100HZ PLLXO

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At the bottom of this article (but please read it through as well!) is a nice little calculator app that will find values for a 24 or 12dB slope Linkwitz-Riley filter.

Linkwitz-Riley Electronic Crossover

I ran it quickly and found 4.7k with 330nF was quite close to your target. Use a robust op-amp ideally, TL072 can be a bit weak on the output, but something like OPA2134 or OPA2227 (both dual) will work great. NE5532 should work too but the BJT input can be as low as 30k itself so filter break points may not be as accurate, probably not an issue here at all.

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At the bottom of this article (but please read it through as well!) is a nice little calculator app that will find values for a 24 or 12dB slope Linkwitz-Riley filter.

Linkwitz-Riley Electronic Crossover

I ran it quickly and found 4.7k with 330nF was quite close to your target. Use a robust op-amp ideally, TL072 can be a bit weak on the output, but something like OPA2134 or OPA2227 (both dual) will work great. NE5532 should work too but the BJT input can be as low as 30k itself so filter break points may not be as accurate, probably not an issue here at all.

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Hello, thanks for the help but I have to ask, is the op-amp really nessary?

This is for a DJ rig so I'm not going to scrutinize the accuracy or sound quality, as long as it works. I wanted something that I could chuck together and just throw inline with my cords.

Let me know, and thanks again!
 
If you only need a low pass, 2 Rs, 2 caps/ channel, and a pre-amp with sufficient grunt to drive the PLLXO. 2nd order PLLXOs tend to be a bit droopy.

TLS.org | Passive Line-Level Crossover

dave

edit: i see Tony beat me to the link :D

Well actually throwing 2x 5K's in series in the signal, with a .47uf and .22uf in parallel from the middle of those resistors to ground it looks like it gives me up until about 150Hz....

I might be on to something :)
 
how to sum channels appropriate when building pllxo for 2.1 system

Hi.I am now listening from Tripath TA2020 amp and TP22 amp.TA2020 to one channel of fullrange and other TP22 amp to subwoofer(just for trying)2. order crossover decrased the signal level a lot.But it seems now only bass frequencies going to subwoofer so sound is good now.Now I want to sum the L and R channels but there is another problem, it seems filter response may be changed.What value do you recommend for the Left and right resistors? 470R each too low?
 

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Hi,

The second stage is very dependant on amplifier input impedance,
and IMO not worth bothering with unless you are sure it will work.
Typically it won't work at all as advertised. The x10 is an attempt
to minimise interaction between the two sections but is crude.

rgds, sreten.

Best to use a simulator like the free TinaTi.
 
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Now it is playing well :)

Hi.I have finished the system.Sound is great.I am very happy.Very clean and detailed.Finally i had an almost true sounding system(at this cost of course)
Fullranges are in a sealed 5 liters box so it is making a naturall roll of about 80Hz.And TA2020 amplifier has a 22k input impedance.A serial 100nF wima mkp10 is also applied to amplifier.So i think it is like applied 2. order crossover to fullranges.
Next step is buffered PLLXO with B1 buffer but i think i am very lazy to finish it this year :D Also because of WAF making me slower.Thank you all for your suggestions.
 

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