Active vrs passive - Page 89 - 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 23rd December 2012, 03:38 AM   #881
diyAudio Member
 
Join Date: Jan 2008
Quote:
Originally Posted by CopperTop View Post
...Isn't a multiway speaker always going to constitute two or more sound sources with different directionality characteristics..........

As always, I'm sceptical that speaker designers know secret stuff that they're just not telling the rest of us. And in these pages I just don't read anything that convinces me that speaker design is anything but a case of following a few rules of thumb.... At least the active DSP people have some better control of things, but it's never going to be a precise science. I'd love to be proved wrong, though.
Just not comprehending all the good info? No need to be skeptical. No secrets held back here. Nothing but truth and a whole lot more.

Phase plots of my previous post are of speaker that follows rule of thumb where drivers are about 1/4 wavelength apart at crossover frequency, and thus function as single source; reflections remain coherent.

A room treats all sounds the same. If sounds entering room are realistic, at least chance exists that they will be perceived as such.

Regards,

Andrew
  Reply With Quote
Old 23rd December 2012, 05:04 AM   #882
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: Kona, Hawaii
Blog Entries: 4
Quote:
Originally Posted by CopperTop View Post
And in these pages I just don't read anything that convinces me that speaker design is anything but a case of following a few rules of thumb, and pot luck when it comes to the finer points of toeing-in etc.
If you want average good speakers, maybe. But there really is more to it than that. It's like any skill, playing a sport or an instrument. Being good means following a few rules, being great means a lot more. As your knowledge grows, you start to notice things you never did before.
__________________
Take the Speaker Voltage Test!
  Reply With Quote
Old 23rd December 2012, 05:40 AM   #883
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 Pano View Post
As your knowledge grows, you start to notice things you never did before.
And the more you learn, the more you will realize how much more there is to learn.

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 23rd December 2012, 03:58 PM   #884
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: Kona, Hawaii
Blog Entries: 4
That's the main problem, isn't it?
  Reply With Quote
Old 24th December 2012, 11:17 AM   #885
diyAudio Member
 
Join Date: Feb 2009
Location: UK
Quote:
Originally Posted by Pano View Post
If you want average good speakers, maybe. But there really is more to it than that. It's like any skill, playing a sport or an instrument. Being good means following a few rules, being great means a lot more. As your knowledge grows, you start to notice things you never did before.
Hi Pano

You've been challenged by an upstart :-)

Can you supply an nice example of how you obtain a better-than-average speaker by going beyond the rules of thumb? Are you suggesting that if we dismantled a highly-regarded commercial speaker we would begin to see strange things within it that caused us to scratch our heads? As I say, I'm sceptical. Within the drivers themselves, yes, I can imagine all sorts of subtle and clever things going on - or maybe it's just a case of basic theory put into practice solidly - but the boxes themselves..?
  Reply With Quote
Old 24th December 2012, 11:24 AM   #886
diyAudio Member
 
Join Date: Feb 2009
Location: UK
Quote:
Originally Posted by Barleywater View Post
Phase plots of my previous post are of speaker that follows rule of thumb where drivers are about 1/4 wavelength apart at crossover frequency, and thus function as single source; reflections remain coherent.
I am very impressed by your phase plots, and I like that rule of thumb, but is it as perfect as you suggest, especially at shallower crossover slopes?

Do you have an opinion on the so-called Stochastic Interleave function described here?
http://www.essex.ac.uk/csee/research...alignments.pdf
  Reply With Quote
Old 24th December 2012, 01:34 PM   #887
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: Kona, Hawaii
Blog Entries: 4
Quote:
Originally Posted by CopperTop View Post
Are you suggesting that if we dismantled a highly-regarded commercial speaker we would begin to see strange things within it that caused us to scratch our heads?
Yes, usually. No speaker (or its parts) is perfect, so getting what you want becomes an exercise in compromise. Knowing what is important to keep, what can be lost, what blends well with what - are all things that take a lot of experience. You can get lucky with "design by the rules" and you certainly should start that way to understand what's going on and to have a decent chance at a good speaker. Learn how to draw before you learn how to paint.

If you are just talking about boxes, then it's simpler, tho not simple. If you are talking about driver choice, crossover design, box design, porting, stuffing, interaction with the room, etc. - then the balancing act gets tricky.
__________________
Take the Speaker Voltage Test!
  Reply With Quote
Old 24th December 2012, 02:22 PM   #888
diyAudio Member
 
Join Date: Jan 2008
Quote:
Originally Posted by CopperTop View Post
I am very impressed by your phase plots, and I like that rule of thumb, but is it as perfect as you suggest, especially at shallower crossover slopes?

Do you have an opinion on the so-called Stochastic Interleave function described here?
http://www.essex.ac.uk/csee/research...alignments.pdf
Shallow crossover slopes:

Simulation of 1kHz crossovers with 1st order Butterworth and 4th order Linkwitz-Riley with 1/4 wave offset at 1kHz:

cross1k 1st v 4th order quarter wave offset.gif

The above pic shows ripple in 1st order filter due to summing of low pass filter attenuation band with high pass filter. As filters become steeper, ripple becomes single dip with width inversely related to filter steepness.

Continued use of low slope filters offers no advancement in speaker design. Their simplicity in design and use highly compromises coherent sound radiation.

I checked out Stochastic Interleave, and it is complex way of saying: Let's compromise on axis performance for improved off axis performance. IMO, junk.

Regards,

Andrew
  Reply With Quote
Old 24th December 2012, 04:02 PM   #889
diyAudio Member
 
Join Date: Feb 2009
Location: UK
Quote:
Originally Posted by Barleywater View Post
Continued use of low slope filters offers no advancement in speaker design. Their simplicity in design and use highly compromises coherent sound radiation.
I like it. What do you define as a low slope? Anything below 16th order, say?

Quote:
I checked out Stochastic Interleave, and it is complex way of saying: Let's compromise on axis performance for improved off axis performance. IMO, junk.
Presumably with steep crossover slopes there is less reason to use it anyway..?
  Reply With Quote
Old 24th December 2012, 04:07 PM   #890
diyAudio Member
 
Join Date: Feb 2009
Location: UK
Quote:
Originally Posted by Pano View Post
Yes, usually. No speaker (or its parts) is perfect, so getting what you want becomes an exercise in compromise. Knowing what is important to keep, what can be lost, what blends well with what - are all things that take a lot of experience. You can get lucky with "design by the rules" and you certainly should start that way to understand what's going on and to have a decent chance at a good speaker. Learn how to draw before you learn how to paint.

If you are just talking about boxes, then it's simpler, tho not simple. If you are talking about driver choice, crossover design, box design, porting, stuffing, interaction with the room, etc. - then the balancing act gets tricky.
Can you give an example of something you have done that lifted a speaker beyond average? And what led you to think it would work before you did it?
  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
Active or Passive bjackson Multi-Way 30 4th April 2005 11:49 PM
Passive into active MethMan Multi-Way 8 12th January 2005 05:58 PM
Active of passive audiobomber Multi-Way 9 31st July 2004 03:31 AM
dB loss by using passive crossovers? Active vs Passive and 1st vs 4th order Hybrid fourdoor Multi-Way 3 11th July 2004 10:16 PM


New To Site? Need Help?

All times are GMT. The time now is 02:52 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