I forgot to mention I've tried the sub crawl, but not sure I heard much difference to my ears, didn't use the spl meter at the time. I will also try jakeman's suggestions below from another thread for calibration. Just concerned about placement...
1. Turn off auto-calibration.
2. Calibrate all your speakers first to 75db.
3. Measure distance then set delay for each of them. You may want to set the surround speakers to slightly more delay for effect.
4. Turn off sound to all speakers.
5. Set the subwoofer volume to -7 (a quarter of the way down to leave you some room for fine tuning).
6. Run the LF sweep on S & V and adjust gain at the sub so the needle spends most of its time at 75db at your favourite seating position.
7. Go and move the sub around to see if you can get less flucuation on the SPL metre at 75db.
8. Play sound through the mains and sub.
9. Flick the phase switch to see whether 0 or 180deg has more SPL at the seating position. Leave the phase at the higher setting.
10. Measure the distance to the sub and input the delay setting for the receiver. Many subs benefit from increasing delay another 3-5 feet than the measured distance depending on room acoustics, so experiment.
11. Test with your favourite music or movie. I you want more bass increase your receiver setting not the gain at the sub.
12. Start over again at #1 and fine tune your calibration.
