About $90 for a good calibrated mic and the measuring software is free.
The UMIK-1 is an omni-directional USB measurement calibrated microphone providing Plug & Play acoustic measurement. From speaker & room acoustic measurement to recording, this microphone provides low noise and accurate results you can rely on.
www.minidsp.com
REW is free software for room acoustic measurement, loudspeaker measurement and audio device measurement and analysis
www.roomeqwizard.com
That combined with SVS' Pro app might help you get it dialed in pretty well, but REW isn't exactly plug n play. You'll need to do some homework to learn to use it effectively, but it's really help me a lot. It does take some work tho, so it comes down to much you're willing to commit to the process.
Blending a sub by ear without any tools is a little trickier but doable. I'd recommend experimenting with that 60 hz filter. A little bit higher like 80 hz might give you a little more punch, but it might also make things a little muddier since you're not working with a proper crossover.