Best cable to use with meridian 508.24?

Try Acoustic Zen Silver Reference or Harmonic Technology Prosilway II or III. Either cable works well. I'm sure they're many others. Everyone has their favorite. But synergy is the key and I know from experience these work well with your equipment.

Meridian uses Van Den Hul cables. I really like the JPS Superconductor interconnect. It lists for about 300. It sounds very natural.

I use Harmonic Technology Prosilway II XLR balanced ICs with my 508.24 into a Krell KCT with excellent results. Very evenly balanced overall with great air and superb dynamics and tight, extended bass.