I’ve read a bit about how adding a subwoofer to a 2 channel music system isn’t just about adding bass but taking the lower frequency work to the sub so the mains can shine.
I have a Cambridge CXA81 that has a mono sub out, but the crossover setting would be on the sub not filtered at the amp.
So is this actually taking the load off the mains, or just adding TO the mains? Or (newb ass question here) is the lower frequency going to the sub because that… how do i say… window is open now?
To properly implement a sub you need to roll off those frequencies (approximately 80hz and below) from your mains. If you do this, you are saving your mains from having to do the large excursions needed for those frequencies and allows them to produce a more accurate midrange. One way to do this is to put a filter consisting of a capacitor between the pre amp and amplifier. The cap value is calculated based on the input impedance of the amplifier. You can do this with separates as well as any integrated or receiver with a pre out/main in.