Where are my audio levels?

T

truelife

Well-known member
I have been mixing audio for 10 years but can't figure out for the life of me how to show a numerical point at which one is supposed to set tone on the Ex1. On the DVX at least there's a + sign to indicate -20db. On the Ex1 the manual says merely to set audio at 5 on the dial, but this makes no sense.

Anyone know of any way to actually see your numerical levels on the eX1 without guessing?
 
Actually, "5" is 0dB gain. You'll need to set your levels first inside the menu to get your mic's sensitivity dialed in and then do the last minute tweaking with the exterior dials.
 
Gain staging on the EX1 is such that a value of about "5" on the "audio level" dials represents the best alignment between preamp level and max digial level (actually, the built in non-defeatable limiter will ensure that you only get within 6dB of digital clipping).
Given the way Sony set up the gain staging, the most effective recording volume adjustment is done through the menu, at the attenuator setup.
If very loud sounds are anticipated, values toward the -11dB end of the setting are in order. If expected sound levels are to be very low, then setting a value equal to the microphone's published gain levels (ie., -38dBv for the Rode NT4) is in order. Live music will require a setting somewhere in between the two extremes.
It is noteworthy that the EX1 employs two limiters--one pre-fader and one post-fader, so proper attenuator setting is essential to avoid bumping into the limiter, which is ugly-sounding due to it's rapid recovery ballistics and slow attack which allows brief clipping. It's somewhat disappointing that the last 6dB of dynamic range at the upper end is effectively unusable due to the limiters, but the good news is the noise floor is low enough that you can boost this in post and won't run into noise problems.
 
Great info, Bass. Did you figure this out via your own testing or is it in print somewhere? Audio is very important to me and I'm still somewhat baffled by the audio chain in the EX1.
 
My tests ferreted out where the "unity" gain setting is. Basically, I keep the dials on "5" and never touch them. Turning them down won't prevent preamp overload (starts with the onset of hyper-limiter action, which sounds ducky). Turning it up past 5 starts to decrease the noise floor and also introduces the possibility of hitting a secondary limiter, whose ballistics sound unpleasant. To make the most use of the camera's dynamic range, it's necessary to adjust the attenuators in the menu. 4 dots below the red dot is where limiting kicks in. Keep levels in mid-scale and you should be getting pristine audio that isn't dynamically limited, or worse, clipped briefly as the limiter catches up with a fast transient.
This is a camera whose audio can be excellent, but you just have to be more careful with your levels than you'd normally need to be with a dedicated pro audio recording system.
 
This is good info. I am, in fact, using a 5 channel mixer sending wirelessly by way of two lectrosonics 400 systems. I am accustomed to setting dials wherever I need to set tone at -20db. My initial question was concerning where I could actually find the numerical levels, which are in the status menu. But leaving the dial at 5 doesn't make clear sense to me, based on my experience in the field. The receivers have an internal limiter and the camera has been set to -41db attenuator.

In FCP the levels have still hovered around -12db which has never made sense to me. I like it to be a little hotter than that and have found I need to bump up the levels in FCP.

Moral of the story, I guess finding that range between how one is sending the audio to the camera- direct from shotgun, or wirelessly from a mixer is important in both setting the internal attenuator and the dials on the camera. I personally find it necessary to set the dial to around 6 for optimal levels from my mixer which is set to mic level output.
 
The two most important things about the EX1 are these:

A setting of "5" for the record level equates to the lowest setting that will produce the onset of digital clipping at the final recording to memory card--it's low enough to maximize the distance between signal and noise.

The second thing is to anticipate your loudest expected sound and set the attenuators to handle it without hitting the limiters on the preamps.

Clipping of EX1 preamps is weird, because it is not a clean clip, due to post processing in the downstream signal path. Clipping looks like ragged high frequency trash on the waveform, but not at 90º or 270º portions of the waveform as you'd expect. This is because of phase rotation that occurs in downstream stages and in DSP processing. As such, it will be difficult to identify with ease, any clipped signals. The fact that the clipping occurs at -5dB makes it even more disorienting to tract down.
 
You must log in or register to reply here.
Back
Top