Audio saturation using SDRPlay RSP1B

[GamerMine]

Hello, first of all this project is very cool!

But unfortunately, I currently have troubles to make it works correctly with my SDRPlay RSP1B.
I am using a Debian 13.3 machine and I installed NovaSDR on it using the installation script.

I ran the NovaSDR setup and configured my sdr as follow (content of receivers.json )

{
  "receivers": [
    {
      "id": "rx0",
      "enabled": true,
      "name": "SDRPlay",
      "input": {
        "sps": 2048000,
        "frequency": 100700000,
        "signal": "iq",
        "fft_size": 131072,
        "brightness_offset": 0,
        "audio_sps": 44100,
        "waterfall_size": 1024,
        "waterfall_compression": "zstd",
        "audio_compression": "adpcm",
        "smeter_offset": 0,
        "accelerator": "none",
        "driver": {
          "kind": "soapysdr",
          "format": "cs16",
          "device": "driver=sdrplay, label=SDRplay Dev0 RSP1B 2402019E60, serial=2402019E60",
          "channel": 0
        },
        "defaults": {
          "frequency": -1,
          "modulation": "WBFM",
          "squelch_enabled": false
        }
      }
    }
  ]
}

Then I started the NovaSDR server and opening the website reveals some issues.

• The default WFM bandwidth seems to be wrong, it is very narrow and the only way to increase it is by using the buttons under Bandwidth adjust. I can't drag the cursors sides to make it larger.
• The sound is very distorted, I don't know why.

See the following video (I had to upload it on Youtube because I couldn't upload it here directly):
WARNING: Because of the distorted sound it may be loud.

https://youtu.be/KSMA9zqOISU

If you need any other information, you can ask me =)

Good day,
Maxime

[ON5HB]

I tested WBFM also, it doesn't seem to be implemented in total yet. It's seems to be a leftover from Phantom in the code.
As such the GUI has no WBFM button yet.

[kg7rdr]

In our instance all of the audio from the RSP devices through Soapy have

1. A 1-2 second delay from the waterfall
2. All sound a bit distorted regardless of mode and bandwidth.

Waiting for one of our other development RX888 to become available for testing, but I am not hopeful as some of the public servers have the same distorted audio.

[Steven9101]

The buttons only work because of a bug it seems, thats why its distorted its not actually increasing the bandwidth, in the config you need to increase the audio sps to make it work :) I will investigate it tho

[ON5HB]

Waiting for one of our other development RX888 to become available for testing, but I am not hopeful as some of the public servers have the same distorted audio.

Have you seen the version number? It's still not 1.x.x meaning it's a public beta at best. Steven is working very hard on improving things when he has time.
Sometimes it takes some time, but then you see enormous progress been made.

I have seen what Steven is capable off, he will fix it sooner or later. This project rewrite of Phantom is only 6 months old, many will change over time.

The delay of the waterfall is caused by not using GPU to accelerate things. OpenCL is the best and offloads FFTW from the CPU, making delays a lot shorter.

As for the RX888 in VHF, it won't do more then 10MHz not 30MHz like on HF, if it ever works. You can run the RSP1x at 10MHz wide, but you will need the GPU to do it. However, due to filters etc, the RSPxx will only do 8-9MHz max.
So waiting for RX888 ding wideband VHF won't help, unless you make a converter/mixer to lift HF to VHF then it will do 30MHz in FM 3M band.