There is really no substitute for a good parametric eq. All systems, when mated to a set of speakers, will lack some frequencies somewhere. What the parametric eq does is allow for slight gains and cuts to get rid of "muddy" bass and "harsh" highs, as well as everything in between. All types of professional bands as well as audio engineers use them. The latest gadgets out are digital surround eq's that allow you to tailor each channel with a wider range of flexibility. Your jaw would drop if you were to take advantage of a good parametric or digital eq with your speakers. Just upgrading a receiver or amplifier is ignorant of what really makes your speakers come alive. These eq's, sometimes built into the higher end receivers, are paramount to tailoring the sound to your room acoustics.