

Home Theater Terms, Explained by the Experts

Foot-lamberts, 4k, Dolby Atmos and more — these are the terms you need to know (and the ones you can ignore) for constructing your awesome home theater.

Phillip Ennis

There’s no shortage of technical jargon in the world of home theater. Phrases and specs are mentioned incessantly by manufacturers hoping to distinguish their expensive black box from the other expensive black boxes. Some of these measurables are relevant, others aren’t. As humans, it’s easy to just think that bigger means better. This survey covers the popular terms being tossed around by salesmen today and includes expert commentary to help you stay focused on what really matters.


Kerry Bright, Bright Home Theater, New York, NY
Theo Kalomirakis, TK Theaters, New York, NY
Tom Manna, Digital Home Systems, Rye Brook, NY
Mark Prancuk, Sight & Sound Showroom, Norwalk, CT


It’s about light and color.

4K Resolution

How it’s defined: 4k refers generally to a resolution in the order of 4,000 pixels. Unlike the standard full HD resolution of 1920 x 1080 known commonly as 1080p today, 4k’s resolution is not exact. Most televisions marketed as 4k today have a resolution of 3840 x 2160 pixels, while the movie projection industry standard is actually 4096 x 2160 pixels. Many manufacturers are also promoting 4k resolutions as “Ultra HD” or UHD.

Does it matter: Maybe. While production of 4k TVs has increased and prices have dropped, there’s still very little content available to consumers in the format today, making the extra resolution of little practical value. Prices for 4k projectors have not yet dropped as dramatically as their TV counterparts.


Tom Manna – “4k is the next technology that’s coming down the road, and that’s twice the resolution as current 1080p. There’s no content yet though in 4k outside of a Sony media server.”

Dennis Erskine – “Right now I wouldn’t be advising anybody to buy 4k in any case for reasons that have nothing to do with picture quality. The real problem is that the current transport mechanism — the method by which we get the picture from the source to display has not been completely settled… In most cases, I don’t think people will actually see a difference from their [HDTV]. I would simply advise them to take some deep thought as to whether they really need that and would be willing to do an upgrade every year or two when some of these innovations are settled.”

Mark Prancuk – “4K is so much better, but, I hate to say it, it almost makes me feel like the picture is too clear. It’s like watching a high-definition video tape because it almost takes away from the movie because it’s so real.”

Aspect Ratio

How it’s defined: A video’s proportion between width and height. The native ratio comes from the camera’s sensor or negative while TVs and projectors both have their own aspect ratios. If a camera shoots 4:3 video (also known as fullscreen or 1.33:1) and it’s shown on a common 16:9 HDTV (also known as widescreen or 1.78:1), there will be “black bars” on both sides of on the HDTV.

Does it matter: Maybe. While almost all HDTVs and HD projectors depict a widescreen 16:9 image, you want to make sure there’s no cropping of the original image. Also, with projectors, you can add curtains to conceal possible black bars.


Tom Manna – “There’s no set format a director will cut a movie in, but the predominant one is around 2.3:1 to 2.4:1. [A home theater setup that can match that] gives you a wide cinematic experience.”

Contrast Ratio

How it’s defined: The ratio of luminance (or brightness) of white to black that the TV or projector is capable of producing.

Does it matter: No. There are no industry standards for how this number is determined, although you do want your TV or projector to display good whites and blacks.


Dennis Erskine – “The problem is that the manufacturer’s specifications for contrast are not real world, and they don’t really tell you what the contrast is going to be once the projector is properly calibrated. If you go into a room and you are projecting a picture on the wall, the minimum standard is an in-room contrast ratio of 150 to 1. And that’s with the little checkerboard display so that the black and the white have a ratio of 150 to 1 between them. That is incredibly hard to get. It’s tough because you are shining light on a screen that’s reflecting light back into the room, which is reflecting that light back onto the screen.”


How it’s defined: A measurement used to gauge the luminance of a projected image in a room, accounting for factors like throw distance, screen color, and ambient light.

Does it matter: Yes. But no projector manufacturer provides this number. Recognize that lumens measures a projector’s luminance in optimal conditions, such as in a room with ambient light and measured a few inches from the bulb. On the other hand, foot-lamberts is a projector’s luminance within a real space, or how bright it will be once you set it up in your basement.


Kerry Bright – “You need to have 13+ foot-lamberts to have a successful image. It’s an old measurement based on candle strength. Foot-lamberts are a real measurement, lumens is not. What you do is you take a measurement from the refracted light, which tells you when you correctly take a measurement from the refraction off the image.

“There’s actually a really great app that you can get to your iPhone. It’s called Projector Pro. You can find the model number of your projector, put in how far back it’s going to be, how big of a projection screen it’s going to be and it will tell you how many foot-lamberts of output it is.”


How it’s defined: Measures the screen refresh rate, which is how many times per second a TV screen image is completely reconstructed.

Does it matter: No. A 60Hz TV is more than capable for whatever media you want to play. At one time, TV manufacturers touted higher refresh rates (such as 120Hz and 240Hz) that eliminated motion blur and it worked great for football games. In films, higher refresh rates are responsible for what’s known as the “Soap Opera Effect”, where a movie (most likely shot at 24 frames per second) on an expensive HDTV may look too smooth and therefore unnatural. Most HDTVs allow you to adjust the refresh rate for different content.

LED Display

How it’s defined: It’s an LCD panel for the colors that uses LEDs for the light. LEDs — light-emitting diodes — can be turned on to produce a color through the LCD or off to display no color, or black. Lower-end “edge-lit” LCD LED displays illuminate the screen only from the perimeter, relying on a diffuser to then spread the light across the full panel, which may create uneven lighting and coloring. Full-array LED-based backlighting found on higher end TVs features rows of LED lights spread across the entire back of an LCD panel. This dispersion allows for more even lighting and great color contrast via a process called local dimming.

Does it matter: Yes. They’re the ubiquitous HDTV on the market today. They are affordable and low-energy, but lack the ability produce blacks as deep as technologies such as OLED.


Mark Prancuk – “The basic LEDs have an LCD panel with LEDs behind [it]. So basically there is a white LED is behind it that intensifies and dims according to what the picture demands. So it’s brightening it up or dimming it down for the colors, and usually on the lower models, it’s around the perimeter. It’s a perimeter LED. The higher-end models have LEDs completely all the way behind the whole panel.”


How it’s defined: It’s measure of the amount of light emitted by a projector.

Does it matter: No. This is one stat to not worry about because there is no industry standard for how to measure lumens. Many manufacturers measure lumens in a bright room a few inches away from the bulb, which does not correlate to how bright a projected image is when thrown onto a screen from a distance.


Kerry Bright – “A lot of people get involved in looking at the lumens of a projector’s light output. It’s a real mistake because a lumens is not necessarily a positive. If you get something that’s producing a tremendous amount of lumens, then the question is what it’s doing to the blacks, and what kind of a screen is it bouncing off if, how far away from the projection screen is it.”

OLED Display

How it’s defined: It is a panel with a thin organic film between two conductors, which responds to an electrical current. Unlike an LED display, an OLED display is one unit with multiple layers for both the light and color.

Does it matter? Yes. If you can afford it and you’re willing to settle for smaller screen sizes (55 inches is the largest TV on the market). This new display technology is low energy and has near-perfect blacks.


Mark Prancuk – “OLED is a true LED, they use actual LEDs for the colors. I was walking in Best Buy… and I walked by an OLED. It was just a small one but I did a double-take, I was like, ‘What is that?’”

Plasma Display

How it’s defined: A display with small cells containing electrically charged ionized gases, also known as plasmas.

Does it matter? Maybe. Plasma TVs used to be touted for their great blacks, but have been discontinued by most manufacturers. Plasma TVs also don’t have much motion blur and have a good viewing angle. Only LG is still manufacturing plasmas and a few companies are still selling older models, although they may disappear completely in a few years.


Dennis Erskine – “You know what I have in my living room? I have a 55-inch Pioneer Elite plasma 720p, and when I have guests over at my house, I have people ask me, is that a 4k? No, it’s not. It’s 720p, and they can’t tell the difference until you get really close to it.”

Quantum Pixel Technology

How it’s defined: Quantum dots are photo- and electro-active nanocrystals that light upon demand like OLED but are inorganic. They can be added as a layer on top of an LED backlight to fine tune the light that you see. Manufacturers are promoting it heavily in 2015 inside high-end TVs as a significant source of image improvement.

Does it matter? Yes. They do add better colors to LED displays for less money than an OLED. How much better than an LED is another question.


Mark Prancuk – “They have a wider variety of colors, the reds are redder, the blues, you know, the color spectrum is better… In theory it’s supposed to be better, but 4K and 1080p look just as good as the quantum color.”


How it’s defined: Increasing the resolution of a lower quality video source to match a higher resolution display.

Does it matter? Maybe. Recognize the size of your original content and what you’re trying to watch it on. At a certain point, the difference will be noticeable.


It’s about rattling bass and audible whispers.

Dolby Atmos

How it’s defined: A new audio format from Dolby for creating and playing back multichannel movie soundtracks. While traditional 5.1- and 7.1-channel surround setups deliver sound from the front, back and sides, Atmos adds sound above you with ceiling speakers or speakers angled at the ceiling. In other words, it gives movie sound a more three-dimensional effect.

Does it matter? Maybe. Movie theaters started to adopt it a few years ago and Dolby Atmos products for the home were released earlier this year. It’s likely the future for home theater audio, but sound engineers still need to adopt the codec before it becomes universal. A Dolby Atmos setup without the content engineered for it is impractical.


Mark Prancuk – “The sound is going to be completely around you rather than in front of you and behind you. So if a helicopter goes over your head, it’s going to go from the front channel to the front top channel up and over you. It’s going to be the standard as far as surround sound and movies.”

Dennis Erskine – “If you can afford it, get it. You can always add the speakers later. If you can’t afford it, don’t.”

Theo Kalomirakis – “You know, it’s incremental improvements. It’s good to have it. You’re more enveloped in the movie if you hear things coming from above. Does it change the way you experience movies? If gives you some initial thrill, and it’s good to have it, but it’s not the difference of watching a movie in DVD and seeing it on Blu-Ray.”

Dolby TrueHD

How it’s defined: It is a lossless multi-channel audio codec common on Blu-Ray players and A/V receivers today.

Does it matter? Yes. It is a common audio codec used today and can handle up to 7.1 channels. You want your receiver to decode it, but it ultimately matters what the audio engineer used.

DTS-HD Master Audio

How it’s defined: It is an uncompressed audio format and available on Blu-Ray discs.

Does it matter? Yes. It’s a very common codec that can utilize 7.1 channels and is only read via HDMI to the receiver.

Surround Sound

How it’s defined: 5.1 (5 speakers and 1 subwoofer) is the standard for surround sound today. Audio engineers create a film track where certain sounds are louder or quieter on particular speakers to reflect the film’s world.

Does it matter? Yes. It’s necessary for a great home theater. Codecs and speakers will be different for each film, but your receiver should have the potential to handle a minimum of 5.1.


Tom Manna – “The format that most people use, except for dedicated theater, is 5.1. There’s 7.2, which is 2 subwoofers, and then you can go beyond 7.2. Dolby Atmos takes 7.1 to the next level. Now, people have played with beyond 7.1 and 7.2, but that really is going to go by the wayside and Dolby Atmos will take over.”


How it’s defined: A power measurement for audio receivers and amplifiers. The more watts an A/V receiver produces, the more power the speakers in a system will receive.

Does it matter? No. Wattage is not a determiner of the quality or loudness of a sound system. Like lumens, manufacturers tend to misrepresent the actual watts provided by their products.


Dennis Erskine – “Today, receivers from name brand manufacturers Anker, Marantz, Emmett, Pioneer, and Sony are all bloody good. Clearly the marketing departments play a specification war, but minor difference in wattage output is not going to significantly change the sound quality.”

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