Do YOU have a flat frequency response in your room?

Except this just isn't true.  Flat = super bright sounding.

kota1

The most basic truth of audio for the last 30 years is listeners prefer a flat frequency response.

Opinion stated as fact.

It isn't just an opinion, it's provably false.  The OP has done very little research.

Fletcher Munson Curve with emphasis on, sometimes less is more.

@mikelavigne , I agree that is a better question, asking if you have the frequency response that you want. To get that answer though you would have to measure it and compare it to a flat response to determine which is preferred. Some speakers are designed to take out the harshness around 2 to 4hz and build in a "gundry dip".

Marantz has a target curve within Audyssey, there is a "Harman" curve as well, good point. Let me rephrase and say that until you know what your desired FR curve is and have achieved it, spending money on new gear is rather frivolous. You still need to measure the FR and dial it in before new purchases to avoid the dangers of an audio money pit. However, you can’t really be too far off base with simply a flat curve to get started.

@erik_squires , I have done some research, here is a good foundation. Even if you don’t agree that flat is your preference, you need to get your preferred response before buying new components. Imagine not liking your speakers, buying new ones, and then finding out the real issue wasn’t the speakers but the FR of getting the speakers dialed into the room.

From "The Measurement and Calibration of Sound Reproducing Systems-1. Introduction"

Flat on-axis frequency response is clearly the engineering objective for most of these systems. Those that deviate significantly earn lower ratings in double-blind subjective evaluations. Although there is more to be considered, a flat direct sound delivered to listeners is the basis for most reproduced sound.