timone, there are a few different ways to get those tones. There are some that can be found online, and there are others that come on CD. I bought
this test tone CD from av123.com that sells for $4.95 including shipping. It goes down to 16Hz.
I'd suggest that you start your receiver volume out at a low level and then work your way up depending on what SPL you measure. The disc that I bought has pink noise as the first track, and that helps you set the volume on your receiver. As a starting point, you could use that track to set the receiver volume so that the SPL measures 70dB on the SPL meter.