Audio Question

[Qframe]

A question to those making on-air content (mainly TV commercials).

In Australia the “FACTS OPERATIONAL PRACTICE OP-29” states that the audio reference level should be -20db (Tone) and peaks should not exceed -12db (allowing 8db headroom).

If -20db (or any other level) is set as the reference level in Edius does this effect the frequency response ie limiting and bit compression ?

I have found that since I’ve been using Edius for my on-air content and despite what reference audio level I set, my audio on-air seems low compared with other content either side. (ie other TV commercials etc.) It seems that the audio has lost much of its frequency response. This is also independent of the original audio source ie jingles/voice mix, vox, and full external mixes.

I have tried supplying the TV stations with much higher levels thinking that they might not be working to OP-29 but I have found that it makes no difference. I have also tried applying heavy multi-band compression using VST plug-ins… same result.

It’s strange that audio exported from our old Premier box appears (sounds) great on-air.

Any ideas or comments would be greatly appreciated.

[biopic]

A question to those making on-air content (mainly TV commercials).

In Australia the “FACTS OPERATIONAL PRACTICE OP-29” states that the audio reference level should be -20db (Tone) and peaks should not exceed -12db (allowing 8db headroom).

If -20db (or any other level) is set as the reference level in Edius does this effect the frequency response ie limiting and bit compression ?

I have found that since I’ve been using Edius for my on-air content and despite what reference audio level I set, my audio on-air seems low compared with other content either side. (ie other TV commercials etc.) It seems that the audio has lost much of its frequency response. This is also independent of the original audio source ie jingles/voice mix, vox, and full external mixes.

I have tried supplying the TV stations with much higher levels thinking that they might not be working to OP-29 but I have found that it makes no difference. I have also tried applying heavy multi-band compression using VST plug-ins… same result.

It’s strange that audio exported from our old Premier box appears (sounds) great on-air.

Any ideas or comments would be greatly appreciated.

The UK/BBC standard is much the same, except we use -18dB as reference. I think the problem you are encountering here lies outside of Edius. The fact that you are talking about commercials is highly significant. It is common practice to make commercials as loud as legally possible in order to GET THE MESSAGE ACROSS. So all sorts of sophisticated processors are used to increase the loudness without exceeding the allowed peaks. There is quite an art to doing this. In your case, you may not have achieved maximum loudness but you may have exceeded the maximum allowed peak, in which case a limiter will probably kick in before transmission and simply pull everything down (and may well degrade the perceived quality in doing so). Personally I have never had any cause to doubt that the audio quality from Edius is not what is should be under all circumstances.

Of course the key question is have you done an A/B comparison with the audio off-tape and off-air?

Afterthought - another possibility is that somehow your audio contains sub- or super-sonic interference that you cannot hear, but will nevertheless kick off the limiter on transmission.

[GrassValley_BH]

Most mainstream music production uses similar techniques - combination of compressor and limiter to reduce the peaks followed by normalization.

Imagine a tube... You can make the tube more full with smooth balls than with spiked balls, because the spikes reduce the "fill" in the tube. Okay, that wasn't the greatest analogy, but I'm a bit tired.

[SRsupport]

All great info.
I want to add something. Audio for a commercial is tweaked in a sound app most of the time. You actually seldom hear the raw audio from the editor.
It is all done in an audio app to make it legally as loud and "sweet" as can be.


Steve

[antonsvideo]

yes, and Soundfore9 is a great tool, especially the wave hammer, also, SF has the VU meter that I wish in Edius

http://www.videoproductions.com.au/edius45/SF9.gif

[STORMDAVE]

Most audio in the pro arenas are done in ProTools by professional sound engineers.

[johannesj]

Protools and Nuendo.

[GreekTV]

For audio pre-processing I use an amazing standalone freeware broadcast software called MBL4 version 4.0.6.

http://www.burnill.co.uk/mbl4_broadcast406.exe

Essentially, it's a 4-band Broadcast processor; similar to what FM/AM stations use prior to the transmitter input. (Clipper/Gated AGC/Compander/Multi-band limiter/Automatic Gain Riding)

What I do is that I edit in the NLE using good audio levels as much as I can. When I'm done with video editing, I then export the rendered final mix to a .wav file and I import it to this MBL4 software. I set the output peak to -12 dBfs. I then import this newly processed audio file to the NLE audio track and I'm ready to export to tape/DVD. I agree that the Graphic User Interface is not the best I've seen, but it gets the job done.

I tried the Wave Hammer option in Sound Forge, as well as other directX plug-in processors such as "Waves" for Adobe Audition. They are all too "harsh" since they are "broadband" compressors/brickwall limiters.

Although I didn't tried it with Edius, taking advantage of its real-time capabilities, you can interface MBL4 with an NLE and do real-time processed voice-overs.

[SRsupport]

From the horses mouth:



MBL4 was the first PC based processor.Development started in 2000 and the first release was in December 2001.
The code MBL4 uses is mainly 16bit. It usesthe the MMX instuction set of Intel & AMD CPUs.The 16bit code gave a poor dynamic range - it sounded hissy.

MBL4 is no longer being developed and is released as freeware.

[GreekTV]

The 16bit code gave a poor dynamic range - it sounded hissy. MBL4 is no longer being developed and is released as freeware.

For ENG/EFP/Feature work I do, I never heard any anomalies with MBL4. The freeware is version 4.0.6 released in November 2006. Perhaps, the site refers to an early version being noisy.

It's true that MBL4 is discontinued, as it has been replaced with a newer 5-band processor called MBL5. Another equivalent product is called SoundSolution XAP. But I'm quite satisfied with MBL4.