When designing your soundbar, make sure your wireless technology delivers the highest quality, reliable audio

As high-definition televisions (HDTVs) get thinner, it becomes extremely challenging to be able to build high-quality internal speakers in them. what’s the result? A huge gap has emerged between the quality of the video and audio experience. Soundbars have entered the market offering consumers a convenient way to improve the quality of their audio experience, but different technologies offer very different experiences when it comes to audio quality and reliability.

By Steve Venuti, Vice President of Marketing, WiSA Technologies

As high-definition televisions (HDTVs) get thinner, it becomes extremely challenging to be able to build high-quality internal speakers in them. what’s the result? A huge gap has emerged between the quality of the video and audio experience. Soundbars have entered the market offering consumers a convenient way to improve the quality of their audio experience, but different technologies offer very different experiences when it comes to audio quality and reliability.

Entry-level soundbars are simply extensions of your TV’s built-in speakers – easily connected via HDMI or optical fiber, providing a somewhat better audio experience. Some may have a subwoofer (aka a subwoofer) wirelessly connected to the soundbar to provide enhanced bass. As convenient as this setup is, the limited number of speakers will never provide the same audio experience as the existing video experience in HDTVs. The only way to bring audio quality to video quality levels is to surround yourself with sound, and the only way to do that is to install speakers both in front of and behind the audience.

Many mid-range soundbars connect wirelessly to the rear speakers, but not all soundbars are created equal. Reliably delivering high-quality audio in a congested wireless environment in a room is a challenge, but with the right technology, a soundbar with rear speakers can also deliver immersive audio at a reliability level that’s essential for creating high-quality immersion A seamless audio experience is critical.

True spatial audio requires speakers that surround the listener

Choose the right wireless technology to create a reliable and high-quality immersive audio experience

It is important to understand the basic technical requirements for transmitting and receiving high-quality spatial audio:

bandwidth: Spatial audio requires multiple audio streams to be sent to external speakers simultaneously. Not only do you need bandwidth to support multiple audio streams, but you also need enough bandwidth to load uncompressed high-bitrate audio, which is what determines the audio quality.

Tight speaker synchronization: Multiple speakers need to work in sync to create a realistic immersive experience. In a 5.1 channel scenario, there will be a center speaker, left and right front speakers, left and right rear speakers, and a subwoofer, and the audio transmission technology needs to keep all speakers in close synchronization.

low latency: Transport latency is critical, especially when playing video, where even the slightest delay between the video and the corresponding audio track is easily noticeable

reliability: Tight speaker synchronization and low latency cannot deliver their benefits if the technology cannot reliably stream audio. Managing communication reliability in an environment where wireless paths are increasingly congested is critical.

What is the correct wireless medium? What is proper wireless transmission?

When choosing a wireless spatial audio technology, there are two basic considerations: medium and transmission. A medium is a wireless technology used to transmit audio signals from an audio source to external speakers.

Transport is the technical layer running on top of the medium that manages the key requirements to deliver an immersive audio experience: the synchronization requirements between speakers and the required latency for video and audio streams to work together seamlessly.

Media: Bluetooth vs Wi-Fi

The most common wireless protocols for interconnecting devices in the home are Bluetooth and Wi-Fi. Both protocols are designed to transmit data, not multi-channel audio. As a result, solutions on the market today tend to use proprietary narrowband or wideband protocols, none of which are compatible with Bluetooth or Wi-Fi.

Bluetooth is a narrowband wireless protocol that can only transmit audio in mono (single channel) or stereo (dual channel). Bluetooth doesn’t support 2.1-channel audio, or any surround-sound format – it just doesn’t have enough bandwidth to support multi-channel spatial audio. There are a lot of soundbars on the market that use Bluetooth to connect to the subwoofer, because latency and sync are not critical to the low-frequency sound the subwoofer produces. Bluetooth was never designed for high-bit-rate, uncompressed, multi-channel audio streaming, and is typically only used on low-cost, entry-level systems that provide wireless connectivity to a single subwoofer.

Wi-Fi is ubiquitous and extremely fast, so it seems like the obvious medium of choice to provide the highest quality and affordable multi-channel wireless audio solution. Most homes have Wi-Fi networks, and the cost of Wi-Fi chips continues to drop. While Wi-Fi has the bandwidth required for multi-channel audio, the protocol itself was never designed to manage the speaker synchronization and critical latency required for immersive audio experiences. Therefore, most multi-channel audio products on the market offer their own proprietary narrowband or wideband solutions, operating in the same 2.4 – 5 GHz frequency band as Wi-Fi.

Proprietary protocols are facing new challenges

This strategy of using parts of the 2.4 C 5 GHz band to run proprietary wireless protocols presents many new challenges. As Wi-Fi technology has matured, regulators and the Wi-Fi Alliance have opened up previously reserved segments of the spectrum. Proprietary multi-channel audio protocols utilize these previously reserved frequency bands to reliably manage multi-channel audio in congested wireless environments, but this is not going to continue in the future. New routers on the market are operating in these newly opened frequency bands and causing problems with current multi-channel audio transmitters and receivers.

WiSA Technologies: The leader in high-quality, multi-channel wireless audio technology

WiSA Technologies Co., Ltd. has more than ten years of experience in developing high-quality, multi-channel, spatial audio transmission solutions. The company’s (formerly known as Summit Wireless) technology has been incorporated into its products by some of the most prestigious audio brands, including top sound system companies such as Bang & Olufsen and Harmon Kardon, as well as HDTVs such as Hisense, TCL and LG. manufacturer.

Over the past 10 years, the market has changed, and sound bars have become an increasingly popular and cost-effective way to bring multi-channel audio into the home.

Wirelessly connecting subwoofers and rear speakers to a soundbar has become the easiest way to achieve a truly immersive audio experience in the home, but without the right transport layer, it’s impossible to deliver the kind of audio that listeners expect. performance.

What makes WiSA’s transport layer so powerful

At the heart of the success of WiSA and its customers is WiSA’s multi-channel audio transport technology, which ensures that multi-channel audio streams arrive at speakers with very low latency and maintains synchronization between speakers. Most importantly, this transport layer ensures the reliability of the audio stream. WiSA has spent more than 10 years developing its transport layer technology.

WiSA’s transport layer technology manages audio streaming, control data, system settings and voice assistance

WiSA Introduces Wi-Fi Compatible DS Solution: Designed to Manage Multi-Channel Audio in Congested Wi-Fi Environments

After building audio technology for high-end audio brands, WiSA Technologies turned its attention to improving wireless audio quality in the soundbar market. WiSA DS technology is designed to bring high-quality multi-channel wireless audio to soundbars, enabling entry-level to mid-range audio systems to deliver unrivaled spatial audio at an affordable price…and to do it reliably.

Operates in the 2.4 GHz band with performance and reliability that exceeds other 5 GHz solutions on the market

WiSA DS runs on an ultra-low-cost 2.4 GHz Wi-Fi IoT transceiver module with built-in antennas and is capable of:

• Supports transmission of 5 channels (4 full-range audio channels and 1 high-fidelity subwoofer channel) uncompressed 16-bit audio at a sample rate of 48 kHz, exceeding CD quality

Transmitter (TX): transmits up to 4 independent audio channels plus a subwoofer channel

Receiver (RX): A single module in RX mode can output up to two audio channels

• Speaker synchronization within ±1 audio sample

• Fixed propagation delay of 30ms compliant with International Telecommunication Union (ITU) lip-sync specification

• Compatible with Wi-Fi protocols: designed to work in Wi-Fi protocols and to be able to operate in highly congested wireless environments

Use cases for WiSA DS modules:

The target market for the DS module is sound bars that want to deliver best-in-class audio technology, and to drive additional external wireless speakers such as subwoofers and rear speakers.

Top use case: being embedded in a soundbar to wirelessly drive two rear speakers and a subwoofer.

Due to the ultra-low cost of the DS module, it can also be used with entry-level soundbars, enabling wireless subwoofers that are usually connected via Bluetooth technology.

Other use cases include connecting a high-definition television (HDTV) via HDMI ARC or eARC to an external adapter that supports DS modules, wirelessly connecting and driving a center speaker, left and right front speakers, and a subwoofer (left). Embedding a DS module into an HDTV does the same thing, but eliminates the need for an external audio adapter (right)

5.1 System using WiSA DS module

Utilize the Smart Center Speaker to connect to your HDTV via ARC/eARC, wirelessly connect 2 front speakers, 2 rear speakers and a subwoofer for a complete 5.1 immersive system.

Create a 5.1.4 Atmos (ATMOS) spatial audio system with a soundbar using the DS mod

Even more exciting and able to demonstrate the unique feature set of DS modules is that audio equipment manufacturers can use this low-cost technology to build new soundbar use cases, including 5.1.2 and 5.1.4 systems, bringing true Dolby Atmos spatial audio comes to market at a very competitive price.

Reliability is the key

Enabling new use cases for wireless audio is exciting, but the most important requirement for wireless audio is the reliability of the audio stream. Operating in the 2.4 GHz band will bring more challenges to reliability. But WiSA engineers have been developing high-quality, reliable wireless audio technology for over a decade, and it has become a staple in wireless audio for many of the world’s top audio brands. WiSA has the deep technical expertise needed to build reliable systems even in the most congested wireless environments – using a 2.4 GHz IoT chip makes it very affordable to add wireless audio capabilities to sound systems.

Independent testing comparing WiSA DS technology with other solutions on the market

The most critical part of any product development process is testing product performance in a real-world environment. While using Wi-Fi as a medium, more and more devices are streaming higher and higher resolution content, and real-world testing can be used to evaluate performance in highly congested situations.

WiSA submitted their technology to an independent lab to test the WiSA DS module and compare its performance to that of the most popular competitors on the market – both at 5 GHz frequency band operation. Novus Labs is a highly regarded test lab with expertise in audio and wireless, working with audio brands such as Bose, Sonos, Roku and Sony.

The premise of the test is very simple: create an environment with a baseline of Wi-Fi data traffic (both 2.4 GHz and 5 GHz) and increase the Wi-Fi congestion from the baseline to 25%, 50%, 75% and up to the last 100 % congestion, when the available bandwidth is completely full of Wi-Fi data traffic. At each congestion level, Novus Labs records the number of audio anomalies that occur over a 10-minute period. The table below illustrates the use of actual devices and activities that generate Wi-Fi data traffic in a typical home, injecting a corresponding amount of congestion into the environment at each level.

The test results are shown below: the gray bar represents the level of audio anomalies that the average consumer can detect, and above the gray bar is the time it takes for the number of audio anomalies to reach a point of system failure.

From the test results, you can see:

• Solution A, even in a relatively uncongested wireless environment (just over baseline congestion), shows a lot of audio anomalies and stops working at 50% congestion level

• Solution B, the market leader and currently used by millions of soundbar products on the market, starts having audio anomalies before the 50% congestion point and stops working at the 75% congestion level

• WiSA’s DS module continues to operate when it reaches 75% congestion level, starts to have audio anomalies when it exceeds 75% congestion level, and stops working when it reaches 100% congestion level

What these congestion levels mean for an average consumer home

From a real-world application perspective, these levels of congestion fit the following approximations:

1. Baseline level: including routers in the home and neighbors’ homes are performing wireless communication normally
2. 25% level: A device data stream equivalent to an HD video stream is added to the baseline level
3. 50% level: A device data stream equivalent to a 4K video stream is added to the baseline level
4. 75% level: A device data stream equivalent to one 4K video stream plus three HD video streams is added to the baseline level

Historically, a wireless audio solution that can operate in a 50% congestion environment is considered a very good solution. WiSA’s solution can operate in an environment with a congestion level of 75%, which is a major breakthrough in wireless audio technology.

Why design a 2.4 GHz solution? How does a 2.4 GHz solution outperform a 5 GHz solution?

The WiSA DS is designed with 2.4 GHz wireless audio for one simple reason: cost. For most consumers, sound bars are the entry point for immersive audio solutions. The ability to use off-the-shelf technology such as 2.4 GHz IoT chips to provide a robust and reliable feature set enables soundbar companies to build feature-rich products without burdening the product bill of materials (BOM).

Cost is an important factor in bringing DS products to market, but if product performance is unreliable, cost is irrelevant. There are two basic reasons why WiSA DS modules are superior to other 5 GHz solutions on the market:

1. Design strategy: The design starting point of other solutions on the market today is to find those sections of the Wi-Fi spectrum that can be “hidden” when wireless data traffic becomes too congested. But this strategy is no longer effective, as regulators, as well as the Wi-Fi Alliance (the body that governs the Wi-Fi specification) are opening up these parts of the Wi-Fi spectrum, trying to hide in underutilized segments of the spectrum is no longer feasible strategy.

2. Multi-channel wireless audio expertise: WiSA Technologies has been designing multi-channel wireless audio modules for top audio equipment brands for many years. Meeting the technical requirements of these brands is extremely difficult and requires the highest level of understanding of the challenges and complexities that exist in the management of critical functions, including but not limited to speaker synchronization, audio latency, etc., and most importantly, the reliability of the wireless link. DS modules bring WiSA’s years of expertise and know-how in providing the most reliable wireless audio transmission. But this time WiSA engineers didn’t design just for high-end products, but designed a module for the soundbar market, a low-cost solution that is now available for consumers designing entry-level and Used by companies with mid-range audio systems.

The Links:   EVM31-050A 7MBR150VR120