Technology FAQ

Technology FAQ

General Questions

What is Audyssey?
We're a company of designers and engineers who care about great sound. We design and develop innovative technologies that make amazing audio possible by fixing the acoustical problems in your home, theater and car. Our technologies help your audio experience be as true as possible to the original studio recordings, movies and live performances.
Why do I need Audyssey technologies?
Your home entertainment experience has many components: content (movies, music or television), hardware (amplifiers, speakers, television and players) and your room. The components are unique and so are the audio problems. Our technologies help them all work in concert for a better experience.
How do I get Audyssey technologies?
Audyssey technologies are incorporated in home theater audio video receivers (AVRs), televisions, audio systems, home theater-in-a-box systems (HTiBs) and automobiles. Find a product with Audyssey technologies by searching our product catalog.
Is Audyssey creating effects to improve my sound?
No. Many audio processing companies add effects to change the original sound. Audyssey is in a different category. Each of our technologies targets a specific audio problem in your home, car or studio and fixes it to give you better sound quality.
How do I know if I'm using Audyssey?

Make sure Audyssey is available in your audio product. If you have an audio video receiver (AVR) for your home theater system, check the front panel for the Audyssey logo.

Make sure Audyssey is ON. Our core technology, MultEQ, uses a microphone to set-up your system and fix the acoustical problems in your room. Some of our other technologies need to be enabled from the setup menu. Check your manual for details because every manufacturer implements their interface differently.

A complete list of products with Audyssey technologies can be found on our product catalog.

Which Audyssey technologies do I need to set up or turn on?

If your product has Audyssey 2EQ, MultEQ, MultEQ XT or MultEQ XT32 you need to complete a one time measurement to optimize the sound of your system in your room. Click here for setup advice and instructions.

If your product (such as a TV) has Audyssey EQ, it has already been optimized for you. You may have other Audyssey technologies such as Dynamic Volume and Dynamic EQ that you will need to turn on.

What if I have other questions?
We’re glad you asked. We built a place specifically to answer all your questions, general or technical. Check out Ask Audyssey. You can also reach us any time on Facebook and Twitter.

MultEQ Questions

What is room distortion and why do I need MultEQ?
Room distortion is caused by reflections from walls and furniture in a room (or car). Sound from the loudspeakers reaches your ears directly but also bounces off surfaces and is reflected. You hear these unwanted reflections a bit later than the direct sound causing distortion. MultEQ analyzes these reflections and corrects the problems they create. Movies, music and games sound the way they were created. Audyssey founders spent 6 years and $6 million of university research to create MultEQ and solve the room distortion problem.
How do I run MultEQ?
Click for a step-by-step guide plus tips for optimal MultEQ results.
What is the difference between the various versions of MultEQ?

Audyssey room correction technology comes in four flavors: MultEQ XT32, MultEQ XT, MultEQ and 2EQ. While they're all built on the same core science, each is designed to operate within the constraints of the available DSP processing power that the manufacturer has selected for their product. Each version has different filter resolutions and number of measurement positions. Click for more details on each solution.

We also have a factory calibrated audio equalization technology Audyssey EQ which can be found in many televisions, HTiB systems and other audio systems that ship with their speakers.

Can I use any mic for MultEQ? Can I use a mic from my previous AVR on my new AVR?
No. To both questions. The Audyssey mic that was included with your AVR has been specially calibrated to your AVR model. Using another microphone for your MultEQ calibration will not produce accurate results. If you can't find the microphone that was included with your AVR contact the manufacturer for a replacement.
How is MultEQ different on AVRs by different manufacturers?
The core Audyssey technology used by all manufacturers is the same. The only differences are in the implementation of the user interface that each manufacturer selected for their products.
How do I know Audyssey MultEQ is turned on?
In an AVR you'll see a glowing Audyssey MultEQ logo or LED when MultEQ is turned on.
What is the benefit of having a professional installer run MultEQ on my system?
Audyssey Registered Installers (listed on our Installer Finder) are trained to use the Audyssey professional calibration kit with our MultEQ Pro software. If your AVR is Installer-Ready a Registered Installer can use the Audyssey kit with MultEQ Pro software to take up to 32 measurements in your home theater.
What are your Installer-Ready / Pro-Enabled AVRs?
Installer-Ready AVRs are those that can be calibrated by Audyssey Registered Installers using our MultEQ Pro software for even more accurate room correction. Here is a complete list of Installer-Ready AVRs.
What makes MultEQ work when so many others have tried to solve this problem for decades?

MultEQ is different from the many systems in the past because of two differentiators:

  1. The way it measures your room
  2. By correcting both time and frequency problems

In terms of calibration measurement methods, there are two types of systems out there today:

  1. Those that attempt to correct for only one seat in the room. This typically makes other seats in the room sound worse because a single measurement does not provide an accurate representation of the problems of the entire room.
  2. Some EQ systems do try to correct for multiple positions. They simply average the measurement results that they gather. Averaging tends to smooth-out common acoustical problems without really fixing them. For example if there's a peak at 200 Hz in one seat and a dip at 200 Hz in another seat (typical room), then the two measurements average each other out and there's no correction made.

In either case these systems only attempt to correct frequency response problems and not time domain problems and this leaves a big part of the problem unsolved.

How does MultEQ measure your room differently?

MultEQ looks at patterns in the time domain responses and classifies them into clusters based on the similarities in those patterns, typically in 3-5 groups. A representative response is created from each cluster, and a final response is then created from grouping the representatives. That response is then used to create the EQ filter. It is a complicated process based on the complex mathematics of pattern recognition and fuzzy logic. But there's nothing fuzzy about the results. If you want to know more, we offer copies of selected publications we've written for technical conferences.

Time and Frequency Correction:
  1. The time domain is where many of the problems are. Parametric and graphic equalizers can only correct for the frequency response and do so in a very coarse manner because they have limited resolution (bands).
  2. Further, whether they have fixed or adjustable bands doesn't matter because bands cause phase problems that most people hear as "ringing" or "smearing." That's why, after thirty-plus years of trying this method, most people don't like the results. And they turn it off.
How does MultEQ address time and frequency problems?

MultEQ filters start in the time domain. They aren't just a few parametric bands. Instead they use several hundred points to represent the room response in both the frequency and time domains.

The trick is to use enough filter points to get the needed resolution but not so many that it overwhelms the processor inside the audio component. So we came up with a way to reduce the number of points without sacrificing accuracy while providing more filter power at lower frequencies where it's needed the most. MultEQ can correct 8 channels by using only a fraction of a single DSP chip. This gives you the best of both worlds: time and frequency correction. Result: room correction that works
for the first time ever.

What about calibrating my system?

In addition to the complex EQ work, we also do the simple things well. During step 1 above, MultEQ checks the absolute polarity of your system and tells you if any speakers are out of polarity (the + - wiring problem). It also measures the acoustical distance (within a 1/4 inch) to each speaker and sets the proper level trims for all channels including the subwoofer. Finally it finds the optimum crossover frequency between each satellite channel and the subwoofer(s) and provides that information to the bass management system.

More MultEQ questions on Ask Audyssey »

Audyssey DSX Questions

Why do you recommend Wides before Heights?
Our research shows that creating the signals in the Wide channels is the most important cue that listeners use to sense the size of a room. Height signals help listeners sense how far back the stage goes. For more details read our technical details section here.
If movies are mixed for 5.1 how does Audyssey DSX create 7.1, 9.1 and 11.1 channels?
We analyze the content as it plays to identify the information that should be sent to the Audyssey DSX Wide and Height channels to expand the soundstage. DSX is scalable and can take a 5.1 system up to 7.1, 9.1 or 11.1 if both Wide and Height speakers are added.
Which AVRs can do both Heights and Wides?
Look for “Audyssey DSX enabled for both Heights and Wides” in the comments field on our current product listing here.
Will Audyssey DSX improve the sound of my video games?
Yup. Especially sophisticated first person shooter games where you explore outdoor environments, go through small and large rooms, and experience complex sound effects.
More Audyssey DSX questions on Ask Audyssey »

Dynamic Volume Questions

Why are commercials so loud?
The trend in advertising has been to boost the volume on commercials. How? They compress the dynamic range of the commercial's audio making everything roughly the same volume. Then they boost the level to the maximum allowable so instead of hearing quiet moments with loud peaks, they sustain the height during the entire playback.
When should I use Dynamic Volume?

Dynamic Volume was designed to let you set the dialog at the level you want. So you never have to worry about the sound getting too soft or too loud. It also takes a film's softest and loudest sound, as designed for movie theaters, and helps match that range to your TV's or home theater's.

It’s ideal for late night TV viewing because it eliminates the large volume fluctuations between channels and within programs and commercials. Dynamic Volume helps level out those fluctuations so you can sit back and enjoy without constantly grabbing the remote.

Will I lose the fidelity of the audio content if Dynamic Volume is turned on?
No. Other methods only bring down the loudest frequencies changing the content. Dynamic Volume acts as an automatic volume control, changing the level without changing the original tonal balance of the content.
How does Dynamic Volume avoid pumping artifacts?

The older methods devised to control volume levels all suffer from one big problem: reaction time. When sounds get too loud they try to bring them down, but they don’t know how fast to react. Most content is changing constantly, from soft to loud, then back, with different timing depending on the action. The old methods start to adjust one way and then swing the other without any knowledge of what’s about to happen next. This results is something called pumping. It sounds like someone is playing games with the remote.

We designed Dynamic Volume with a look-ahead feature that analyzes how fast it should react before the content is played. It makes the necessary adjustments without any artifacts.

More Dynamic Volume questions on Ask Audyssey »

Dynamic EQ Questions

Why can’t I hear my surround sound and bass when I turn my volume down?
The scientific reason? It's so you can sleep at night. If we could hear low frequencies at the same levels as the higher frequencies, our heart and other vital organs, which produce a lot of noise at low frequencies, would keep us awake. But evolution wasn’t aware that one day we'd want to watch movies the way they were created. When designers mix sound for movies they listen at very high levels. The decisions they make about the balance of frequencies and the level of surround sound is done for the loud volumes in movie theaters. When we listen at home the sound is a lot quieter, and so our balance is completely different. That's why movies sound like they're lacking bass and surround. Dynamic EQ is designed to fix that. It restores the proper balance by making adjustments for human perception at lower listening levels.
What are the best Dynamic EQ settings for movies, music, and video games?

Movies are mixed in rooms calibrated for film reference. To achieve the same reference level in a home theater system each speaker level must be adjusted so that –30 dBFS band-limited (500 Hz – 2000 Hz) pink noise produces 75 dB sound pressure level at the listening position. A home theater system automatically calibrated by Audyssey MultEQ will play at reference level when the master volume control is set to the 0 dB position. At that level you can hear the mix at the same level the mixers heard it.

Audyssey Dynamic EQ is referenced to the standard film mix level. It makes adjustments to maintain the reference response and surround envelopment when the volume is turned down from 0 dB. However, film reference level is not always used in music or other non-film content. The Dynamic EQ Reference Level Offset provides three offsets from the film level reference (5 dB, 10 dB, and 15 dB) that can be selected when the mix level of the content is not within the standard.

0 dB (Film Ref): This is the default setting and should be used when listening to movies.

15 dB: Select this setting for pop/rock music or other program material that is mixed at very high listening levels and has a compressed dynamic range.

10 dB: Select this setting for jazz or other music that has a wider dynamic range. This setting should also be selected for TV content as that is usually mixed at 10 dB below film reference.

5 dB: Select this setting for content that has a very wide dynamic range like classical music.

More Dynamic EQ questions on Ask Audyssey »