apco pROJECT 25 aUDIO qUALLITY cONCERN

Jun 17, 2025

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So I’ve finally gotten my Uniden Barecat BCD996P2 digital trunking scanner working the way I want it to (I had one setting set wrong and it was decoding everything.) However, I want to gripe about the audio quallity of P25 Phase I.

West Virginia uses P25 Phase I and Phase II for a lot of state communications. Phase II is only deployed in a select few regions, and I’m fairly sure this is a recording of Phase I, but the audio quallity is terrible. I know digital is far better in terms of bandwidth use compared to analog, but P25 digital sounds horrible.

Excuse the background noise, my interface was picking up some noise.

Recorded using ProScan software connected to a Uniden BCD996P2 scanner and a FocusRite Scarlett Solo audio interface.

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4 responses to “apco pROJECT 25 aUDIO qUALLITY cONCERN”

EugeniuszPompiusz

June 20, 2025

Sorry for a second comment in a row: The better subjective quality score has the open-source Codec2, which serves the similar purpose mainly for HAM operators.

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EugeniuszPompiusz

June 20, 2025

The nerdy thing about A/I/mbe codec in general is that one can set a ratio between voiced and voiceless thing. they are transmitted with clear markings and clear classification inside.

It is a classic example of a vocoder so nothing special should be expected

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KanawhaCountyWX

June 17, 2025

P25 radio is based on the propriotary IMBE codec at a bitrate of 4.4 Kbps. Total over-air bitrate is 9.6Kbps, but that also includes signaling protocals and other such things. So makes sense that its similar in profile to the 2G CDMA codec, although that had around 14Kbps to play with, including signaling overhead.

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blazy-enterprises

June 17, 2025

audio quallitty reminds me of 2g CDMA

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apco pROJECT 25 aUDIO qUALLITY cONCERN

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4 responses to “apco pROJECT 25 aUDIO qUALLITY cONCERN”

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