there is no 'best'), one needs to dig deeper and listen beyond the 'immediately obvious'.
Marco.