Go Back   Home > Forums > >

Multi-Way Conventional loudspeakers with crossovers

filters/crossovers a little understanding needed
filters/crossovers a little understanding needed
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
Old 18th February 2015, 09:21 PM   #1
charlie2 is offline charlie2  England
diyAudio Member
 
Join Date: Oct 2012
Location: Uk
Default filters/crossovers a little understanding needed

hi

just trying to understand something what may appear comon sense/ second knowledge to others.

all speakers have a range on the 20-20 scale lets say,

but what i am trying to learn is

they need a cut off point towards the lower scale regards breaking up not been able to reproduce, but what about the higher up the scale of the speaker when breaking up/dropping off.

hope this makes sense

filters/crossovers a little understanding needed



A will have a low pass filter to compensate C

but does point B need anything to compensate D

the quick scetch is over exagerated and should compensate a woofer taking over and a tweeter at points C and D
  Reply With Quote
Old 18th February 2015, 10:50 PM   #2
rayma is offline rayma  United States
diyAudio Member
 
Join Date: Apr 2011
Quote:
Originally Posted by charlie2 View Post
what about the higher up the scale of the speaker when breaking up/dropping off.
Some two way speaker systems do use the natural woofer hf rolloff to match with the tweeter. See the Dynaco A25 for a good example.
Otherwise, a wider response on the top end of the woofer range than necessary is needed, so that the crossover network works accurately.
The same goes for the low end of the tweeter.

Last edited by rayma; 18th February 2015 at 10:57 PM.
  Reply With Quote
Old 19th February 2015, 09:11 AM   #3
giralfino is offline giralfino  Italy
diyAudio Member
 
giralfino's Avatar
 
Join Date: Feb 2009
The answer should be a bit more complete as the question is a bit vague.

If that FR is from a woofer, you typically do nothing on A, and do something on B or on a frequency < B (a low pass filter) if:
1) B is higher than the crossover point you want
2) the natural rolloff is not what you need (example 1st order acoustical and you need more)

On the other hand if the FR is from a mid or tweeter, you need to create a high pass filter on a frequency > A, even if the rolloff you see before A appeals you, because driving full range a mid or a tweeter will limit severely the power you can put on that driver.

Point B for a mid works the same as a woofer, point B for a tweeter should be a non issue as it should be more or less at 20KHz (so do nothing).

Ralf
  Reply With Quote
Old 19th February 2015, 01:33 PM   #4
system7 is online now system7  United Kingdom
diyAudio Member
 
system7's Avatar
 
Join Date: Aug 2008
Location: Portsmouth UK
The first thing you need to understand is that the cone breakup region is reasonably constant for ANY driver. A 8" breaks up at 3kHz, a 6" at 5kHz and a 5" around 7kHz. That's geometry. This is an 8" paper cone with a simple coil.

An externally hosted image should be here but it no longer works. Please upload images instead of linking to them to prevent this.


By using a more damped material for the cone, like plastic, or a big 8" or 10" heavy paper cone you have natural rolloff at these frequencies which helps.
H1471-08 CA22RNY

With small paper or metal cones you will need some more filtering effort.
H1456-08 ER18RNX

Cone breakup isn't always obvious on a frequency response. But the S shaped kink in phase at 3kHz for a paper 8" below is the first serious breakup mode.
Attached Images
File Type: png S7 Series Filter Cone Breakup 3kHz FR.PNG (19.0 KB, 40 views)
File Type: png S7 Series Filter Cone Breakup Phase 3kHz.PNG (23.7 KB, 40 views)
__________________
Best Regards from Steve in Portsmouth, UK.
  Reply to this post

Reply


filters/crossovers a little understanding neededHide this!Advertise here!
Thread Tools

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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Need some help understanding high & low pass filters & crossovers Haz Multi-Way 13 12th May 2012 02:03 AM
Phase shifts with 'all pass' filters - understanding sought! HankMcSpank Solid State 25 11th February 2010 10:13 AM
Understanding AC line filters better pjpoes Parts 0 18th May 2008 05:08 PM
Understanding interpolated FIR Filters jackinnj Digital Source 0 24th March 2005 12:45 PM
Active crossovers and notch filters Saurav Multi-Way 15 26th February 2004 09:25 PM


New To Site? Need Help?

All times are GMT. The time now is 08:05 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki