Can wrong ohms speaker kill a system?

[swee'pea99]

I have an old Braun radiogram, which I'd like to check out, but this would mean attaching a speaker. There's no marking indicating what ohm rating any attached speaker should have. I happen to have a couple of speakers hanging around, and would like to plug one in, just to make sure there's actually a signal coming out (the thing hasn't been used in 30 years), but I'm afraid of blowing the amp. Is this possible? Or would it just come out very quiet or loud or something? This is purely for a test; I don't plan on connecting it for any more than a few seconds. Thanks.

 

[Sh4rkyBloke]

Don't think it would work if the ohmage is wrong - just be a case of 'too much resistance' for the amp to output against... can't see it doing any damage as it's not feeding anything back to the system. Then again though, I'm not a hi-fi buff.

 

[Ticktockmy]

8 Ohms is the norm for older gear

 

[Panter]

I destroyed a car stereo once by using speakers with the wrong impedance

 

[mark i]

If the resistance (ohmage as you quote) is too high then there will be less current flowing in the speakers and the amplifier. It should not do too much harm, but you may not hear much.
If the speaker is significantly too low in resistance then the current will be correspondingly higher. If this current gets too high then it will damage your amplifier, unless there is protection in the amplifier. Probably try the highest resistance speaker first and see how you go?

 

[Spinney]

Have you got a multimeter? Can you see if there is any voltage between the speaker outputs?
(No idea if this would work or not, but might be worth a try).

 

[TheDoctor]

Keep the volume low and it should be fine. It's having an impedance mismatch with high power that blows things up. And if it's old, you may have a valve amp, which are more tolerant anyhow.
[/electronic engineer hat]

 

[Dan B]

What mark said: too low is bad, too high just means it will be less loud

 

[swee'pea99]

Thanks all. Hmmm, well if 8 ohms is standard, then the 6 ohm ones I have are a bit on the low side, but I guess if I keep the volume way down it should be ok...(it almost certainly is valves - it's from the early '60s).