by GlassWolf » Sat Apr 01, 2006 6:04 pm
I'm not sure what they're thinking then, but also remember as you go up in power (higher voltage, lower load, etc) you lose more to heat, so the calculation is never exact, and you still need to figure for efficiency which can affect input power to output power by as much as sixty percent.
Keep in mind when you talk about RMS power ratings though, you're talking about continuous power at full volume with a non-reactive load, and a tone generator running 20-20,000Hz pink noise. In short, the power you'll actually put to speakers at normal listening volumes with music playing is a small fraction of that power rating in reality. The rest is just dynamic headroom.
With that in mind, it's easier to talk about percentage differences when talking about power differences of an amp with an unregulated power supply at 12 or 14 volts than it is to ask about "how much power" you'll really get.
If you have such an amp, you'll get 20% more power (approximately) at 14.4VDC than you will at 12VDC.
That's what you really want to know.
Then you can figure that twice the actual power to a speaker yields a +3dB increase in volume. This is the same increase as adding a second identical speaker without increasing the power at all.
A +10dB increase in output is equal to double the audible volume, or increasing power by a factor of ten.
The result of a 20% increase in power is barely audible, if at all, especially when considering the dynamic nature of music to begin with.
I'm not sure what they're thinking then, but also remember as you go up in power (higher voltage, lower load, etc) you lose more to heat, so the calculation is never exact, and you still need to figure for efficiency which can affect input power to output power by as much as sixty percent.
Keep in mind when you talk about RMS power ratings though, you're talking about continuous power at full volume with a non-reactive load, and a tone generator running 20-20,000Hz pink noise. In short, the power you'll actually put to speakers at normal listening volumes with music playing is a small fraction of that power rating in reality. The rest is just dynamic headroom.
With that in mind, it's easier to talk about percentage differences when talking about power differences of an amp with an unregulated power supply at 12 or 14 volts than it is to ask about "how much power" you'll really get.
If you have such an amp, you'll get 20% more power (approximately) at 14.4VDC than you will at 12VDC.
That's what you really want to know.
Then you can figure that twice the actual power to a speaker yields a +3dB increase in volume. This is the same increase as adding a second identical speaker without increasing the power at all.
A +10dB increase in output is equal to double the audible volume, or increasing power by a factor of ten.
The result of a 20% increase in power is barely audible, if at all, especially when considering the dynamic nature of music to begin with.