The sunn Forum

Sunn Musical Equipment => Q & A => Topic started by: green shag on May 09, 2002, 01:08:00 pm

Title: how do I determine ohms of an unmarked speaker?
Post by: green shag on May 09, 2002, 01:08:00 pm

I have (2) 12" Sunn guitar transducer speakers with the aluminum cones and they no markings. How do I determine if they are 4 ohm or 8 ohm speakers. I've installed the speakers in a 2-12 configuration wired in series. Do I double the resistance in ohms when wired in series?  :eek:

Title: how do I determine ohms of an unmarked speaker?
Post by: green shag on May 09, 2002, 01:15:00 pm

Quote

On 2002-05-09 12:08, green shag wrote:
I have (2) 12" Sunn guitar transducer speakers with the aluminum cones and they have no markings. How do I determine if they are 4 ohm or 8 ohm speakers. I've installed the speakers in a 2-12 configuration wired in series. Do I double the resistance in ohms when wired in series?  :eek:

Title: how do I determine ohms of an unmarked speaker?
Post by: JoeArthur on May 10, 2002, 08:42:00 am

The DC resistance of the voice coil is usually less but close to the impedance rating of the speaker.  For example, a 4 ohm speaker usually has a DC resistance of 3.2 ohms.  So... measure the resistance of the voice coil and round UP to the closest common impedance.

Speakers connected in series should have their individual impedances summed to determine the total impedance.  Two 4 ohm speakers will give 8 ohms total - it's double only because it is two speakers with identical impedance ratings.