is it watts that drive the speaker? (I know that if I put the + & - lead of my vm on the corresponding speaker posts. I get an AC volt reading which varies depending upon volume level.) But if it is watts that drive the speaker, and every watt is equal to every other watt, what is it that makes speakers sound different with different amps?
@immatthewj Watts drive the speaker. But most speakers are designed to be ’Voltage driven’. "Voltage driven’ is a short hand phrase that basically says the amp, while making power, should be able to act as a Voltage source, which in turn means that the amp can make the same Voltage regardless of load. You are familiar with what this looks like already: if the amp can double power as the speaker load impedance is halved, then its a Voltage source.
So the short hand can be confusing. However Voltage does not exist without current being present and vice versa. So in the end Watts are actually driving the speaker.
The reason amps sound different is how they make distortion on a particular speaker. Our ears convert distortion (harmonics) into tonality in the same way that harmonics of musical instruments define the tonality of those instruments. The ear is particularly sensitive to higher ordered harmonics (the 5th and above) since it uses them to tell how loud a sound actually is. But those harmonics can be masked from causing tonality if the 2nd and/or 3rd harmonic is high enough- this is why SETs seem to sound so musical despite having a lot more distortion (including higher orders) than any other kind of amp; the 2nd and 3rd harmonics are masking the higher orders.
Solid state amps often have much lower amounts of distortion overall, but the higher orders are not masked, causing the amp to sound brighter and harsher.
The most musical amplifiers are those that make very low amounts of distortion (SETs are typically 10% at clipping so they are right out) and that distortion will be the 2nd and /or 3rd harmonic, enough to mask any higher orders.
@invalid Yes, that’s true. But they advertise that pesky current thing on their website- take a look (and click on 'specifications').
Now lets do the math:
Giving the amp the benefit of the doubt, we set the speaker load impedance to one Ohm. Using the Power formula thus the Power the amp makes is the current squared. This amp does not make 160,000 Watts! They claim 6000 Watts into 2 Ohms, so the current flowing at that time is only 54.77 Amps... and if it doubles power into 1 Ohm (which it probably can do but not to full power) it would be double the current or only 109.54 Amps.
Obviously that current spec is something entirely different!! Most likely its 400Amps that flows when the power supply is shorted out for 10mS. So its really a measure of the capacitance in the power supply rather than the current that the output section can produce.