DCR variance on driver?

Top Shelf · 22nd November 2010, 04:40 PM

Hey guys/ gals has anyone run into this, I have a woofer that originally measured
6.5 ohms and the resistance has been going up. 12, 13.6, 113, 1k, 23 Mohms. Could
this be a loose connection or something else?
I have tested it with 2 different meters... Same thing, any ideas?
No I haven't been using it.

whgeiger · 22nd November 2010, 06:10 PM

Quote:

Originally Posted by Top Shelf

Hey guys/ gals has anyone run into this, I have a woofer that originally measured
6.5 ohms and the resistance has been going up. 12, 13.6, 113, 1k, 23 Mohms. Could
this be a loose connection or something else?
I have tested it with 2 different meters... Same thing, any ideas?
No I haven't been using it.

Suspect that a cold solder joint in the voice coil circuit has oxidized over time. Hopefully it is at a terminal. If this is the case re-solder both of them. Heat sink the voice coil leads when doing this.
Regards,
WHG

Top Shelf · 07:11 PM

Quote:

Originally Posted by whgeiger

Suspect that a cold solder joint in the voice coil circuit has oxidized over time. Hopefully it is at a terminal. If this is the case re-solder both of them. Heat sink the voice coil leads when doing this.
Regards,
WHG

Thanks , I had checked resistance across the leads @ the spider so this is probably a lead/vc
connection problem..... Shiite!

DcibeL · 23rd November 2010, 02:47 AM

Hate to state the obvious, but wiggle the leads and move the cone with your meter connected.

Top Shelf · 23rd November 2010, 03:52 AM

Tried that before, got a varying resistance with cone movement not with wiggling the leads but then again the
leads are sewn into the last two pleats of the Spider.

head_unit · 23rd November 2010, 05:28 PM

to clarify, your measurements are days apart?

It would be an entirely different thing if you measure DCR and while you are watching the meter, the impedance goes up and up and up. That would imply a capacitor is in-line and charging or some such.

By the way-23.4 Mohms? that sounds like not even a connection.
--> Are your sure your METER leads aren't fritzy?
that's happened to me a few times, they were slowly breaking internally.

Be sure when you make these measurements the lead wires are well socketed, and lying on something so they are not flopping around.

richie00boy · 23rd November 2010, 06:11 PM

Moving the cone will throw the meter reading right out as it's putting voltage back into the meter.

22nd November 2010, 04:40 PM	#1
Top Shelf diyAudio Member Join Date: Apr 2010 Location: Midland, Ontario	DCR variance on driver? Hey guys/ gals has anyone run into this, I have a woofer that originally measured 6.5 ohms and the resistance has been going up. 12, 13.6, 113, 1k, 23 Mohms. Could this be a loose connection or something else? I have tested it with 2 different meters... Same thing, any ideas? No I haven't been using it. __________________ JEREMY M_________________________________ I like it loud, BUT NOT TOO LOUD!.... Hey do you hear that high pitched ringing sound ?

23rd November 2010, 02:47 AM	#4
DcibeL diyAudio Member Join Date: May 2003 Location: Saskatchewan	Hate to state the obvious, but wiggle the leads and move the cone with your meter connected. __________________ The power of Science compels you!

23rd November 2010, 03:52 AM	#5
Top Shelf diyAudio Member Join Date: Apr 2010 Location: Midland, Ontario	Tried that before, got a varying resistance with cone movement not with wiggling the leads but then again the leads are sewn into the last two pleats of the Spider. __________________ JEREMY M_________________________________ I like it loud, BUT NOT TOO LOUD!.... Hey do you hear that high pitched ringing sound ?

23rd November 2010, 06:11 PM	#7
richie00boy Did it Himself diyAudio Member Join Date: Nov 2003 Location: Gloucestershire, England, UK	Moving the cone will throw the meter reading right out as it's putting voltage back into the meter. __________________ www.readresearch.co.uk my website for UK diy audio people - designs, PCBs, kits and more

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23rd November 2010, 05:28 PM	#6
head_unit diyAudio Member Join Date: Feb 2004 Location: Los Angeles	to clarify, your measurements are days apart? It would be an entirely different thing if you measure DCR and while you are watching the meter, the impedance goes up and up and up. That would imply a capacitor is in-line and charging or some such. By the way-23.4 Mohms? that sounds like not even a connection. --> Are your sure your METER leads aren't fritzy? that's happened to me a few times, they were slowly breaking internally. Be sure when you make these measurements the lead wires are well socketed, and lying on something so they are not flopping around.

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