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Discussion Starter #1
I dunno if I should post this question here or in the myths, but I'll ask here anyway.

couldn't find any inductor coils for my low pass filter, so I have been told at the shop that wiring a capacitor in parallel to the speaker makes a low pass filter too.

if I wire this capacitor in parallel, would the amp see it as a capacitive load?
I have also been told by someone else that a capacitive load is dangerous for the amp, are these true?
 

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your buddies are talking out of thier ass. passive filters have exsisted since the invention of speakers. they are not harmful to an amplifier in any way, shape or form.

you dont want a capacitor in parallel with the speaker for a LPF in though. Although a parallel cap or a series inductor are both a LPF, you wont see the Parallel cap config in speaker design. (unless you are building a 2nd order or higher filter)

as chaos posted. read the section on filters.
 

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Discussion Starter #5
thanks for all these quick replies, just now my friend took a peek at my system, he said:
you have a 2 way 2nd order crossover, it would be nice to put an extra capacitor in parallel with the midrange to emphasize your tweeters, because its too weak.
should I follow his advice? wouldn't it mess up the crossover frequency point (or whatever thing)?
 

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stop listening to this friend! lol.

an "extra" capacitor? did he specify a value or just throw whatever in there? did he specify what effect that will have? in a 2nd order crossover the values of the inductor and cap follow a formula to make sure the two will function as a pair and not end up with 2 crossover points or a ton of ripple. you cant just add more caps!

at any rate, that will not emphasize the tweeters more. it will do 1 or two things, depending on if it is a HPF or LPF.

1) it will change the lower freq cut-off, good way to blow up your midrange.
2) it will change the high freq cut-off, this will only change the interface between the midrange and the tweeter. it will create overlap or a hole. either way it wont make the tweeter louder.

if you want to increase the volume of the tweeter, then you have to increase power to the tweeter or reduce power to the midrange. obviously if you are on passives, you cant increase power to the tweeter. put an L-pad on the midrange to lower its output, that will increase the appearant volume of the tweeter if you need more treble.
 

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Discussion Starter #7
stop listening to this friend! lol.

an "extra" capacitor? did he specify a value or just throw whatever in there? did he specify what effect that will have? in a 2nd order crossover the values of the inductor and cap follow a formula to make sure the two will function as a pair and not end up with 2 crossover points or a ton of ripple. you cant just add more caps!

at any rate, that will not emphasize the tweeters more. it will do 1 or two things, depending on if it is a HPF or LPF.

1) it will change the lower freq cut-off, good way to blow up your midrange.
2) it will change the high freq cut-off, this will only change the interface between the midrange and the tweeter. it will create overlap or a hole. either way it wont make the tweeter louder.

if you want to increase the volume of the tweeter, then you have to increase power to the tweeter or reduce power to the midrange. obviously if you are on passives, you cant increase power to the tweeter. put an L-pad on the midrange to lower its output, that will increase the appearant volume of the tweeter if you need more treble.
he told me to fit any capacitor to the LPF, which, according to him, will give much more power to the high pass.

and if I were to put an l-pad, what value of resistors should I use? is there any calculator for this?
 

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Discussion Starter #9
Your friend is an idiot, no offence to you. As I explained, it doesnt work that way. he obviously has no idea how anything works in electronics.

L pad calculator - attenuation dB damping impedance decibel loudspeaker speaker voltage divider - sengpielaudio Sengpiel Berlin
well, it was a good thing I asked here first before following his advice, or else I might have wasted my last pair of german mb quart speakers!
thanks,
I will start making the l-pad now.
BTW can't I buy any pre-built l-pads?
 

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you can, but most car audio speakers are 4 ohm. most pre-built l-pad are designed for 8-ohm speakers.

check out madisound and PE
 

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Discussion Starter #11
you can, but most car audio speakers are 4 ohm. most pre-built l-pad are designed for 8-ohm speakers.

check out madisound and PE
oh, all right thanks though, I just finished making my l-pad. but my tweeters sound too shrill now, maybe because I made a -9dB l-pad, maybe i'll try making another one.
 
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