Passive Hipass filters.

[mightycicadalord]

Howdy folks, had a quick question.

I'm in the market for a low cost solution to split the signals from my subs to mains. I've kinda ruled out the minidsp hd because I owned one previously and it kind of degraded the sound so I got rid of it. My subs have no problem with their own filters, but my mains are still playing down to ~40hz. I noticed there are some hi pass passive filters out there and was curious if these are an alternative. I don't know much about crossover components other than caps cut highs, but part of me assumes these filters would have negative effects on other aspects of the signal. The minidsp flex is an an option but out of stock for awhile and pricey for me.

Thanks in advance.

 

[digitalfrost]

This will absolutely not work. The speaker impedance varies wildy, especially around the resonancy frequency of the chassis (Fs). See any impedance graph in a passive speaker review here. Example from https://www.audiosciencereview.com/forum/index.php?threads/revel-f228be-review-speaker.23659/

Any filter that was calculated via textbook will fail, because each speakers impedance response is different. This would have to be linearized via an RLC parallel to the chassis to make any of this work. Forget passive filters in the bass. They will not work, and if made to work they will be very expensive.

There is a reason this is usually done on the line level or via DSP.

 

[mightycicadalord]

I figured as much, thanks.

 

[airborne]

if you can tap into the signal chain before the amplifier you could filter out those low frequencies in any number of ways but if you are trying to do it between the amp and speakers then it will be very very bad ...

like so bad you're better off just setting your speakers on fire ...

 

[mightycicadalord]

if you can tap into the signal chain before the amplifier you could filter out those low frequencies in any number of ways but if you are trying to do it between the amp and speakers then it will be very very bad ...

like so bad you're better off just setting your speakers on fire ...

I'd love to do it with my motu m4 and some sort of software routing but have not been able to figure it out yet. It would also be a total pain to try to route this software wise with production work I do. Oh well, might just be better off leaving things as they are, it does sound very nice.

 

[mightycicadalord]

Success! I was able to get things filtered and routed with voicemeter banana. Holy moly things sound good. No more excess woofer movement with the tops, definitely a big improvement at higher volumes. Subs are integrating better.

Voicemeter, neat little program.

 

[dlaloum]

Howdy folks, had a quick question.

I'm in the market for a low cost solution to split the signals from my subs to mains. I've kinda ruled out the minidsp hd because I owned one previously and it kind of degraded the sound so I got rid of it. My subs have no problem with their own filters, but my mains are still playing down to ~40hz. I noticed there are some hi pass passive filters out there and was curious if these are an alternative. I don't know much about crossover components other than caps cut highs, but part of me assumes these filters would have negative effects on other aspects of the signal. The minidsp flex is an an option but out of stock for awhile and pricey for me.

Thanks in advance.

These worked well for me:

Amazon.com: Harrison Labs FMOD Inline Crossover Pair 50 Hz High Pass RCA : Electronics

Amazon.com: Harrison Labs FMOD Inline Crossover Pair 50 Hz High Pass RCA : Electronics

www.amazon.com

The have high pass and low pass models... and at different XO points (this assumes you can place them before the power amp input)

 

[restorer-john]

Many subwoofers have inbuilt high pass filters for connected satellites and it's as simple as a large NP (non polarized) elctrolytic. You can do exactly the same with a series connected NP electrolytic and you have the benefit of inbuilt DC protection if an ampliifer goes bad.

People love to over complicate what has been done for most of a century with great results and at low cost.

 

[mightycicadalord]

Appreciate the suggestion, but tough to go to passive when I've got these fancy active filters.

 

[dlaloum]

I am now using the active DSP XO filters in my Crown XLS amps... (BiAmping my mains) - but if they could be switched out of the circuit and the amps run "clean" I would be using the passive method.... as it is, given that they are permanently "in circuit" - I simplify things by removing the passive components. Personally I would have preferred the passive alternative.