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4 Ohm Rear Speakers In 6 Ohm Amp


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#1 Swil

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Posted 19 October 2009 - 07:30 PM

I've got 8 ohm front speakers and want to use some 4 ohm speakers I have lying around as rears into one of these:
http://www.pioneer.c...s/VSX-519V.aspx
which is a 6 ohm amp.

Will I get away with it or eventually destroy my amp?

What if I stuck some resistors inline with the speakers to push them over 6 ohm?

Who was that masked man?

Help me, brave forumgoers.

#2 Basil

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Posted 20 October 2009 - 07:57 AM

I've got 8 ohm front speakers and want to use some 4 ohm speakers I have lying around as rears into one of these:
http://www.pioneer.c...s/VSX-519V.aspx
which is a 6 ohm amp.

Will I get away with it or eventually destroy my amp?

What if I stuck some resistors inline with the speakers to push them over 6 ohm?

Who was that masked man?

Help me, brave forumgoers.



Modern day electronics are very forgiving but its best to match the rears to the Front,according to Pioneer it can cause the output Transistors/Board to fail as 4 Ohm speakers can drop to 1-2 Ohms for extended periods,thats why they recommend 6 Ohm+ for most of their Amps. I'm a few Years out of Date but genuine 4 Ohm Amps.,eg Onkyo, had an additional circuit board which was activated when 4 ohm Speakers were selected.
There's a heap of info. available if you do a Google but a lot of the Technical stuff can get complex and misleading.

#3 POV

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Posted 20 October 2009 - 08:12 AM

Modern day electronics are very forgiving but its best to match the rears to the Front,according to Pioneer it can cause the output Transistors/Board to fail as 4 Ohm speakers can drop to 1-2 Ohms for extended periods,thats why they recommend 6 Ohm+ for most of their Amps. I'm a few Years out of Date but genuine 4 Ohm Amps.,eg Onkyo, had an additional circuit board which was activated when 4 ohm Speakers were selected.
There's a heap of info. available if you do a Google but a lot of the Technical stuff can get complex and misleading.



The 'additional circuit board' that i believe you are refereing too here is simply a lowering of the voltage on the main voltage rail. This reduces the amount of current the amp stage of the AVR can produce and there by protecting THE AMP form overheating. I suggest giving it a go and see what happens, the 4 ohm switch that is on some amps is a precautionary tool and please believe me they have no concern with protecting speakers......... If you reduce the current available then you reduce the headroom available (which is already severely limited on cheap AVRs) and you will therefore get better sound quality IMO by leaving the amp in it's 6 oh or 8 ohm mode, providing you are not listenning at very high volumes for extended periods then you most likely wont have any problem, especially with surrounds. It is very unlikely that you will destroy your amp as you put it as well, it will begin to overheat and you will know that there is an issue.

Running a resistor in line with your speakers is a no go. You are confusing DC resistance with impedance, which are different parameters.

check out the FAQ for more info.


EDIT: I just remebered there is an article from Colin Whatmough on this subject and as luck would have it he refers to your exact amp:

http://a1audioonline...e.aspx?ID=26428

Edited by Drew............, 20 October 2009 - 02:09 PM.