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An-i-no

Notch Filter for home use = EQ in a car?

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So I'm trying this whole active thing out with drivers I had laying around. I was actually pretty impressed how the random drivers sounded so I figured I could spend some money on stuff.

But before I purchase, I keep seeing people saying that to make a certain driver sound good it needs a "notch filter" to smooth out the response. I researched and now I know exactly what it means, but I don't want to build one (mostly because I have no clue how to do that) so I was thinking...and I realized that they're using the notch filters for the same thing we use an EQ for in a car...right?

I can smooth out the response pretty well (or I can pony up and buy equipment that can) electronically...so there's no need to do it physically, right?

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Not sure where and why you've read you need a notch filter....unless of course you are looking at exotic cones with uber nasty breakup modes. If that's the case you should stop and use something else to run active first.

Electronically it is rather easy IF you have a processor that allows it.

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I can smooth out the response pretty well (or I can pony up and buy equipment that can) electronically...so there's no need to do it physically, right?

Whether you are doing it actively or passively, digitally or analog, it's still electronic. I'm not sure what you mean by doing it "physically", though I'm guessing you meant doing it passively. "Physically" would be a whole 'nother can of worms.

As M5 said, generally a notch filter is used to tame a cone breakup that occurs either within the passband or just past the crossover point if the break up is severe.

I think the first question should be why you think you need a notch filter.

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Not sure where and why you've read you need a notch filter....unless of course you are looking at exotic cones with uber nasty breakup modes. If that's the case you should stop and use something else to run active first.

Electronically it is rather easy IF you have a processor that allows it.

Wellllll, I was just browsing through drivers to play from 400-up to wherever I cross my tweeter (so 3500-4000) and in the reviews I kept reading "a notch filter at XXXXhz will tame this/that/whathaveyou," and it wasn't one driver, it was all over the place whether it be full ranges, 5", 6", 7" it was everywhere. So maybe I was just over thinking it. I agree though I'll stay away from drivers with nasty cone breakup/resonance (is that the same thing? Cone breakup and cone resonance?) issues.

I can smooth out the response pretty well (or I can pony up and buy equipment that can) electronically...so there's no need to do it physically, right?

Whether you are doing it actively or passively, digitally or analog, it's still electronic. I'm not sure what you mean by doing it "physically", though I'm guessing you meant doing it passively. "Physically" would be a whole 'nother can of worms.

As M5 said, generally a notch filter is used to tame a cone breakup that occurs either within the passband or just past the crossover point if the break up is severe.

I think the first question should be why you think you need a notch filter.

Well..like I said it was everywhere on Parts-Express and Madisound.

And oops. By physically I meant by using inductors and capacitors to affect what the woofer plays, but you're right, passively was the word I was looking for.

Thanks all.

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There is a huge difference in running a full range driver full range and only using part of the range. Where you read the need for a notch was to address breakup...so to avoid it don't pick a driver that has breakup in the range you will be playing it. :)

400-3500Hz?? Really? I assume you are attempting a 3 way, but if you've never run active I'd highly encourage against that in the first round. 2 way is your friend.

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A notch filter would be beneficial if you had a peak somewhere that needed to be tamed. But, you would need to know exactly where this peak was (with test equipment) and measure again to see if the filter you designed actually hit the peak.

I have used notch filters for decades with passive crossovers. They are designed into the circuit when there is a an audible peak. Normally the filter has to be very precise (like taking an inductor and removing a few windings until it measures exact) to even work right. Additionally, I have to use acoustic measuring before and after. In other words, a lot of technical crap.

Most of the time if you go active and have some sort of processing (eq) you can deal with these problems much easier thna doing it in the passive realm after the last amplification stage...

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There is a huge difference in running a full range driver full range and only using part of the range. Where you read the need for a notch was to address breakup...so to avoid it don't pick a driver that has breakup in the range you will be playing it. smile.png

400-3500Hz?? Really? I assume you are attempting a 3 way, but if you've never run active I'd highly encourage against that in the first round. 2 way is your friend.

Yep. I'm waist deep in it already lol. The mids/midbasses I chose for my 2 way sound like ass when I crossed them where I wanted to (2500+).

Not only that, but they were really expensive.

Not only THAT, but I damaged one, so I can't get nearly what I paid back for them. I figured they'd be worth more as speakers than as money at this point.

They're wonderful for midbass though. So I have that down.

A notch filter would be beneficial if you had a peak somewhere that needed to be tamed. But, you would need to know exactly where this peak was (with test equipment) and measure again to see if the filter you designed actually hit the peak.

I have used notch filters for decades with passive crossovers. They are designed into the circuit when there is a an audible peak. Normally the filter has to be very precise (like taking an inductor and removing a few windings until it measures exact) to even work right. Additionally, I have to use acoustic measuring before and after. In other words, a lot of technical crap.

Most of the time if you go active and have some sort of processing (eq) you can deal with these problems much easier thna doing it in the passive realm after the last amplification stage...

That sounds like some ish I don't want to do. EQ it is!

Edited by An-i-no

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Start over. What do you have and what are you lacking?

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