Available Sound Properties; Design Guidelines - Motorola V550 - Cell Phone 5 MB Technical Manual

Technical Specifications for MP3:
Bit Rate: 65kbps max
Recommended File Size: 100K
Maximum Duration (NW dependent): 16-30 secs

Available Sound Properties

The following table describes the available MP3 encoding properties on the V550.
File
Type
MP3 44.1kHz
MP3 24kHz
MP3 24kHz
MP3 16kHz
MP3 16kHz
*Overall bit-rate cannot exceed 64 kbps. Any MP3s encoded higher than 64 kbps will not
play on the device.
Note: There is no stereo speaker support for the Motorola V550. Stereo ring tones will be
played in mono. If the handset supports a stereo file and a stereo headset is attached, the
file will be played in stereo.
Depending of frequency content of the material the recommended properties for MP3 ring
tones are:
MP3 44.1kHz
MP3 24kHz

Design Guidelines

Since ring tones need to be at a consistent audible level, compressing the original content
to reduce the peak-to-average ratio is necessary. After the audio is compressed it is
advisable to re-normalize the audio to 0db before saving the compressed MP3 file.
Note: Ring tones are generally between 15-20 seconds in length. Based on the
recommended bit rates that would yield a file size between 75-150K per tone. It is
advisable to keep file size beneath 100K to allow the end-user to download multiple tones,
but there is no file size limit except for total free memory available on the device.
Sampling Bit
Frequency Depth
16
16
16
16
16
16
16
Bit-rate
Mono/Stereo (kbps)
Mono
Stereo
Mono
Stereo
Mono
Mono
Mono
64
40
40
40
32
64
40
23