How important is a flat response?

I second what Ptmconsluting wrote.

Ethan Winer is a noted acoustician and here's a link to a discussion forum he moderates. Notice the graph of the bass response in his personal room. It's definitely not flat. Room modes make it virtually impossible to attain flat response.

I am using a panasonic digital receiver and philips 963 dvd player with Piega p10 speakers using home depot cables. Could the equipt. have any effect on the response? I am getting a Rowland concerto in 2 weeks and better cables. I will test it out when i get them hooked up. Any body used the parc device? How dramatic was it? I thought i heard a review and it said it was effective but "subtle".

Of course equipment can influence response. Much of the peaking comes from the speakers, speaker-room interaction, and amp-speakers coupling (usually less so). You have good speakers.
Look into the room & speaker placement to reduce modes.
You want to trim the peaks. Leave the "valleys" alone for now:)
However, wait till you get your new amp, to see what's going on there.

It depends how important it is to you. Achieving flat response could be part of the learning process,and it is doubtlessy important.However, I do not think I would recognize it. I think I assign it importance because it is held as one of the markers of an accurate system and a pathway to fidelity. I value that very much, even if only in an ideal.And I would be pleased to be able to descern the difference, which perhaps I will someday. But as it stands, my system colors recordings unbelievably and I go happily along.I imagine the degree of its value to your listening would arrive with your exerience of it, so that you had some way to compare.

A judiciously treated room will transform your system from a "bar sound" to that of a "concert hall". It will not fix the response of a flawed component.