The IC-M700's stock audio is optimized for voice intelligibility in a noisy engine room on a fishing trawler. It's punchy but lacks low-end "warmth." For amateur SSB operation, where you want a fuller, less fatiguing sound, the is essential.
for amateur radio or expanded use, the most comprehensive "paper" available is the Technical Write-up by Elliott Liggett (W6EL) This repository and its associated video guide