What is wireless audio?
This is the first in a series of blog posts on the subject of wireless audio. Our objective is to simplify what to the average music lover is a complicated and confusing subject. We will publish a new installment about every two weeks, so please check back again. As always, we welcome your comments and participation.
Most people reading this will already know that “wireless audio” means “audio signals that travel without wires;” but that’s just the beginning of the story. In fact, wireless audio provides features and conveniences that were never possible even with the most elaborate wired systems. The paradigm shift is so profound that it can safely be said that the future of audio is wireless.
For 100 years, audio signals have moved from Point A to B via wires. It’s a tried and true technology, but it has many practical limitations as well as technical weaknesses. With wireless audio, many of those problems are eliminated. But first, exactly what is wireless audio?
Wireless audio uses a radio-frequency transmitter to convey an audio signal to a radio receiver (this sometimes called streaming). The audio data signal, along with other non-audio data, is broadcast as a radio wave. The range of transmission is determined by the type of radios used, and things that can affect the transmission of radio waves such as walls inside a house. The signal may be broadcast directly from the transmitter to the receiver (as with Bluetooth) or through another device such as router (WiFi) but the end result is the same.
As you might guess, wireless audio sounds suspiciously like cellphone technology and in fact they are fundamentally the same. However, whereas a cellphone can send a voice signal around the world using telecommunications network, wireless audio is more modest. Wireless audio refers to systems that encompass, for example, a room or a house.
The radio part of wireless audio can use familiar technologies such as Bluetooth and WiFi. Both are wireless transmission systems that work over short distances such as in a home. Although Bluetooth and WiFi can deliver many kinds of signals, they are also adept at audio. Wireless audio products can piggyback onto these technologies to cost-effectively deliver audio throughout your home.
We should note that the audio signal itself is formatted as a digital code. This allows more efficient transmission, and protects the audio content from noise and distortion as it travels through the air. We should also note that wireless audio is used to convey “line-level” signals. Amplified signals, such as the output from a power amplifier, are not conducive to wireless transmission. Thus a wireless speaker also contains a power amplifier. This is not really a limitation; in fact, as we’ll see in a later installment, combining the speaker with the amplifier offers several advantages.
A wireless audio system thus begins to take shape: in the most common application, an audio signal originates in a source such as a smartphone and is wirelessly conveyed to a playback unit housing a power amplifier and a speaker. The playback unit can be controlled with its own set of buttons, but it’s more likely that the system is conveniently controlled at the source.
It’s important to note that the playback unit must be compatible with the source. It’s not unlike the situation in a wired system where a plug must fit into a compatible jack. In a wireless system, compatibility is needed because the playback unit must recognize the signals from the source, and likewise be able communicate data back to the source. As you might guess, this leads to questions such as Apple versus Android; we’ll cover that topic in a later installment.
For now, the takeaway is that wireless audio cuts the cord, and that gives audio designers an entirely new palette of audio technology to explore. So, should you switch from wired to wireless? We’ll consider that question next….
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