Not sure if this has been commented before but I get big volume variations between the channels on Freeview HD when watching on my Sony with built-in tuner - is this normal?
Rock Research - NZ's online marketing research experts. We like to blog too.
You should really only noitice a difference between TV3 and the remaining channels if you are viewing the AC3 feed on TV3 as this is marginally quieter than every other channel using AAC.
This is one of the biggest problems we have in audio. There are so many sources coming from so many distributers these days. But these days we automate so much. Presentation directors have a very limited control of volume as a programme goes to air. To compensate the major stations put an Optimod across the final path of audio. This compresses or reduces the dynamic range, therefore in theory equalizing the volume.
But commercials want to be heard. So in the production houses they limit and compress very hard as well, knowing the optimod is in place. To boost it even further. Yet when we make a programme we try to be subtle with our audio mix.
There is a standard of minus 18db reference tone delivered on all programmes and commercials with a peak level of minus 10. This is used to set a level for ingestion into the system. But this will not account for the "percieved loudness" of the material. And the people who do the ingesting are not audio people. No offence to them, I know very little about video levels. But with budget cuts, automation and 30 jobs going from our department alone( broadcast services) there is very little human input (and even less to come) put into the final product you hear at home.
Optimod can balance up audio levels quite well, Radio stations use it as well, but it can be very harsh and fatiging on your ears. If used too hard it causes what we call pumping. I ask to have the optimod turned off when doing a live sport event like Tennis, were there are low and loud elements, this reduces the rushing up of the low levels, only to be squashed back down when a cheer or another loud element comes in. A new system we are looking at reads the bext information of an ingested audio file. As it goes to air, the system compensates and puts out heavily compressed audio next to dynamic audio at an equal "percieved loudness"(at a predetermined level). It is very clever, with very impresive results. But only works on pre recorded material (which most of TV is these days) so when there is a live event people like myself really earn our money.
But after explaining all that, only some stations use an optimod,TV1,2,3,4. I think Maori and Prime do. I can only assume sky don't. Just by listenting to local breakouts on UKTV, Discovery....there is a massive jump in audio levels.I do know that TVNZ 6 and 7 have no optimod. What you are hearing is totaly raw audio as it came out of the production studio. And good example of percieved loudness.
I hope this clears it up, could go on for hours. But I don't want too.
Are you subscribed to our RSS feed? You can download the latest headlines and summaries from our stories directly
to your computer or smartphone by using a feed reader.
Trusted
Retired Mod
Biddle Corp
