Two Simple Steps in Capturing Clean Audio
Watch the video for two simple steps to capturing clean audio on DSLR cameras and camcorders.
Capturing professional sound is important to your video productions. It should also be easy and hassle free. That is why at Beachtek we’ve always strived to design DSLR and Camera adapters that are powerful and simple to use, without compromising sound quality.
In order to get good clean audio, you just need to perform two simple steps:
- Reduce the camera gain to reduce the hiss.
- Set the proper recording levels.
Here is why these two steps are critical in achieving the best possible sound.
Most Camera preamps are rather noisy at high gain. It is quite simple: The higher the gain, the higher the noise. Therefore, you want to reduce the gain as much as possible. That will effectively get rid of the noise. However, reducing the gain will also reduce the signal level of your audio and will most likely result in a very low recording level. To compensate for this, you need to use a good quality, low noise external preamplifier. This will provide a strong signal to the input of the camera which will not require much further amplification from the internal camera preamps. This is the key to capturing very clean audio. We have basically increased the signal-to-noise ratio of the captured audio by replacing the noisy gain of the camera preamps with the very clean gain of the external preamplifier.
The second important step is making sure that you are recording at the proper levels. For this you must use a VU Meter – either the one built into the camera or an external VU Meter if the camera does not have this feature. A VU Meter is simply a gauge that shows what the relative recording levels are. The maximum recording level is usually indicated at the 0dB mark. Any audio recorded over this level will usually result in clipping and distortion so you want to record at a lower level than this. However, you don’t want to record at too low a level as this will bring your signal near the noise floor of the preamplifiers and result in excessive hiss. The ideal recording level for most DSLR cameras is an average reading of about -12dB. This gives you enough headroom for any transient peeks that may occur so that you don’t bump into the 0dB area and clip the signal. This recording level will also keep you well above the noise floor to provide you with clean audio. This is how to maximize the signal-to-noise ratio.
So now we know that we need a low noise external preamplifier and a VU Meter to get the best audio, the DXA-SLR ULTRA and the DXA-POCKET adapters are designed for just this purpose, with powerful low noise preamplifiers and VU Meters.
As an example let’s look at a typical set up, using the DXA-SLR ULTRA to capture clean audio directly to a DSLR camera, which will always be in sync with the video.
On cameras that have manual audio controls set the audio levels the lowest gain possible, on the Nikon D800 set the manual audio mode with the gain at 5. Refer to the adapter manual for the settings on your particular camera.
On the DXA-SLR ULTRA set the gain switch to HIGH and do a test recording and adjust the level controls to give you a reading of about -12dB on the adapters’ VU meter.
We’re now using the very clean gain of the preamplifiers in the adapter and minimizing the gain in the camera. This will always give you the best signal to noise ratio.
I hope this helps you understand how you can achieve the best recording on your DSLR or Camcorder.