The principles of home cinema: quiet

Last month we started a series about principles of good home cinemas, as we outlined them in our blog ‘What goes into a home cinema?’. 

This week we’ve made it to the second principle: quiet.

Home cinemas can feel quite strange when you enter them. Because they’re rooms within rooms designed to fulfil a certain purpose, the make-up of the room differs from the rest of the rooms in a home. That strange feeling we can get when we enter a home cinema has to do with sound. 

Home cinemas and media rooms differ in this way (amongst several others that you can read about here). In home cinemas, professional installers are aiming to achieve ‘studio reference levels’ of audio quality. In a media room, the target for audio quality is lower, as there are greater external influences affecting what the professional can achieve. 

Sound quality should never be bad in a media room (the right professional will never let it be), however there are different expectations set for what can be achieved without the padding of the room-within-a-room home cinema. 

One of the most effective ways to improve the audio performance of a home cinema or a media room is to reduce the ambient noise of the room: to make it quieter. That means that the sounds produced in the content you’re watching can have more impact without turning the volume up to 100. 

Keeping sound in and out

Sound isolation is key for making home cinemas quieter. That’s why home cinemas are rooms within rooms - they follow the same engineering principles as recording studios. These build outs for home cinema creation mean that walls can be thickened with multiple layers of soundproofing and acoustic treatments, doors and windows can be sealed, and sound is prevented from both escaping and entering the room.

The baseline of unwanted background noise is called the noise floor. Some noise floor is inevitable, but its presence can be managed when a room is designed with the intention of keeping the noise floor to a minimum. The lower the noise floor, the easier it is for the audio of a cinema to be clean and immersive. 

Low frequencies are the hardest to manage, even with the best sound absorptive materials installed. That’s why you can hear the boom of an onscreen explosion from the screen next door during your outing to see the latest comedy. 

A key reason to engage a professional to build your home cinema is that they know what else needs to be considered in such a sealed room. That’s with heating, cooling, and ventilation on a macro level, and also with the micro decisions that go into how these are installed to reduce the noise-levels in the room. Your installer can advise on how ducting should be done and where bends are placed whilst keeping the system high-performing.

The best way to achieve maximum dynamic range in a home cinema is to lower the noise floor of the room. Dynamics, as we learned in our article about why home cinemas should be immersive, are key to getting the best experience possible from your project.  

Materials matter

Different surface materials affect sound. We sing in the shower because the echo of our voices bouncing off the tiles makes us sound good. That’s why the materials we choose for our home cinemas matter. 

To keep the room quiet, thick carpets and soft furnishings are advised (and that’s not just because they’re more comfortable, even though we’ll cover that principle in a few weeks). These absorb sound rather than bouncing it around the room like harder materials. 

Acoustic treatments are used in home cinemas to enhance this absorptive effect further. Acoustically transparent materials are used to hide speakers in walls and ceilings, and also to hide absorptive layers for soundproofing. 

An acoustically transparent fabric allows soundwaves to travel through them without distortion. They’re good as wall coverings in a cinema, and they come in patterns and colours to suit every style. Your installer should be able to recommend fabrics to you (or your interior designer) that suit the look you’re going for in the room - whether that’s full dark and moody cinema mode or otherwise.

And the best thing about keeping a quiet home cinema? You can ssh your viewing companions as much as you like without judgement. It’s your cinema after all.