Quick Question: Amp Damage?

[idiot 10+ year member]

If my amp is putting out a 4 Ohm signal to my speakers, which are 8 Ohms, which component runs the risk of being damaged?

The reason I ask is that I have a really old (and cheap) pair of speakers from an RCA shelf system that I would like to hook up temporarily to my amp (until my speakers come in and I have time to install them… a few weeks perhaps). However, I can’t find any documentation for them, and don’t know their impendence. I don’t mind blowing the speakers (they’re low quality and haven’t been used in years), but I’m wary of harming my amp.

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[Acidburn 5,000+ posts]

amps don't put out a # ohm signal

if the speakers are 8 ohms and the amp is stable at 8 or below then it'll work, they will just get less power

 

[idiot 10+ year member]

amps don't put out a # ohm signal
if the speakers are 8 ohms and the amp is stable at 8 or below then it'll work, they will just get less power

True. I was in a hurry and mistyped.

But if my amp is stable at 4 Ohms and the speakers are wired to 4 Ohms, even if their nominal impendence is 8 Ohms, I don't risk harming either component? The only difference is in power output?

 

[Acidburn 5,000+ posts]

if you put a 4 ohm load on a 4 ohm stable amp then everything should be fine

 

[idiot 10+ year member]

I don't know what load I'll be putting on the amp. That's my problem. I don't know the impendence of the speakers, or else I could wire them accordingly.

 

[Acidburn 5,000+ posts]

can't you jsut use a DMM to measure it?

 

[idiot 10+ year member]

Perhaps. But I don’t have one. So unless it’s possible to measure impendence with a multimeter, which I do have, then I won’t be able to determine that.

And since I wanted to hook the speakers up tonight, it’s not possible for me to get a DMM, unfortunately.

 

[Acidburn 5,000+ posts]

if your multimeter has a setting for resistance (ohms) it should be able to do it

 

[idiot 10+ year member]

Well, I just tried it, and I’m not sure how to interpret my results. The speakers gave a reading of ~1.3 Ohms. Then I tried my home audio speakers, which I know are 8 Ohms, and I got the same result.

So...