Live Sports Broadcast

Live Sports Broadcast


  • Logistics:

Live Sports Broadcasts are high pressure events and time is of the essence. Clearly the time and complexity can be curtailed by installing a single SoundField microphone over having to rig a plethora of mono microphones across an entire stadium.

  • Downmix Compatibility:

Creating a 5.1 mix from multiple spaced microphones introduces phase differences between the signals which can cause serious downmix issues. As the SoundField microphone is phase coherent, perfect downmix compatibility is guaranteed.

  • Consistency across events:

One of the major challenges with live 5.1 productions for broadcasters is to maintain consistency in sound across different events when there is a different audio engineer and a different set of microphones. By standardising on a SoundField as the main 5.1 ambience microphone consistency in sound quality between events is radically improved.

Live Sports Broadcast

Football/American Football:

A typical football game consists of the following audio elements: Crowd Ambience, Effects (ball-kicks, referee, body impact, etc.), Commentary and Sound Effects/Music.

Football_Pitch no mic low res

The SoundField microphone will take care of the 5.1 crowd ambience; it is the placement of the microphone that will create the desired result. There are two microphone placements commonly used for football, both are placed around the centre line but differ in the height of their placement. Position 1 has the microphone high above the audience and gives a very constant distant ambient sound. Position 2 places the microphone about 3m to 4m above pitch level (a sturdy microphone stand does the job nicely) in between the pitch and the crowd, resulting in a far more discrete ambience.

The other elements in the mix such as the ball-kicks and commentary will then get mixed in as desired. One could for example, mix the ball-kicks panned slightly left and right or phantom centre and have the commentary panned hard-centre or diverged across the three front channels.

Live Sports Broadcast

The approach for creating a live 5.1 football mix can easily be adopted for capturing live 5.1 mixes of any “stadium”  based sport (or any other audience event). Broadly speaking, all such events can be broken down in the following audio components: Surround Ambience/Crowd/Excitement, Effects microphones, Commentary and Sound Effects. P   Tennis: Although very different from football, with its smaller crowd and a smaller field of play, the SoundField approach to creating a 5.1 mix works incredibly well. The microphone is placed on a small stand by the net – opposite side from the referee – with all the sounds from the court in front of the microphone and the crowd and excitement behind it, forming a great 5.1 ambience bed. This will then form the basis to mix in the effect microphones – ball bounces, racket hits, groans, etc. – the commentary and the sound effects. P Boxing: boxing ring and the audience. Once more this forms the ambience bed for the effect microphones, commentary and sound effects.Again the same approach for a totally different event; here the SoundField microphone gets placed in between the

Live Sports Broadcast

Something a little different – Motorsports

Motorsports offer a very different challenge in that the sound pressure levels generated by the sport itself far outstrip those of the spectators.P In order to capture the engine notes at full speed without overloading the microphone while still picking up the subtleties of the crowd as the cars disappear in the distance requires a microphone with high SPL handling capabilities as well as a big dynamic range. The SoundField microphone offers both of these in abundance. As shown in the diagram there are different positions ideally suited to capturing 5.1 ambiences using a SoundField microphone.

  1. As in the previous example we have the race track in front and the grandstand with the audience behind the microphone. Here the microphone is well positioned for shots of the straight and the grandstand during the race.
  2. Placed directly on top of the start and finish line facing down to the starting grid, the microphone can capture pre and post-race shots as well as the all-important start of the race.
  3. Placed directly above the pit lane, the microphone is ready to capture the sounds of the tense moments of a pit stop.

Live Sports Broadcast

Linear Events

Not all events are confined to a stadium or venue; take a marathon, a bicycle road race or a ski slalom, as examples. So how can we go about creating an exciting 5.1 mix for such events?M

If we for example look at a marathon through a city we can place a SoundField microphone at the start and the end to capture the crowd either end of the race. The question is how to create a 5.1 ambience for the duration of the marathon with audio captured under difficult circumstances from motorbikes, cars and helicopters. Capturing and then transmitting stereo audio back to the OB truck is hard enough let alone doing it in 5.1. TSL SoundField offers a very elegant solution to this problem in the form of the highly regarded UPM-1 and Stereo to 5.1 upmix converters. The sound engineer will create a well-balanced stereo ambience (from all the signals being send back from the aforementioned motorbikes, cars and helicopters) and then send this to the SoundField upmixer to create a 5.1 ambience bed. As with the SoundField microphones, this 5.1 ambience will form the basis of the mix for all other elements – such as commentary and sound-effects – mixed in to generate a downmix compatible 5.1 sound track.

Live Sports Broadcast

Downmix Compatibility – Why it really matters: It is extremely important that any 5.1 anywhere in the broadcast chain is stereo downmix compatible. Although it is possible to manually create a stereo as well as a 5.1 mix – thus bypassing downmix issues – there is a very high likely hood that a customer at home will be listening to an automated downmix from the 5.1. In most parts of the world – there are a few exceptions – when HD video is accompanied by 5.1 a separate stereo track is not transmitted. Therefore anyone tuning in to the HD feed will always receive the 5.1 audio track regardless of whether they have a 5.1 playback system. Downmix Issues: Downmix issues manifest themselves in several ways, those that broadcasters struggle with most are:

  • Build-up of ambience which drowns out the commentary.
  • Frequency colouration and comb filtering (even when this is relatively subtle it will affect the width of the stereo image

Mixing with SoundField rumble: Both new and old SoundField users have told us how easy it is to sit the SoundField 5.1 ambience in the mix in comparison to ambiences derived from multiple microphones. “We no longer have to fight for space to sit our effect microphones in the mix.” A. User Low Frequency Rumble: Many large stadiums once filled with a roaring crowd tend to have a large amount of low frequency energy between 100Hz and 150Hz. This doesn’t always translate very well when played back over loudspeakers. Applying High Pass filters to the main channels (with a cut-off frequency between 100Hz and 150Hz) is a very simple way of counter-acting this. When using the LFE channel adding a Low Pass set to around 80Hz will really tighten this up as well. Dynamic Range and Compression: When capturing ambience for live sporting events we need to be very aware of the large dynamic range that can be generated. The level difference between 50.000 football fans calmly watching game play and half of them celebrating a goal is big and importantly instantaneous. Using some well-defined compression will keep this in check while ensuring that the excitement is still portrayed. Sample Compression Settings:

  1. Set the “Threshold” so that under calm audience conditions it is just not reached
  2. Set a relatively gentle “Ratio” of about 3:1
  3. Set a fast “Attack” time of about 20ms to deal with instantaneous transients
  4. Set a slow “Release” time  of about 200ms + to avoid any pumping

One mic, limitless much control:

A very powerful feature of the SoundField DSF-B microphone system is the amount of control over the microphone and the resulting surround sound that is offered from the comfort of the Audio Control Room.

This control is either available from the DSF-3 remote front panel or through the DSF-3 Remote App.

Upmixing and Downmix Compatibility

As already mentioned, any 5.1 anywhere in the broadcast chain needs to be downmix compatible, this is no different when this 5.1 has been generated through upmixing. The SoundField upmix algorithm achieves downmix compatibility by ensuring that all the elements in the five channels are de-correlated.

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