But What About The Long-Term Tests?

There still is the glitch I mentioned above. After eight months of listening to a given microphone, day in and day out, you will have a different and far more intimate sense of its quality than you can possibly obtain using ABX and ABCD tests. You will be able to hear and utilize things about the mic that go way beyond any insight you could possibly gain from a quick listen. As a result, your preferences may change.

There are also weirdnesses that occur. One of my favorite stories is about the Golden-Eared Studio Owner who felt a certain power amp gave him far superior imaging and depth compared to a previous amp. “Night and day,” he called the difference. However, when confronted with an ABX test of the two, he couldn’t tell them apart.

The usual interpretation of this is that the he was imagining things. This may in fact be the truth of it, or possibly he was attributing qualities to the amp that should have been attributed to new mic preamps, or a different recorder, or something. However, there remains the strong possibility that he was right in both cases: (a) he really couldn’t hear the difference in ABX tests and (b) he really did perceive pronounced differences in character of the amps over the long term.

So how do you reconcile this? Floyd Toole suggests that you can characterize audio differences as being big (like 10 dB, f’rinstance), medium (3 dB), small (1 dB) and vanishingly small (.1 dB). ABX and ABCD testing will instantly reveal the big and medium differences, and fairly quickly reveal the small ones, but it may not pick out the vanishingly small ones. Are such differences important? In music, you better believe it, and you ignore them at your peril. The reconciliation of the quandary comes out of the recognition that such differences are in fact small, usually vanishingly small.

There’s a tradeoff here. As you really get into working with a device, you lose perspective, becoming focused on the tree and losing sight of the forest. This is OK, but you need the perspective too, to be able to see the forest as needed. It’s fine to obsess – often it’s a pre-requisite for making music. But we need to keep in mind that when the differences between our tools are small or vanishingly small, we probably will be able to work successfully with any of them, and maybe we’d be better off basing our buying decisions on elements other than sound quality. It may also be considerably more important to concern ourselves with issues of quality in the areas where there are medium or big differences in the systems, in preference to obsessing over the micro-details.

Now in the case of microphones and loudspeakers, the differences tend to be at least medium and sometimes big. When you measure them objectively, you find they look different on paper. This is where ABCD really shines. By focusing your attention on the differences in sound quality, these tests allow you to quickly and intuitively develop a preference between systems that are obviously different.

So, when you boil it all down, the results of these tests should give you a fund of information that makes it a whole lot easier to pick out one or more of these microphones for your particular purposes. We certainly hope so, because that was the reason we went to all this trouble. So, good luck, and don’t forget to write. Let us know how you make out.

The Envelope, Please . . .