Inline Low Pass?

[Blackout67]

Want to piece out a component set, getting the woofers and tweeters separately and avoid using the external X over box component sets use.
The tweeters I want to use are efficient aluminum domes so I was going to put them on headunit power to avoid running 2 sets kf wires to each side and put the woofers on on amp.

Issue I'm having is there doesn't seem to be any affordable inline lowpass crossovers and the lowpass on my amp only goes to 500hz. Was tryna find one to eliminate 3.5khz and up but can only find expensive ones that block only around 500hz and up

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[CertifiedHoodClassic]

You could just use an inductor if you don't need/care about a steep slope. It's like using a capacitor as a low pass filter if you've ever done that.

First find the inductance you need:

Low Pass Filter Calculator

The low pass filter calculator helps you design and build a low-pass filter circuit, with support for passive (RC and RL) as well as active (op-amp based) filters.

www.omnicalculator.com

I got about 180 micro henry, I'll just round to 200 which gives about 3.2 khz crossover point. You could also do 150 uH for 4.2 kHz.

then just go to parts express or ebay and find one (make sure it's not one of those tiny ones because they can't take much power)

Dayton Audio 0.20mH 20 AWG Air Core Inductor Crossover Coil

Dayton Audio 0.20mH 20 AWG Air Core Inductor Crossover CoilDayton Audio 20 gauge air core inductors are a great choice and the best value for building high quality crossovers. Features fully annealed refined copper wire, perfect layer windings and air core construction to ensure no hysteresis...

www.parts-express.com

says it's 1.38"x 0.5" so it might be too big, but that's how you'd do it.

 

[Blackout67]

You could just use an inductor if you don't need/care about a steep slope. It's like using a capacitor as a low pass filter if you've ever done that.

First find the inductance you need:

Low Pass Filter Calculator

The low pass filter calculator helps you design and build a low-pass filter circuit, with support for passive (RC and RL) as well as active (op-amp based) filters.

www.omnicalculator.com

I got about 180 micro henry, I'll just round to 200 which gives about 3.2 khz crossover point. You could also do 150 uH for 4.2 kHz.

then just go to parts express or ebay and find one (make sure it's not one of those tiny ones because they can't take much power)

Dayton Audio 0.20mH 20 AWG Air Core Inductor Crossover Coil

Dayton Audio 0.20mH 20 AWG Air Core Inductor Crossover CoilDayton Audio 20 gauge air core inductors are a great choice and the best value for building high quality crossovers. Features fully annealed refined copper wire, perfect layer windings and air core construction to ensure no hysteresis...

www.parts-express.com

says it's 1.38"x 0.5" so it might be too big, but that's how you'd do it.

This is what I got from the calculator? How would inuse that to find the ride inductor? Looks like on PE they are all rated by mH. Not sure what that is

 

[spokey9 5,000+ posts]

...never mind I misread

 

[CertifiedHoodClassic]

This is what I got from the calculator? How would inuse that to find the ride inductor? Looks like on PE they are all rated by mH. Not sure what that is

pick the RL filter (L is an inductor). It's the one that works when you have the inductor in series with the resistor (the speaker). Sorry about not mentioning it.

inductors are measured in Henries. mH = millihenry. uH = microhenry. So 1 mH = 1000 uH. So the calculator will give you about 180 uH or 0.18 mH.

 

[Blackout67]

Oh so how then do i connect it to the speaker? I think I've only ever seen one set use a inductor for an inline LPF, the Alpine S series components have it attached to the basket

Any ideas?

 

[1aespinoza Premium Member]

Oh so how then do i connect it to the speaker? I think I've only ever seen one set use a inductor for an inline LPF, the Alpine S series components have it attached to the basket

Any ideas?

Connect it inline on the positive of the voicecoil.

 

[Blackout67]

Connect it inline on the positive of the voicecoil.

Just solder it to the positive terminal?

 

[1aespinoza Premium Member]

Just solder it to the positive terminal?

Yes.