Adjustable Passive Crossover?

[nonsuchpro]

Hey all,
Are there any "adjustable" passive crossovers out there? The only one I could come up with is this guy, but it's a but more than I wanna spend.

http://www.vidsonix.com/vidsonixnew/boxlit2.pdf

Thanks!

[rvrazvan]

you can build something similar i guess. but what's the point? go active(digital)

[Helmuth]

Originally Posted by nonsuchpro

Hey all,
Are there any "adjustable" passive crossovers out there? The only one I could come up with is this guy, but it's a but more than I wanna spend.

http://www.vidsonix.com/vidsonixnew/boxlit2.pdf

Thanks!

With bipolar capacitors and switches it would not be to expensive, only coils will be and high cost.

serie coils you can ad the value parallel them L=1/(1/L+1/L)
capacitors parallel you can ad the value series C=1/(1/C+1/C)

Why make it this difficult, just calculate the XO. And buy a big coil then unwind the to big coil to the right value. You need to measure the value with a LCR meter. Or buy 3 coils one almost the right value and two small ones who you can place in series and paralel lets say 3mH and two 1mH. Then you can make 0,42mH 0,5mH 0,75mH 1mH 1,75mH 2mH 3mH 3.5mH 4mH 5mH .

buy not the calculated capacitor but parallel small ones to the right capacitance so you can remove rome and have smaller value or bigger when adding more capacitors.

[nonsuchpro]

Originally Posted by rvrazvan

you can build something similar i guess. but what's the point? go active(digital)

Well honestly, i want something I can install in a speaker like an L-Pad. I just haven't come across such a beast

[nonsuchpro]

Originally Posted by Helmuth

With bipolar capacitors and switches it would not be to expensive, only coils will be and high cost.

serie coils you can ad the value parallel them L=1/(1/L+1/L)
capacitors parallel you can ad the value series C=1/(1/C+1/C)

Why make it this difficult, just calculate the XO. And buy a big coil then unwind the to big coil to the right value. You need to measure the value with a LCR meter. Or buy 3 coils one almost the right value and two small ones who you can place in series and paralel lets say 3mH and two 1mH. Then you can make 0,42mH 0,5mH 0,75mH 1mH 1,75mH 2mH 3mH 3.5mH 4mH 5mH .

buy not the calculated capacitor but parallel small ones to the right capacitance so you can remove rome and have smaller value or bigger when adding more capacitors.

Easier said than done, I'm not an "internals" expert. lol
But i'm learning

Thanks for this!

[MCPete]

A passive filter's cut-off frequency is dependent on load impedance. A two way speaker system including two woofers and two tweeters would give you three different crossover frequencies switchable at the speaker.

For the woofers, one woofer can be connected into the network and the other one left out, or the woofers can be connected in series or parallel. If the nominal impedance of each of the woofers is 8 Ohm, this gives you 8, 16, or 4 Ohms load impedance.

The switching of the pair of tweeters would be the same as that of the woofers.

When connecting in parallel, the voltage sensitivity would increase by 6 dB relative to the two other load settings. Compensating for that would make the set-up somewhat complicated, but if you can live with a 6 dB jump in that one case, the manual switching circuit isn't going to be too difficult to implement.

Unlike a L-pad, the above only allows for large steps in the crossover frequency, not at all close to an infinitely variable change. If you wanted something infinitely variable and passive, then that is probably relatively much more complicated and expensive.

Another possibility would be a ganged L-pads for each of a single woofer and single tweeter in a two-way system, except that you modify the variation of series and parallel resistance of each L-pad to increase or decrease load impedance.

My apologies if either of the two above proposals are the same as the vidsonix method (I didn't take a look at that yet).

Regards,
Pete

[Francec]

you can build something similar i guess. but what's the point? go active(digital)

Yep, easier and better.

[MCPete]

Originally Posted by nonsuchpro

Hey all,
Are there any "adjustable" passive crossovers out there? The only one I could come up with is this guy, but it's a but more than I wanna spend.

http://www.vidsonix.com/vidsonixnew/boxlit2.pdf

Thanks!

Did you want to have an adjustable crossover frequency adjustment as a permanent feature of a finished speaker system, or a temporary rig for settling on the best crossover frequency for a speaker?

I like the idea, so I'm just curious as to what you hoped to accomplish with it.

Regards,
Pete

[BinaryMike]

I wonder if a variac would make a good variable inductor for this purpose. Anybody know what inductance range to expect?

[nonsuchpro]

Originally Posted by MCPete

Did you want to have an adjustable crossover frequency adjustment as a permanent feature of a finished speaker system, or a temporary rig for settling on the best crossover frequency for a speaker?

I like the idea, so I'm just curious as to what you hoped to accomplish with it.

Regards,
Pete

Yes, as a permanent feature of the speaker. I think it would have good advantages like driver swap outs and possible room adjustments, wall distance, etc.... IDK, something different... tired of the same ol