Determining a nominal impedance of a finished speaker
 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
 25th October 2008, 12:00 PM #1 rabbitz   diyAudio Member     Join Date: Jul 2003 Location: Newcastle, Australia Determining a nominal impedance of a finished speaker I've been trying to find if there is any set guidelines to determining the nominal impedance of a finished loudspeaker. You get your peaks and dips in the impedance plot and wonder if it's a percentage added to the lowest impedance, or average over a certain portion. I'm looking how it applies for amplifiers that specify say 4 ohm min impedance and am wondering how low the dips can go and for how much of the plot. __________________ No longer DIY active
 25th October 2008, 12:46 PM #2 speakerdoctor   R.I.P.   Join Date: Sep 2006 Location: New England The best way I know is to run a test with a Woofer Tester. It will show you the complete imp. plot for the entire freq. spectrum. Then you can find the lowest impedance point along the curve and decide if it's a real problem for your amp. __________________ "It's all about the music!"
 25th October 2008, 12:57 PM #3 BobEllis   diyAudio Member     Join Date: Sep 2003 Location: Upstate NY How low an impedance dip an amp can handle depends on many factors - the magnitude and phase of the load, the signal level at the dip, the heat sinking, number of output devices, how aggressive the protection circuit is, etc. For a bit of a rule of thumb, if your worst dip is to 3 ohms or greater with less than 45 degrees phase, you're probably safe with any 4 ohm rated amp. Worse than that (greater phase angle, lower impedance) then look for an amp with lots of output devices and massive heat sinks.
 26th October 2008, 01:49 PM #4 rabbitz   diyAudio Member     Join Date: Jul 2003 Location: Newcastle, Australia Thanx for the replies. I've got a dip down to 3R6 and 22° phase. My AKSA 55 has no problems with it but I tried a new Yamaha A-S1000 last week. The day after running the speakers the Yamaha went belly up stuck in protection mode when running other speakers that have a minimum impedance of 6R9 and 4° phase. I'd say the amp has an internal problem not related to the speaker as it's stuck on protection mode with nothing attached. __________________ No longer DIY active
 26th October 2008, 02:00 PM #5 HK26147   diyAudio Member   Join Date: Jan 2008 I use WTII and also recommend it. I think you are right about the defective amp. I have used the same amp for over 25 years and put a wide variety of cabs ( mostly DIY ) on it. I have observed the effect of EPDR but have not had it cause a problem.

 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         Holton Precision Audio         CSS         Dx Classic Amplifiers         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 Ted205 Multi-Way 4 10th September 2008 11:26 AM SamClassA Multi-Way 10 28th September 2006 09:17 AM goskers Solid State 1 6th April 2003 01:24 AM GeniX Multi-Way 3 14th October 2002 03:40 AM

 New To Site? Need Help?

All times are GMT. The time now is 11:56 PM.