Originally Posted by AmerCa
Thanks for the detailed guide. Your advice comes in handy more than you think. Why? I have an Onkyo entry level receiver which doesn't have any kind of proper EQ program. Should I gather the courage to or be in need of some EQing, I'd have to do it manually. Based of what you just wrote, I could do the following:
a) download individual test tones from YouTube, and run them individually like you indicate in your procedure.
b) downloand a SPL app (not ideal, but it's no so easy to get a hand on a proper meter or microphone)
From there on, try to do my best, because I have literally never done something like this. But I wouldn't want to get too far ahead of myself; first I need my sub. Less than two months to go! ( This wait is killing me).
I feel blessed for having guys like you and mthomas schooling me on these subjects.
Thanks but I'm hardly an expert in these matters. I've just been hanging around these parts long enough and had enough experience tinkering with my own gear to impart whatever experience I've had.
In the old days (read: 1990s), everyone just went down to the local Radio Shack and got the same meter that everyone else had and just played test tones from a CD or similar source (Stereophile had a disc they published for this purpose back then).
These days you can buy calibrated USB microphones for a reasonable cost and hook them up to a PC. The PC plays the test tone through the speakers, the mic records it and everything happens quickly and precisely. The main reason I didn't do this was that I already had the old Radio Shack meter sitting in a drawer and decided to use it and do the manual process from 10-20 years back. If you had a calibrated USB mic and a proper test tone and measuring program, the software could do the entire sweep of frequencies and give you a nice pretty chart all in the press of a button....way easier than manually entering values in a spreadsheet. But both work for the sake of this exercise.
At the end of the day, you're looking for as flat a response over the frequencies the subwoofer lives in based on the crossover point you selected. If you choose a higher crossover like 80 or 100 hz, then the higher frequencies will end up being relevant, like 200 and 160 hz. I was able to ignore them since I chose a lower point like 50 hz. If you find that your subwoofer placement gets you a nice reasonably flat profile (within +/- 3 dbs of your expected frequency) then declare victory and go home. If you find that you have significant nulls or peaks in the data (I found +/- 10 dbs in some places!), then your only choices are either to move the sub (difficult or impossible in some rooms) or start changing the phase on the sub and retest.
The crossover point can also make a difference too. Originally I had chosen a higher point (63 hz) but I found it was easier keeping that flat response at a 50 hz crossover. My 2-channel tower speakers are old....Soundwave Grand Soliloquys from the mid 1990s). They are big and imposing but I never really spent a lot of time measuring their lower range until recently. And there isn't a lot of data on them other than very old reviews from the era. But SVS's Merlin database did list them as crossing over at 50 hz which is about what I saw. It's not that they don't have some depth below that but it starts falling off to the point where they clearly need help. Most modern towers roll off lower....40 hz or below these days.
In the end, the SB13-Ultra is a pretty nice and occasionally obvious addition to the music I play. I played the new Beyonce/Jay-Z album that dropped yesterday on Tidal...hip-hop usually has a deep bass groove and the music wouldn't have been the same without the lower frequencies played effectively. Best of all the sound is even, tight and controlled.