Impedance Question - 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 1st June 2006, 01:19 PM   #1
jwatts is offline jwatts  United States
diyAudio Member
 
Join Date: Jan 2004
Location: Erwin, Tennessee
Default Impedance Question

Can I estimate the frequency response of a loudspeaker by using a plot of its impedance?
  Reply With Quote
Old 1st June 2006, 03:07 PM   #2
soongsc is offline soongsc  Taiwan
diyAudio Member
 
soongsc's Avatar
 
Join Date: Mar 2005
Location: Taiwan
No.
__________________
Hear the real thing!
  Reply With Quote
Old 1st June 2006, 03:36 PM   #3
Speakerholic
diyAudio Moderator
 
Cal Weldon's Avatar
 
Join Date: Jan 2004
Location: Near Vancouver
The high end will be tough to guage but if you have the impedance graph, you can tell the resonant frequency and have a good idea how low it can go as not too many drivers are much good below it.
__________________
Next stop: Margaritaville
Some of Cal's stuff | Cal Weldon Consulting
  Reply With Quote
Old 1st June 2006, 05:11 PM   #4
jwatts is offline jwatts  United States
diyAudio Member
 
Join Date: Jan 2004
Location: Erwin, Tennessee
Default Measurements

What is the best way to determine it? Can I calculate somehow from the woofers Thielle Small parameters?
  Reply With Quote
Old 1st June 2006, 07:54 PM   #5
Speakerholic
diyAudio Moderator
 
Cal Weldon's Avatar
 
Join Date: Jan 2004
Location: Near Vancouver
Why don't you post what you know about the driver and we'll see what we can do.
__________________
Next stop: Margaritaville
Some of Cal's stuff | Cal Weldon Consulting
  Reply With Quote
Old 1st June 2006, 11:01 PM   #6
jwatts is offline jwatts  United States
diyAudio Member
 
Join Date: Jan 2004
Location: Erwin, Tennessee
Default 10 Inch Sub

I was asked to find the Thielle Small parameters and properties of a subwoofer for a friend of mine. All I need is the frequency response. The parameters I have found so far are listed below. I can set up and do a near field frequency response measurement but if I could just calc it somehow it would make my life easier.


Fs(Hz) = 33.79
Qms = 5.2537
Qes=.4616
Qts=.4883
Vas(ft^3)=.83
Bl(N/A)=7.82
Efficiency(%)=.09
Rvc(Ohms)=1.79
Le(uH)=652.19
Xmax(In) Peak to Peak = 1.17
Sensitivity 85 db@1w/1m
SdIn^2) = 51.84
Vd(ft^3) = .035
Inverted Cone Volume(ft^3) = .047
Magnet and Cone Volume(ft^3) = .092
Mounting hole ID 9-1/4(In)
Mounting depth 8 inches (In)
Continuous power 500 watts RMS
80 oz double stacked magnets
  Reply With Quote
Old 2nd June 2006, 12:05 AM   #7
diyAudio Member
 
Join Date: Nov 2004
Location: sk
Send a message via AIM to ocool_15 Send a message via Yahoo to ocool_15
your frequency response of a sub(any speaker) will be dependent on the enclosure. You can get an idea of its response <~300hz from the T/s parameters but measuring a speaker with a mic will be most accurate when done properly.
  Reply With Quote
Old 2nd June 2006, 12:08 AM   #8
jwatts is offline jwatts  United States
diyAudio Member
 
Join Date: Jan 2004
Location: Erwin, Tennessee
Default Low End

How about the low end? What is the lowest possible frequency this sub can produce? Can I get that from these parameters or impedance curve.
  Reply With Quote
Old 2nd June 2006, 12:14 AM   #9
diyAudio Member
 
Join Date: Nov 2004
Location: sk
Send a message via AIM to ocool_15 Send a message via Yahoo to ocool_15
fs is an indication. get WinISD(free!) and check how it performs, you will have cabin gain to add to the low end. This looks like a car sub that is not optimized for sealed or ported specifically.

F3 is when output power has dropped down to half and it used most often
  Reply With Quote
Old 2nd June 2006, 12:25 AM   #10
soongsc is offline soongsc  Taiwan
diyAudio Member
 
soongsc's Avatar
 
Join Date: Mar 2005
Location: Taiwan
There are three basic things that limit the low end Fo, driver area(size), and Xmax. The LinkWitz Lab site has a maximum SPL calculatorwhich is convenient.
__________________
Hear the real thing!
  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
Impedance question jetbat Tubes / Valves 4 8th May 2009 06:35 PM
diy impedance question caza125 Multi-Way 3 4th September 2006 02:54 AM
question about impedance glazarou Multi-Way 10 26th August 2006 05:30 AM
Another Impedance Question Sherman Multi-Way 25 19th March 2004 12:39 AM
Impedance Question Jhovis Multi-Way 3 20th December 2003 11:49 PM


New To Site? Need Help?

All times are GMT. The time now is 01:56 PM.


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