Discussion in 'Home Cinema Building DIY' started by Hysteria, Sep 2, 2004.
Any danger in running an 8ohm speaker with a 4ohm amp?.
If you do a search (or post the question) over on the "Speakers" forum you might find out quicker..... (Don't know for sure myself, an 8ohm speaker will present a higher load for the amplifier, couldn't do it much good...........)
I doubt it. It's normally the other way around you have to worry about The lower the resistive load the higher the current draw for the same power output. What is the amp in question?
Don't take this as gospel, but:
You can run an 8 Ohm speaker off a 4 Ohm amp without any problems, but you need to turn the volume up by a lot more than if you were using 4 Ohm speakers. If you want to play it really loud you may then run into distortion problems at lower volumes than if you were using 8 Ohm speakers. As suggested by Daneel, running 4 Ohm speakers off an 8 Ohm amp is definitely a no-no.
A lot of modern amps can take a wide range of Ohmage so long as you don't try and mix and match.
Haha! I like it. Don't mind me, I'm really tired.
"The ability of an amplifier to accept speakers of different nominal impedence"
As a biochemist, I make up and /or pervert the rules of nomenclature in pure sciences wherever possible.
A lot of modern amps give you the ability to use 4,6, or 8 Ohm speakers but restrict whether you can mix A and B's etc at diferent impedences (which is what I meant by ohmage)
I asked a similar question about a kajillion times to a kajillion different people and they all said different things - even Arcam support said different things depending on who I spoke to. One thing I did find out was that 8 ohm is often a nominal impedance and the mode 'ohmage' may be lower.
Alritle cool, all seems good so far.
Daneel: I've built a sub and am using an old sub amp I have to test it out. No idea what amp it is.
Your speaker will be rated 8 ohms but will only actually be rated at 8 ohms at a specific frequency. The rest of the range will be higher than this (Generally).
A lower ohmage ie 4 ohms will draw a greater current from the amplifier and thus could cause the transformer to blow! This would only occur if you're driving the speaker/amp combo hard (again generally!)
Amps can run higher than stated impedences and be OK, but they dislike driving lower than specified impedences. As long as you don't push too hard most combinations should be fine IMO.
Any further info would help to confirm this just as back up tho'!
There's a lot of good stuff here:
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