subs "ohmage"

[chronicblazen 10+ year member]

okay, it took me a while to accept it, but my subs are sh!t

they're pioneer 12's 305dvc

i was wondering why it had already ****ed up 2 tsunamis that i had wired to them "wired two twelves to 1 ohm" so i decided to investigate

turns out, they're not 4 ohm as they claim to be, but both have gone down

one of them is at 3.4 and the other 3.6, both voice coils on each....

i guess this is making it lower than 1 ohm current when theyre wired the way i had em and it was too much for the amp...

does anybody know what causes this for a sub, ?

and should i burn them, throw em in a lake, through my ex's window, or my bosses truck?

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[LoudCrownVic 5,000+ posts]

This is common for all subs to have this "ohmage nuance" the more accurate the ohm reading is, i think the better the amp can work with the subs, altough I'm pretty sure that amps aren't spot on what they say. It's kind of a hit and miss type thing. For instance, I have a pair of Orion 15's. their ohm reading is now about 4.4 due to God knows what, oxidation or something, but from the factoy it's like 3.7. If this destroyed your amp is anybody's guess. I folowed those posts and what happened is totally unique to me. As for the Pioneer's, hook them up to the wall and video tape it with a digi camera. People will love it, including me!

 

[DanWiggins 10+ year member]

What you measured is the DC Resistance, Re, which is NOT the impedance of the sub. DCR (Re) is just the impedance at 0 (zero) Hz. Actual impedance of the driver is ALWAYS higher than the DCR, and typically by quite a bit. In fact, with a DCR of 3.4 Ohms, you're probably averaging close to 6 Ohms across the used range (15 Hz to 100 Hz, for example).

If you're popping amps, but not drivers, take a look at your amp wiring/setup. It's the problem, not the drivers.

Dan Wiggins

Adire Audio

 

[Strecker25 10+ year member]

id like some clarification on this too, ive got myself a multimeter with ac, dc, Ohm, etc...

when put on ohm and put to the terminals of a speaker is this the ohm of the coils, or at least close?

 

[InhumanAcura 5,000+ posts]

What you measured is the DC Resistance, Re, which is NOT the impedance of the sub. DCR (Re) is just the impedance at 0 (zero) Hz. Actual impedance of the driver is ALWAYS higher than the DCR, and typically by quite a bit. In fact, with a DCR of 3.4 Ohms, you're probably averaging close to 6 Ohms across the used range (15 Hz to 100 Hz, for example).
If you're popping amps, but not drivers, take a look at your amp wiring/setup. It's the problem, not the drivers.

Dan Wiggins

Adire Audio

/\Baller/\

 

[DanWiggins 10+ year member]

Strecker,

What you measure is the DC resistance of the voice coil, in Ohms. It has very little to do with the actual impedance of the loudspeaker.

A loudspeaker has a DC resistance (the measured impedance at rest), and an AC resistance (the impedance as it moves). When you have the multimeter hooked to the driver and set to Ohms, push on the cone. You'll see the Ohm value change all over the place. This is because the driver has an impedance that changes with frequency (and will also change with box size and type).

Bottom line - the DC resistance you measure sets the absolute lowest level you can ever see; over the used range for subs (16 Hz to 100 Hz), the actual average impedance is typically 1.3 to 1.5 times the DC resistance (or higher).

Dan Wiggins

Adire Audio