Whilst increasing the gauge of the wire invariably changes the sound in some way the original post talks about Improving Sound Quality...
Increasing speaker cable size (for example w/AQ the cable sizes move up in size from 15AWG to 10AWG) improve sound quality?
For me - improving sound quality encompases
- eliminating tonal colourations - i.e getting to a natural sound
- increasing the gauge will CHANGE the colouration, but will not reduce them
- this is because the surface area of the insulation that comes into contact with the metal of the wire increases.
- The Dielectric Constant of the insulation needs to be as low as possible in order to reduce coloration
- faster dynamics - i.e. crisper percussion instruments
- this can be achieve by improving the metal of the wire
- e.g. OCC copper instead of OFC wire
- OCC solid silver wire provides the fastest dynamics at present
- this can be achieve by improving the metal of the wire
- improving clarity and details - and as a result, improving image
- this can be achieved by using a better cable geometry, which reduces the noise actually generated within the cable between conductors
- using solid wire as opposed to stranded wire - improves clarity and dynamics
NOTE: changing one of the above will improve sound quality a little, but the more things you change the better the sound quality
If you want to read more on this topic take a look at this thread
What I have found makes a good cable
And if you really want to get into the nitty gritty of DIY cables take a look at
Duelund conversion to diy helix geometry cabling
Regards - Steve