TS parameters and added series coil - 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 2nd June 2011, 07:18 AM   #1
jamikl is offline jamikl  Australia
diyAudio Member
 
Join Date: May 2005
Location: Melbourne
Default TS parameters and added series coil

I have asked this on another thread but no response. Panomaniac and a few others have suggested that sometimes a series coil should be added to the woofers on an open baffle, presumably to cut the high end a bit. Does doing this alter the TS parameters in anyway or is it only the resistance of the coil which makes a slight difference to Qes?
jamikl
  Reply With Quote
Old 2nd June 2011, 10:07 AM   #2
AllenB is offline AllenB  Australia
diyAudio Member
 
Join Date: Oct 2008
They both have an effect but the resistance is normally the only one worth worrying about, and you may even be able to ignore that.
  Reply With Quote
Old 2nd June 2011, 11:11 AM   #3
flg is offline flg  United States
diyAudio Member
 
flg's Avatar
 
Join Date: Jul 2005
Location: North East
Of coarse you are refering to Inductive Reactance? But, there is also resistance(DCR). And they both play a role in the voltage/frequency across the driver.
__________________
"It was the perfect high end audio product: Exotic, inefficient, expensive, unavailable, and toxic." N.P.
  Reply With Quote
Old 2nd June 2011, 11:36 AM   #4
diyAudio Member
 
speaker dave's Avatar
 
Join Date: Nov 2009
Location: The Mountain, Framingham
Quote:
Originally Posted by jamikl View Post
I have asked this on another thread but no response. Panomaniac and a few others have suggested that sometimes a series coil should be added to the woofers on an open baffle, presumably to cut the high end a bit. Does doing this alter the TS parameters in anyway or is it only the resistance of the coil which makes a slight difference to Qes?
jamikl
Thiele Small parameters are an idealized look at the woofer bottom corner response and as such don't capture the effect of woofer impedance beyond DCR. (As you say, impacting Qes) External crossover components should be considered as a secondary response shaping block preceeding the T/S defined woofer/cabinet response system. It is complex in the end, because high inductance can shift electrical resonance somewhat.

T/S predictions really work best for systems in 2 pi (half space) with minimal network or inductance.

David S.
  Reply With Quote
Old 2nd June 2011, 11:57 AM   #5
jamikl is offline jamikl  Australia
diyAudio Member
 
Join Date: May 2005
Location: Melbourne
Thanks to AllenB, flg and speaker dave.
jamikl
  Reply With Quote
Old 2nd June 2011, 01:27 PM   #6
diyAudio Member
 
Join Date: Jan 2002
Location: Tyrone Ga. U.S.A.
Here is a calculator to find the effect on qts with an added resistance.


http://www.mh-audio.nl/newqts.asp
  Reply With Quote
Old 3rd June 2011, 05:42 AM   #7
rabbitz is offline rabbitz  Australia
diyAudio Member
 
rabbitz's Avatar
 
Join Date: Jul 2003
Location: Newcastle, Australia
Generally keep the DCR of the inductor to < 10% of the driver's Re for a small as possible change in driver Q (Theile JAES 1976).

There is another figure of < 5% of the driver load impedance (incl impedance comp circuit) at the xo frequency.
__________________
No longer DIY active
  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
TS parameters and specs for these drivers??? Bull Multi-Way 1 9th March 2011 12:15 PM
TS parameters. who's correct??? dallaire Multi-Way 6 16th December 2007 08:03 PM
Formulas to calculate new TS values when mass added macky888 Multi-Way 8 14th February 2004 06:36 PM
TS parameters for ScanSpeak 21W6554 jq Multi-Way 0 21st May 2003 04:09 AM
Help in Testing TS Parameters r_s_dhar Multi-Way 1 13th June 2002 12:54 PM


New To Site? Need Help?

All times are GMT. The time now is 09:52 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