Can we assume that the voltage sent to the speakers is the same voltage as the power supply?

Eg, if my amplifier is powered y 25 volts DC, can we assume the speakers see 25 volts? So if we have a "100 Watt" amplifier, then the speakers will see 25V @ 4A? Wondering about class D amps in particular.

 

Can we assume that the voltage sent to the speakers is the same voltage as the power supply?

No.

if my amplifier is powered y 25 volts DC, can we assume the speakers see 25 volts? So if we have a "100 Watt" amplifier, then the speakers will see 25V @ 4A? Wondering about class D amps in particular.

It can be 25Vpp from a D amp, but the average voltage is determined by the audio signal in which determines the duty-cycle of the output to the speaker.

 

average voltage is determined by the audio signal

What about audio peaks? I assume the voltage at the speakers cannot exceed the amplifier power supply voltage.

 

What about audio peaks? I assume the voltage at the speakers cannot exceed the amplifier power supply voltage.

Wrong again. A bridged amp can deliver nearly twice the supply voltage p-p. And one with a transformer output can deliver any voltage you want.

 

A bridged amp can deliver nearly twice the supply voltage p-p. And one with a transformer output can deliver any voltage you want.

Perfect answer. So, is this correct?

• a non-bridged amp without a trafo can't exceed Vsupply
• a bridged amp without a trafo can nearly double Vsupply
• a step-up trafo will multiply whatever Vmax is coming from the amp

 

Actually, as an RMS voltage, a bridged amp can reach 0.707 X Vs, and a non-bridged, non transformer one can reach only 1/2 that. Class D amps are typically bridged.

I actually misspoke in my previous post, though I did say p-p.

 

X Vs

What X Vs? Amp supply?

 

Yes, supply voltage.