Do individual crossover components have polarity?

[renton]

Hello all,

I am starting to piece together the crossovers for my NatP build and it struck me, do the individual crossover components have polarity? I could not see markings on anything, so does it matter which end of a cap hooks to say, another cap? If their is a polarity, how do you tell if it is not marked?

I searched around and could not find any information.

[Chris7]

With the exception of electrolytic capacitors (which you're probably not using), crossover components have no polarity. You can use them in either direction.

[Andy_G]

With the exception of electrolytic capacitors (which you're probably not using), crossover components have no polarity. You can use them in either direction.

Even electrolytics used in crossovers must be of the non polarised type. The signal we are dealing with is an Alternating signal, so all components must be non-directional.
The polarity of drivers is not to do with which way the signal runs, but to do with which way the cone moves in response to a signal.

Disclaimer: There may be circumstances where polar components are used in a passive x-o, but in 40 odd years, I have never seen one.

[cjd]

Disclaimer: There may be circumstances where polar components are used in a passive x-o, but in 40 odd years, I have never seen one.

Maybe in pairs...

[Chris7]

Even electrolytics used in crossovers must be of the non polarised type. The signal we are dealing with is an Alternating signal, so all components must be non-directional.
The polarity of drivers is not to do with which way the signal runs, but to do with which way the cone moves in response to a signal.

That's the whole reason people moan about electrolytics. Many commercial speakers that use electrolytics use polar types for cost reasons. They don't explode because the signal is not DC; they can handle temporary inversion.

[ThomasW]

Disclaimer: There may be circumstances where polar components are used in a passive x-o, but in 40 odd years, I have never seen one.

You need to get out more often.....

There are plenty of commerical and DIY crossovers that use polarized electrolytic caps. Look at cheap generic prebuild XO's for examples of this practice.

That said, IMO just say no to any kind of electrolytic cap in a crossover.

[TacoD]

That said, IMO just say no to any kind of electrolytic cap in a crossover.

I use bipolair for caps > 100 uF, with a MKP bypass. In a LCR network you sometimes need large values :T :roll:

[Davey]

Many non-polar electrolytics are actually two polarized capacitors connected back to back.

Polarized or non.....electrolytics probably are best avoided in speaker crossovers.

Davey.

[renton]

Awesome - thanks everyone.

On a side note -Pretty much completed 1 of my NatP towers last night! Got the crossover built, cabinet loaded and temporarily hooked everything up to make sure it was correct. I tentatively attached the speaker inputs and turned on my receiver. Holy hell, I was blown away at how good it sounds! I was even more astounded that is was this good with just one speaker playing. Even my girlfriend, who usually is not really "into" this type of stuff, was very impressed. They just sounded much larger than they were. The bass was plentiful, but still very clean and smooth.

The only problem is that I want to skip out of work now to go home and finish the other tower . . .

Thanks to everyone for all of the help.

[Andy_G]

You need to get out more often.....

There are plenty of commerical and DIY crossovers that use polarized electrolytic caps. Look at cheap generic prebuild XO's for examples of this practice.

Can you show me a schematic where a polar cap is used in a x-o.
By non-polar I mean one that clearly has a plus side and a minus side. ?

[renton]

Wouldn't non-polar by definition mean that it doesn't have a plus or minus side?

Can you show me a schematic where a non-polar cap is used in a x-o.
By non-polar I mean one that clearly has a plus side and a minus side. ?

[Dennis H]

SL uses back to back polarized electrolytics for huge values in some of his prototype speakers. Example, two 1000uF, 50V caps back to back in series give a 500uF, 100V non-polarized as Davey mentioned.

http://www.linkwitzlab.com/proto.htm

[Andy_G]

Wouldn't non-polar by definition mean that it doesn't have a plus or minus side?

DOH !! Editted that.. early morning here , not awake yet 8O

[Andy_G]

SL uses back to back polarized electrolytics for huge values in some of his prototype speakers. Example, two 1000uF, 50V caps back to back in series give a 500uF, 100V non-polarized as Davey mentioned.

http://www.linkwitzlab.com/proto.htm

Oh, so he is really using a non-polar cap, just made out of two polar caps back to back, like any other non-polar electro, just not in the same container.

Apart from this circumstance, I cannot think of anywhere that a polar cap is used "specifically" as a polar cap in a x-o.

If I need big value caps, I use these...

http://www.soundlabsgroup.com.au/c/Electrolytic-Visaton/Visaton+SAF

[Davey]

Andy,

There have been a number of "passive" crossovers designed with back-to-back polarized capacitors with the "+" leads tied together and then the pair biased with a constant DC level. (In my mind this makes the crossover an "active" crossover.)
However, some of the more "creative" engineer/subjectivists think this makes electrolytics "sound" better.

I don't recall seeing any applications where a single, (not DC biased) polarized capacitor is used in a conventional arrangement in a high level crossover. I don't see how it could work effectively in that type of topology. Maybe some of the guru's here could enlighten me on that.

Cheers,

Davey.