Confused on 4-8 ohms

[markyefs]

I Have Just Purchased A Yamaha Rx-v357 Av Amp , On The Back Of The Amp It Says Speaker Impedance 6-8 Ohms , But My Home Cinema Speakers Have A Impedance Of 4 Ohms (60w Max) , I Have Contacted Where I Brought The Amp From And They Say That It Will Run The Five 4 Ohm Speakers Fine . But Could You Please Tell Me Is This Correct ,or Will It Damage The Amplifier.,

Just Need A Bit Of Help Here , It Seems To Be Working , But Dont Want To Damage It !!!

 

[markw]

As long as you don't crank it you'll be fine.

4 ohm speakers draw more current than higher impedance speakers. The manufacturer's specifty the higher impedance speakers moreso as a hedge against the amp overheating as opposed to any real damage. Odds are that if you run out of power your amp will simply shut down until it's cooled off.

 

[mulester7]

I Have Just Purchased A Yamaha Rx-v357 Av Amp , On The Back Of The Amp It Says Speaker Impedance 6-8 Ohms , But My Home Cinema Speakers Have A Impedance Of 4 Ohms (60w Max) , I Have Contacted Where I Brought The Amp From And They Say That It Will Run The Five 4 Ohm Speakers Fine . But Could You Please Tell Me Is This Correct ,or Will It Damage The Amplifier.,

Just Need A Bit Of Help Here , It Seems To Be Working , But Dont Want To Damage It !!!

.....Markyefs, hook them up and enjoy....if you hit "thermal cutout", you will know....no charge.....

 

[markyefs]

Thanks ..what About Differnt Speakers

Thanks , i also have some missions that i could use on the front, but these are 6 ohms , would this be tempting fate if i included theses. eg ...2 x back at 4ohms 1 x centre at 4 ohms and 2 x front a 6 ohms.

 

[rschleicher]

Generally speaking you will be fine with lower-impedance speakers all around as long as you only have one set of speakers hooked up.

It is also worth repeating that the lower-impedance switch setting on the back of Yamaha receivers basically just limits the current. This provides some level of protection against possible thermal overload, but also limits the maximum power that can be delivered before clipping occurs. My contention has always been that clipping during short-term transient peaks is a far more likely problem than having thermal overload. Thus, my advice is to leave the switch in the 8-ohm position, regardless of the impedance of the speakers that are hooked up. This will enable your receiver to put out its full power capability during transients. Tests of Yamaha receivers into 4 ohm loads show that the power delivered is much higher with the switch in the 8-ohm position, than with the switch in the lower-impedance position. That said, it is always a good idea to watch out for your receiver getting too hot, if you have 5 or 7 of the channels going at high volume levels.

If you send an e-mail to Yamaha's web site they will confirm as much.