Ohm load impacts output? (1 Viewer)

[robert bartsch]

I have an old Denon 3300 receiver that is rated at 105 watts into 8 ohms at THD .05%. The spec sheet from Denon says the receiver will accept speaker loads from 6 to 16 ohms but the maximum power rating is not provided into 16ohms.

I am considering the purchase of a set of 16 ohm speakers.

Will the Denon output be reduced if it is used to drive 16 ohm speakers?

Is it possible to use a set of 16 ohm speakers for the fronts and 8 ohm speakers for the rears, for example?

 

[Allan Jayne]

As a very general rule, an amp will deliver more watts given a lower impedance speaker output load (or fewer watts given a greater impedance output load).

But an amp should never be connected to an output load lower than what the amp is rated for. This can cause burnout of the amp output stages if a loud passage comes along and the amp then tried to deliver much more than its rated power.

To prevent having too low a net speaker load impedance using multiple speakers on a channel, connect the speakers in series (or in a combination series-parallel network) rather than in parallel.

Video hints: Video Technicalia Made Easy

 

[chuckg]

IF the speakers were simply resistors, then you'd get half the output (watts)with double the resistance (ohms). But, speakers are a touch more complicated than that, and the actual impedance (ohms) of the speakers varies with frequency. This is one thing that makes different speakers sound different.

So, the simple, mindless answer is: with 16-ohm speakers you'd have about 52 watts output from the amp.

BUT this does not mean that the loudness of the sound would be half. If your 16-ohm speakers are about three dB more sensitive than some other, 8-ohm, speakers then the sound level might not be very different.

See? It's all so easy!