Can someone tell me

GoldWave general discussions and community help
Post Reply
quartetman
Posts: 2
Joined: Wed May 01, 2019 10:26 pm

Can someone tell me

Post by quartetman » Wed May 01, 2019 10:57 pm

what is happening here? To back up, I have used Goldwave for probably around 15 years. I am a church music director and am trying to integrate a new camera into our set up going directly from the house mixer to the camera. I have times the audio quality is presumably too hot or not hot enough, but I had never seen visually anything on Goldwave like this (that I recall) until the past few weeks with the camera. The meter shows it is way too hot (in the red), but the top part of the audio visually is good, but there are lines going under about as far in the -db as they can. Knowing if I am interpreting the visual correctly might help me figure out what is happening to cause the audio issues on the camera. Thanks.

DougDbug
Posts: 2033
Joined: Wed Feb 16, 2005 3:33 pm
Location: Silicon Valley

Re: Can someone tell me

Post by DougDbug » Thu May 02, 2019 2:33 pm

So... The mixer-output goes into the camera? Are you connected to a line-input? (You'd only find line-in on a higher-end camera.)

Then you open the audio/video file (audio only) in GoldWave?

Check to see if the camera has Automatic Gain Control (AKA Automatic Volume Control or Automatic Level Control)). That can really mess things up... If there is a pause (or quieter moment) the gain goes up, which brings-up the background noise. Then when the normal sound comes-back you get blasted and you get distortion until the AGC re-adjusts.

quartetman
Posts: 2
Joined: Wed May 01, 2019 10:26 pm

Re: Can someone tell me

Post by quartetman » Sun May 05, 2019 1:05 pm

It does have an automatic, but I shut that down. Yeah we have it line out (1/4 - old mixer) to XLR cable for the camera using a cable with the 1/4 male on one end and XLR male on the other. More puzzling is that the things that strictly come through that mixer (except for one podium mic) seem to be fine. Things that come through the submixer on stage seems to be where the trouble is. I can diminish the output, but I am not sure if there is a cable picking up noise or what. It just seems strange that even when the camera meter shows okay, there is distortion, and what I see in Goldwave which is in the red on the meter, but dipping way down on the waveform. But the quiet moments seem fine it is just in certain parts of the music or speech. I wanted to make sure I understood what I saw in Goldwave which is the red on the bar is obviously too hot, but the wave form doesn't visibly go too high, but underneath. Does Goldwave go red in the top even when too low? :?: I wish I could upload a screenshot.

EDIT: I will double check that the automatic is off, I have tried both ways, and am sure the last was giving back control to us. I did notice on today's that the distorted places do get too hot on the waveform, but they are short spikes, and don't stay there.

DougDbug
Posts: 2033
Joined: Wed Feb 16, 2005 3:33 pm
Location: Silicon Valley

Re: Can someone tell me

Post by DougDbug » Sun May 05, 2019 1:46 pm

Yeah we have it line out (1/4 - old mixer) to XLR cable for the camera using a cable with the 1/4 male on one end and XLR male on the other.
The XLR input on the camera is almost certainly a mic input (unless it has a mic/line switch). You may need an attenuator to bring-down the signal.
that even when the camera meter shows okay, there is distortion,
Yes, that's strange. A line-level signal into mic-in would normally show too hot on the meter. But depending on the circuit design, the distortion may be happening before volume-control (and metering) is applied.
It just seems strange that even when the camera meter shows okay, there is distortion, and what I see in Goldwave which is in the red on the meter, but dipping way down on the waveform.
Yes, that's strange too. Tool -> Amplitude Statistics will show the actual peak levels, even if they are not showing-up visually.

Of course it's possible to get clipping/distortion in the analog signal without hitting 0dB digitally, but if you are "seeing red" on the recording meters, you are at-least close to clipping.

Post Reply