Passive filters with active crossovers?

[xplo5iv]

Has anyone studied the potential benefit of post-amplifier passive filtering on an active crossover design in order to reduce reproduced distortion?

I know it's common to add a HPF to protect the tweeter, but I'm thinking about e.g. a passive low pass filter on mid/sub to reduce amplifier created harmonics that are above the desired range, but still within the reproducible range of the driver. Obviously it would need to be high enough to not mess up the desired signal as shaped by the DSP.

I hope that what I've said is understandable!

PS I'm well aware that with the best amps this is probably irrelevant, but 6 channels of Purifi isn't within current toy budget

Thanks for any input

Jonathan

 

[gvl]

Amp distortion is negligible compared to that of the driver even in case of some questionable amps, so I’d think there’s no real value in doing that.

 

[Zvu]

Has anyone studied the potential benefit of post-amplifier passive filtering on an active crossover design in order to reduce reproduced distortion?

I know it's common to add a HPF to protect the tweeter, but I'm thinking about e.g. a passive low pass filter on mid/sub to reduce amplifier created harmonics that are above the desired range, but still within the reproducible range of the driver. Obviously it would need to be high enough to not mess up the desired signal as shaped by the DSP.

I hope that what I've said is understandable!

PS I'm well aware that with the best amps this is probably irrelevant, but 6 channels of Purifi isn't within current toy budget

Thanks for any input

Jonathan

@KSTR spoke before about benefits of adding inductor to a woofer of powered loudspeaker with active crossover. Search for that.

I'm using active filtering for everything below 1000Hz. Passive filters become to expensive or complicated to implement that low. Hybrid approach is best in my opinion.

Three way loudspeaker that is biamped and has active crossover between woofer and midrange. Crossover between midrange and tweeter passive with its own amplifier chanel. Best of both worlds. You're saving on one dsp, dac and amp channel without any loss of performance.

 

[kipman725]

Distortion from a cored inductor will be worse than a high performance amplifier. For compresion drivers though there is a benifit to passive crossovers to reduce the voltage sensitivity otherwise amp hiss can be a big issue. The JBL M2 uses a passive crossover on the comp for this reason https://www.erinsaudiocorner.com/loudspeakers/jbl_m2/ . I made a 3 way speaker that uses a passive mid/high crossover to reduce amp channel count and to protect the compression driver https://www.diyaudio.com/forums/multi-way/335062-bm-d446-ph-4220-a.html.