I'd try it. Start with the volume failrly low, and turn it up. If you get as loud as you want with no ill effects of bad sounds, you're okay. Speakers usually sound bad before they give out, if it's due to excessive excursion, which is what driving guitar speakers with a bass can do. Listen for non-musical sounds, like the sound of the voice coil hitting the back plate. If you hear that, back off, you've gone too far. Also, make sure that the 2x15 is plugged into the 16 ohm jack if you're using it by itself, not the 8 ohm/extension jack.