In the past I have had all tube systems cryoed tubes, all kit differentially balanced. zzwhen you get up into JC 2 territory, I think the differences are slight, but no tubes to worry over, or wait to warm up, or have to turn off...
It seems a lot of powered sub inputs have not taken output into proper consideration
Also Class D amplifier chipsets have advanced significantly, but I doubt many powered sub manufacturers are using newest tech
If i do it over I will get passive subs and power with outboard amp/s, or maybe a passive integrated