Speak about “wireless” and most people spontaneously think of streaming via WiFi or Bluetooth. The WiSA standard, or Wisa wireless technology, however, wants to make short work of those other difficult cables in the room: the speaker cables.
The Wisa wireless technology from 2013
Is the WiSA technology new? Absolutely not. In fact, we were there when the new standard was launched at the CES fair in 2013. You read that right: seven years ago. After that it remained silent for a long time about this technology, except at Bang & Olufsen. The Danish luxury brand immediately jumped out and implemented it in a series of products. But other manufacturers would rather look the cat out of the tree. Why now suddenly pay attention to WiSA technology? And what is WiSA again? We will answer these two questions in this article.
Get rid of the speaker cable
For clarity: the WiSA standard (fully Wireless Speakers and Audio) is not intended as a replacement for the network cable. It is therefore not a WiFi variant and also not technology to build a multi-room system, but wireless technology that works from point to point. From sender to receiver, that is. It might look like Bluetooth, which was also designed to take the place between two devices. A smartphone and a speaker, but also a PC and a printer that would otherwise be connected via a USB cable. But the difference is that with WiSA the transmitter can be a streamer / preamplifier, game console or other source and the receiver is always a speaker. So WiSA is really only an alternative to the speaker cable.
There have been other attempts to make the link between the audio system and speaker wireless, for example with KleerNet. This technology operates at 2.4, 5.2 or 5.8 GHz and is used by Dali, among others, to provide its wireless Callisto speakers with music from a central hub. You can also find it with certain wireless headphones, including Sennheiser. KleerNet certainly has its plus points. Music is sent lossless at CD quality (44.1 kHz / 16-bit), there is little delay (important when watching TV) and the range is excellent (100 meters). In addition, there are all kinds of other wireless alternatives, which are used, among other things, to provide audio for subwoofers at sound bars wirelessly.
Also for surround
Yet WiSA is a much more fascinating cable replacement, partly because it is suitable for more scenarios than most rivals. Demanding audio enthusiasts, for example, will be satisfied with how audio data is sent: lossless and up to a maximum of 96 kHz / 24-bit. The WiSA standard also scales well, from stereo to 7.1 or 5.1.2 setups.
Setting up is easy. A WiSA transmitter automatically recognizes the speaker configuration in a room and will divide the audio stream coming from a source into the different channels. Each channel is then sent to the correct speaker.
With multi-channel sound you naturally immediately think of film sound, and then synchronization between image and sound is extremely important. Fortunately, the inventors of the standard have thought of that. The latency should be virtually zero, according to the WiSA group, ranging from 2.6 to 5.2 ms, depending on the audio stream resolution. The synchronization difference between the different speakers in a 7.1 setup should also be a maximum of one millionth of a second. That is very impressive.
Away from WiFi
A major problem with wireless technology is that the many WiFi networks pollute the radio spectrum. The original WiFi frequencies around 2.4 GHz are busy anyway, because in addition to the many WiFi devices there are also Bluetooth devices and other wireless technologies are present (such as KleerNet and Zigbee). In addition, just around the 2.4 GHz point there is also a lot of interference from sources such as microwave ovens, baby telephones and car alarms. That is why the latest WiFi standards offer an alternative around 5 and around 5.9 GHz. The reality is a bit more complex than the figures show. In practice, WiFi devices can choose from a number of channels around those key frequencies (2.4, 5.0 and 5.9 GHz) and these channels in turn have a certain width (20 to 80 MHz). Consequently, Wi-Fi networks occupy a larger part of the frequency range than those figures show, making it even more difficult to prevent interference.
The Wisa wireless technology standard opts for a radical approach. It completely avoids the WiFi frequencies and looks for a piece of relatively unused radio spectrum (U-NII, running from 5.2 to 5.8 GHz). This piece of frequency range is partly license-free, partly sporadic in use by military systems and radar applications. DFC rules apply. DFC means that consumer devices are allowed to use it, but that they must regularly check that no radar activity is detected. If this is the case, the device must leave that channel immediately and stay away for up to 30 minutes. With WiSA, that is less a matter because the standard is currently focused on use within one room. The WiSA signals are not that powerful and travel no farther than the walls.
If interference nevertheless occurs, then Dynamic Frequency Selection (DFS) is provided in the standard. When the audio stream threatens to falter, the WiSA devices will quickly look for another frequency. The listener should not notice this.
Why is there attention for Wisa wireless technology now?
The super short answer is: LG. Since the 2019 model year, various LG televisions (including the OLED models) are WiSA ready making this technology potentially suddenly accessible to a larger audience. Equally important was the announcement that the various Xbox One consoles also supported the standard. A small snag is that you cannot simply connect an LG TV or Xbox console with WiSA speakers.
A WiSA adapter that you plug into a USB port of the television or game console is a requirement . There are currently two adapters on the market: a reference USB stick transmitter for around 70 euros and a larger Axiim Link WiSA USB puck that costs around 250 euros. You can consider these sticks as complete substitutes for AV receivers; they decode the stream coming from the television and split the audio data into the desired number of channels. You can also use these USB channels as external sound cards with a PC.
LG is not the first to discover Wisa wireless technology. As mentioned, Bang & Olufsen jumped on the cart very early, just like Klipsch. For example, the American company Klipsch has made a bookshelf speaker, center and subwoofer from the Premiere Reference line active and equipped with WiSA, so that you can indeed build a 5.1 setup without cables.
At B&O there are several speakers available that work with WiSA. , such as the Beolab 18 and the mighty BeoLab 90. Harman Kardon’s new Citation line also works with Wisa wireless technology, although it seems to only be used to provide the audio stream between soundbar, subwoofer and rear speakers. Purely for “internal” use, but not surprisingly. With sound bars with separate wireless rear speakers, the problem of busy radio frequencies also plays a role. It is even very urgent, because wireless rear speakers may not experience any lag compared to the soundbar. Brands such as Sonos and Boers & Wilkins therefore use proprietary technology at 5 GHz for the connection between soundbar and rear speakers, Harman Kardon opts for WiSA.
Recently a number of hi-fi brands have embraced WiSA. Swedish Primare surprised the world by announcing that its SC-15 Prisma and SC-35 Prisma pre-amp / network players always had a deactivated WiSA transmitter on board. A firmware upgrade recently activated this feature, just in time to work with the Silverback Legend speakers from the Danish System Audio. We got this system demonstrated at the New Music Show in Brussels and sounded pretty audiophile. We are currently working on a test setup around a LG OLED55C9 and a number of WiSA speakers, so that we can report on how well this technology works in a later article. To be continued, so!
What does the future hold?
That Wisa wireless technology is an interesting evolution in the market cannot be denied. The idea that you can install a new OLED and connect it immediately to a surround setup without needing an AV receiver or cables is quite attractive. It is also interesting if you want to listen to stereo in high quality through active speakers.
There seems to be a bit more interest in Wisa wireless technology. A few more members have recently joined the WiSA association, including a number of TV brands such as TCL and Compal (Toshiba). At CES 2020, Sharp also presented a prototype of an 8K television with the WiSA Ready label dangling. Visitors to the fair could also discover WiSA sound bars and audio systems at American home automation brand Savant. Not spectacularly big names, but an indication that WiSA is being taken longer and more seriously. A good thing, because who doesn’t want to get rid of those tricky cables?
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