{{Update, inaccurate=y, date=January 2012
On December 28, 2005,
XM Satellite Radio
XM Satellite Radio (XM) was one of the three satellite radio (SDARS) and online radio services in the United States and Canada, operated by Sirius XM, Sirius XM Holdings. It provided pay-for-service radio, analogous to subscription cable televisi ...
announced that it had teamed up with
Neural Audio Corporation
Neural Audio Corporation was an audio research company based in Kirkland, Washington.
The company specialized in high-end audio research. It helped XM Satellite Radio launch their service using the Neural Codec Pre-Conditioner, which was design ...
to introduce XM HD Surround, XM HD Surround broadcasts XM channels in 5.1 digital
surround sound
Surround sound is a technique for enriching the fidelity and depth of sound reproduction by using multiple audio channels from speakers that surround the listener (surround channels). Its first application was in movie theaters. Prior to sur ...
. For a time XM broadcast a variety of special shows and live music performances in this format. According to th press release
Denon
is a Japanese electronics company started in 1910 by Frederick Whitney Horn, an American entrepreneur. Denon produced the first cylinder audio media in Japan and players to play them. Decades later, Denon was involved in the early stages of de ...
,
Onkyo
is a Japanese consumer electronics
Consumer electronics or home electronics are Electronics, electronic (Analogue electronics, analog or digital electronics, digital) equipment intended for everyday use, typically in private homes. Consu ...
,
Pioneer Electronics
commonly referred to as Pioneer, is a Japanese multinational corporation based in Tokyo, that specializes in digital entertainment products. The company was founded by Nozomu Matsumoto in January 1, 1938 in Tokyo as a radio and speaker repair ...
(USA) Inc., and
Yamaha Yamaha may refer to:
* Yamaha Corporation, a Japanese company with a wide range of products and services, established in 1887. The company is the largest shareholder of Yamaha Motor Company (below).
** Yamaha Music Foundation, an organization estab ...
will introduced home audio systems capable of playing XM HD Surround in 2006.
The 5.1 surround sound is encoded in the stereo wave for transmission and is thus compatible with any mono/stereo/matrix-style receiver. If played on a 5.1 audio set equipped with
Neural Surround
Neural Audio Corporation was an audio research company based in Kirkland, Washington.
The company specialized in high-end audio research. It helped XM Satellite Radio launch their service using the Neural Codec Pre-Conditioner, which was design ...
decoder, the
watermarks
A watermark is an identifying image or pattern in paper that appears as various shades of lightness/darkness when viewed by transmitted light (or when viewed by reflected light, atop a dark background), caused by thickness or density variations ...
(i.e. spatial cues) in the waveforms are detected and the signal is recovered to its original 5.1 form. The technology is similar to
parametric stereo
Parametric Stereo (abbreviated as PS) is an audio compression algorithm used as an audio coding format for digital audio. It is considered an Audio Object Type of MPEG-4 Part 3 (MPEG-4 Audio) that serves to enhance the coding efficiency of low ban ...
, in which a mono signal is recovered to stereo. The
bitrate
In telecommunications and computing, bit rate (bitrate or as a variable ''R'') is the number of bits that are conveyed or processed per unit of time.
The bit rate is expressed in the unit bit per second (symbol: bit/s), often in conjunction w ...
for XMHD surround broadcasts is ~70 kbit/s using
aacPlus
High-Efficiency Advanced Audio Coding (HE-AAC) is an audio coding format for lossy data compression of digital audio defined as an MPEG-4 Audio profile in ISO/ IEC 14496–3. It is an extension of Low Complexity AAC (AAC-LC) optimized fo ...
from
Coding Technologies
Coding Technologies AB was a Swedish technology company that pioneered the use of spectral band replication in Advanced Audio Coding. Its MPEG-2 AAC-derived codec, called aacPlus, was published in 2001 and submitted to the MPEG for standardizatio ...
.
XM HD Surround Channels (as of 12/11/08)
* XM77
Sirius XM Pops
Sirius XM Pops is a Sirius XM Satellite Radio online station devoted to popular classical music. It was formerly available on XM channel 75 (previously 77), Sirius channel 75 (previously 79). Until February 9, 2010, it was heard on Direct TV ...