Do YOU have a flat frequency response in your room?

@duckworp , I agree that that once you have a flat frequency response component upgrades can provide many benefits you simply can't measure with one microphone and a computer. We listen with two ears so things like soundstage can't be measured. My premise is to dial in whatever your preferred FR is before trying to change other parameters.

DSP is very limited in what it can correct. According to the paper I posted in section 2.4 Room Equalization is a Misnomer:

Equalization is very limited in what it can “correct,” yet the notion that changing the signal supplied to a sound system consisting of an unknown loudspeaker in an unknown room can “equalize” or “calibrate” a system is widespread. In the context of a practical application where there is an audience of several listeners conventional equalization cannot: • Add or remove reflections • Change reverberation time • Reduce seat-to-seat variations in bass • Correct frequency dependent directivity in loudspeakers • Compensate for frequency dependent absorption in acoustical materials and furnishings. The exception is in the highly reflective sound field at very low frequencies.

@esarhaddon 

Your premise is potentially fallable. You assume engineering and production for best sound quality may have been the goal…which isn’t always the case. More than a few productions may have been mixed to optimize sound from a boombox …or an automobile system…or earbuds.

Ideally I would love to hear what the original intent was provided they each shared sound quality as a goal. But alas, no two do to the same level or degree of honesty.

Flat frequency response at the listening position is not desirable.  What most people want is a smooth frequency response curve with varying degrees of downward sloping as frequencies increase.  Room decay times are actually just as important as frequency response.

@retiredfarmer , that is a little harsh to dis the whole country because of one anechoic chamber

@esarhaddon , you make a great point. Are you hearing what the engineer heard when they mixed it. That is called the "circle of confusion" and is one of the topics that paper attempts to address. Check out the diagram (Fig. 1) on the second page and then the author states:

Significant uniformity throughout the process is needed if customers are to hear what the artists created. This is the “circle of confusion” shown in Fig. 1. For the system to function sensibly, mixing and mastering engineers need to experience sound that resembles what their customers will hear. Acknowledging that audio systems in widespread use are not necessarily very good, audio professionals in the music side of the business have often used “bad” loudspeakers to check their mixes. The problem is that loudspeakers can be “bad” in countless ways. The dominant characteristics of small low cost audio devices are a lack of bass and reduced sound output capability—a high-pass filter in the playback signal path is a practical way to simulate that. The author’s book [1] (chapters 2 and 18) illustrates the past and present situation in consumer and professional-monitor loudspeakers. Flat on-axis frequency response is clearly the engineering objective for most of these systems