I know 12 and 24 db/oct but - diyAudio
Go Back   Home > Forums > Design & Build > Parts
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Parts Where to get, and how to make the best bits. PCB's, caps, transformers, etc.

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
Thread Tools Search this Thread
Old 5th September 2003, 01:11 PM   #1
diyAudio Member
punchpeanut's Avatar
Join Date: Jul 2003
Location: twin cities
Default I know 12 and 24 db/oct but

what about 6 and 36 db/oct crossovers, how are they laid out?
  Reply With Quote
Old 5th September 2003, 01:15 PM   #2
SY is offline SY  United States
On Hiatus
SY's Avatar
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 2
A 36 dB/octave (six pole) is just two three-poles in series (with their resonant frequencies and Qs appropriately chosen). A 6 dB/octave (one pole) is just a single reactance and resistance.
"You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is."
  Reply With Quote
Old 5th September 2003, 01:23 PM   #3
Electrons are yellow and more is better!
diyAudio Member
peranders's Avatar
Join Date: Apr 2002
Location: Göteborg, Sweden
Blog Entries: 4
An active section can produce max 12 dB/octave and a passive produce 6 or 12. If you want more you have to connect sections in series.....but this is a comlex subject when it comes to more than 24 dB/octave.

Walter Jung has written good things about this and many many others. Active filters are the favourite subject at unversities but many of those people haven't build anything just cretaed theories and beautiful formulas. The opamps used are often "ideal".

Walter Jung on the contrary has written about practical circuits and the latest book is here which is very good and for free.
/Per-Anders (my first name) or P-A as my friends call me
PA03 LM4780 amplifier group buy, SIGN UP HERE for the group buy 0 boards left. 118 paid.
  Reply With Quote
Old 5th September 2003, 03:14 PM   #4
diyAudio Member
stokessd's Avatar
Join Date: Nov 2002
Location: Grantham, NH
IF you are talking about speaker driver filters, it's hard to get a 6 dB per ocative effective rolloff when using typical drivers in typical configurations. 6 dB per octave is quite shallow and covers a lot of the audio band before significant attenuation occurs. To get a 6 dB/octave acoustical rolloff, your driver needs to be flat significantly past the filter knee. In my experience with drivers, this is rarely the case. The driver may be flat where the filter starts filtering, but eventually the driver starts rolling off itself (at at least 6 dB per octave) and you get an effective rolloff at a much higher order.

  Reply With Quote
Old 5th September 2003, 04:49 PM   #5
diyAudio Member
punchpeanut's Avatar
Join Date: Jul 2003
Location: twin cities
Thanks guys, I am looking to use the 6 db/oct slope on some Dynaudio speakers. That's what Dyn uses on all their speakers, so I thought I would give it a try. And yes I am interested in and electronic crossover, not a passive.
  Reply With Quote


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

New To Site? Need Help?

All times are GMT. The time now is 01:57 AM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2