Here's an article that a friend of mine once sent me that discussed the effects of using different gauge speaker cables. I found it interesting.
Also the effects of resistance within a wire are not constant across the full audible bandwidth. A long run of #24 cable will measure differently across the 20-20K spectrum than a short run of #12, and will react differently into speakers of different impedence. So it isn't just a matter of changing the volume when it comes to selecting the proper gauge. This is a case of cables making an audible difference, that's why I try to preface my comments with statements there is essentially no difference between "well-designed, or properly-chosen cables." You can always force a positive test by comparing against a measurably inferior cable.
This why my general rule is to buy #12, or at least #14, and not worry about the rest.
** Begin Article **
Shortly after, I stumbled upon an old magazine article which discusses
the audible differences between speaker cables ("Speaker Cables: Can
You Hear the Difference?"; Laurence Greenhill; Stereo Review, August
1983, pp.46-51). At the time, I simply ignored this article, convinced
to be on the safe side with my "telephone cables" and not being a
proponent of "listening by numbers" in the first place. But recent
postings on speaker cables in rec.audio.* led me to reread the
article, this time with greater interest.
In the article, three cables (11-gauge, 16-gauge and 24-gauge) were
put to controlled listening tests using an ABX comparator. All three
cables were 30 feet long and essentially showed the same one-wire-
per-conductor construction (the 11-gauge cable was a specialty speaker
cable; gauge extrapolated). The relevent listening tests can be
briefly summarized (In the ABX comparator system, "X" is either "A" or
"B" --- the "testee" has to predict which of "A" or "B" unknown "X" is
--- , the two results being equally probable. So remember that random
predictions, or guessing, are likely to be correct 50% of the time):
5. With pink noise, the 24-gauge cable was distinguished from either
of the two heavier cables almost 100% of the time, i.e. well
above the psychoacoustically significant point (75%). Unanimous
comment from the listeners: audible decrease in sound level.
In fact, 1/3 of the amplifier output power was not reaching the
speaker, for it was dissipating in the cable (insertion loss).
6. With choral music, sonic differences between the 24-gauge and
11-gauge cables were identified correctly 69% of the time, i.e.
to statistical significance (3 listeners out of 11 did it to
7. With pink noise, the panel distinguished the 11-gauge from the
16-gauge cable 65% of the time, with 3 panelists scoring over
75% (the internal dissipation was about 4% larger in the 16-
8. With choral music, the listening panel as a whole was essentially
guessing (49%) when asked to differentiate the 11-gauge cable
from the 16-gauge cable (3 listeners out of 11 scored above 66%
but below psychoacoustical significance).
NOTE: The above tests were done with levels UNmatched.
The author of the article opined that wide-dynamic-range musical
material decreases the ability of listeners to distinguish small sonic
differences between cables. He also mentioned that, besides producing
sound level differences, the high resistance (impedance?) present in
thin cables like the 24-gauge can interact with the speaker's
impedance, affecting audibly the speaker's frequency response. Indeed,
in a matched-level test of 24-gauge vs. 11-gauge with pink noise, 4
listeners out of 11 still heard differences in at least 75% of their
trials (unfortunately, a similar listening test wasn't performed in
the 16-gauge-vs.-11-gauge comparison).
With shorter cable runs in test #8., the overall cable impedances
would have been lower and the tester would have found a (critical)
length below which the "testees" can no longer perceive (to either
psychoacoustical or statistical significance) audible differences
between the 16-gauge and 11-gauge cables for that particular amp-
speaker setup. For the same 30' cable runs in test #8., the use of
14-gauge zip cord instead of 16-gauge would have resulted in less
impedance differences and in more (if not mere) guessing from the most
reliable listeners. 14-gauge zip cord was used against costly biwired
cables in recent controlled listening tests that ended in a draw
("Wired Wisdom: The Great Chicago Cable Caper"; Tom Nousaine; Sound
and Vision, Vol. 11, No. 3, 1995, pp.73-76; Errata: Vol. 11, No. 4,