Active Filter Questions - diyAudio
Go Back   Home > Forums > General Interest > Car Audio

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
Reply
 
Thread Tools Search this Thread
Old 23rd June 2005, 08:21 PM   #1
diyAudio Member
 
Join Date: May 2005
Location: Appleton
Question Active Filter Questions

Here's the deal, I'm trying to filter at about 250 hz. for my 4x6 fronts. The fronts are 2-way Pioneer. I realize that the passive filters are more common but I was going through and can't find the capcitance on the 2-way highpass filter. I was wondering if the opamp would serve as a buffer between the two RC circuits? Meaning the RC circuit in the speaker and the RC circuit out in front of the opamp. Or would the combination of the internal circuits of the opamp+Rc circuit out in front+the capcitor in the speaker throw the phase of the signal into chaos?
  Reply With Quote
Old 24th June 2005, 04:13 PM   #2
diyAudio Member
 
Join Date: May 2005
Location: Appleton
Hope I didn't stump anyone, the thing I have a hard time believing is that with all the semi-conductors in an opamp that the one cap could possibly overcome that. One other question, that hopefully will get answered. If I want a gain of one on the Opamp do I need to apply the positive/negative DC to VCC & VEE.
  Reply With Quote
Old 26th June 2005, 06:37 PM   #3
diyAudio Member
 
Join Date: Nov 2003
Location: California
Use an opamp as a buffer between filter sections before the amplifier, not after. Opamps are typically not high current devices. They work better into high impedance loads (like the input of an amp, maybe 20kohms or so) as opposed to the low impedance load of a speaker (8 ohms, 4 ohms, etc.).

If you want to add on passive crossover components after the amplifier outputs, your best bet is to measure the frequency response and impedance of the two drivers you're trying to design a crossover for and then simulate the response with added components. That will let you see what adding additional components does to the repsonse.

If you want to use an active crossover (with opamps), put it before the amplifier driving the 4x6's.

To set the gain of an opamp, you need to use the correct resistors in the feedback loop. The exact details depend on whether you're using the opamp with an inverting or non-inverting input. Read the data sheet for the opamp for more details.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
I need an active sub filter! hernanstafe Subwoofers 18 4th December 2007 09:32 PM
active sub filter questions paulspencer Subwoofers 19 22nd October 2005 01:24 PM
active filter from rod elliot and sub filter questions wuffer Parts 0 2nd October 2005 01:12 PM
Active 3 Way vs Active 2.1: Too many alignments and too may questions. goldyrathore Multi-Way 1 22nd April 2005 02:42 PM


New To Site? Need Help?

All times are GMT. The time now is 01:26 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2