To help match the best speakers and receivers for your listening needs, THX has established certification categories to ensure your home theater system can deliver crisp, clear THX Reference Level sound in the room size you desire.

Which THX Certification is Right for You?

7.1 Surround Sound Speaker System Set Up

A 7.1 surround system has seven discrete audio channels, Left, Right, Center, Left Surround, Right Surround, Left and Right Back, and of course, the Subwoofer.

• Front Left & Right Speakers (L & R): Place the Front Left and Right speakers at ear height, producing a 45° angle as viewed from the main seat. This delivers a wide sound stage and precise localization of individual sounds.
• Center Channel Speaker (C): Place the Center channel speaker either above or below the display. Then, aim the speaker either up or down to point directly at the listener. If you have a perforated projection screen, center this speaker both horizontally and vertically behind the screen.
• Surround Left & Right Speakers (SL & SR): Place the SL & SR speakers between 90° to 110° to each side and 2 feet or higher above the listener. The SL & SR speakers recreate the enveloping sound and intense special effects that you experience in the cinema.
• Surround Back Left & Right Speakers (SBL & SBR)*: The SBL & SBR speakers should be the direct firing type and placed together on the back wall. This allows the THX Advanced Speaker Array, or ASA technology to deliver its maximum effect. If the SBL and the SBR speakers can not be placed together, refer to your THX Certified Pre-amplifier or Receiver’s “THX Set Up” menu for alternative configurations.
• Subwoofer (Sub): There are a few variations for subwoofer placement, depending on how many subwoofers you have in your room. If you have four subs, place one in the middle of each wall. If you have two, put them in the middle of opposing walls. If you have one, place it in the middle of the front wall.

5.1 Surround Sound Speaker Set Up

A 5.1 surround system has five discrete audio channels: Left, Right, Center, Left Surround, Right Surround and the Subwoofer.

• Front Left & Right Speakers (L & R): Place the Front Left and Right speakers at ear height, producing a 45° angle as viewed from the main seating position. This delivers a wide sound stage and precise localization of individual sounds.
• Center Channel Speaker (C): Place the Center channel speaker either above or below the TV. Then, aim the speaker either up or down to point directly at the listener. If you have a perforated projection screen, center this speaker both horizontally and vertically behind the screen.
• Surround Left & Right Speakers (SL & SR): Place the SL & SR speakers between 90° to 110° to each side and 2 feet or higher above the listener.
• Subwoofer (Sub): If you have two Subs, put them in the middle of opposing walls. If you have one, place it in the middle of the front wall.

Dolby® TrueHD or DTS-HD Master Audio™ Set Up

If you use Dolby® TrueHD or DTS-HD Master Audio™, your back surround speakers should be separated to produce a 60° angle from the main listening position. In addition, you should go to the “THX Set Up” Menu in your THX Certified AV Receiver/Pre-amp and set the ASA Surround Back Speaker setting to “Apart (greater than 48).”

Desktop System Set Up

• Monitor Viewing Distance: There should be a 28 inch viewing distance from your desktop display to your seating position.
• Front Speakers: If you have a 5.1 desktop system, the Front Left and Right speakers should be placed to the side of your display, with the Center Channel Speaker either above or below the display —aimed at the listening position.
• Surround Speaker Set Up: If you have a 5.1 desktop system, the Surround speakers should be positioned 56 inches from your seating position.

Check out the THX Home Audio Buyer Guide before buying your next system.

How big should my system be?

The size of your living room or home theater plays a big part in what kind of system you should consider purchasing. A good surround sound system needs to be powerful enough to fill your room with crisp, clear sound. If you get one that doesn’t have enough horsepower, it can distort when playing at higher volumes. 

THX has created “room size categories” to help you find the right products to accurately reproduce movies, music and video games in your home. THX Select and Select2 Certified loudspeakers are designed for medium sized rooms 2,000 cubic feet in size, with a 10-12 foot viewing distance from the screen. THX Ultra2 Certified loudspeakers bring the cinematic experience to large home theaters, 3,000 cubic feet with a 12 foot or greater viewing distance from the screen.

Think before you buy

Before choosing an audio system for your home, ask yourself one basic question: “What am I going to listen to?” Are you looking for an audio system to connect with your iPod® or digital music library? Is it for multi-channel movies or just improving how your TV sounds? If you want to watch movies, TV or play games in surround sound, then you should consider a 5.1 or 7.1 surround sound system. If you are looking to improve how your iPod sounds in your bedroom or desktop, consider a 2.1 or 5.1 multimedia system.

What is 5.1 and 7.1 surround sound?

You have probably heard the terms 5.1 and 7.1 surround sound before. But, what do these numbers actually mean? The numbers 5 and 7 correlate to the number of audio channels used to mix the film, music or video game. They also refer to the number of speakers in the home theater system. For example, a 5.1 surround sound system typically has 5 speakers and 1 subwoofer, and a 7.1 system has 7 speakers and 1 subwoofer.

Click here to find out where each speaker should be placed in your room.

HTiB or separates?

If you prefer to buy all of your home theater components in one stop, then you should consider an Integrated System or “Home Theater in a Box” (HTiB). These “all-in-one” packages include speakers, subwoofer and an AV receiver. Some even come equipped with a DVD or Blu-ray player. The benefit? Everything is included in an HTiB, even the cables. And set up is easy.

The downside? Many HTiB systems lack the power and performance to really bring your home theater to life. THX recently teamed with Onkyo to launch the Onkyo HT-S9100THX, an all-in-one speaker/receiver package that delivers the best of both worlds—great THX performance at an affordable price.

What is an AV receiver, and why should I care?

You will need an AV receiver to experience surround sound—there is no denying this. The AV receiver is the hub of your home audio system. Receivers accept all audio and video sources, including satellite and cable TV, DVRs, DVD and Blu-ray players, as well as gaming consoles. It then distributes the sound from these sources to your surround system, accurately powering all of your speakers.

THX Certified receivers range in price from $500 to $9000. The price difference is often defined by product features and technologies. High-end receivers feature a number of listening modes, calibration technologies and video processing. Higher priced receivers may also be upgradeable via firmware updates in case a new technology appears on the market.

When deciding on the right AV receiver for your system, start by making sure there is enough amplifier power to drive the speakers for your particular room size. Then, evaluate the various processing modes. If you play video games or enjoy movies in surround sound, THX Listening modes and THX Loudness Plus will greatly improve the experience. In addition, you should try to pick a receiver with enough inputs (HDMI, component, etc.) for your home entertainment system.

Check out AV receivers, amplifiers and pre-amps from Onkyo, Integra, Pioneer, Denon, Marantz, Yamaha, Lexicon, Meridian, Anthem, ADA, Halcro, JBL Synthesis, NAD and Parasound for more details.

What about speakers?

Speakers can be purchased as a package (5.1 and 7.1) or separately. And there are a lot of brands to choose from, each with its own unique sonic signature. Depending on the aesthetics of your home theater or living room, you can pick between traditional box speakers that are visible to viewers, or choose in-wall and in-ceiling speakers that disappear into the ceiling and walls. If you choose the latter, some drilling, cutting and running speaker cable is required. Not to fear though, if you are not the DIY type, a
THX Certified Professional can help with speaker installation.

Today, there is a number of great THX Certified in-wall and in-ceiling speakers that deliver the same, solid performance as THX Certified box speakers. Companies such as Sonance, Klipsch, Polk Audio and Atlantic Technology, have raised the bar for in-wall/in-ceiling performance.

What about on-wall speakers?

On-wall speakers are box speakers that are mounted on the wall. However, you need to make sure that the box speakers you purchase are actually designed for wall mounting. Why? A wall creates an acoustic boundary that reflects low frequencies (bass). If you mount traditional box speakers (not designed for wall mounting) the result could be a very bass heavy sound. THX recommends on-wall speakers from Teufel and Jamo.

Do larger speakers perform better?

The size of your speakers does make a difference in the way they perform. While many well known speaker brands push smaller speaker concepts, THX recommends resisting the temptation to go too small. The smaller the speaker, the more you may compromise in terms of output and low frequency performance. Try to find a balance between the size you desire and the sound quality you expect. THX Certified speaker brands, such as Sonance and Atlantic Technology, are renowned for their design aesthetic, creating high performing speakers that blend with any décor.

Do I need a subwoofer?

Yes you do! Don’t even think about getting a home theater system without a subwoofer. Subwoofers provide the low frequency bass that creates the rumbles of the jet engine in Iron Man or freeway bridges collapsing in Die Hard 4. THX recommends getting the biggest subwoofer that your living space and budget will allow. In the world of THX Certified speaker systems, a 12-inch or 2×10-inch subwoofers is a minimum requirement.

Can you mix and match speakers?

Yes, mixing and matching speaker brands and styles is fine. In fact, the whole concept of THX certification is based on the idea of being able to mix and match components from different manufacturers. The THX certification process standardizes all electrical and output parameters, so that all THX Certified speakers and receivers work together.

You can potentially have box speakers for the Front and in-wall or in-ceiling speakers for the Surrounds. However, THX recommends that you keep groups of speakers similar. This means, the Front speakers should be from the same manufacturer and designed to work together. And, the Surround Left and Right speakers should also be identical to each other, as should the Surround Back speakers.

Discover the latest products from Teufel, Snell, Polk Audio, M&K, Crystal Acoustics, Sonance, Logitech, Klipsch, Creative Labs, Razer, BG, Atlantic Technology, JBL Synthesis, Jamo, Velodyne, and other partners to come off the THX Test Bench.