Desktop speaker amp that cuts low frequencies with a sub connected?

Hello all,

Been using the SMSL AD18 for a few years now for speakers but I’m curious what’s out there that will cut the low frequencies to the speakers when a sub is connected, and is also a good size for a desk. I switch off between micca mb42x and rb42. What’s out there that checks these boxes?

this is very late as i just saw it. sprout100 auto crosses speakers@120hz if a subwoofer is connected.

if you want to use a passive subwoofer, there are many 2.1 amps with 50watts/channel stereo + 100 watt subwoofer amp. they all have built in lowpass for the sub, and most have bass and treble control as well.

alternatively you can add a passive highpass filter into your chain.