Here's a 3-pole filter with gain, if you want a sharper rolloff:

View attachment 346468

thank you

 

The circuit I saw is a "High Cut" circuit for a fairly low frequency. Others have shown actual low-pass filtering. At this point I suggest a high resolution graphic equalizer. By that I mean one with a whole lot of frequency bands, not one of those octave-band cheap ones.

 

The circuit I saw is a "High Cut" circuit for a fairly low frequency. Others have shown actual low-pass filtering. At his point I suggest a high resolution graphic equalizer. By that I mean one with a whole lot of frequency bands, not one of those octave-band cheap ones.

That'd be out of my budget range. I only need a "moderate" low range emphasis, nothing as versatile as an equalizer.
but thank you for your comment.

 

One more question (I hope) about this circuit . . .Why are the polarities of C1, C2 and C3 situated as - to +? (These come from schematics I found over the past year.)

 

Why are the polarities of C1, C2 and C3 situated as - to +?

They are large capacitors, which are typically polarized electrolytics, and can not tolerate reverse DC polarity.

 

Like "C" stated, those capacitors are electrolytic, and so they are polarized. That is much less obvious in this audio coupling application, but certainly the negative side of those three capacitors traces back to the system "common, while the positive side traces out to segments of the circuit that are a bit more positive than the "common" side. It is entirely possible that it might not matter in those three locations, but if polarity matters, the choices indicated are correct.

 

When I asked "Why are the polarities of C1, C2 and C3 situated as - to +?" I was not asking why I have electrolytics caps there.
I was questioning whether the orientation was correct, and if so, why. (I am used to seeing such a cap oriented + to - as with the signal flow.
But I am sure that's generalizing.
Anyway, I do believe that in this portion of the circuit it does not matter.