Here's a five-channel Linkwitz-Riley active crossover designed to drive two high channels, two midrange channels, and one subwoofer. Usually audio circuits use high quality film capacitors that are bulky, but this uses SMD capacitors, mostly for the small size but also because they're much cheaper.One of the design goals of any analog audio circuit is a "star ground", which reduces any possible cross-talk between different parts of the circuit due to the impedance of various circuit traces. This round circuit lets me put all ground leads directly to the "axle" point, taking the star ground concept to the extreme!There's a lot of repetition in a circuit like this, so it lends itself nicely to sculptural assembly.Unfortunately, I build this with the crossover point to the subwoofer at 150Hz, about twice as high as it should be, so I've never used this circuit in an amplifier