Does creating a loom in cables in a system make a significant difference?

I use a mix of different cables for interconnect, speaker and digital cables.  I have no complaints. The music sounds great!   I seize upon good values for superior cables from Audiogon and Audiomart US.  I'm setting up a system in another room  and I'm wondering if I should stick with one brand of cable throughout or just keep buying high quality cables regardless of brand.  I'd appreciate your thoughts.