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Discussion Starter · #1 ·
Absolutely nothing


Ok all (bad) jokes asides this is more of a question about the theory of Ohms not a specifc question. I don't understand why the specific rating for Ohms matter and are quoted so much. From what have read here, as long your in the 4-8 ohm(maybe 2-16 range) it doesn't matter if the speaker and receiver match. Why wouldn't everything just be 8 ohms or even better 4 or 2 ohms like car audio. That way you would double or quadruple the power your receiver puts out.


Thanks.
 

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The ohms matters. Power amp output stages carry all the current that is passing through the load. As the load impedance goes down, the current goes up, and the higher current means increased heat dissipation. Eventually the amplifier my become overstressed and either be damaged or shut down. Driving higher impedances is not the issue--those mismatches are fine. But driving an amp into a lower than rated load can be a problem if taken to extremes--very loud, very long time, or both.
 

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I don't know much about these things, but I guess it's harder to make amplifiers that are able to output something like 2 ohms while maintaining high quality. Especially when you consider AVR systems that can have 4-9 speakers. An amp that drives, say, a 7.1 system where all the 7 speakers are 4ohm has to be pretty "powerful", and you can't really skimp on the components on an amp like that. You have to be able to deliver to required current without messing things up.
 

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Quote:
An amp that drives, say, a 7.1 system where all the 7 speakers are 4ohm has to be pretty "powerful", and you can't really skimp on the components on an amp like that. You have to be able to deliver to required current without messing things up.

The power requirements depend also on the sensitivity of the drivers. 100dB 1W/1m 4 ohm drivers need a fraction of the power that 90dB 1W/1m 4 ohm drivers.
 

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Quote:
Originally Posted by Dahlyn /forum/post/19526583

Absolutely nothing


Ok all (bad) jokes asides this is more of a question about the theory of Ohms not a specifc question. I don't understand why the specific rating for Ohms matter and are quoted so much. From what have read here, as long your in the 4-8 ohm(maybe 2-16 range) it doesn't matter if the speaker and receiver match. Why wouldn't everything just be 8 ohms or even better 4 or 2 ohms like car audio. That way you would double or quadruple the power your receiver puts out.


Thanks.


The rating itself is kind of misleading because all speakers have impedance curves and not single impedance values.


Everyone should really know the impedance curve of their speaker and then will be able to determine what amp requirements they need.


Impedance curve is an important part of the speaker design because its the load that the amp sees.
 

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Discussion Starter · #6 ·
Hmm very interesting...Thanks all.


@ Penngray -Thanks. I read something along those lines and I wasn't clear about it. That was going to be my follow up question after I got a handle on the basics. So where do they get the ohm rating for a speaker - would you say it is something along the lines of the mean, median, mode or some other way of calculating it.
 
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