Low freq amp

not directly Arduino related

I'm looking to take an audio sample, a sine wave and amplify it through an amp efficiently but the audio quality is NOT a concern. just need to take an audio signal that's already amplified @ about 100-200W and then run it through a low pass and re-amplify it.

just kind of looking for some guidance.

cminke:
not directly Arduino related

I'm looking to take an audio sample, a sine wave and amplify it through an amp efficiently but the audio quality is NOT a concern. just need to take an audio signal that's already amplified @ about 100-200W and then run it through a low pass and re-amplify it.

just kind of looking for some guidance.

If audio quality was a concern, you would not need to run the output through a low pass filter!

Paul

An [u]R-C filter[/u] gives you a slope of 6dB per octave. If that's not a sharp-enough filter you can make more-advanced filters with op-amps, and there are online resources to help you with that. A typical crossover for a subwoofer would be 12dB or 18dB per octave.

200W into 8-Ohms is 40VAC and audio line level is about 1V so you'll need a ~40:1 [u]voltage divider[/u]. The resistor values should add-up to about 10K or more. If the resistor values are too low, you'll dissipate (more) power in the resistors and you'd need power resistors

If the 2nd amplifier has a volume control you can calculate the voltage divider for a "hotter" signal. And if you are making a basic RC filter, you can just add a capacitor to the voltage divider.

The MOST efficient audio amplifier would be a class D amplifier.

Paul

DVDdoug:
An [u]R-C filter[/u] gives you a slope of 6dB per octave. If that's not a sharp-enough filter you can make more-advanced filters with op-amps, and there are online resources to help you with that. A typical crossover for a subwoofer would be 12dB or 18dB per octave.

200W into 8-Ohms is 40VAC and audio line level is about 1V so you'll need a ~40:1 [u]voltage divider[/u]. The resistor values should add-up to about 10K or more. If the resistor values are too low, you'll dissipate (more) power in the resistors and you'd need power resistors

If the 2nd amplifier has a volume control you can calculate the voltage divider for a "hotter" signal. And if you are making a basic RC filter, you can just add a capacitor to the voltage divider.

Can this work in tandem(but not at the same time) with a low power audio signal that would be a standard line level un-amplified audio?

ideally id like it to be able to sens whats being input and direct it accordingly but I figure I could just use a 2 pos, switch to open one and close the other so only one is working at a time.

Is there a way to make a level sensing variable divider? The Input may vary between 100W up to 200W