When we talk about 'great home cinema' itās easy to think we're just talking about āloudā home cinema. Part of this is down to when we show off our system. We tend to reach for films filled with smashes and explosions to show off what the equipment can do. In reality, every single film recorded with sound benefits from a well mastered and thought out soundtrack, and in turn these soundtracks benefit from being replayed on a good home cinema system. Hereās what makes a standout piece of multichannel audio.
Tone Matching
First and most importantly, a soundtrack must match the tone of the film. In some cases this is pretty obvious; explosions shouldnāt sound like a cough and vehicles crashes need to portray BIG forces of impact. But thereās more to it than that, small scale cinema needs a soundtrack thatās in proportion. A soft footstep on a floorboard shouldnāt trouble a subwoofer for example. Sound should always compliment images on screen.
On a more minute by minute level, this also means that whatās on screen must always be the focus of a soundtrack. Itās tempting to use the surround channels to pump energy into the room but unless it relates to whatās on screen, itās just a distraction! If somethingās played through the rear channels, is it heading to our screen or directly relating to something on the screen - creating a sense of the space the scene is in for example? If the soundās there and doesnāt fit either of those, chances are itās a distraction rather than a compliment.
Dialogue
This is especially important with dialogue. A soundtrack needs to ensure that when whatever else is going on at the same time, you can always hear and understand whatās being said on screen (unless made intentional) This is always going to be helped by a good centre channel that can make sense of the information.
Good soundtracks manage this SO well you wonāt even notice it, but there are plenty of bad examples where dialogue gets lost in the mix and alters the film. Dialogue is usually one of the first things that suffers when a film is replayed on TV compared to its Blu-Ray counterpart.
Voices hold a special place in soundtracks for other reasons too. Even when a film is filled with aliens, monsters and other-worldly beings, the human voice acts as an anchor point to reality. Itās a sound thatās hardwired into our consciousness over thousands of years. A soundtrack has to handle voices in such a way that makes them immediately believable. With big name stars weāve seen across loads of films we know what they sound like, even at a subconscious level. Itās vital that a soundtrack conveys this well.
Sound Effects and Score
In more reality based films, there are more sounds that need to be recorded believably and with the right scale. It used to be a standing joke in vintage Hollywood movies that any car on screen was given the same muscle car soundtrack even if it was a golfcart. Nowadays huge amounts of effort is put into making sure that sound effects are convincing and recorded well.
The final ingredient to a soundtrack that can tip it over from good to straight up amazing is the score. Would Jurassic Park be the adored classic without its jaw dropping, incredible score courtesy of John Williamsā? That discussions for another day, but you get the idea! Music has to be worked into a film soundtrack extremely carefully. Again, it has to compliment the levels and information on screen at the time. Whether the score has been recorded using orchestral instruments or a rock band for example, itās another set of 'fixed reference' sounds that need to be handled correctly to sound convincing. The results are always more than worth the effort!
Essentially, a soundtrack is a jigsaw of requirements and concepts that needs putting together to work. The effort it takes is more than worth it as the added realism and immersion that an amazing soundtrack can bring to a film is something thatās hugely beneficial to the final film. In the hands of a good quality system, the results are stunning and mean much more than making an explosion sound good. Film has always been about the visuals but only when the whole package is done properly can the results be absolutely massive!