Low pass filter

[grrr_arrghh]

Hi.

I'm about to build a low pass filter, just because I think the change they make to the sound is really quite cool. There's no good reason why I can't run one from +-4.5v is there?

Also, A Low Pass Filter removes all the frequencies above a certain point yeah? So the result is a sound wave containing just the frequencies below this point, yeah?

Cheers,

Tim

 

[Nigel Goodwin]

Hi.

I'm about to build a low pass filter, just because I think the change they make to the sound is really quite cool. There's no good reason why I can't run one from +-4.5v is there?

Also, A Low Pass Filter removes all the frequencies above a certain point yeah? So the result is a sound wave containing just the frequencies below this point, yeah?

It doesn't 'remove' them, it attenuates them, at a rate determined by the slope of the filter - this measured in dB/octave - where the higher the value the faster it rolls off the high frequencies. However, the higher the slope the more it affects the sound around the turnover point, in particular giving large phase shifts.

You can happily run one off +/-4.5V, as long as you keep the signal levels through it reasonably low.

 

[grrr_arrghh]

It doesn't 'remove' them, it attenuates them, at a rate determined by the slope of the filter - this measured in dB/octave - where the higher the value the faster it rolls off the high frequencies. However, the higher the slope the more it affects the sound around the turnover point, in particular giving large phase shifts.

hmm, that makes sense, and explains a few things!! As I said, its for nothing better than making a cool effect, so i'm not to bothered about the slope.

You can happily run one off +/-4.5V, as long as you keep the signal levels through it reasonably low.

ok, well they'll only be line level signals.

Thankyou

Tim