Anyone prefer horizontal bi-amping their monos?

You'll need two more amps.

Anyone prefer horizontal bi-amping their monos?

Yes! I have four true monoblock amps.

With bi-amplification both the Low frequency and high frequency portions of the system now have their respective amplifiers. That gives a reduction of intermodulation distortion. That said, active bi-amping horizontally, as I do, will give additional advantage from the elimination of lossy inductances in the low frequency portion of a conventional passive dividing network, and the result is significantly better amplifier damping factor, as seen by the low frequency driver. Active bi-amping is two notches above my passive crossover. See article below: Hope that helps Mike 😎

https://sound-au.com/biamp-vs-passive.htm

I use mono blocks for the high end and a stereo amp for the low end in my basement setup. Sounds great to me.😁

Horizontal bi-amping

@re-lar-kvothe thanks for sharing the diagram. Clears up any confusion.

"A picture is worth a thousand words".