How loud for television broadcast?

D

dasonras

Well-known member
I completed a tv show that i edited in avid xpress pro. My show will be airing on my town's local access station. What i hate is when you flip through the cable channels and pass the local access station and immediatly you know it is local access. I specifically hate how the audio for the shows are either too loud or too soft.

I want my show to have "good audio volume." So that it is the same as any other tv show.

What is the broadcast standard for how loud audio is? In the timeline i can clearly see that the audio is unbalanced in that there are very high peaks and very flat peaks. Visually, how big should the peaks be?

Sorry for sounding so ignorant. I know close to nothing about audio. My field is cinematography.
 
You should check directly with the station. Most stations have specific requirements for audio levels and should be able to tell you. They will probably also want tone at the begining of your program, so you need to find out what their requirements are for tone too.

Phil
 
How are you delivering it? Betacam or digital tape? If Betacam, audio should be at 0dB analog with some peaks above being ok. If it's digital, most places would say -12dB. The station should have outboard compressors/limiters that level out the volume between programming, but still, you want to take a lot of care to keep your levels in check from cut to cut, and it may be wise to do some compression of your own to achieve some more perceptual loudness/consistency if that's what you're going for. Either way, be sure to put tone on the tape at 0 or -12, so they know what your reference level was.

Compression reduces the dynamic range between the loudest and quietest parts, making it easier to keep a signal hotter. Look at the waveform from a commercial rock music CD and you'll see what I'm talking about. It looks like it's always peaking. But it also kills the dynamics when abused.
 
What they said ^^^^

Be sure to write on the tape and notes what the reference tone is. For digital it is usually -20 but some places expect -12. If set wrong....oh boy! :(
 
yeah, so many places will want reference at -12 or -20, but what exactly does this mean for your program peaks and rms values?

I reckon its important to note that peak levels govern very little other than broadcasters shouting at you, because certain peaks are so fast we dont even register distortion (transients?). But RMS is where the real VOLUME (or perceived volume) comes into play - i believe the relationship between the two is termed "crest factor" (open to correction here).

So i've mixed my mix, and now I want to send it out. Lets say the broadcaster has asked for -12dBFS reference (lets say its going out on DV or something), where should my peaks and RMS be sitting for a good, loud TV mix?

Im no expert on this, but I know Im on the right track from a LOT of reading (im quite interested in sound post, even though I dont do very much)... if someone could clear that up, id appreciate it.
 
Well, if you think of 0dB analog as being the norm, and +6dB being the acceptable peak level, monitoring your same digital signal through an analog source (mixer, Betacam deck, etc.) that is properly calibrated (-20dB or -12 registering as 0dB), that will tell you. In other words, I don't go above around -10dB digital.

There would only be a peak distortion issue if the station dubs your tape down to analog. Practically-speaking, if it's digital (or a digital copy which would not change the audio), as long as it never hits 0dB digital, the station's limiters are gonna knock the peaks back to keep in it check upon broadcast. But do yourself a favor and set it right to begin with.

Or, how about just calling the station engineer and asking him.
 
You must log in or register to reply here.
Back
Top