Designing the Ultimate Home Theatre

Designing the Ultimate Home Theatre

Followers of this blog know this guide has been long awaited. As one of the top home theatre equipment providers in Australia, Selby customers want to know: How should I design my home theatre? Well, you've asked, so we're here to deliver. This is everything you need to know about setting up a home cinema, whether it be in an existing room or building an entirely new room.

 

It All Starts With You

 

What most people don't realize is that designing a home theatre all begins with identifying where you specifically will sit. Home cinemas are critically different from commercial  theatres in that they shouldn't be designed to fit the maximum possible number of seats. Instead, they should be designed to create the best cinema experience from the optimal listening position (your seat). This location can also be referred to as "the king's chair".

 

Everything else -- the sound system, the screen, lighting, the other seats, should be designed around it. So, it's important to keep that in mind throughout the entire designing process, and the location of the king's chair should be one of the first layout decisions you make. However, you will notice that all of the components of a home theatre interact with each other, so you will probably go back and forth adjusting different things as you develop a layout. It's all about finding the right balance to create a space where the visuals and sound fit together in harmony.

 

Room Size and Dimensions

 

Before we get into room layout, let's back it up a bit. If you are adding an entire new room onto your house, you'll have to determine the exact size you want the room to be. There are only a few rules in terms of room size itself. You will want the room to be no smaller than 20 feet long and 15 feet wide, otherwise it can easily get cramped and will limit the size of the projector screen you can fit. Additionally, you want the ceiling to be at least 7 feet high. This is also to accommodate the screen, as you'll need to mount it at least 2 feet above the ground for comfortable viewing.

 

When considering room size, don't forget about the space required for the sound system, A\V and equipment racks, lighting fixtures, walkable aisles, d├ęcor, and fun installations like a bar or concession stand. Mapping out the specifics of viewing angles and speaker placement is probably a good idea before deciding how big the room needs to be.

 

More important than the exact size of the room is the shape of the room. Dimensions and wall ratios have an immense impact on acoustics, so this is one thing you want to get right. While there is no "perfect room shape" there are a few things you definitely want to avoid. Ideally, the width of the room should be at least 1.6 times the height of the ceiling, and the length should be 2.3 times the ceiling height.

 

Obviously, if you are converting an existing room into a home theatre, you might not be able to achieve these exact dimensions, so just try to pick a room that gets close. At the very least, ensure that the room is rectangular, not cubic. If all the dimensions of the room are the same or similar, you will get terrible acoustics. Regardless of the room proportions, you'll want to install sound proofing and absorption materials, which we'll go further into detail about later on.

 

Picking a Projector and Screen

 

Screen Size and Aspect Ratio

 

When it comes to choosing a projector screen, you should try to get the biggest one possible for the room configuration. The biggest possible screen depends on a number of factors.

 

Firstly, you'll have to decide which aspect ratio you want: 16:9 or 2.35:1. If you are a true cinephile, you probably want the latter. That is the aspect ratio most movies are filmed in, also known as Cinemascope. The downside is that you will see black bars on the sides of the screen if you decide to watch TV or stream shows. The right aspect ratio for you just depends on your preferences and what you normally watch. You can also look into a multi-format screen.

 

Brightness

 

The next thing to consider is the brightness of the room. Of course, if you want an immersive home theatre experience, you need to make sure you have total control over the ambient light in the room. Once you have that, understanding foot lamberts can help you determine the brightness capabilities you will need from the projector depending on the screen size. Foot lamberts (ftL) refer to the amount of light that should be reflected off of a movie screen in one square foot area. The higher the ftL, the brighter the image. You should aim to have around 16-30 ftL for a dark room. Use an online ftL calculator to determine the total luminance based on your equipment.

 

Foot lamberts are influenced by two things: the projector lumens and the screen gain. Projector lumens refers to the amount of light that the projector puts out, and screen gain refers to the reflectivity of the screen. For a light controlled room, you probably don't need a screen gain higher than 1.3, and a projector lumen output of about 1,500. Play around with combinations to find one that produces the right amount of foot lamberts for your desired screen size.

 

Throw Distance

 

One other factor that can impact your projector choice is limitations or preferences on placement. Assess the throw ratio that you'll need based on where you can place the projector. Throw ratio refers to the ratio of the distance between the projector and the screen to the size of the screen. A regular throw ratio is 1.5:1, which should fall somewhere behind the optimal viewing point. A short throw projector has a 0.8:1 ratio, and an ultra short throw projector has a 0.25:1 ratio. These are used for placing the projector pretty much right in front of the screen.

 

Additionally, if you are not prepared to mount your projector in the exact ideal location, then you should get one with strong lens shift capabilities. Lens shift allows the projector lens to move vertically and/or horizontally to give you greater flexibility on projector placement without compromising resolution. This is useful if you have obstacles like a support beam in the room.

 

Viewing Angles and Projector Placement

 

Screen size and seating placement is where viewing angles really come into play. While it may seem cool to have a floor to ceiling display, this is actually not ideal. Consider the most comfortable viewing angle from the optimal viewing point. When sitting in the king's chair, the top of the lower third of the screen should be at eye level, which is typically 42 - 48" off the ground. This way, the viewers in the bottom row don't have to look above a 15 degree angle.

 

As for the horizontal viewing angle, there are two main recommendations. The Society of Motion Picture in Theater Engineers (SMPTE) recommends a 30 degree viewing angle, whereas the THX standard is 36 degrees (closer to the screen). As per the THX standard, the optimal seating location should be 1.34 inches away for every 1 inch of diagonal screen size. So, for a 100" screen, you should sit 134" away for a 36 degree field of view. While it is all about the King's chair, if you have a wider room (more seats in each row) it will have a greater effect on viewing angle. The seats on each side may see a washed out or blurred image. If you want to avoid that problem for your guests, consider moving the seating back a bit. If you can't achieve these viewing angles, you might need to get a smaller screen.

 

As stated before, where you choose to place the projector can impact the throw distance you need, as well as lens shift. Factors like room size and obstacles can impact the best projector location. You don't want anyone interfering with the image by walking past the projector. This is why most people choose to mount it from the ceiling. Alternatively, you can build a shelf on the back wall to store the projector and other equipment like media players and receivers.

 

Sound System

 

Type and Number of Speakers

 

We've covered visuals, now for the audio. If you are into movie-watching, you might already have a speaker system and the challenge will just be about integrating it into the space. If you are migrating a system into a significantly larger room, you should definitely consider adding some components. The setup that worked in your living room might not cut it when you're talking about an immersive home cinema experience.

 

If you're starting from scratch, firstly, welcome to the world of hi-fi audio. You are about to enter a deep hole that you may never emerge from (*evil grin*).

 

In all seriousness, you have options when it comes to the type of sound system you can buy; the biggest limitation here is budget. If money is no object, you can opt for a dedicated home cinema sound system, like a Krix Real Cinema at Home package. This kind of system features speakers that are installed behind the projector screen on the front wall, as well as additional in-wall or in-ceiling surround speakers and subwoofers. For this setup to work, you need an acoustically transparent screen, which allows the sound waves to pass through without rippling the screen or interfering with the audio.

 

The other option is to get a standard surround sound system, either in a package or piece-by-piece. This setup will include a centre speaker, left and right speakers, any number of rear or surround speakers, and at least one subwoofer. Having speakers placed on the sides and in the back of the room is extremely important for full sound immersion when watching a film.

 

You may or may not be familiar with sound system size descriptors. When you see numbers like 7.2 or 9.2.4 this refers to the number of speakers, or channels, in a system. The first number is the number of standard speakers, and the second is the number of subwoofers. If there is a third number, this indicates the number of overhead Dolby Atmos speakers. So, a 5.1 channel system has five speakers (centre, left, right, 2 rear) and one subwoofer. The number of speakers you need simply depends on your preference and your budget. The more speakers you have, the more accurate and detailed the audio image becomes. Adding a second subwoofer can deliver powerful bass that shakes the soul.

 

Speaker Placement

 

Always place subwoofers on the ground. Their specific placement is the least important, as long as they are located away from corners. The centre speaker should be as close to sitting height as possible, preferably just below the screen. All other standard speakers should sit at ear level when seated (remember, from the king's chair). It's up to you whether you place the speakers on stands, mount them to walls, or recess them into the walls. Of course, overhead speakers are installed overhead.

 

5.1 vs 7.1 vs 9.1 Channels

 

For a minimal system setup with 5 standard channels, the left and right speakers should be positioned 22-30 degrees outward from the listening point on either side (imagine an invisible line from the listener to the screen as 0 degrees). This should more or less form an equilateral triangle with the listener. The rear speakers are placed at a 110-120 degree angle on either side. If there is only one subwoofer (as in a 5.1 channel system), it should ideally be centered below the screen.

 

For a 7.1 or 7.2 channel system, the positioning of the rear or surround speakers changes. One pair of surround speakers is placed 90-110 degrees from the listener, so pretty much directly on either side. The other pair is placed at a 135-150 degree angle. If there are two subwoofers, one should be on the left and one should be on the right.

 

For a 9.1 or 9.2 channel system, you simply add an additional pair of surround speakers at a 50-70 degree angle. This should position them just in front of the listener.

 

Dolby Atmos Overhead

 

Overhead speakers can offer a unique film-watching experience as they add height to the audio image. If you have two overhead speakers (as in a 5.1.2 channel system), they should be placed slightly in front of the listener on the left and right sides. With 4 overhead speakers, the initial pair should be pushed further in front, and the second pair should be behind the listener. It's highly recommended to have a professional install these speakers because it can be hard to get right.

 

A/V Receivers and Separates

 

Once you have a speaker system picked out, you can look into receivers and separates. To be clear, you need either a home theatre receiver or home theatre separates.

 

A receiver is an electronics component that processes audio and visual data from multiple sources and delivers the signal to the appropriate devices, while providing amplification for loudspeakers. Separates means you are purchasing two devices to serve the same purpose: an amplifier (for amplification) and a preamplifier/processor (for all the rest). Receivers offer the convenience of a single device and are typically more affordable, while separates give you more control over the specifics of your system and allow you to upgrade each component individually. The choice is yours.

 

Whichever route you take, you need to ensure your equipment can handle your audiovisual requirements. Make sure your gear can accommodate:

  • The number of channels in the speaker system and future upgrades you might want to make
  • The number of HDMI ports for all your media sources
  • 4K resolution compatibility (or 8K)
  • Dolby Atmos compatibility

 

Acoustics and Soundproofing

 

You should put a considerable amount of attention towards the acoustic treatment of the room. Poor acoustics can ruin the audio experience of a multi-thousand dollar speaker system. Needless to say, don't breeze over this section! We've discussed acoustic treatment before, but here's the basics:

 

Soundproofing is different from acoustics. This simply refers to the amount of sound that is audible from outside the room. You should definitely soundproof your theatre room unless you want everyone in the house to hear your movie along with you. There are a few ways you can do this:

  • Opt for carpeting or a large rug that covers most of the floor
  • Install a second layer of drywall in the walls or a sound-reducing wallboard
  • Make sure the door is solid and install door draft stoppers, door sweeps, or weather stripping to close gaps
  • Consider putting sound-absorbing panels on the walls, although this might give the room a more industrial look

 

Acoustic treatment is all about optimizing the reverb that occurs within the room. All of the sound waves that are produced by speakers bounce and reflect off of other surfaces, which impacts the tone of the sound and the frequency distribution. The goal in home theatre acoustic treatment is to make the amount of direct sound (sound that travels from the speaker to the listener) equal to the amount of reflected sound (sound reflecting off of any surface). This is done by eliminating barriers and adding absorption and diffusion materials.

 

The right acoustic setup depends on the exact layout and dimensions of the room, so it might take some experimenting on your end. Generally, you can follow this formula:

  • Cover 20% of the ceiling and walls with absorbing material at least 2 inches thick.
  • Cover 30% of the ceiling and walls with diffusion or sound scattering material at least 4 inches deep.
  • Leave the other 50% to reflect sound on its own.

 

Seating

 

Of course, seating is an important factor in home theatre design. The type of seating you choose is completely up to you, and there are a variety of routes you can take, from sofas, to recliners, to loungers and more.

 

When deciding the number of seats in each row and the number of rows, consider the size of the room and the aisle spacing. You should leave at least 20 inches of space for each aisle. Typically you'll just want to have two aisles, one on each side. As for row, usually 1-3 is a good number for a home theatre. It all depends on how much space you have and the type of seating you choose. Again, you should leave at least 20 inches of space between rows. Don't forget to accommodate the ideal positioning of the king's chair. This might impact the alignment of the rows.

 

If you opt for risers for the rows in the back, they should be about 12 inches high. This usually gives enough clearance to see over the row in front of you.

 

Lighting

 

This is a commonly overlooked component of a home theatre, but it really makes a huge difference in terms of the ambience and overall experience. Consider investing in recessed lights, dimmers, rope lights, and soffits.

 

The biggest requirement with home theatre lighting is the ability to dim the lights gradually. This allows you to have multiple "scenes" or levels of brightness in the room and creates that exciting "dim the lights!" theatre moment. Other than that, get creative with lighting designs, layouts, and colors.

 

Make sure you don't have any lights pointing toward the screen. This can significantly degrade the experience when watching with the lights on.

 

Wiring and Outlets

 

Wiring a home theatre room is a complex topic, so we can only cover the basics here. If you are constructing the room entirely you should install wiring before you finish the walls. If the room already exists and you're not doing any construction, you can hire an electrician to run cables in the walls or use cable covers to keep them hidden. Here are some additional tips:

 

  • Make a complete plan of outlets and wiring before beginning any construction
  • Add 50% onto your estimated cable lengths
  • Run conduits to make it easy to replace or upgrade cables
  • Use premium cables if your HDMI cables are longer than 30 ft
  • Ensure that your total equipment power draw is not greater than the power rating of the breaker
  • There's no such thing as too many outlets
  • Consider floor outlets for electric reclining chairs
  • If you're not confident, hire a professional

 

Additional Considerations

 

If you've made it this far, congratulations! Here are some extra considerations to make when designing your ideal home cinema:

 

  • Wall paint: The exact color is not important, but always opt for a darker color
  • Door placement: Having the door on the side rather than the back can prevent the outside light from hitting the screen when someone exits or enters the room
  • Remotes and control systems: You'll definitely want to have a universal remote that allows you to control everything from one place, including the lights, projector, speakers, etc.