Miss match?

[George McLellan]

My amp says 8 ohms on the external sport jac, I’ve been using a black widow speaker. It seems to work just fine but I’m wondering if it makes any difference if the speaker is 8 or 4 ohms, I can't find any markings on the speaker.
Geo

[Donny Hinson]

The speaker in the amp is probably an 8-ohm, so adding another 8-ohm speaker would pull the total load down to 4-ohms. (Apparently, that's what the manufacturer is recommending as a minimum.) But if the additional speaker was 4-ohms, the total load would drop down to 2.67 ohms, which is pretty low. Now, you might get away with that if the volume was kept low and you weren't driving it hard. But if you pushed the amp, you'd be risking overheating the output stage, and it might burn something out.

I'd get a cheap multimeter and check the resistance of the additional speaker just to be safe. (About $10 at Harbor Freight.) The DC resistance is always slightly lower than the rated impedance, so a speaker that measures around 6 ohms DC resistance is likely 8-ohms impedance, and one that measures around 3 ohms resistance is likely a 4-ohm speaker.

Hope that helps!

[George McLellan]

Thanks Don. That’s what I wanted to find out. The speaker is a Black Widow so I can assume it’s 4 ohm as that’s the only ohm I’ve heard of.
Geo

[Jonathan Cullifer]

The speaker is a Black Widow so I can assume it’s 4 ohm as that’s the only ohm I’ve heard of.
Geo

There are several 8 ohm Black Widows, like the 1201-8.

I would disconnect the speaker and measure its resistance to verify.

[Travis Wilson]

If you wire you speakers in parallel it halves the impedance, if you wire in series it doubles it. Eg 2x8ohm parallel=4ohm; 2x8ohm series 16ohm

[b0b]

If you wire you speakers in parallel it halves the impedance, if you wire in series it doubles it. Eg 2x8ohm parallel=4ohm; 2x8ohm series 16ohm

External speaker jacks are never series. Almost all are parallel. The rare exceptions have a separate transformer coil or power amp.

Series wiring (which increases impedance) is only used internally in multi-speaker extension cabs.

[George McLellan]

Thanks Jonathan. I found a small tag by the terminals. It states. “1504 8 ohm”.
Geo