Welcome Novalis!
One more thing I'll add to the above is that I would be very careful about using that receiver to play your new speakers loudly as damage to the speakers might result.
Most speakers can absorb pretty high amounts of power, as long as the signal is clean. When an amp is overdriven (clipping) or your getting some other types of funky crackling, etc., the speaker is not being asked to reproduce musical waveforms (generally somewhat smooth and "rounded"), but jagged waveforms produced by the crackles or overdriven amp. These can damage speakers at lower volumes much more easily than a clean, loud signal.
