Amphony h2500 情報ガイド
Q: Is the technology used in these headphones similar to Bluetooth or MP3 ?
A: Even though both our headphones and Bluetooth / MP3 use digital audio, there is a fundamental
difference between Bluetooth and how audio is transmitted to our headphones. Bluetooth is only
able to transmit audio data at very low data rates reliably (typically up to 200 kbps). Therefore, only
compressed audio can be transmitted via Bluetooth. A commonly used technique to compress
audio data is MP3. Our headphones, however, do not compress the audio and transmit the full bit
rate. As a result, the audio quality is not degraded such as with MP3. Also, the audio latency (audio
delay) of MP3 compressed audio is fairly high and thus not suitable for television or video
applications. Since our headphones do not compress the audio and since only a minimum of data
buffering is used, the audio delay is minimal.
difference between Bluetooth and how audio is transmitted to our headphones. Bluetooth is only
able to transmit audio data at very low data rates reliably (typically up to 200 kbps). Therefore, only
compressed audio can be transmitted via Bluetooth. A commonly used technique to compress
audio data is MP3. Our headphones, however, do not compress the audio and transmit the full bit
rate. As a result, the audio quality is not degraded such as with MP3. Also, the audio latency (audio
delay) of MP3 compressed audio is fairly high and thus not suitable for television or video
applications. Since our headphones do not compress the audio and since only a minimum of data
buffering is used, the audio delay is minimal.
Q: How does the transmitter connect to my audio equipment ?
A: The transmitter connects to any standard analog audio line output via the supplied stereo RCA
audio cable and to coaxial and optical digital audio outputs. In cases where no analog line output
(RCA audio out) is available, the transmitter can also connect to other audio outputs via appropriate
adapters which are not supplied with the product. By using a Y adapter which has either a 3.5 mm
or a 6.3 mm audio plug on one side and 2 RCA plugs on the other side, the transmitter can be
connected to headphone outputs.
audio cable and to coaxial and optical digital audio outputs. In cases where no analog line output
(RCA audio out) is available, the transmitter can also connect to other audio outputs via appropriate
adapters which are not supplied with the product. By using a Y adapter which has either a 3.5 mm
or a 6.3 mm audio plug on one side and 2 RCA plugs on the other side, the transmitter can be
connected to headphone outputs.
Q: What is Forward Error Correction and why is it used in these headphones ?
A: Occasionally, there may be some data which is corrupted during transmission. This may be the
case when there is interference, such as other transmitters, electrical sparks or if you move around
and the signal is temporarily lost. Forward Error Correction as it is used in our headphones can in
most cases repair the data which is received to guarantee 100% correct data reception and
therefore 100% correct audio reception.
case when there is interference, such as other transmitters, electrical sparks or if you move around
and the signal is temporarily lost. Forward Error Correction as it is used in our headphones can in
most cases repair the data which is received to guarantee 100% correct data reception and
therefore 100% correct audio reception.
Q: Can the transmitter connect to the digital audio output of my audio equipment ?
A: Yes, in addition to the analog audio interface, the Model 2500 transmitter features a coaxial and
an optical digital audio interface. By using one of these interfaces, the transmitter can be connected
to any standard digital audio output. The transmitter will format the digital audio data and send it to
the headphones without making any changes to the audio data or sample rate and without applying
any audio compression. Therefore, the audio data received by the headphones is exactly the same
as the data which is received at the digital input. The digital inputs of the transmitter bypass the
integrated analog-to-digital converter and eliminate any unnecessary analog-to-digital or digital-to-
analog conversion. Since no noise or audio degradation is introduced by the digital audio interface,
the signal-to-noise ratio is highest when using a digital audio interface. Please note that the digital
audio interfaces only process uncompressed linear audio data at the sample rates of
32 kHz, 44.1 kHz or 48 kHz. They do not process compressed multichannel audio data. In such a
case, an external surround decoder is necessary or the analog audio interface can be used.
an optical digital audio interface. By using one of these interfaces, the transmitter can be connected
to any standard digital audio output. The transmitter will format the digital audio data and send it to
the headphones without making any changes to the audio data or sample rate and without applying
any audio compression. Therefore, the audio data received by the headphones is exactly the same
as the data which is received at the digital input. The digital inputs of the transmitter bypass the
integrated analog-to-digital converter and eliminate any unnecessary analog-to-digital or digital-to-
analog conversion. Since no noise or audio degradation is introduced by the digital audio interface,
the signal-to-noise ratio is highest when using a digital audio interface. Please note that the digital
audio interfaces only process uncompressed linear audio data at the sample rates of
32 kHz, 44.1 kHz or 48 kHz. They do not process compressed multichannel audio data. In such a
case, an external surround decoder is necessary or the analog audio interface can be used.
© 2004 Amphony 2