Power while running active...

[Slayerx 10+ year member]

Just a quick question since I don't fully understand how amplifiers work.

If I'm running active, and the amp is only seeing, say, 5khz-20khz, does this increase potential output power by the amp, since it no longer has to amplify and output the lower frequencies(80-5khz)? I know lower frequencies require more power. Would this make any difference at all; even if it's negligible, is it there?

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[maylar 10+ year member]

No.

 

[Fi-brations 10+ year member]

Do lower freq cause more stress and draw more power? I've never heard that before

 

[trumpet 5,000+ posts]

The output of the amplifier is dictated by the energy content of the input signal. It's not the same amount of energy at 5 kHz as 50 Hz, generally speaking. You also tend to want more output below 60 Hz than anywhere above that, so your tune is going to require less power at higher frequencies. This is greatly simplifying this so please don't jump on me for leaving things out.

 

[neo_styles 10+ year member]

I don't remember who put it this way, but I've always remembered it as such:

Amplifiers are dumb. They'll amplify anything you put into it and don't understand it anyway. Doesn't matter if they're HF, LF, or midrange signals, they'll amplify it all the same.

Hope that helps...

 

[blobb454 10+ year member]

I don't remember who put it this way, but I've always remembered it as such:
Amplifiers are dumb. They'll amplify anything you put into it and don't understand it anyway. Doesn't matter if they're HF, LF, or midrange signals, they'll amplify it all the same.

Hope that helps...

Agree. But the buttons and pots or Adjusters are kind of like passive filters. On and or off. Pots obviously for adjusting for fine tune like

 

[neo_styles 10+ year member]

Agree. But the buttons and pots or Adjusters are kind of like passive filters. On and or off. Pots obviously for adjusting for fine tune like

Thinking about it electrically, all you're really doing with the pots is widening or narrowing the band for it to amplify or, in the sake of Q adjustment (Bass EQ on monoblocks), does have some minor filtering, but at a preset level or band. However, the overall purpose of an amplifier is just to boost or diminish a signal. Without going solid state, there's no extra thought put into it. Once you're solid state, you have the ability to control things through DSP, but for all intents and purposes my original statement applies.

 

[Slayerx 10+ year member]

No.

tl;dr

I don't remember who put it this way, but I've always remembered it as such:
Amplifiers are dumb. They'll amplify anything you put into it and don't understand it anyway. Doesn't matter if they're HF, LF, or midrange signals, they'll amplify it all the same.

Hope that helps...

That's what of what I figured, but when I thought about it, how come you can set your gains just below clipping with a 50hz tone, but if you go and play a 25hz tone, you can clip? I though it was cause the amp needed more power (which it doesn't have) to play that lower frequency.

And also, with the way passive xovers work, the full amps power goes to both speakers (assuming they are the same impedance) in the corresponding frequencies that the xover directs to them. eg. 100w amp connected to comps, both speaker receives 100w, one getting 4khz up, the other 4khz down

 

[neo_styles 10+ year member]

tl;dr


That's what of what I figured, but when I thought about it, how come you can set your gains just below clipping with a 50hz tone, but if you go and play a 25hz tone, you can clip? I though it was cause the amp needed more power (which it doesn't have) to play that lower frequency.

And also, with the way passive xovers work, the full amps power goes to both speakers (assuming they are the same impedance) in the corresponding frequencies that the xover directs to them. eg. 100w amp connected to comps, both speaker receives 100w, one getting 4khz up, the other 4khz down

It's harder for the sub to hit that 25Hz note compared to the 50Hz, so the amp has to work harder to overcome the resistance to motor force the sub is providing. If it helps, just understand impedance isn't always constant in an electrical system and will fluctuate slightly. That's one thing I'll give to JL with their regulated power supplies since they found a way to work around this.

 

[maylar 10+ year member]

how come you can set your gains just below clipping with a 50hz tone, but if you go and play a 25hz tone, you can clip?

Where'd you get that from? Unless there's some boost going on at 25Hz the output of the amp will be the same at either frequency.

I though it was cause the amp needed more power (which it doesn't have) to play that lower frequency.

No.

And also, with the way passive xovers work, the full amps power goes to both speakers (assuming they are the same impedance) in the corresponding frequencies that the xover directs to them. eg. 100w amp connected to comps, both speaker receives 100w, one getting 4khz up, the other 4khz down

Sort of. The amp is a constant voltage source. The power to each speaker depends on the impedance of each speaker at that frequency and the output voltage of the amp. A perfect amp would maintain the same exact voltage across the whole audio spectrum - in fact that's what the amp's frequency response spec is all about.

tl;dr

Your question was clear enough, and the answer is still "No". You didn't ask why.