John,
Try plugging a better quality speaker into the radio. I personally find this does wonders to increase fidelity. Icom should be ashamed of the speakers in the D-Star HT's. I'm not sure, but there also may be something else going on as well. If I set up my 80 or 880 and connect to a reflector and do the same with the ID-1 using the same speaker, the fidelity improves big time with the 80 and 880 but the ID-1 still sounds much better (and the RF signal is much weaker). Gary KB2BSL WG2MSK repeater From: dstar_digital@yahoogroups.com [mailto:dstar_digi...@yahoogroups.com] On Behalf Of n2gyn Sent: Wednesday, September 01, 2010 2:27 PM To: dstar_digital@yahoogroups.com Subject: [DSTAR_DIGITAL] Re: Bit Rate? Thank you all for you reply and comments. Let me make myself clearer. I would like to see the audio quality of D-Star be improved. To MY ears' everyone sound like a robot. I thought this was due to the low bit rate. I am NOT impressed with the digital voice mode. I want to hear a more natural sounding voice. My telephone sounds better. How could this be achieved if not by bit rate? John ==================================================== --- In dstar_digital@yahoogroups.com <mailto:dstar_digital%40yahoogroups.com> , "Ted Wrobel" <twro...@...> wrote: > > Hi John, > > Not quite sure what you are thinking, but here is a brief overview of the > DStar data stream. > > The input to / output from the data processing 'module' of the radio is a > 9600 Baud stream - which equates to roughly 960 eight bit characters per > second. > > The logic of the system digitizes the voice in and passes it to the AMBE > Vocoder that compresses the data stream - a lot. > > It is the compresion by the Vocoder that is both the strength and weakness > of DStar. The compression makes a low data rate (and thus low bandwidth) > possible, but it also means that the re-constituted voice is an > approximation of the voice input. Generally the reconstructed voice is > pretty good, and given the bandwidth it is really quite remarkable. > > In any case, the baud rate of the system is fixed and cannot be modified at > any stage of the process without making the resulting stream unrecognizable > to other DStar systems. > > Note that the data rate over the internet can be much higher, but the chain > from repeater controller to / from the radio is fixed for DV comms at 9600. > > > 73 > Ted > W1GRI > > _____ > > From: dstar_digital@yahoogroups.com <mailto:dstar_digital%40yahoogroups.com> [mailto:dstar_digital@yahoogroups.com <mailto:dstar_digital%40yahoogroups.com> ] > On Behalf Of n2gyn > Sent: Tuesday, August 31, 2010 16:54 > To: dstar_digital@yahoogroups.com <mailto:dstar_digital%40yahoogroups.com> > Subject: [DSTAR_DIGITAL] Bit Rate? > > > > > Most radios are sent to 8bit. Can all radio's bit rate be changed? > I believe it is the LOW bit rate that lowers the quality of d-star's audio. > Is there a sub menu in the radio's. Also can the repeater's rate be change > to a higher rate? > John >
