With content being consumed in a growing range of environments what size of room should we be mixing TV content in? I was recently in a position where I was listening to a theatrical mix in a domestic living room and the dramatic elements were way too loud and this got me thinking. Are some of our high-end TV dramas and high budget entertainment shows being mixed in suites designed for theatrical releases and is this why we are finding as a family that we are having to resort to sub titles more and more to be able to follow the plot?
We know from the various standards including the ATSC recommendations that the recommended sound pressure levels for larger rooms is higher.
Categories of Audio Control Rooms used in Television Production
|1||Principal audio monitoring control rooms with specialized acoustics and sound systems. Channel range up to 5.1 (3 front/2 surround/0.1 low frequency enhancement). Well isolated from other operations. Widest frequency and dynamic ranges equal to best home cinemas properly aligned. This type of room may be used for quality control at the network level, for example checking program material for conformance to delivery requirements when a question arises at ingest stations. Sound monitor quality dominates over production requirements in this category of room. Broadcast organizations might be expected to have only a small number of such rooms.|
|2||Audio-mostly production spaces with equipment needs and placement supplanting absolute audio monitoring conditions, although audio monitoring is still expected to be good. Channel number equal to the highest number used for material originating in the room. Good isolation from other operations. This type of room may be used for program origination, with its output occasionally subject to check in a Category I room. Low-frequency range and headroom may be somewhat restricted compared to a Category I room.|
Sound Pressure Level For Different Size Audio Control Rooms
|Categories||Room Volume in Cubic Feet||SPL in dB re 20 μN/m2|
|1, 2||> 20,000||85|
|10,000 < 19,999||82|
|5,000 < 9,999||80|
|1,500 < 4,999||78|
Both tables from ATSC Recommended Practice: Techniques for Establishing and Maintaining Audio Loudness for Digital Television (A/85:2013) ￼Dated 12th March 2013
Bigger Means Higher?
The National Association Of Broadcasters Engineering Handbook states that larger rooms with a higher reference SPL will yield wide dynamic mixes where smaller rooms with a lower SPL will yield more constrained mixes.
Could the size of the mixing space be having an impact on TV mixes? if mixing TV content in larger theatrical spaces is producing mixes that are too dynamic, what size of room should we be mixing in?
Should we be mixing TV sound in rooms of a similar size to domestic front rooms? But bigger rooms can handle lower frequencies better so what we hear is a truer representation in larger mix spaces, but those same low frequencies won't be reproduced correctly in a domestic living room. So which is preferable?
Our normal response would be to use the best quality possible, highest sample rate, largest bit depth etc, so the bigger room should win. But I would argue that the fact that larger spaces encourage more dynamic mixes which don't play well in small rooms, that we should be mixing TV in rooms closer to a normal domestic living room.
If we do end up mixing in a larger room what should we do to make sure that the mix will work in a smaller space like a domestic front room? Please do share your thoughts.
Is It The Fault Of The Loudness Specs?
All of this brought me back to the need to resort to sub titles more and more these days and wondering what has changed? I have seen comments around and about that these problems can be laid at the door of the new loudness specs. As someone who has spent a lot of time researching and understanding loudness related workflows, it is my view that the standards are not to blame. With any spec, they can be abused and fudged but I believe that the loudness workflows have been liberating and enabled us, as sound mixers, to take back control of the sound mix delivered to the end user and to add dynamic range to our mixes with opportunities to add dramatic moments
Is The Dialog Level Dropping?
It would seem to me that the loudness of the dialog in more and more productions is lower relative to the integrated loudness. We saw it when I analysed Planet Earth 2 and Top Gear in my article Are TV Mixes Becoming Too Cinematic where the dialog was around 3LU quieter the integrated loudness figure and the music was around +6LU or 9LU above the dialog. As I pointed out then, with a mix that dynamic we found as a family that if we set the volume so the music was comfortably loud, the excellent commentary from Sir Richard Attenborough was too quiet and we had to resort to the sub titles.
What About Loudness Range?
But it hasn’t always been this way and I started to think about what has changed over the last few years? Yes the loudness workflows have come in, EBU R128 here in Europe and ATSC A/85 in the US and Canada, but as I have said, I don’t believe it is the standards that are at fault.
Maybe there is something in the loudness workflows that can help. Earlier this year, the UK based Digital Production Partnership (DPP) updated their unified UK delivery specs for all UK broadcasters. The v5.0 spec includes changes to the audio spec, tightening both the live and prerecorded delivery specs for loudness to bring them into line with the EBU R128 standard.
The DPP v5.0 spec has a section on Loudness Range, or LRA, which is one of the parameters added in the loudness workflows. LRA was something else I highlighted in my article "Are TV Mixes Becoming Too Cinematic?" The table in paragraph 2.2.1 states the following....
Loudness Range - This describes the perceptual dynamic range measured over the duration of the programme - Programmes should aim for an LRA of no more than 18LU
Loudness Range of Dialogue - Dialogue must be acquired and mixed so that it is clear and easy to understand - Speech content in factual programmes should aim for an LRA of no more than 6LU. A minimum separation of 4LU between dialogue and background is recommended.
I am of the opinion that an LRA of 18LU is way too wide for any content being delivered into a normal domestic environment, on the grounds of listening environment ambient noise and the quality of the equipment being used in people's homes as well as the size of rooms too. I would prefer an LRA recommendation of 12LU rather than 18LU.
What Has Changed?
When we mixed to peak normalisation before loudness normalisation came in, the dialog was often one of the louder, if not the loudest element, of a mix, with the speech regularly hitting PPM6, here in the UK, and everything else built around it and, by and large, below it.
With these old-school mixes, the dialog was much closer to the overall average, as it tended to be the loudest thing in the mix, and even the music, being compressed and so louder, tended to be mixed so it did not come across as louder than the dialog. Nowadays it seems to me that the trend seems to be changing so that the music is routinely louder than the dialog and so the dialog will have to sit below the overall average for the whole programme.
This got me to thinking, maybe because the dialog is now no longer the loudest thing in the mix, I need to have subtitles on, where as for old-school mixes, especially drama and documentaries, I never needed the subtitles to follow the plot, so has the trend for louder music and effects contributed to the lack of intelligibility in TV mixes?
What Should We Do?
As I have said before and stress in my tutorial series Understanding Loudness, the additional headroom now available to us with a digital end-to-end workflow is liberating. It provides us with the creativity to have loud dramatic moments that go about the peak normalisation ceiling we used to work to. But if we have content that stays loud for long periods of time that is going to skew the overall average and push the relative dialog level down, and push the dialog outside the comfort zone.
Is it because more TV is being mixed in bigger spaces that inherently encourage more dynamic mixes that we are mixing TV that won't translate to the domestic living room?
Should we be mixing TV in smaller rooms? Would that fix some of the dialog intelligibility issues in TV sound? Discuss...