Rilands,
Sounds like the typical thump when using a subwoofer amplifier that has an auto-on circuit. When the amp senses a signal, it turns the amp on. I've heard this thump in many setups that have an amp that uses an auto-on circuit.
I would guess that the built-in amp in your NHTs has an auto-on circuit and you are hearing the amp turn on and "thump" the woofer.
TIC
Sounds like the typical thump when using a subwoofer amplifier that has an auto-on circuit. When the amp senses a signal, it turns the amp on. I've heard this thump in many setups that have an amp that uses an auto-on circuit.
I would guess that the built-in amp in your NHTs has an auto-on circuit and you are hearing the amp turn on and "thump" the woofer.
TIC