BillFitzmaurice.info

so, I emailed oaudio about changing some resistors(or whatever else needs to be changed) to raise the high pass filter that's built in, but they aren't able to help with my questions.

Does anyone know a way to raise the high pass filter to 25hz(or around there) on this http://oaudio.com/300W_SUBAMP.html . Obviously, I'm looking for a solution inside the amp...not an external high pass filter.

Let me know if I'm dreaming thanks,
mike

Let me know if I'm dreaming thanks,

You are not dreaming, but it would involve wiring in a filter circuit on the input section of the amp, and implies a knowledge of the amp circuit in question.
AudioXpress had an article ( a few years back ) in which an individual did the same thing.
IMO: It's much easier to buy/build an external infrasonic filter. They are available.

Syd

The foster amp on that site has the HP filter and has all the values on how to change it to fit your needs. But as Syd pointed out, you would need knowledge of the circuitry, so you would have contact Bash for that. If that doesn't work you can always buy the f-mod filters.

And you use an LC circuit not resistors.

Syd

Sydney wrote:And you use an LC circuit not resistors.

Syd

If there's a high-pass filter on the input it is almost certainly an RC filter. LC filters are mainly used in high frequency applications and speaker crossovers.

On a certain level it's circuit hair splitting:
There will be always be a capacitor involved, sometimes additional R sometimes L
Granted RC is very common, perhaps the most common, but usage of both is found in audio amplifiers and other circuitry for filtration - highly dependent on the circuit design.
A high pass T filter is one example that comes to mind ( 2 caps and a coil )

Syd