Do these impedances matter?

When used with 2-ohm speakers, your amplifier has a rated power output of 169 watts per channel. Your speakers are rated for 75 and 110 watts. If you use that amp for the speakers, you'll need to be very cautious to avoid damaging the speakers from excess power. Turning down the gain will help. If you're using them for normal music listening, at reasonable volume levels, you shouldn't have a problem. Just don't let anyone play around with your system.