Quality of Audio – Internal recording vs external recorders

The Sony A7s has a built-in microphone and built-in speakers, both of which I wouldn’t use even for home movies (are you going to subject your loved ones to terrible audio?). But it is useful for one thing, as we shall see.

The camera has two ports for audio:

  • 3.5mm stereo jack for a microphone, mic level
  • 3.5mm stereo jack for headphones

The formats being recorded are (24-bit 48 KHz):

  • XAVC S: LPCM 2 channels
  • AVCHD: Dolby Digital (AC-3) 2 channels
  • MP4: MPEG-4 AAC-LC 2 channels

For best results, one must always use LPCM 2 channels. In this lesson we’ll compare three types of audio. Here are the recordings, converted to 32-bit 48 KHz, no compression or processing applied (right click on links and Save As… to listen to audio):

  1. In-Camera Microphone (Stereo)
  2. Lavalier connected directly to Camera (Stereo)
  3. Shotgun connected directly to Camera (Mono) (Second channel removed)
  4. Lavalier recorded by DR-60D (Stereo)
  5. Shotgun recorded by DR-60D (Mono)
  6. Lavalier to DR-60D, recorded CAMERA IN to Camera (Stereo)
  7. Shotgun to DR-60D, recorded CAMERA IN to Camera (Mono) (Second channel removed)

Which one do you prefer?

Personally, I think connecting external microphones directly to camera sound great. The disadvantage is that you need an external preamp to connect more than one microphone, and the route the audio to the correct channels.

I prefer a bit more freedom and options, so I recommend the external recorder. It has these benefits:

  • If you are buying a preamp, might as well buy a recorder
  • Up to four inputs on the Tascam DR-60D, so I can use more microphones
  • Each channel can be controlled individually
  • Each channel can be monitored individually
  • I can send a reference tone to the camera for syncing, though it is unnecessary in practice
  • I can send audio to the camera for dual recording, for safety
  • I can record two levels of audio for safety
  • I can organize my audio better
  • I can control the specifications of the audio
  • It allows me to record reference audio using the in-camera microphone
  • I can do a preroll recording
  • I can add gain, limiting, etc., on each channel, etc.

We’ll look at these benefits in more detail in subsequent lessons.

Click on the link below to the next lesson or head over to the main menu (above). If you need help with something, feel free to send me an email. I’ll try to get back to you as soon as possible.