LX-mini Crossover Article

[GOES211]

It can be adjusted for the Lxmini with subs, and you have to add an external
low pass filter for the subs. Probably worth a small article.

Yes please

 

[pomello60]

I've been patiently waiting. And it's going to be just in time for a nice speaker project. This is super great!

EV3

Hello, would like to know if the lxmini cut-off frequency could be easily converted to 1200hz ,and how to do the mods for this frequency
Thanks
Maurizio
Italy

 

[Nelson Pass]

Referring to the previously published schematic, you could get close with
C3 = 5 nF, C4 = 5 nF, C13 = 10 nF, C14 = 15 nF. You can trim this with
adjustments to R1, R2, R3, R4

 

[joshua43214]

So...

What I would love to have for the new year is a nice active crossover for my 3-way horn system with added subwoofer.

I think we need to get out the pitch forks and camp on Papa's porch again

 

[Rewind]

Hear, hear...

 

[Jeffreyjuice]

OMG �� I agree!! Please Papa, why do we have to beg for a three way?

 

[pra3718]

Sir,

Is it possible to build this crossover with OpAmp ? if Yes What should be the order ?
1. LP = LP then EQ
HP = EQ then HP
2. LP = EQ then LP
HP = HP then EQ

- Is Buffer required ?
- Is 25KPot required ? if Not, should I use 22K resister signal to Ground ?

 

[Nelson Pass]

Op amps are very easy - pick one that makes a good unity gain buffer.

You can put the filters in any order you like.

Any resistor to ground at input is fine, just large enough not to load the signal
source too much.

 

[pra3718]

Thank you sir

 

[pra3718]

Thanks to creator of LxMni and analog crossover.

I tried with opamp its playing. Complete one channel I build, size is 4x2 Inch. It is not professional work but playing error-free.

Thanks

 

[Nelson Pass]

 

[mcluxun]

I'm running into an intermittent issue where the crossover is running alright at one point and after a few minutes of playing it doesnt work anymore.


No voltage on R1-4, R31-32, I wonder what the problem it might be.


I'm running it dual mono in balanced mode:

 

[Zen Mod]

observe rail voltage in time

sole possible explanation is that it's starved somehow - either bad PSU or part in power filter section

 

[MarkS]

I'm running into an intermittent issue where the crossover is running alright at one point and after a few minutes of playing it doesnt work anymore.

Post a photo of your soldering on the rear of the pcb, might help in finding a possible electro mechanical problem...

 

[mcluxun]

I resoldered the whole board now all the testing are going well with my oscope.
But the crossover produces massive noise when connected to a power amp.
The other crossover works perfectly with either amps. They share the same power supply too.

 

[Nelson Pass]

You did not describe the noise character.

Both channels?

Since you have a scope, look for a hint as to whether it is grounding
noise, ripple from the supply, or oscillation.

 

[mcluxun]

You did not describe the noise character.

Both channels?

Since you have a scope, look for a hint as to whether it is grounding
noise, ripple from the supply, or oscillation.

Yes in all channels.


This is what the noise looks like in oscope.

 

[Zen Mod]

trace the noise from PSU output node backwards to input

 

[Nelson Pass]

Looks like switching power supply noise.

 

[mcluxun]

Got it figured out, it turned out to be a wiring issue.
Now it's serving my ESL 63 + linkwitz subwoofer system: