The first part of the series focuses on local streaming. We call it local because it’s not about streaming music over the internet, but specifically covers the field of consumer electronics. Here, digitally stored content is transferred digitally from one device – this could be an MP3 player, laptop, or dedicated audio network player – to an amplifier, and then finally to the speakers. This gives us two key factors for the highest possible quality data transmission: the file format and the transmission method.
File Formats
Instead of diving into the jungle of abbreviations (.wav, .flac, .aac, .aiff, .ogg, … the list can go on almost indefinitely), it makes sense to make some basic distinctions. First, there are compressed and uncompressed audio formats. Behind this is the idea of reducing the amount of data (compressing the data) when transmission options are not optimal, to ensure a smooth data stream. In this context, the importance of bitrate becomes clear, as it is specified for MP3 files, for example (common values are 128 kBit/s, 192 kBit/s, 320 kBit/s). Here, the data throughput rate per second is limited, so a specific amount of data is not exceeded per unit of time. This ensures that weak connections are not overwhelmed by large amounts of data.
But that’s not all. Audio file compression can be either lossless or lossy. Algorithms that work losslessly allow a bit-identical reconstruction of the original signal, while lossy algorithms only store the signal approximately in less relevant portions or cut it out entirely. This affects very high frequencies, for example, which lie at the upper end of the human hearing spectrum. When evaluating lossy codecs, the bitrate provides the key clue regarding the expected audio quality.
A reliable reference point for evaluating lossless formats is the good old compact disc. After all, music is also stored digitally on CDs. Unlike analog records, which have continuously changing grooves, CDs have so-called "pits" and "lands" that are scanned by the laser in a CD player. CDs operate with a word length of 16 Bit and a sampling rate of 44.1 kHz. These values refer to the accuracy with which the audio signal is represented digitally. Audio files can also have a much finer resolution, for example with a word length of 24 or 32 Bit and sampling rates up to 192 kHz. These particularly high word lengths and sampling rates previously played a greater role in music production. Since the first A/D conversion of recorded signals usually takes place there, the argument of the highest possible precision in digital reproduction carries far more weight there than factors like file size or transmission speed. Meanwhile, storage space is hardly a limiting factor anymore, and data transmission is becoming faster and more reliable all the time. This is why high-resolution files are also becoming interesting for end customers.
Quick Overview of Common Audio Formats
Transmission Method
Much like with file formats, there are various systems when it comes to transmission, each with its own advantages and limitations that must be considered. One option is transmission via an Ethernet interface. This wired variant (using CAT6 or CAT7 network cables) offers fast and reliable transfer even of large amounts of data – ideal for high-quality audio and video material.
As an alternative, there is the option to stream via wireless LAN. This largely eliminates the need for cables, which keeps things tidy and looks neat. However, there are also some drawbacks. WLAN networks operate in a relatively small frequency range, so they often interfere with each other in tight spaces. This can lead to problems with connection speeds, especially in densely populated areas. Using WLAN repeaters also impairs transmission. To better assess which networks are active on-site and which channels are available for the least interference possible, there are corresponding analysis tools, such as the inSSIDer program (http://www.metageek.net/products/inssider/).
As a rule of thumb: Data at CD quality or lower can be streamed via Wi-Fi relatively easily. High-resolution music and video files, however, overwhelm most wireless networks – this leads to sporadic errors and dropouts during transmission. PowerLAN can provide a solution in this case. Here, data is fed from a network cable into the home electrical system using a socket adapter. The high speed and easy setup make the PowerLAN standard appealing. Additionally, the system is relatively secure against interference. Problems can occur if there are different circuit breakers.
Benefits of Streaming
Some benefits have already been mentioned. Studio-quality "Hi-Res" audio files offer audiophile listening experiences that can far exceed the familiar CD quality. When it comes to your own home, you can remove the phrase "cable clutter" from your vocabulary, and there are plenty of other conveniences as well. First off, you can conveniently access your own media archive from anywhere in the house and adjust various parameters like volume, song selection, etc. to suit the situation. This is especially handy when you don’t want to get up from the couch. Thanks to the wide range of web radios, online streaming services, and download portals, new content is also available at all times.
Another highlight: So-called multi-room solutions bring audio and video to every room. This allows multiple displays and speaker setups – both classic stereo setups and multi-channel configurations – to be controlled from a central location as needed. Integrating various devices, such as iDevices, smartphones, MP3 players, or USB drives, opens up enormous flexibility, and thanks to the numerous apps available, there are also individual control options for your system.
Wireless, Great Sound: Sonos Play:3 with SUB
Final Thoughts
Even though the topic of streaming in the consumer electronics space is just catching on: It is definitely not a short-lived trend, but the future. Physical media will be pushed into the niche, where they will certainly still have their place, while high-quality digital content will flow through increasingly fast and reliable networks and be available to users at any time and anywhere.
The desire for digital high-end music enjoyment has now reached the industry and music distributors. Recently, Neil Young made headlines with his PonoPlayer, whose crowdfunding campaign far exceeded its initial goal of 800,000 US dollars within 24 hours. Additionally, there are currently rumors that Apple may soon offer high-resolution music files in the iTunes Store. This move would in turn put pressure on the competition. This means the chances are good that the selection of "Hi-Res" audio files will grow in the future, and access to them will be significantly easier via the large providers.
If you’ve now been caught up in curiosity, we would be happy to advise you thoroughly.
0 comments