Setting up a sub-woofer ?

[Dom]

Try this. Sine Wave Generator - I think I have got things right ? At 50 to 40Hz there's a noticeable increase in volume. I have now smoothed that out. Flattened.

 

[SpursGator]

Keep in mind that below 80 Hz or so, you are getting all sorts of resonances from every direction. And tying to measure a long bass wave with a small mic has certain limitations. Do you know about this (free) utility? Room EQ Wizard. Really excellent and it gives some additional measurements that help with this task.

One of the most useful adjustments for a sub is variable phase. I recently tuned a subwoofer that was pointed into the corner of a room and I was just pulling my hair out with the boomy bass. It was pointed away and I had remembered to reverse the phase to account for it bouncing off the wall. But I hadn't fiddled! Because the sub was farther from my ears than the sats, the bass was out of phase, which the ears interprets as slow and boomy bass. By adjusting the phase to account for that delay, I found a spot in the range where the boominess just was gone. It is surprisingly easy to find that point by ear, and by doing that first and THEN fiddling with the volume (EQ and overall), it all fell into place.

Shoppers for a sub or sub amp should not underestimate the value of a variable phase knob (or the same adjustment in software) as opposed to a simple invert switch. It absolutely can be the difference between boomy and hifi.