ZOOM Telephonics

Zoom Telephonics modems

Zoom Telephonics modems can be powered by either Lucent or Rockwell chip sets. Refer to this table to determine which one is for you:

Your modem You should select Chip set
ZOOM(r) FAX/MODEM 56K Voice DualMode EXT model 2949 Zoom External 56K Voice Rockwell
ZOOM(r) FAX/MODEM 56K Voice Video DualMode INT model 2822-25-06 Zoom Internal 56K Voice Rockwell
ZOOM(r) FAX/MODEM 56K Voice DualMode PCI model 2925 Zoom 56K PCI Faxmodem Lucent (LT)
ZOOM(r) FAX/MODEM 56K Voice DualMode EXT Zoom External 56K Voice LT Lucent (LT)
ZOOM(r) FAX/MODEM 56K Voice Video DualMode INT Zoom Internal 56K Voice LT Lucent (LT)
Lucent (AT&T) based modems, including PCI Win Modems
Available Voice Codecs 
Method Bit Depth Sampling Frequencies Comment
PCM 16-bit linear 16 7200, 8000, 11025 The best sound quality
PCM 8-bit unsigned 8 7200, 8000, 11025 Very good sound quality. Though this codec is not in the list of supported algorithms, Lucent modems seems to use this codec instead of linear PCM.
PCM 8-bit linear 8 7200, 8000, 11025 Very good sound quality. If the program produces distorted sound with unsigned PCM, use this codec.
IMA ADPCM (Intel/DVI) 4 8000 Considerable sound quality
A-law PCM 8 8 8000 Very good sound quality. Sometimes may have a problem with playback.
u-law PCM 8 8 8000 Very good sound quality. Sometimes may have a problem with playback.

 

Since these modems are Lucent compatible, the Lucent LT Win Modem FAQ at 56K.com is an appropriate resource for them.

Zoom modems with Rockwell chips

Available Voice Codecs
Method Bit Depth Sampling Frequencies Comment
PCM 8-bit unsigned 8 7200 Very good sound quality
Rockwell ADPCM 4 7200 Good sound quality

Read more about Rockwell-compatible modems here.

Modem Notes Modem Notes