cheap watts vs. expensive ones

[jesterjames]

Okay so this is kinda nerdy but I'm going to college for engineering, and this is the way I think.

All magnetism formulae that i know all use amperage, not voltage, to measure magnetic force, and therefor the force of the bass.

Now, remembering that watts is equal to: volts * amps.

Doesn't it make sense that the difference between the cheap 1600 watt amps, say a brutus, and a way more expensive one, a t1500-1 is that...

Brutus formula for watts... big VOLTS * little amperage = 1600 wattss

Where the rockford might be... little voltage * big Amps = 1600 watts

The rockford would be louder because there is more amps and therefor more magnetic force

Just a thought... anybody have an opinion?

Maybe you should look at ohms law a little bit more there bud. Your missing a crucial part of this equation. OHM's....

amps are relative to the voltage and ohm load. If you have 2 amps that put out 1600wrms at 1 ohm. The voltage MUST!! be the same. OHMS law doesnt care if you paid $1 for your amp or $10000.

http://www.the12volt.com/ohm/ohmslaw.asp

Now with that said, The t1500-1bd is a much better built amp than the brutus. Subs are a reactive load, not a static. The amp could see anywhere from 1-20ohms at different frequency's. In a perfect world power doubles for every 1/2 cut of an ohm load (400wrms at 16 ohms would be 800 at 8 ohms) last i checked though the world isnt perfect and RF disproves this theory with there CP line of amplifiers

[rusty959]

No, we are talking about output power, everything is on the speaker output side.

ah ok, I think I see what you are getting at now. I believe the differences you are talking about just deal with how the speakers handle the wattage? (efficiency at various voltage/Amperage ratios)

[audioanonymous]

Nope, not true.

After hundreds and hundreds of tests. Myself and dozens of other top SPL guys have found differences with the same power, but different volt to current ratio.

Heck yea. That's why I only prefer certain brands.

[Kandrew279]

He mentioned that the formula for magnetic force uses amperage, not voltage, which is true, but it also includes the number of coils. and the more times you wrap that wire, the more resistance you're building, causing higher voltage requirements.

[HHR Ed]

ah ok, I think I see what you are getting at now. I believe the differences you are talking about just deal with how the speakers handle the wattage? (efficiency at various voltage/Amperage ratios)

Well yes, different woofers and different wiring configs of multiple voice coils will yield different resuts.

But even on the same woofers, 2 amps of the same power, that are outputting different volts and amps, would translate to different SPL results.

There are many different amplifier topologies and designs.

An amplifier can be set to amplify a certain input voltage to a certain output voltage, and its most often thought that this cannot be done with the current, that current draw is just dependant on the impedance of the load. But its also dependant on the voltage, and the current capabilities of the amplifier devices and design.

If you upgrade amplifier components to handle more current, you can draw more current and receive more power.

Not all amplifiers are created equal, some may now amplify voltage as greatly as others, but they may have components with very high current capabilities.

And other amps may be designed to boost voltage a great amount, but the components are not capable of much current.

Then you have things like dual mono amps that are 2 boards in one case, they may be series bridged internally, or parallel bridged. These 2 options will determine output voltage and current capabilities, but can yield the same power.

[rusty959]

Going back to ohms law as stated earlier, if the ohm load is staying the same, how can the voltage and current change yet keep the same power? If the voltage goes up, the current HAS to go up at a specific impedance, and thus power goes up. Voltage can't go up and amperage go down unless the impedance goes up as well.

I don't disagree with the info stated about amplifier components needing to be able to flow a lot of current... the amp needs to be able to flow current to produce power no matter how you look at it. If it can't handle the current it can't cleanly output the voltage in order to provide the power.

[HHR Ed]

Voltage can't go up and amperage go down unless the impedance goes up as well.

Ding Ding Ding.

Speakers and reactive loads.

Impedance rise changes with different voltages. This can change current, current creates more heat, impedance rise changes again.

[rusty959]

why didntcha say so?

Impedance rise is something I don't have any experience with, so I have no reason not to go with you on that one.

[InfiniteRuckus]

some of the big differences between amplifiers is the quality of signal/reliability/efficiency. Cheap amps will often have cheaper parts.

that was my first guess when i started reading this. seems like just because they may produce the same power, the signal itself would be more clearly reproduced in a higher quality amplifier.

[ChampN252]

I kinda understand the topic at hand, but all I can really add is that one of my loudest setups was Earthquake powered. I alway hear the dirty power thing with them.