Damping factor is the standardized specification for amplifier output impedance

Evidence

Output impedance, also called internal impedance, is rarely specified but it sometimes appears as a standardized calculation called damping factor. Some manufacturers with highly recognizable brand names disclose neither specification. A low impedance or a high damping factor are desirable specifications. — Toole, Floyd E, Sound reproduction- the acoustics and…, 1151

Categorization

• DEFINE: Defines damping factor as the standardized way some manufacturers disclose output impedance.