Hi,
I have Outlaw 1070 receiver and Klipsch bookshelf and subwoofer. When calibrating speakers, I used receiver test tone and adjusted all speakers and subwoofer to have the same readout (dB) as measured by SPL meter at the listening position (based on the Outlaw receiver manual instruction).

I read some discussions on the net that we should adjust the subwoofer output to a few dB higher than other speakers to achieve the balance between speakers. It is because of our sensitivity to low frequency and high frequency. What do you think?

Thanks,
Think Green

My recommendation is generally to trust the SPL meter (keeping in mind that most SPL meters are a bit inaccurate at low frequencies - there's an adjustment factor chart for Radio Shack's meter in SV Sound's subwoofer setup FAQ) to calibrate the system, but to not be afraid to adjust slightly after that to achieve the sound that you like. Personally, I run my sub at the calibration setting, but plenty of people run a few dB "hot" to get a bit more punch from the low end. Bottom line: your ear knows best what you need.