Capacitor type question for the Speaker

[vadimgal]

Hi to all,
I have a question regarding type of caps which I can use for upgradinfg of my Kef Reference model two speakers. I looked at the crossover and saw only BI- Polar and NON-Polar capacitors has been used.
Could somebody tell me please what is the difference between them( Bi-Polar and NON-Polar caps) and could I use let say Mundorf Supreme caps. instead ( but nothing said what kind of type they are.), or I have to replace Bi-polar with Bi-Polar and NON-Polar with NON-Polar ones.
Tanks.
Vadimgal

 

[v-bro]

Bi polar is what they say on caps that look (constructively) the same as electrolytic caps, just to make sure if you have a collection of both types you don't mix them up. (because they have a completely different function)

Basically they do the same thing as non polar types.

Basically parallel placed caps (parallel to the driver...) can better be the cheaper bi polar ones, low loss results in higher loss (for as far as I know) when placed in parallel with the driver/signal...

Series placed caps better be good low loss quality and high voltage rating non polar foil caps. Quality starts at mylar (MKT) than MKC (don't know what plastic they use in there from my head...) than MKP (which is way better than what most commercial designs have already...

Than there are exotic ones....

PS bipolar can be raw or smooth foil, never use raw ones as they are generally too poor quality for any application in speaker filters....

 

[jhnmdahl]

Bipolar and non-polar mean the same thing, and all capacitors sold as speaker crossover capacitors will be non-polarized. Polar electrolytic or tantalum capacitors must be hooked up with one terminal positive and the other negative, and are really only used for things like power supply filtering and not for audio crossovers.

As for different types, bipolar electrolytics are a starting point, with metallized film such as metallized mylar/polyester being next, and meta film and foil capacitors being significantly larger and more expensive, but arguably better suited for crossovers. In practice, the differences are difficult if not impossible to discern, especially between film and foil or metallized film capacitors.

All foil in electrolytic capacitors is etched, and isn't "smooth", to increase the surface area of the electrode and the capacitance of the capacitor. Also, it doesn't matter a great deal whether the capacitor is in parallel or serial, as both are "in the signal path" and affect the audio signal, otherwise you'd just leave out any parallel capacitor.

Good luck,

John

 

[v-bro]

Bipolar and non-polar mean the same thing,
John

Just like I said...

Basically they do the same thing as non polar types.

Also, it doesn't matter a great deal whether the capacitor is in parallel or serial, as both are "in the signal path" and affect the audio signal, otherwise you'd just leave out any parallel capacitor.

It does matter, even when it technically matters little, it matters a lot in price. For instance when I want to lowpass a woofer it is not wise (even technically) to use a high quality cap. It can cause serious problems. I don't know what these problems are called in English, but in dutch it is called 'opslingeren'. A higher loss cap (with more parasitic properties) is simply better suited and costs only a fraction of even mylar caps...(which can become pretty expensive when you want to filter low, because of the high capacity that is needed).