Introduction

This week, while shopping for a new headphones amp, I've been looking for “best” headphones amps. This begs the question: how do we best compare audio equipment?

Resolution vs. profile

Okay, so obviously on a high level the “best” audio equipment produces the “best” audio. However, what constitutes “best” audio turns out much more challenging than you might expect.

An easy (and in my not-quite-an-expert opinion, bad) definition of “best” audio relates to resolution. You could say the “best” audio equipment setup utilizes the most and loses the least music “information” in producing audio. However, as I covered in a previous post:

1. Even when listeners can tell the difference between lower- and higher-resolution audio, they often prefer the lower-resolution version provided it still has reasonable resolution.
2. Independent of your audio equipment, the people responsible for making the music often exhibit greater influence on the final fidelity of the audio.

In that post, I appealed to the general idea of a “profile” as more practical and important. Implicitly, this stands against the negative stereotype of an audiophile, who will scream about gold cables and lossless audio codecs until you stopped listening 15 minutes ago.

Taste

I find that getting into audio equipment feels a lot like getting into tea or coffee. You pour hot water over it ☕. By that I actually mean there does not exist a universal best variant, yet preferences still somewhat align, and there does exist a fluid set of commonly agreed best variants.

In effect, I cast doubt on any recommendation “for everyone,” yet I still take recommendations from people I trust. In the most extreme hypothetical position, you could claim “since everyone has different taste, you should never rely on any recommendation.” Well, maybe I and no other human have the taste to listen to my music through the carne asada at my local Chipotle's! In seriousness, I trust my tastes close enough to some people I've chosen so that what works well for them should work well for me.

Trial

Yet the extreme hypothetical position has a point. What works for someone else, even if you usually have similar taste, will not always work well for you. You should still do some exploration and experimentation within the set of trusted recommendations. To do so without draining your wallet and enthusiasm, you can try products at specialty stores or borrow from friends.

Objectivity

You need to try audio equipment because even people whose taste you trust cannot perfectly communicate audio. If they tried to send you audio, it would get encoded into some file or stream and decoded by your audio system. Rather uselessly, it would then become a reflection of your current audio system, oops!

So we use words. However, I find most people have a lot of trouble capturing the experience of sound in words. In a past life, I played in a youth orchestra. My favorite flautist told me how her tutor, a flautist for the Detroit Symphony Orchestra, instructed her to play colors. Play this section more “purple.” Excuse me? “Purple”? Unless my friend knows how to turn into a juicy wine grape, I don't know what “purple” means.

My friend understood her tutor because they shared an understanding of what “purple” means. However, for an audience as broad as people interested in audio equipment, we want a more objective characterization of sound.

In scientific terms, sound comes from vibrations. You can break a vibration down into two main dimensions: frequency (i.e. pitch) and amplitude (i.e. volume). Frequency and amplitude alone, however, do not fully characterize sound. If a flute and a saxophone played the same note at the same volume, you could tell the difference. In music theory, we call this difference timbre. Timbre arises from the mixture of frequencies and amplitudes of some sound, and how that mixture changes over time. If you wanted to visualize the timbre of a particular sound, you could make a spectrogram:

However, people in the realm of audio equipment don't care about any particular sound, they care about how the equipment produces human-perceptible sound overall. For this purpose, we can plot the relative volume produced by some system playing a frequency sweep, a tone of increasing frequency holding amplitude constant. We call this a frequency response graph:

Reading a frequency response graph requires quite a bit of contextual knowledge and experience. The site from which I took the graph has a long guide on how to read frequency response graphs. So fortunately, we have an objective expression of a “profile.” Unfortunately, you need a lot of context to make use of it.

Conclusion

Does something strike you about the frequency response graph? I'll tell you what strikes me: boredom. Very few graphs alone make me not-bored. I want someone to tell me a story about the picture I see; people engage with facts better when you weave a story around them. Here we come back to our trusted curator. Find someone you can trust to use a thorough objective basis and similar taste to provide consistent, unbiased recommendations. Then you have found your best audio equipment.