Difference between revisions of "Other hardware"

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(Headphones, A2DP)
m (Headphones: SPL definiton more accurate)
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* Impedance - Doesn't mean much by itself, but in general, impedence should be matched across a system.  
 
* Impedance - Doesn't mean much by itself, but in general, impedence should be matched across a system.  
  
* SPL@1kHz, 1V rms - How "loud" the unit is at 1 volt input (rms not peak-to-peak).
+
* SPL@1kHz, 1V rms - [http://en.wikipedia.org/wiki/Sound_pressure_level#SPL_in_audio_equipment Sound Pressure Level]. How efficient the unit converts electrical energy to sound energy.
  
 
* Neodymium - The magnet of choice for high end headphones.
 
* Neodymium - The magnet of choice for high end headphones.

Revision as of 17:27, 4 July 2006

Bluetooth (A2DP)

Advanced Audio Distribution Profile (A2DP)

Supports the codecs: Sub Band Codec (SBC)

Optionally supports: MPEG-1,2 Audio, MPEG-2,4 AAC and ATRAC,

With the bitrate limited by the bluetooth link

Sub Band Codec

  • Sampling Frequency - 16000, 32000, 44100, 48000 (some are optional, see references)
  • Channel Mode - mono, dual channel, stereo, joint stereo

The bitrate used for CD quality audio is 229 kbps and 328 kbps for middle and high quality, respectively.

Reference: BLUETOOTH Advanced Audio Distribution Profile 1.0

Headphones

Terminology used for comparing headphones

  • Frequency response - The range of frequencies the headphones can reproduce
  • Impedance - Doesn't mean much by itself, but in general, impedence should be matched across a system.
  • SPL@1kHz, 1V rms - Sound Pressure Level. How efficient the unit converts electrical energy to sound energy.
  • Neodymium - The magnet of choice for high end headphones.