Using Panasonic FC's in crossovers?

[Hybrid fourdoor]

Now I know everyone says ONLY USE bipolar capacitors in crossovers, but is this just for safe being? If you have a traditional amplifier with red being hot and black being ground (IE not BTL), can you use a "normal" capacitor like a Panasonic FC or whatever? Just as long as you pay attention to the polarity and don't hook it up wrong.

Seems like high rating (like 100uf) are hard to find in bipolar axial form.

[av_affected]

Hybrid,
You really don't want to use polarized electrolytic capacitors in a crossover. First, they're asymmetric and expect to have a DC bias. Despite what you might be led to believe by the red + and black - on the amplifier output terminals, there is no DC here (regardless of tube, transistor, bipolar, mosfet, single ended, push-pull, OTL, differential, or otherwise). You can wire two electrolytics "back to back" and have something that works but of course you need twice the value for each (the bonus is that you also get twice the voltage rating).

But more importantly, electrolytics sound like **** in a crossover. There's a reason people pay big bucks for poly and teflon caps in crossovers.

If you're looking for caps in the 100uF range, either you're doing a high-order design or a very low crossover frequency, like for subwoofer applications. Forget about passive crossovers for subs, you're much better off active.

[markp]

Originally posted by Hybrid fourdoor
Now I know everyone says ONLY USE bipolar capacitors in crossovers, but is this just for safe being? If you have a traditional amplifier with red being hot and black being ground (IE not BTL), can you use a "normal" capacitor like a Panasonic FC or whatever? Just as long as you pay attention to the polarity and don't hook it up wrong.

Seems like high rating (like 100uf) are hard to find in bipolar axial form.

Red does not mean only positive voltage in this case. The voltage out of the red terminal swings both ways relative to the black ground terminal making the cone move both in and out relative to its at rest position. That is why you need bipolar caps in a crossover, pos and neg voltages are present so there is no one polarity. You can use electrolytic bipolar caps but bypass them with a nice film cap of at least 10% of the value needed.