My experience using RM Noise with FlexRadio

psundquist

I wrote a detailed blog article on my experience using RM Noise with my Flex. It's not perfect and it has limitations, but WOW. http://www.bitofsnow.com/2023/10/20/ai-noise-suppression-is-an-amateur-radio-breakthrough/

Trucker

Interesting blog. I have been testing RM Noise for a couple of months now. As you stated, it works extremely well. The only Noise Reduction I have heard and used that I consider better , is the noise reduction in Thetis for the Anan radios.( and also available for the Hermes Lite radios) It is all client side processing and latency is extremely low compared to RM Noise. To me I would rather have a client side application doing the processing independent of having to use an off site server to process the audio. As more users use the server (s) ,latency will increase. For now, it is quite acceptable. Not only that, should the system go offline for any reason, then you are back to using the default system in your radio. It could be as problematic as when SmartLink started having issues. The Noise Reduction in Thetis using Dr Warren Pratt's WDSP library is proof that good, reliable noise reduction is possible without having to use AI and an internet server to provide good audio. The algorithms used in WDSP library are well known. ( proven back in the late 1980's) Flex Radio just has to decide to make the commitment to improve the DSP functions in SmartSDR. None of us should have to resort to using a 3rd party application, much less, AI off site processing, to have good quality audio.

Should Flex Radio come out with server based AI audio processing, I will sell my radio. It's nice when it works, but when it goes down, it will make the complaints about SmartLink when it goes down,seem like nothing.

James

WD5GWY

psundquist

Thanks for sharing your experience with Thetis. I’ve read how noise reduction was improved with Thetis but didn’t know it was this good. I know that things will start changing now that folks understand what is possible. It’s an exciting time to see these advancements. These advancements can be packed up and put into radios which will start happening.

km8v

I have also messed around with RM Noise and it is indeed pretty impressive.

Thetis is open source, so perhaps the Flex devs can take note, and take a look at it...

Darryl

NR2, available in Thetis software working with Anan or Hermes lite-2 hardware has been around for a long time. Many Flex users have asked that the phenomenal noise reduction of NR2 be put into Flex. The requests have fallen on deaf ears. I don't understand Flex's reticence.

I have a Flex-6300 and like it. The networking is great and it is a very solid radio, but the radio that is quiet and just fun to operate is the HL2 running Thetis with all the options and new features available as a result of the Thetis development team of volunteers.

Very frustrating.

I'm not an op that runs contests multi-multi. Noise reduction is a feature I would pay for. So is Pure Signal.

Darryl

N0DP

David Decoons, wo2x

The only thing I don’t like about NR2 is it does “color” the audio. If rag chewing for long periods, I’d rather reduce AGC-T and have better sounding RX audio (I hang with a group that runs 50 - 4000 on TX. And yes, where we operate there is plenty of room on that portion of the band.

73

Dave wo2x

Trucker

https://community.flexradio.com/discussion/comment/20608257#Comment_20608257

Maybe it is my hearing, but, I don't notice any coloring of the audio using NR2 in Thetis. I also adjust the eq to make the audio sound better to me. I have always liked the receive audio in Kenwood radios. Especially, my Kenwood TS-890. It has a very crisp, natural sound to it. I also use the EQ in the 890. I have found that careful adjustment of the RF Gain and not being too aggressive with NR1 setting, yields the best results. My 6600M, while still very good, has a tendency to bury a weak signal when using the noise reduction and trying to reduce the background noise and hiss. If you lower the AGC-T to compensate for the noise, the weak signal gets covered up by the noise reduction. That is something that NR2 in Thetis doesn't do.

James

WD5GWY

John K3MA

There is one concern that many people may not realize when it comes to taking something (coding) that is open source and implementing it into a closed system like SmartSDR. Depending upon the open source licensing doing so might require Flex to provide visibility into their closed source code. I am not an expert in this area so I mention this only as something that Flex has to consider when users ask for code such as NR2 to be implemented in SmartSDR.

I know this exact issue is a problem with many Chinese companies that have taken open source code (or are suspected of doing so) and built it into their own products without disclosing or providing visibility to the open-source development community.

Franksr-N9GQR

I could not get RM Noise to work with the powered speakers?

I never could figure out how the configuration is supposed to work

with the 6400M in SmartControl Mode.

Any Advice?

Trucker

R M Noise works with a DAX channel from your slice receiver. I used DAX channel 1 for RM Noise. If it is working, you will see an indication ( green indicator moving with the receive audio) in the Dax control panel that DAX is sending audio to your computer. In RM Noise, you have to go into the setup screen and select DAX 1 as your source and your PC's audio output for audio.

It will not send the processed audio back to your radio for playback.

James

WD5GWY