What creates the impedance peaks in ported cabinet? - diyAudio
 What creates the impedance peaks in ported cabinet?
 User Name Stay logged in? Password
 Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read Search

 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
 26th February 2007, 07:36 PM #1 teemuk   diyAudio Member   Join Date: Nov 2004 Location: Suomi, Finland What creates the impedance peaks in ported cabinet? A ported cabinet has two peaks in it's impedance plot: http://www.audioholics.com/productre...age001_000.gif As the lumped model of a ported speaker cabinet consists of parallel and series resonant circuits (http://www.audioholics.com/productre...p_image002.gif) I’m a bit clueless how these two peaks are actually created. A parallel resonant circuit creates a peak with “gain” but the peak from the series resonant circuit should have a “negative gain”. Are these two peaks just overlapping or is something else happening here?
Svante
diyAudio Member

Join Date: Feb 2004
Location: Stockholm
Re: What creates the impedance peaks in ported cabinet?

Quote:
 Originally posted by teemuk I’m a bit clueless how these two peaks are actually created.
Lces and Cmes results in the driver free air resonance fs.

Lceb and Cmep results in the helmholtz resonance fh.

At fh, the series circuit has a minimum, and so has the impedance of the entire circuit.

Above fh the series circuit is inductive and adds to Lces, two inductors in parallel resuts in a lower inductance and a resonance frequency higher than fs. This resonance is the higher of the two peaks in the impedance curve.

Below fh the series circuit is capacitive and adds to Cmes, two capacitors parallel resuts in a higher capcitance and a resonance frequency lower than fs. This resonance is the lower of the two peaks in the impedance curve.
__________________
Simulate loudspeakers: Basta!
Simulate the baffle step: The Edge

 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 Forum Rules
 Forum Jump User Control Panel Private Messages Subscriptions Who's Online Search Forums Forums Home Site     Site Announcements     Forum Problems Amplifiers     Solid State     Pass Labs     Tubes / Valves     Chip Amps     Class D     Power Supplies     Headphone Systems Source & Line     Analogue Source     Analog Line Level     Digital Source     Digital Line Level     PC Based Loudspeakers     Multi-Way     Full Range     Subwoofers     Planars & Exotics Live Sound     PA Systems     Instruments and Amps Design & Build     Parts     Equipment & Tools     Construction Tips     Software Tools General Interest     Car Audio     diyAudio.com Articles     Music     Everything Else Member Areas     Introductions     The Lounge     Clubs & Events     In Memoriam The Moving Image Commercial Sector     Swap Meet     Group Buys     The diyAudio Store     Vendor Forums         Vendor's Bazaar         Sonic Craft         Apex Jr         Audio Sector         Acoustic Fun         Chipamp         DIY HiFi Supply         Elekit         Elektor         Mains Cables R Us         Parts Connexion         Planet 10 hifi         Quanghao Audio Design         Siliconray Online Electronics Store         Tubelab     Manufacturers         AKSA         Audio Poutine         Musicaltech         Aussie Amplifiers         CSS         exaDevices         Feastrex         GedLee         Head 'n' HiFi - Walter         Heatsink USA         miniDSP         SITO Audio         Twin Audio         Twisted Pear         Wild Burro Audio

 Similar Threads Thread Thread Starter Forum Replies Last Post saabracer23 Subwoofers 34 8th April 2008 09:52 AM Sherman Multi-Way 25 16th July 2004 01:21 PM Goldenboy Multi-Way 6 15th June 2004 06:44 PM eStatic Multi-Way 0 20th December 2003 02:12 AM mike Multi-Way 1 25th December 2002 12:25 PM

 New To Site? Need Help?

All times are GMT. The time now is 03:21 AM.