3rd order hi-pass

keyser · 6th December 2004, 01:54 PM

hi guys,
does any one of you know how to make a 3rd order high-pass filter at 40 hertz, and one at 50 hertz?
my plate-amp doesn't feature a high-pass, so i guess i should build one myself. thanks!

BassAwdyO · 6th December 2004, 04:33 PM

Do you want passive or active? I'd suggest active, as I've heard they dont have some of the phase problemes that passive filters have, and when you add inductors and capacitors to the speaker circuit, you lose a bit of power. WinISD has circuitry design calculators, but only has designs for 1st and 2nd order filters. I'm no expert, but I'd say you could wire a 1st and 2nd order active filter in series and get a 3rd order filter. The first filter would cut down to 6db/octave, then the second filter would cut down another 12db/octave giving you a total of 18db/octave. There might be some problem with that I dont know about. There's probably a design using a single transistor.

keyser · 6th December 2004, 11:20 PM

thanks.
i want to use an active filter (low-level) between plate-amp and poweramp. Wouldn't it be better to make a good 3rd order filter from the start?

simon5 · 7th December 2004, 12:30 AM

I found a webpage that calculate everything, you might want to try it out.

http://ccs.exl.info/calc_cr.html

xplod1236 · 7th December 2004, 01:13 AM

try filter pro from texas instruments

6th December 2004, 01:54 PM	#1
keyser diyAudio Member Join Date: Oct 2004 Location: The Netherlands	3rd order hi-pass hi guys, does any one of you know how to make a 3rd order high-pass filter at 40 hertz, and one at 50 hertz? my plate-amp doesn't feature a high-pass, so i guess i should build one myself. thanks!

6th December 2004, 04:33 PM	#2
BassAwdyO diyAudio Member Join Date: Jun 2004 Location: Illinois	Do you want passive or active? I'd suggest active, as I've heard they dont have some of the phase problemes that passive filters have, and when you add inductors and capacitors to the speaker circuit, you lose a bit of power. WinISD has circuitry design calculators, but only has designs for 1st and 2nd order filters. I'm no expert, but I'd say you could wire a 1st and 2nd order active filter in series and get a 3rd order filter. The first filter would cut down to 6db/octave, then the second filter would cut down another 12db/octave giving you a total of 18db/octave. There might be some problem with that I dont know about. There's probably a design using a single transistor. __________________ The golden rule of DIY: Build nice, or build twice!

7th December 2004, 12:30 AM	#4
simon5 diyAudio Member Join Date: Nov 2004 Location: Québec, Québec	I found a webpage that calculate everything, you might want to try it out. http://ccs.exl.info/calc_cr.html __________________ DIYaudio for President !

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
supravox 4th order band pass	sub_arctor	Subwoofers	10	10th April 2008 07:53 PM
1st order low-pass filter, which cap ?	Thmartin	Parts	4	17th November 2005 08:37 AM
6th order band pass. what drivers?	noyzmunky	Subwoofers	3	26th July 2005 03:16 AM
Aleph P.17 1st order high pass filter	Ignatz	Pass Labs	2	30th October 2002 06:56 PM


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

6th December 2004, 11:20 PM	#3
keyser diyAudio Member Join Date: Oct 2004 Location: The Netherlands	thanks. i want to use an active filter (low-level) between plate-amp and poweramp. Wouldn't it be better to make a good 3rd order filter from the start?

7th December 2004, 01:13 AM	#5
xplod1236 diyAudio Member Join Date: Dec 2003 Location: On the couch	try filter pro from texas instruments

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read