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Holy this is crazy man i never seen guys get so technical tell i came to this site i mean i thought i was technical but you guys make me look like a walk in the ball park. Anyways so which is it current or amperage? I think that amperage idea is stupid personally
Posts: 404 | From: Canada | Registered: Nov 1999
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posted
I guess what I' trying to sat is which is more important current or voltage.
They are of equal "importance", I suppose. The difference between a high current and a high voltage amp of the same power rating is a high voltage amp uses a higher voltage at it's output than the high current amp. The high current amp can, however, source more current (or in other words it can drive a lower impedance load). If you try to load a voltage amp with the same load as the current amp, the voltage amp will get toasty. If you try to load the current amp with the same load as the voltage amp, the current amp will produce less power since it's output voltage is less.
I think that a voltage amp has an advantage over a current amp. The higher voltage at the output means less power loss in the speaker wire; same reason the power company uses high voltage on their power lines. Just a thought...
Posts: 76 | From: Quispamsis, New Brunswick, Canada | Registered: Oct 1999
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You statement about the high voltage lines makes sense but doesn't really matter if you amp is reasonably close to you sub. The only thing left to do is find someone who can test this for us. Know anyone who has the funds or equiptment to try it.
Posts: 38 | From: Canada | Registered: Oct 1999
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Voltage and Current are equally important! One way of looking at it is that if a high voltage amp has no current it won't produce much power and if a high current amp has no voltage it won't give any power either. Therefore both are equally important.
Another thought how do you get 30 amps and 200 volts to a 5.2 ohm load?
This does not compute! You see say your amp produces 200 volts. When that amp sees a 5.2 ohm load it should give about 38 amps and when it yeilds 30 amps it should be at 6.67 ohms. Are these measured results or are they calculations? Just a thought.
Bottom line - you guys think WAY TO HARD! I have to go now, I need to take some Advill
The 200v @ 30 amp figure was measured at the outputs of the am while driving 6 8ohm subs.(3 in parallel / 3 in parallel then series the groups. 5.2ohms at rest.)I have just begun to take impedance measurements at 1/2 power in the van. (The Linear X meter won't let me go to the full 200v output.)
It really makes the subs JUMP!
Now if I can just get the vans accoustics to quit fighting me, I'll be in good shape!
Thunder. Because Size Does MATTER!
PS: I am in favor of high voltage amps just due to the fact that I like driving higher impedance loads and keeping the dampening factor up. (It's all about control!) :-)
[This message has been edited by Thunder (edited 11-18-1999).]
Posts: 541 | From: Pearl, MS | Registered: May 1999
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Well guys I'll give this one a try. This is a little bit before the power gets out of the amps, but may help with some insight for the rest of you.
lets start with ohms law (v = i * r) voltage = ampheres * resistance. car audio amplifiers run on the same principles that powerlines, home audio, and anything else that requires electrical power. The main difference is the input voltage which so far no one has mentioned. Once you factor in this variable you find that the reasoning is quite simple, efficiency. If you have 10,000 volts AC you will have a very small current(amps) likewise if you have 14.5 volts DC you will have high amps. take the 100watt light bulb if you plug one into your home socket you only need .9 amps if you plug a 100 watt bulb that is used in a car you will need 6.8 amps.
So if your car audio amplifier is drawing 40 amps @ 14.5 volts it is making 580 watts of power, but you then have to factor in the efficiency of the amp to get the total power that it is outputing. You really don't need to mess with the output voltage amperage at all, but I do see where it could be useful knowlege. It all comes down to efficiency for the manufactures because not all people want to have 200 amps of power being drawn from there electrical system that only gives you about 20 extra amps to play with anyway. If you take a home amplifier that puts out 580 watts on 110vac you will find that it only requires 5.2 amps to do this.
Posts: 8 | From: Fleming, OH, USA | Registered: Nov 1999
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Anybody thought of the cummulative effect of the winding count on the speaker? 4 ohm driver get's more current going to it's fewer windings. 8 ohm driver get's less current going to more windings. Winding count is also a property in field strength. hehe
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I dunno if this has anything to do with this thread... but like, say you have a 4 ohm sub. Amplifires put out X amount of power at X amount of ohms. When you lower the ohms, you get X^2 power i think, right? So if you got a power resistor that was 4 ohms, then wired it in parallel with a sub, you would get more power right? Basicaly what im trying to get at is can you use a resistor to get more power?
Posts: 223 | From: Boise, ID, USA | Registered: Jul 1999
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sure, you could lower the resistance and gain extra power out of the amplifier with a resistor. But, all of that extra power gained would be wasted in the form of heat through the resistor. So, you're not gaining anything, just putting more stress on your amplifier.
------------------ Tim Dreager Autosound Audio Technologies '87 Buick Grand National '90 Nissan Maxima SE I A S C A Pro SQ 301-600
Posts: 65 | From: Tulsa, OK | Registered: Nov 1999
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what are impedance droppers like accumatch and punch match made of. I always thought resistors but your right you wouldnt get any more power that way. Anyone want to put this whole thing to the test Orion makes high current amps and high voltage with the same rated powers. I think it should be done with the same brand of amps just to keep things as equal as possible.
Posts: 38 | From: Canada | Registered: Oct 1999
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I have been reading this string and although some of the members share my sentiments, I didn't reply up till now, but with one question; At what frequency? The only other comment I may suggest is in referance to the intitial poster's use of the term "Rated at". That term is very misleading and very INACCURATE. The specification sheets that accompany any amplifier (including affectionatly referred to "Birth Certificates"), are showing that the unit was "TESTED" under the following conditions. Power specifications are misleading if they do not include all of the following: 100 Watts per channel, all channels driven from 20Hz-20KHz +/- 3dB at 4Ohms. That +/-(X)dB is ususally missing. And ALL amplifiers are tested into a resistive load such as a resistor, which is a constant load, unlike a speaker, whose impedance changes in reactance to cone/voice-coil position in the magnetic field. which begs my question, at what frequency??
------------------ E.C. Wuz here
Posts: 1057 | From: Vancouver, British Columbia, Canada 'eh | Registered: May 1999
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The magazine "Car Sound" uses both resistive and reactive loads. Resistive for every reading(4 ohms sterio 2ohms ect.) Except for bridged. Bridged they run it at 60 hertz 1% distortion. When they run it on resistive loads they take the lowest reading for power from 20 to 20,000 hertz
[This message has been edited by k-dawg (edited 11-23-1999).]
[This message has been edited by k-dawg (edited 11-23-1999).]
posted
In reply ELI47's post, Id like to note that that +/- 3dB particularly -3dB is half power. That means 50w at some frequency's. That’s a pretty big difference, and typical I think.
[This message has been edited by mr.dank (edited 11-23-1999).]
Posts: 1269 | From: Fullerton. CA ,USA | Registered: Oct 1999
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So theioreticly i would gain an extra 30 watts from my amp, per channel. But it wouldnt really translate into power for the sub itself just waste heat on the resistor?
------------------ 2 MTX Thunder 3000 12" Power Acoustik 500x2 130watts x 2 Can you say DISTORTION!?
posted
Accumatch and RF's impedance matching equivalent are transformers. Basically two coils or sets of winding share a core so a coupling effect happens. Changing the winding count on either side changes the ratio current to voltage. 1 volt on a 10 winding primary: thereotical 1 volt on a secondary winding of 10 turns. (same amperage) " 2 volt on a secondary winding of 20 turns (half the amperage) " .5 volt on a secondary winding of 5 turns (double the amperage)
'Where there's a will there's a wall' 'Would you like a little SQ with your SPL?'
Posts: 926 | From: Sugarland, Tx | Registered: May 1999
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