Musings: On Loudspeaker Accuracy

If you’ve ever visited an audio website or forum, you’ll have undoubtedly heard people talk about how Speaker X is more accurate than Speaker Y. It’s a curious statement for any number of reasons. Perhaps speaker X has better on and off-axis frequency response, but Speaker Y has better low end extension and dynamic capabilities. More to the point though, just what is loudspeaker accuracy?

Think about it for a second. Microphones take sound and converts it into an electrical signal. Engineers then proceed to work their magic, and eventually you have a recording. What is a recording? Regardless of format, a recording is still a representation of an electrical signal.

Next step, playback. Regardless of whether your device sends a digital or analog signal to your receiver or pre/pro, odds are the latter is converting things into the digital domain to handle things like bass management. From there, its on to the digital to analog converter (DAC) and ultimately, your amplifier. There, a low level signal is amplified into the kind of juice needed to power a set of speakers.

The speakers are obviously where the rubber meets the road. Unfortunately, the electrical signal they’re fed contains a limited amount of information. More to the point, speaker designers obviously have full control of what their product will do with that signal. Things like frequency response profile, dispersion pattern, and linear output capabilities are all considerations (among other things).

Of course, some will point to the work of gentlemen such as Dr. Floyd Toole and Dr. Sean Olive to say this is what accuracy is all about. The flaw with that argument is simple: their research is about establishing the parameters that correlate with listener preference, nothing more and nothing less. In other words, getting back to the original event is a practical impossibility, but we can at least enjoy the output of our speakers and appreciate what our ears interpret to be a reasonable approximation of a band playing in our room.

Now personally, I’d listen to the guys with the Ph.D.’s who’ve research what makes a good sounding speaker to help guide my buying choices. But accuracy? Dr. Toole talks about the “circle of confusion” for a reason folks. Accuracy is mostly a misnomer.

So what makes a good speaker that people tend to like? Under anechoic conditions (read: not normal circumstances), such a speaker should have a flat frequency response, controlled dispersion, and an off-axis frequency response that shelves down higher frequencies gradually. Ideally, such a speaker would be capable of high levels of output without a lot of distortion as well.

An example? I’d regard my speakers as good, albeit not state of the art. Detailed measurements can be found here.

An example of a speaker that doesn’t follow this design philosophy? These speakers lack a waveguide to control tweeter dispersion. As a result, there’s a lot of high frequency energy going into the room. To a listener, this could be perceived as extra brightness, or possibly, extra detail.

And there’s the rub. Some people do appreciate those “less favorable” / “less accurate” / “colored” speakers more than a “neutral” / “accurate” speaker, and there’s nothing inherently wrong with that either. At the end of the day, the best we can hope for is to buy something that makes us happy.