3 way without inductor? - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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 26th April 2016, 07:21 AM   #1
diyAudio Member
 
Join Date: Dec 2015
Default 3 way without inductor?

I was introduced to a person recently who -to my understanding- had created a way to generate a 3 way loudspeaker without the use of induction coils. According to him, his project was realized by only using multiple capacitors... and by multiple, I mean many, many, many capacitors,

He told me that he was able to achieve his goal through a lot of multi-amplified and digitally-processed bi and triampification which, of course makes perfect sense, when filtered through some rather exotic signal processing.

I was quite confused by what he presented to me. If he is using several amplifiers, and it is digitally processed, this makes perfect sense to me. There is nothing new here. It is akin to an electronic crossover. Hardly earth-shattering and new, conceptually. But, I am still confused by what he was speaking about.

Capacitance and no inductance.

Last edited by jazbo8; 26th April 2016 at 08:17 AM. Reason: clarification
  Reply With Quote
Old 26th April 2016, 08:08 AM   #2
Juhazi is online now Juhazi  Finland
diyAudio Member
 
Juhazi's Avatar
 
Join Date: Mar 2007
Location: Jyväskylä, Finland
Just a multi-way active speaker with dsp control for xo etc.
Minidsp is very popular https://www.minidsp.com/applications...eo-34way-xover
Click the image to open in full size.
__________________
AINOgradient speaker project
  Reply With Quote
Old 26th April 2016, 08:38 AM   #3
AllenB is offline AllenB  Australia
diyAudio Member
 
Join Date: Oct 2008
The thread title reminded me of a phase I went through building passive crossovers without using capacitors.

Inductors are not terribly practical, nor essential in electronic filters such as a line level crossover. The fact that your friend specifically mentions them suggests to me that he is making use of the analogue variety of active filter.
  Reply With Quote
Old 26th April 2016, 06:19 PM   #4
Ron E is offline Ron E  United States
diyAudio Member
 
Ron E's Avatar
 
Join Date: Jun 2002
Location: USA, MN
You can make a passive lowpass filter with a capacitor and a highpass with an inductor (both opposite from how it is normally done) but either involves a series resistor and some insertion loss. I suppose you could set yourself a challenge to make a capacitor only passive filter, but it likely wouldn't be practical, IMO.

http://hyperphysics.phy-astr.gsu.edu...c/filcap2.html
https://en.wikipedia.org/wiki/RL_circuit

Active filters generally use only caps.

There are many cheap 3 ways that only have series caps on the midrange and tweeter
__________________
Our species needs, and deserves, a citizenry with minds wide awake and a basic understanding of how the world works. --Carl Sagan
Armaments, universal debt, and planned obsolescence--those are the three pillars of Western prosperity. —Aldous Huxley
  Reply With Quote
Old 26th April 2016, 06:44 PM   #5
sreten is offline sreten  United Kingdom
diyAudio Member
 
Join Date: Nov 2003
Location: Brighton UK
https://en.wikipedia.org/wiki/Gyrator

Hi, all inductive elements can be replaced by capacitors, rgds, sreten.
  Reply With Quote
Old 26th April 2016, 06:50 PM   #6
infinia is offline infinia  United States
diyAudio Member
 
infinia's Avatar
 
Join Date: May 2005
Location: Californication
Quote:
Originally Posted by ShaneF View Post
3 way loudspeaker without the use of induction coils.
seems a pointless approach considering most voice coils themselves are inductive..but marketing always needs some sort of hook.
or just byproduct of active filtering most all do not choose expensive single sourced components like precision inductors.
__________________
like four million tons of hydrogen exploding on the sun
like the whisper of the termites building castles in the dust

Last edited by infinia; 26th April 2016 at 06:53 PM.
  Reply With Quote
Old 26th April 2016, 06:56 PM   #7
diyAudio Member
 
Join Date: Dec 2015
that's what I thought too. "Seems pointless"
  Reply With Quote
Old 26th April 2016, 07:00 PM   #8
diyAudio Member
 
John Busch's Avatar
 
Join Date: Oct 2007
Location: Hill country, Texas
Hmmmm.... It can be done passively.. it's all about driver selection. You will need a couple of caps and resistors and it usually works out close to 2nd order butter-worth. And with a nice 10" on the bottom too. Just gotta think about it a bit. The woofer selection is the key to it all.
__________________
Commercial Website: http://www.manzanitaaudiosolutions.com/index.html
  Reply With Quote
Old 26th April 2016, 07:17 PM   #9
infinia is offline infinia  United States
diyAudio Member
 
infinia's Avatar
 
Join Date: May 2005
Location: Californication
Quote:
It can be done passively.. it's all about driver selection
yes this was (is) done all the time, seen em on Yamaha low end 3way speakers. their mids are pretty sweet!
can usually spot the concave dust caps to limit high end on-axis response in mids and woofs. Special papers and doping helps cone break-up too IMO It's all about limiting the upper end response to "pistonic" motion , so the on-axis to off-axis response tracks well.
it'd be a disaster with fancy metal cones and pole pieces
__________________
like four million tons of hydrogen exploding on the sun
like the whisper of the termites building castles in the dust

Last edited by infinia; 26th April 2016 at 07:45 PM.
  Reply With Quote
Old 28th April 2016, 11:49 AM   #10
TMM is offline TMM  Australia
diyAudio Member
 
Join Date: Sep 2007
Location: Australia
Send a message via AIM to TMM
If you're padding down a mid/tweeter by use of a series resistor or L-pad, placing a parallel capacitor will achieve a 1st order low pass. It's just an RC filter instead of RL or LC/RLC.

The downside is that the impedance drops at frequency increases, and it's difficult to implement an electrical 2nd order lowpass filter without inductors (RC cascaded with another RC) unless you need to pad down the mid/tweeter a lot (10dB+), or you live with presenting an unusually low impedance to the amplifier. Using RC high passes most of the time is not practical as the capacitor will have to deal with heavy currents from low frequency content, neither the amplifier, capacitor or resistor will be happy about that.

In low cost commercial speakers using RC filters where appropriate is a valid technique to reduce cost (inductors are expensive, capacitors are cheap), especially to get 'another order for almost free' in a filter design. A 1st order lowpass may also be enough if the driver already has a steep acoustic roll-off. It's pretty dumb to try to use it to avoid inductors completely though.

Last edited by TMM; 28th April 2016 at 12:02 PM.
  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
Coil replacement TO COIL 330UH IN THE pathway regulator 7809 ? dazzz Parts 14 16th September 2013 05:52 AM
Help with Induction heating for steam jacob.jacob0 Power Supplies 16 7th February 2008 07:35 PM
Induction planars APi Planars & Exotics 12 6th August 2007 06:53 PM
Papst Induction Motor. Paul Dimaline Analogue Source 3 20th March 2006 10:24 PM


New To Site? Need Help?

All times are GMT. The time now is 07:35 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.
Copyright ©1999-2016 diyAudio

Content Relevant URLs by vBSEO 3.3.2
Wiki