EnABL - Technical discussion - Page 140 - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way

Multi-Way Conventional loudspeakers with crossovers

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 18th January 2013, 01:00 AM   #1391
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
Quote:
Originally Posted by tuxedocivic View Post
By nonlinear I mean harmonic distortion
By using a global term for something very specific that is but an infitesamal aspect of the global term is very limiting to one's thinking of the whole picture.

dave
__________________
community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi
p10-hifi forum here at diyA
  Reply With Quote
Old 18th January 2013, 01:16 AM   #1392
diyAudio Member
 
tuxedocivic's Avatar
 
Join Date: Jan 2011
Location: Ladysmith, BC
Like I said, sorry. Harmonic distortion is often referred to as nonlinear distortion in speaker testing, although there are other tests and form of nonlinear distortion. I was asking you what you think needs to be measured.

White noise is 20 to 20,but I'm not sure what software can resolve the two signals. That's why separated inputs would be better. I suppose you could do bands of sound rather than a single frequency. 1000 to 2000 at 0db, 2000 to 3000 at -10, 500 to 1000 at -20db, etc.
  Reply With Quote
Old 18th January 2013, 01:17 AM   #1393
diyAudio Member
 
tuxedocivic's Avatar
 
Join Date: Jan 2011
Location: Ladysmith, BC
I do a similar test method to measure compression which you are familiar with. I find it quite useful.
  Reply With Quote
Old 18th January 2013, 01:24 AM   #1394
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
Baby steps...

There are lots of examples where measures, theories, etc are simplified until doing it is possible with existing tech, but far too often the simplification is then used to catagorize the much more complex phenomenom. That is a trap we want to avoid.

dave
__________________
community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi
p10-hifi forum here at diyA
  Reply With Quote
Old 18th January 2013, 01:36 AM   #1395
diyAudio Member
 
tuxedocivic's Avatar
 
Join Date: Jan 2011
Location: Ladysmith, BC
But it might show something. And if it did?

If it didnt then we're neither ahead nor behind. I don't see a trap?
  Reply With Quote
Old 18th January 2013, 01:44 AM   #1396
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
It might very well, if nothing else, help push measurement techniques. Start simple and then with each baby step push towards the ulimate goal learning from the successes and failures of earlier runs.

I am encouraging you, not discouraging you

dave
__________________
community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi
p10-hifi forum here at diyA
  Reply With Quote
Old 18th January 2013, 02:00 AM   #1397
diyAudio Member
 
tuxedocivic's Avatar
 
Join Date: Jan 2011
Location: Ladysmith, BC
Cool

I may give this a go on a crappy and nice driver of similar size, use, and sensitivity to see what happens. Problem is getting WAV files that do what I need.
  Reply With Quote
Old 18th January 2013, 02:06 AM   #1398
diyAudio Member
 
Join Date: Jan 2008
Yes, lots of good measurement techniques for observing low level effects present close to stimulus.

None are used here. Avoiding measurements perpetuates time available for filling empty thread.
  Reply With Quote
Old 18th January 2013, 02:18 AM   #1399
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
Quote:
Originally Posted by Barleywater View Post
Yes, lots of good measurement techniques for observing low level effects present close to stimulus.
Please detail.

dave
__________________
community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi
p10-hifi forum here at diyA
  Reply With Quote
Old 18th January 2013, 03:30 AM   #1400
diyAudio Member
 
Join Date: Jan 2008
Single sine, multiple sine, swept sine, multiple swept sine, band pass MLS, shaped bursts, and various combinations.

As more sine waves are added to signal, potential IMD components would grow geometrically, but each IMD component taps energy from formant harmonics, pulling measured harmonic value down.

Example:

Burst stimuli are used to explore steepness of crossover slope in rejecting harmonic and IM distortion with small full range driver:

Click the image to open in full size.

Peerless 2" full range is run with two conditions: Linkwitz-Riley 24dB/oct high pass filter and with 1024 point FIR high pass filter. Each condition is also brick wall filtered with 4096 point FIR 1kHz low pass filter. The upper trace shows a sea of output above 1kHZ for LR4 high pass filter consisting of harmonic distortion and IMD. FIR results show defined much lower simple harmonic peaks against the true noise floor.

Signal passed to driver with low slope 24dB/oct filter and no signal above 1kHz results in significant output above 1kHz. Reality is dirty byproducts continue down below 1kHz. Most of this is induced by relatively low stimulus passed in driver resonance region. When this is rejected as with steep FIR filter, bandwidth is narrower, less cluttered, and produces far fewer distortion components, and at significantly lower level.

This translates directly to listening experience with these crossovers. FIR filter allows much more power before driver gets rough to listen to.

Good old battle of bandwidth and dynamic range.
  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



New To Site? Need Help?

All times are GMT. The time now is 08:09 AM.


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