MOX - active crossover

[moamps]

Hi, all

here is my prototipe of an active crossover - SK filter with 6-12-18-24 dB slope, Q from 0.5 to 1, and standard 1/3 octave central frequency. I'm using this crossover now in an active PA speaker project of mine. Schematics and pcb's have been tested and are working fine. PCB's are one layer style with a couple of jumpers, opamp is placed on a small "daughter" board and can be IC or discrete. If you find it useful, feel free...

Regards

 

[moamps]

LPF filter schematic

 

[moamps]

HPF filter schematic

 

[moamps]

discrete opamp

 

[moamps]

complete xover

 

[moamps]

measurements...24dB/oct LPF, middle decade

 

[moamps]

measurements...1kHz lpf 24dB/octave, diferent Q

 

[moamps]

parts list

 

[Peter Daniel]

I'd say, you'd finished what Grey started. Congratulations on a job well done. Will definitely try this one.

 

[Peter Daniel]

Looking at the schematic, I see you have 10K volume pots for ea. section of the crossover.

It seems like a perfect setup to use APOX SHM controller here, as one could set permanently offset levels and then adjust all 4 channels simultaniously. By increasing the gain of op amp, one might combine preamp function with high quality active crossover.

From the schematics I've seen so far, this one seems to be the most appealing (especially when it's based on XVR1)

 

[moamps]

It seems like a perfect setup to use APOX SHM controller here, as one could set permanently offset levels and then adjust all 4 channels simultaniously. By increasing the gain of op amp, one might combine preamp function with high quality active crossover.

Hi,

this is good idea. Also, one another solution is using 4 channel resistor attenuator with proper screening between sections if remote control isn't needed. Tracking between channel and filters in this case must be very good.

Regards

 

[vytas]

Nice work

It seems simple and quit good solution!

 

[roddyama]

Excellent job Moamps,

Looking at the schematic, I see you have 10K volume pots for ea. section of the crossover.

It seems like a perfect setup to use APOX SHM controller here, as one could set permanently offset levels and then adjust all 4 channels simultaniously. By increasing the gain of op amp, one might combine preamp function with high quality active crossover.

From the schematics I've seen so far, this one seems to be the most appealing (especially when it's based on XVR1)

If you wanted to get real fancy, you could let the APOX processor do the frequency and slope switching with a set of relays driven from the processor. Than have the frequency and slope displayed on the screen.

 

[tiroth]

Very nice work. A project like this was definitely needed. Even for those not biamping this is a great (and inexpensive) tool for designing crossovers.

 

[chris ma]

group buy

Hello moamps,

Have you consider making and selling the PCBs?

Regards
Chris

 

[Andypairo]

Re: group buy

Hello moamps,

Have you consider making and selling the PCBs?

Regards
Chris

Since my spare time is very limitated I can't but agree with Chris, also providing the main components (I.E. the double fet and the resistor/capacitors array) would be very appreciated.

Cheers

Andrea

 

[roddyama]

Re: group buy

Hello moamps,

Have you consider making and selling the PCBs?

Regards
Chris

I would be in for that as well, multiples.

 

[jam]

Good job Moamps!

..........Rodd will buy anything.

Regards,
Jam

 

[roddyama]

..........Rodd will buy anything.

What are you selling Jam, anything?

 

[jam]

Not today Rodd...............but I am reading this new book......