I started out buying polypropylene components, film/foil for the little ones and metalized film for the larger ones. That's a no-brainer for me. A long time ago, I switched to using those types because I could hear the difference. Take a 10uF polypropylene and a 10uF electrolytic, and you'll notice it right away. But frankly, I tried some boutique parts and couldn't hear the difference between them.

Things have changed since then, some new companies have sprung up and others have gone away. Some have sprung up, gone away and come back again. So now I think it's time to look at this anew.

The list of components used in π Speakers is actually pretty small. I've always tried to make good designs that were both highly optimized and also highly modular. Those two approaches are sometimes at odds with each other, but not in this case. Most of my designs have certain similarities, and that has allowed me to optimize them while keeping many of the same components.

Most of the crossovers use one or more of these components:Capacitors: Inductors: Resistors:
0.47uF 0.5mH 16 ohms
8uF 0.6mH 20 ohms
10uF 1.0mH 30 ohms
22uF 5.5mH

The components used in the stock crossovers are pretty good. They have polypropylene capacitors, non-inductive resistors and air-core or low-hysterisis laminated core coils. But I'm going to try an assortment of some of the premium components, and if I find any that are truly spectacular, I will provide them as upgrade parts. The first batch is already on their way.