Performance Comparisons

Now you're well-versed on microphones and how to connect them to your camcorder, the obvious next question is how they perform in terms of quality. To test performance, we used a high-quality, digitized recording of a woman speaking, and played back over computer speakers at a standardized volume. To create ambient sound, we left all office equipment running, which created a distinct hum of background noise.

We set up the Sony VX2000 approximately 10 feet from the speakers, and then recorded the audio using the various microphones shown in Figure 2.3. During each recording, we used the VX2000's manual-gain controls to boost the audio to an acceptable level. While you'll notice some minor volume differences in the waveforms you're about to review, the most significant differences are found in the detail captured by the microphone and the amount of noise in the signal.

Let's start by looking at the difference between the best and the worst, shown in Figure 2.6, which contains waveforms produced by the camcorder microphone and the Shure Lavaliere microphone. You'll notice that the waveform on the bottom shows higher peaks and valleys, indicating higher volume. You'll also see that when there was no speech, on the right side of the waveform, the line of noise produced by the camcorder was thicker, indicating that it picked up more ambient noise from the room than the lavaliere, which translated to a more noticeable hum during playback.

Figure 2.6. Comparing the quality of audio captured by the VX2000's microphone with the Shure Lavaliere.

Most striking, however, is the degree of detail missed by the camcorder. As shown in the picture, the speaker says the word "tutorial," and there are noticeable peaks at the Ts and I with the Shure Lavaliere. There are no such peaks in the camcorder's waveform, indicating that the onboard microphone's recording of the speech was muffled and hard to understand. If you listened to the results, you would find the Shure audio clear, crisp, and natural, while the camcorder audio would sound tinny almost like it was shot in a barrel.

Overall, the results produced by the Sony wireless Lavaliere system, and the three Shure wired microphones were very similar and all of them clearly superior to the results produced by the two shotgun microphones. This is illustrated in Figure 2.7.

Figure 2.7. Comparing the Sony ECM-HS1 shotgun microphone with the Shure Lavaliere.

Again, the Shure solution produced a higher volume, a crisper signal, and slightly less noise. Overall, while the ECM-HS1 and ECM-Z37C produced better audio than the camcorder microphone, the difference was much less striking than that produced by the microphones used closer to the source.

Don't take this as a sweeping indictment of all shotgun microphones. Both the Sony models are relatively inexpensive and rather small, and Shure, Sony, and other vendors offer larger, more sensitive models that would likely produce better results. In the price range we surveyed in this review, however, you'll produce the best results if you use or attach a mike at the source.

Now let's turn our attention to the difference in quality produced by connecting through the Radio Shack Line-Matching Transformer and the quality output by the BeachTek DXA-8. This is shown in Figure 2.8.

Figure 2.8. Comparing the Lavaliere microphones output captured via Radio Shack and BeachTek products.

As you can see, the Radio Shack approach doesn't duplicate the monaural signal to both tracks, which is why there is only one waveform. To work around this, there are hardware adapters you can buy to duplicate the audio, otherwise you'll have to duplicate the channels in your audio editor to make sure you have sound coming from both speakers. The detail on the mono signal is quite good and slightly less noisy than the bottom signal, which was produced using the BeachTek unit.

The Radio Shack waveform creates less noise because its signal is lower than the BeachTek's, which sounds much more vibrant. The BeachTek signal is also much more nuanced than the Radio Shack signal, which sounds a bit flat. Overall, most listeners would clearly find the BeachTek audio the more pleasing of the two.