On Tuesday, May 16, 2017 at 2:36:42 PM UTC-4, Ian Field wrote:

Depends what you paid for it - audiophools would go into shock at the
thought of NP electrolytics in speaker crossovers.

Anything decent will have some kind of metalised film caps - and you don't
necessarily have to pay audiophool prices to get it.

Audiophools go into shock easily. Keep in mind how delicate a proposition it must be to maintain their faith.

Many "decent" speakers have one/the-other/both inside. It is largely about real-estate and price-point as well as how critical the value might be. For critical and highly 'designed' applications, film caps are the only way to fly. For things that are less critical, an electrolytic might do just fine..

Maggie speakers are an example of where there are multiple choices. Many after-market 'upgrades' to their outboard crossovers use either/both, although it is my impression that most factory-originals were film.

Suffice it that any speaker cap must be able to operate in an AC environment, meaning NP for electrolytics. No more complicated than that at the most basic level.

Peter Wieck
Melrose Park, PA