The results were very impressive – the GH4 has the best specs of any DSLR we have ever tested.
We tested it with the camera gain at the lowest setting of -12dB with the limiter off. It has excellent low THD+N and a very high signal to noise ratio of 78dB at the maximum -29dBu input level. What is even more impressive is the frequency response of 70Hz to 20kHz (-3dB down points). This is where most DSLR cameras suffer – usually dropping off at 140Hz or so. The limiter works remarkably well at avoiding clipping with hot inputs. With the limiter on the S/N ratio drops a bit to 72dB but is still excellent. However, the frequency response improves to 30Hz to 20kHz which is remarkable for a DSLR camera. Careful listening tests confirmed the very clean, wide bandwidth sound. This makes the GH4 suitable for recording not only voice but music and sound effects as well where capturing low frequencies is important.
GH4 audio improvement with the DXA-SLR ULTRA
It is refreshing to see such great results in a DSLR camera. The high quality front end on the GH4 allows you to record professional audio directly to the camera without having to use external audio recording gear and then having to sync everything in post. Our DXA-SLR ULTRA adapter makes this very easy. We recommend that the camera be set to -12dB with the limiter on. This will calibrate the camera to the DXA-SLR ULTRA and provide exceptional audio performance.