Horizontal or vertical amping to drive speakers/subs combo


I have two Luxman M900u amps and a set of Wilson Audio Alexia full range speakers and a set of Wilson Audio Watchdog passive subs. I am interested in hearing what people think about using one amp to drive the subs and the other to drive the Alexia speakers versus or using one amp to drive the left sub and left Alexia and the other amp to drive the right sub and right Alexia.

I listened to a video post by Paul where he prefers horizontal bi-amping. But in that video he seemed to be talking about bi-amping a single full range speaker (that offers bi-amp binding posts) rather than the best way to drive a set of full range speakers and a set of separate subs using two identical stereo amps. I’d be interested hearing peoples’ options, and Paul’s (if you have time Paul :slight_smile: ).

One benefit of a horizontal configuration is the subs’ demands on the sub amp has no impact on the main speakers. One benefit of a vertical configuration is it offers great left/right separation. In either case I don’t think the load on either amp will be that taxing (each amp offers 300w+300w into 4 Ohms and usually I don’t dip into that reserve too deeply).

Two other pieces of data are; Luxman suggested a horizontal configuration and if I go with a horizontal configuration I could plug the main speakers’ amp into a P15 I just bought last week and plug the sub amp directly into the wall as it might be too taxing to plug both amps into the P15 with all the other equipment too. I have eight 10 gauge dedicated 15 amp circuits wired for my stereo room - so the sub amp would have a decent circuit to plug into.

Just an FYI, I seem to lean towards a vertical configuration for the separation it provides, but that’s an uneducated opinion.

Any input is appreciated!


The Watchdog should have its own amplifier.

The current generation of the Watchdog is passive. The previous generation Watchdog had built in amp but I think they ended that generation about 10-15 years ago.

I know. When I said the Watchdog should have its own amplifier, I mean just that, it’s own amplifier in addition to itself.

Thanks. I will do that.