Like me, I’m sure you’ve heard the statement in the title of this article from quite a few sound folks, some of them real “heavy hitters” in the business.

While some of them may have “golden ears,” I think these folks may be missing some of the finer points of system equalization, or more appropriately, system “optimization,” and the shortcomings of human hearing.

So let’s see if we can break this down and First, let me say that your ears are the best tools for optimizing any sound system.

After all, the only thing that really matters is that the system sounds appropriate for the application and exhibits good polar response.

Systems that measure ruler flat may not “sound good” (which in itself is pretty subjective) depending on the room geometry, room acoustics, and the intended use of the system.

I don’t think anyone will argue that a system reproducing popular music like rock, pop, hip-hop, country, etc., will probably need some pretty exaggerated low end response (read “thump”), so the LF response will be as much as 6 to 10 dB higher than the mid-range response. We would probably want some extended HF response above 6-8 kHz as well to get that “air” in the cymbals.

On the other hand, if the system is primarily used for speech reinforcement, we would probably want the LF response to roll off from around 100 Hz and down while an extended HF response may result in too much sibilance. If this were all that were involved in optimizing a sound system, then the “golden ears” of the world may be able to tune the system by ear. .. on a good day.

Wait! What do you mean “on a good day”? Well, it depends on what you’ve been doing for the last few hours, the last day or so, even years. it depends on how old you are. It depends on how many years you spent mixing heavy metal and punk bands. It depends on how well you slept last night.

It depends on how loud you’ve been listening to this system and for how long while tuning it. It depends on how long your flight was from here to there. It depends on what, if any, drugs you have taken, including aspirin and antibiotics. It depends on how much noise there is in the room. Heck, it might even depend on what you had for breakfast this morning!

I don’t think there is any argument from anyone that loud music and noises can cause temporary, even permanent hearing loss, but studies show that certain medications, too much earwax, sinus problems, allergies, and ear infections do have an impact on our hearing and perception. Basically, our hearing is not static, absolute or consistent, but many of us do have reasonably good relative hearing.

Very few of us can listen to a system in one room and then listen to a system in another room and accurately define subtle differences between the two. We probably could listen to the same system in the same room with the same conditions on two different days and think we hear something different.

That’s why we do blind A-B listening tests with all conditions being equal and we can instantly switch between sources to make our evaluations.