What Makes WiSA Certifications Different From Other Wireless Speaker Solutions

Editor's Note: The following is a sponsored Editorial by Alan Ruberg, Chief Technologist, WiSA Association. From time to time we like to get industry perspectives on emerging technologies, and this is one about WiSA is straight from the mouth of one of its chief architects.

Established in 2011, the Wireless Speaker and Audio (WiSA™) Association (pronounced WEYE – suh) provides the first cross-industry standard for high-definition wireless audio. The Association fosters interoperability testing between CE devices and high-performance wireless speakers. 

Current member brands of the WiSA Association and its technical advisory committee include,  Accent Digital, Amber Technology, Anthem® , Aperion Audio®, DALI®, Definitive Technologies, Gibson®, GGEC, Hansong, Klipsch®, Martin Logan®, Meiloon, Nyne, Onkyo®, Paradigm, Pioneer, Polk Audio®, Sharp®, Silicon Image®, Summit Semiconductor and Sam Runco.  Any speaker brand, AV manufacturer, CE company, Electronics and Speaker OEMs or ODMs, CE retailers, or custom installers, can join the Association for a nominal annual fee, giving them full access to the compliance specification and reference designs.

WiSA certified speakers, AVRs, and playback devices use the same frequencies and transmission scheme of 802.11a, but WiSA speakers work very different from Wi-Fi speakers and other wireless speakers on the market.  WiSA speakers do not sit on the local area network, and purposely avoid Wi-Fi traffic, so there is no interference between audio and computers, and vice versa.

WiSA systems utilize the Dynamic Frequency Selection (DFS) channels between 5.2 and 5.8 GHz.  These channels are unlicensed, but not unregulated.  The DFS channels were previously reserved for weather and military applications. Consumer devices can use these DFS channels, as long as conflicts with these important services are actively avoided.  There are rules that the channel in use must be monitored for interfering with radar, a new channel must be selected in this event, and a channel must be free of radar for one minute before being selected. WiSA systems take this one step further – a new channel is selected on the event of any interference.

WiSA- certified devices are required to look-ahead to determine the next open frequency.  Conflicts are rare, but when the speaker system encounters interference from another device, it will automatically jump to the next open frequency without dropping any of the audio that is playing.  Then, it will automatically begin looking for another open frequency, so it always has a backup DFS ready for immediate use.  The result is no conflicts, no dropouts, no interference, and no hassles. Installation techs will no longer need to deal with conflicting Wi-Fi devices causing interference.

WiSA-compliant systems not only follow DFS rules, but go a step further to define a transmission protocol that has been specifically built for multi-channel audio.  The WiSA transmitter broadcasts up to 8 channels of audio (i.e.  7.1 surround sound) to powered loudspeakers around the room.  The speakers reproduce uncompressed, 24-bit, audio using the native sampling rate of the media being played, up to 96kHz.  There is a 5ms system latency, shorter than most TV video processors, so it is perfect for video games.

According to Wikipedia.com:
Bluetooth, is a wireless technology standard for exchanging data over short distances (using short-wavelength radio transmissions in the ISM band from 2400–2480 MHz) from fixed and mobile devices, creating personal area networks (PANs) with high levels of security.

Bluetooth speakers are not good for video games, because the latency is normally a lot longer than 5ms.  This is why they are sometimes used as battery powered surround sound speakers in a “quadrophonic” setup, meaning the consumer has two 2 large stereo front speakers, and two rear surround sound speakers added for movies.  Bluetooth speakers are also used as a way to listen to stereo music wirelessly from a smartphone, iPod, or MP3 player, where the latency and dropouts are less critical.

Dropouts and latency aside, Bluetooth has other limitations.  Consumers may purchase a Bluetooth subwoofer or stereo sound bar, but they will not find a 7.1 Dolby and DTS certified surround sound system based on Bluetooth technology.  The devices may also need to be manually paired each time they are used, to save on battery life.   And what happens when the batteries die in the middle of movie night?

Another wireless speaker manufacturer making big waves is Sonos.  Consumers can now “stream” (or beam?) the latest deadmau5 track from their iPhone to their wireless Sonos speakers.  Sonos uses a mesh network technology like ZigBee, which works well if you are pushing 2 channel stereo audio to different rooms in your house.  Party time!

But movie time is different.  Speakers that are adequate for background music are not always adequate for films or critical listening.  Qualities like speech intelligibility, timbre, dynamic range, and frequency response are important, as well as perfect silence during some scenes.  No one ever said “I wish this movie was more garbled, and compressed, and had more static, pops and clicks”.

The WiSA Association does not dictate how good a speaker should sound, or how well it should be made. The WiSA 1.0 Certification Test Specification (or CTS) ensures that the wireless link between two devices will not affect the sound quality adversely.  In essence, it will sound as good as copper wire, if not better.  Because the audio is transmitted digitally to the amplifiers, which are customized by the manufacturer to match the cones and cabinets, some say that WiSA certified wireless speakers actually sound better than wired versions of the same speaker.
A lot of people in the industry like Apple AirPlay devices because they work so well with other Apple devices.  The WiSA Association has a similar goal: when a consumer sees the WiSA logo on a wireless speaker, they will know it will work flawlessly with another WiSA certified product.  The speakers can cost $500 for a surround setup, or $50,000 a piece, it doesn’t matter.  If the WiSA logo is on the product, it will work with another product bearing the logo, without dropouts or interference.  The current specification says the product must work up to 96kHz sampling rate in a  x 30 foot (9 x 9m) room.

Getting back to AirPlay, there is no reason that AirPlay devices and WiSA certified devices can’t work together.  Basically, someone can take the stereo or HDMI output from the AirPlay receiver and plug it into an input on the WiSA certified audio hub, see diagram below:

WiSA certification is a game-changer in the wireless speaker world.  It IS the new industry standard for high quality surround sound in the home theater. WiSA speaker technology can also be used in portable speaker applications too.  Here are some examples:

1. Surround speakers that are removable. Use them for movie night or the big game and then put them away to make room, clear paths, and for charging.
2. A church or house of worship movie night.  Surround sound speakers can be setup in the temple, multi-purpose room, basement, gymnasium, cafeteria, , etc.
3. Yoga, Pilates, and Zumba classes can be hosted in flexible event spaces like ballrooms or lobbies
4. Small towns can host outdoor movie nights with full surround sound.  The speakers can be setup a couple hours before each event and packed up after the film so they are not prone to vandalism.

In summary, each wireless technology has its place, but no one is offering wireless surround sound audio for the home theater with all of the WiSA benefits such as multi-channel surround sound that is interoperable with any compliant system; transmitting uncompressed, interference free HD audio that is easy to set up and easy to use.  

- Alan Ruberg, Chief Technologist, WiSA Association