Complete Home Cinema Guide: 7 Safe Steps|Home Cinema Lab

A complete home cinema is not bought: it is designed

This complete home cinema guide is the English twin of the Italian version: in a complete home cinema project the order of decisions matters more than the budget. Read our buying guides for real products, and treat this complete home cinema guide as a checklist, not a shopping list — a complete home cinema is designed floor by floor.

The difference between a room that gives you goosebumps and a living room with a big TV and flat audio is not the budget. It is the order in which you make your decisions.

Whoever starts from the product — “I got this projector, what do I pair it with?” — ends up with capable gear wasted in a hostile room. Whoever starts from the room’s numbers buys less and gets more.

This complete home cinema guide follows the right order: first the numbers, then the screen, then the audio, then the room. Every figure quoted comes from a standard (THX, SMPTE, Dolby) or a manufacturer, not from forum folklore.

First step: measure, don’t imagine

Before reading a single spec sheet, you need five numbers from your room: sofa-to-screen distance, wall width, floor area, ceiling height, and how much light comes in during the day.

They sound obvious, yet they are the numbers almost nobody brings to the store. The result is the classic 75-inch TV that looks like a monitor from the seat, and a soundbar that “you can’t understand the dialogue with”.

If you want to skip the manual math, our tools section has the calculators: distance → inches, projector lumens, subwoofer by room size. They run in the browser, no data sent.

TV or projector: how to choose

The screen is the mother of all choices, and the fork resolves with three questions.

How many meters between eye and screen? Under 3 meters a large TV (65-77″) remains the simplest and brightest solution. Beyond 3.5-4 meters the projector starts offering diagonals no TV sustains on price: 120 inches becomes normal.

How much light is there by day? The projector lives on darkness: in a bright living room it loses contrast and color, the TV doesn’t. With real ambient light, the projector needs an ALR screen, which costs as much as a good TV panel.

Install or living room? The projector demands a clear throw, possibly a ceiling mount, and a certified HDMI 2.1 cable like this KabelDirekt cable running to the source. The TV hangs on the wall and works.

Installer’s rule: TV up to 88 inches where you need light and practicality, projector from 100 inches up where you can control the light. For the full detail, the dedicated projector guide is coming in the guides category.

Screen size: the math of THX and SMPTE

The most common mistake is staying “prudently” far away. The standards say the opposite of what you believe: the immersive image is bigger than you expect.

SMPTE (the society of cinema engineers) recommends a horizontal viewing angle of 30°: the “minimum viable” band for a good front row. THX, for the cinema-seat experience, goes up to 40° of coverage.

Translated into numbers: at 3 meters of distance the recommended minimum is about 73 inches, while the THX band reaches around 99. If it feels “too big”, you are normal: the eye adapts in a few days and never goes back.

The same principle works in reverse: a 55-inch at 3.5 meters is a second-row angle from a 1990s multiplex. No cable or upscaling fixes a geometry error.

Audio: the tiers, no fluff

Surround reads like an address: the number before the dot is ear-level channels, after the dot the subwoofer, after the second dot (in Atmos formats) the height channels.

2.0 / 2.1: stereo, or stereo with subwoofer. The base of everything: if the front stage doesn’t convince you, no surround will save the system.
5.1: the real entry-level surround, with a dedicated center for dialogue and two rears. For 90% of home rooms it is the sensible endgame.
7.1: adds the back rears; it makes sense only if the room is long and the seats far from the walls.
5.1.2 / 7.1.4 (Atmos): adds height channels that recreate vertical effects. You hear the jump in Atmos, not in the catalog numbers.

The most important channel is not the sub: it is the center. Most of the “I can’t understand the voices” complaints come from a weak center, or one hidden behind the TV, not from the rest of the system.

The crossover: the number that makes the difference

In the receiver’s menu (or the serious soundbar’s) there is a setting almost nobody touches: the subwoofer crossover. The professional-format reference value, used by THX and Dolby, is 80 Hz.

Below 80 Hz sound becomes essentially non-directional: you might as well send all the low frequencies to the subwoofer, which handles them better, and leave the satellites the job they are actually good at.

Setting speakers to “Small” with an 80 Hz crossover is therefore not a compromise: it is the configuration the standards were designed around. You refine by ear afterwards, but that is the right starting point.

Atmos: when the second dot is really worth it

Dolby Atmos speakers are bought in pairs and placed in the ceiling or above the front speakers. Dolby’s installation guidelines set precise boundaries.

In the reference 7.1.4 configuration, the elevation angle of the height channels relative to the seat is 45°, with an acceptable range between 30° and 55°.

There is a room requirement nobody mentions at the store: for upward-firing modules (or “Atmos enabled” speakers) to work, the ceiling must be flat, rigid and reflective — drywall, plaster, wood.

The ideal height is between roughly 2.3 and 3.7 meters. Slanted, beamed or sound-absorbing ceiling? The effect collapses.

Conclusion: if the room allows it, going from 5.1 to 5.1.2 is worth the money. If the ceiling is hostile, better to invest that budget in a better center: you will hear more of a difference.

The room: RT60 and your first absorbers

Here is the part that separates good systems from memorable ones: how long sound takes to die away in your room. It is called RT60, the time it takes to decay by 60 decibels.

For a home theater, the quality range sits roughly between 0.3 and 0.5 seconds.

A bare room (tile floor, glass walls, thin curtains) sings: dialogue overlaps, bass booms. No automatic receiver calibration adds acoustic panels that are not there.

Order of intervention, by value for money: heavy curtains behind the seats, a dense rug between TV and sofa, two absorber panels at the first lateral reflection points. For a few dozen euros you recover more than any “movie mode” on the remote promises.

The cable nobody explains: eARC

All the audio passes through a single point: the HDMI link between TV and system. The old ARC carries little more than compressed audio; the eARC standard reaches 37 Mbps, enough for lossless Dolby TrueHD and full Atmos from the player.

The digital optical port, which many use “for convenience”, is physically limited: its bandwidth — a few hundred kbps at best — admits at most a compressed Dolby Digital 5.1. If you have invested in a worthy system, optical is strangling it.

Simply put: TV → receiver or soundbar via HDMI eARC, and every source (set-top, console, Apple TV) into the TV or into the amp. A certified Ultra High Speed cable is plenty: the 80-euro cables do not improve a single bit.

Three realistic budgets to start

Under 300 EUR (real living room): a good 3.1 soundbar with wireless subwoofer beats any “home theater in a suitcase” with tiny satellites. Dialogue stops competing with bass, and in a small room the sub works well.

Around 800 EUR (the serious jump): a 55-65 inch OLED or Mini-LED TV, an entry 5.1.2 receiver, real front speakers on stands and a 10-inch sub. It is the configuration that sounds “like the trade show” because the speakers sit at ear height and are properly spaced.

Over 2,000 EUR (dedicated room): 4K projector + acoustically transparent screen, real 5.1.2 with two ceiling channels, microphone calibration included. Here the room is half the price and must be treated as a component.

The three mistakes never to make

The sub in the far corner. Expect heavy boom. Before buying magic potions, try moving it: even 30 cm change the response.
Speakers at uneven heights. The fronts go at seated ear height and at the same height as each other.
Buying everything at once. Screen first, audio second, room last: you will live each purchase knowing what is actually needed.

Frequently asked questions

Start with the TV or the audio? With whatever you watch most. If the picture disappoints you every evening, the screen first; if “you can’t understand the voices”, the center or the soundbar first.

How many watts does good audio need? Fewer than you fear: in a 20-25 m² room, even 80-100 watts per channel is wildly overkill. Speaker sensitivity and the room count, not the number printed on the back.

Is automatic calibration worth it? Yes, but as a refinement: it corrects distances and levels, it does not move speakers off the wrong cabinet nor conjure the rug that isn’t there.

Do I need an AV receiver if I have a good soundbar? If rear channels don’t interest you, a modern 3.1 or 5.1.2 with eARC handles everything alone. If you want a wired system with real amplification, the AVR remains the heart of the setup.

Can I keep the TV above the fireplace? You can, but your neck hurts and the viewing angle worsens. The right height puts the screen center roughly at seated eye level.

Sources

How big should the screen be, by viewing distance: SMPTE vs THX reference values.

Gear and further reading

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Complete Home Cinema Guide: 7 Key Steps