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THESE GUYS PHYSICALLY CUT ANOTHER AMP IN HALF WITH A PORTER CABLE TIGER SAW POWERED BY A JBL AMP FED A 60HZ SINE WAVE-

CLICK HERE FOR THE VIDEO


They do it in order to argue the advantage of high current vs. high power, and to state that lower amps and higher volts can feed subs more overall power without overheating and destroying voice coils-- (those little shiny things in speakers you can't see)


My family has sold Crown and JBL professional amplifiers for years, and now that JBL has purchased Crown, their bulletproof and innovative technology has found it's way into JBL's car audio line-- Very cool video everyone should watch--

These new JBL amps with Crown tech are some of the best money can buy, but as of now they're still kinda spendy--

I was pretty excited when I found out as Crown has been a very respected name in Pro-Audio for years and is known to build one of the best amplifiers on the planet per dollar compared to any standard. I knew these new JBL products would be in a value/dollar class of their own...

This is some good info about subs and amps work together-- Kinda funny too -- This is the sort of stuff engineers like to do with their free time--

MJHSC400

Yeah-- I thought it was awesome too--

engin_ear

iTrader: (1)

Funny!
Would have liked to see more of the analysis though, including actual comparisons of current thru each of the woofer types, vs. voltage.

MJHSC400

I'd like to understand the voltage vs. amperage advantage better, but it makes sense, and I guess the engineers just expect us to believe them--

So I wonder why amperage hurts thin wire more than voltage-- is it somehow related to the frequency of the power wave or amplitude??? I'm curious--

engin_ear

iTrader: (1)

V=IR, P=VI, and P=I2R.
Amperage (otherwise known as current, or quantity of electron flow) is what causes heating in wiring, based on the resistance of the wire, Since thin wire has higher resistance and less capability to carry current, it heats more. This is commonly known as I2R (I squared R) loss, or the power dissipated in the wiring itself.
Voltage is basically the force behind the electrons that causes their movement. You can have a lot of voltage across wiring that has a much higher resistance and still not get a lot of current flow. (Sort of like a badly stopped up drain pipe (wire) - you need a plunger (battery) with a lot of force (voltage) to get water (current) to flow. When the drain clears, its resistance goes down, and water (current) flows easily again.)
So the heat generated in thin wire by passing too much current thru it causes it, or the structure surrounding it, to melt. (BTW, this is how a fuse works, only with a fuse the current to melt it is calibrated.)
This is also why you need heavier gauge wire (4ga, 2 ga) for high-current amp power wiring - you don't want to dissipate power as heat thru the higher resistance of thin wiring. That dissipated power causes a reduction in voltage at the amp.
This has nothing to do with frequency directly. Separate discussion.

SO basically what is going on with the higher voltage amp is that they are trying to trade off current and voltage. Drop the current by 2, raise the voltage by 2, and you still have the same power. The part I'm missing is that the speaker only cares about the magnetic field generated in the voice coil, since this is what causes the suspension to move, when the field of the electromagnetic voice coil and the fixed speaker magnet attract or repel, depending on polarity. The magnetic field of the voice coil is determined by the number of windings and the CURRENT passing thru them (which is determined by the voltage applied and the voice coil resistance (2 ohms, 4 ohms etc.). I'm not seeing what this tradeoff is, but if I go back and look at equations of magnetic fields of inductors relative to voltage, there's probably something to it.
PS: The ONLY reason that 60HZ was used for the saw is because that is what it runs on for standard 120V power. If you use other frequencies thru the amp, the saw motor becomes terribly inefficient and produces more heat than movement, eventually melting itself.

MJHSC400

I understood the 60hz part--

The amperage vs voltage tradeoff made sense, I just thought I'd ask for a more detailed exp from someone like an electrical engineer--

Looks like I got one--

I could ask my neighbor, but he graduated with a 2.5 or something, and would probably say, "I don't know man, when are we goin to tha club???" --

Thanks --

DrexLex

The main point he was making was that when using a higher impedance voice coil, the current is reduced, and that means it's possible to use a thinner guage wire, hence reducing the moving mass. But to generate the same magnetic field in the voice coil, they need to add more windings, hence the mass is not really reduced.

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Morel likes to highlight their hexatech windings which increase density-- I wonder if increasing density with tighter windings from smaller wire will allow a lesser overall amt of total wire mass-

Just a thought--