Quick Q on ohms

[ad0lescnts]

is it bad to hook up an amp to a speaker if the amp is 4 ohms and the speaker is 8? and also is it bad to hook up an amp to a speaker if the amp is 8 ohms and the speaker is 4?? (just examples)...

T

[Track Rat]

It would depend on the load range of the amp itself. Generally, if an amp is rated load is 4 ohms and you put an 8 ohm speaker, it's not as bad as an amp rated for 8 ohm load driving a 4 ohm speaker. The lower the impedence of the load, the higher the current draw on the amp which can roach it.

[ad0lescnts]

so you generally should just keep them matched? (4-4, 8-8)

?

T

[Blue Bear Sound]

Well, sorta.... the amp actually has an intended operating load range... some amps are rated to handle only down to 8 ohms, others handle down to 4 ohms... the better (and most expensive) handle down to 2 without problem........

When you say "the amp is rated at 4 ohms..." it generally means "the amp will handle as low as 4 ohm loads..."

To complicate it further, these aren't even absolute numbers (because these values are nominal or "averaged") -- actual load varies according the frequency of the signal being reproduced!

So anyways, it's not so much a question of matching the speaker and the amp in as much as it making sure the nominal (ie, rated) speaker load isn't lower than what the amp will handle..........

[lyonhard]

Bear is right on in his response. If you want to know a bit more on the technology this site is a bit for tech-heads but there is some good info.

http://www.edcorusa.com/gadgeteer/tech_notes/tn18.htm

Lyon

[M.Brane]

.... do not mismatch the impedence. If it's solid state as long as you don't go below the amp's lowest rating you'll be fine. Most SS amps are good down to 4, some 2 in "bridged mode". If in doubt check the manufacturer's website for specs or give 'em a call.

It really does depend on the design of the amp though. Some amps can handle no load and others can handle a dead short. Just be sure what you have goin' on before you hit that power button unless you like the smell of burnt electronics.

[knightfly]

Amen, bro - once you "let the smoke out", it gets kinda pricey to have somebody "put the smoke back in" so it'll work again... Steve