apache-labs.com

Wishlist.
Noise reduction on transmit audio. I know it must be complex to write something like that into thetis. But I heard my buddies noise reduction in his sun sdr radio via software and it was good. It blanked out all the noise in the background. Pretty cool, similar to sonars noise reduction.

Wouldn't properly adjusted microphone settings accomplish the same thing?
James
WD5GWY

How about the already built in Downward Expander with look-ahead??

IMHO this is not an unreasonable request. People with noisy shacks that have fans running, etc. often have trouble with background noise.

Conceptually it would not be hard to use NR2 on the transmit audio. Of course you probably are aware that the console code in Thetis is quite complex (complex being a charitable word for "spaghetti" ), hence it might not be as straightforward as all that.

That said, there are a lot of simple things that can be done to improve the situation even before noise reduction is used.

First and foremost is to reduce the distance between your mouth and the mic. This allows gain to be reduced substantially. If your mic becomes very bassy sounding when you do that then you can fix that with the TX EQ feature. You may also wish to add a foam or screen type filter to eliminate breath sounds and pops.

The second thing that can be done is to make the room less live. Rugs, wall hangings and that sort of thing will absorb unwanted sounds and sound reflections. There are a wide variety of inexpensive acoustic foam panels available. Not only will these quiet a room, but putting them behind equipment where the fans are exhausting is also very helpful.

Thetis also features a very capable downward expander (DEXP). It has extensive controls available (just right click the button). The downward expander forms the basis of the VOX control but is available to be used by itself. If you are not familiar with how to use a downward expander to suppress background noise there are many good tutorials on Youtube, for instance:



Here is a screenshot of my settings as a starting place:



The larger you make the Exp. Ratio the more of a brick wall it will be, with 30dB corresponding to a noise gate rather than just an expander.

Finally, short of TX NR being implemented, you can process your audio through either studio rack equipment or in software (e.g. Voicemeeter, DAWs like Reaper, etc.) to achieve whatever effects you desire.

I use the downward expander but just doesn't cancel the noise in the shack. I am going to treat my room with some sound panels My al-82 amp is the challenge. I do talk close to the mic so not to gain much. I like keeping this simple hence the wishlist, but I can use sonar from steelseries which has the AI noise feature built in and works way better than a noise gate.

n2gq wrote:I use the downward expander but just doesn't cancel the noise in the shack.

It will cancel 30dB worth of your shack noise. How much more do you need?

In addition to what Scott advises above: a strongly cardioid dynamic mic, with "variable-d" characteristics (or equivalent) will go a long way in taming down a noisy shack (like mine).

73,
Bryan

W4WMT wrote:

n2gq wrote:I use the downward expander but just doesn't cancel the noise in the shack.

It will cancel 30dB worth of your shack noise. How much more do you need?

In addition to what Scott advises above: a strongly cardioid dynamic mic, with "variable-d" characteristics (or equivalent) will go a long way in taming down a noisy shack (like mine).

73,
Bryan

Bryan the dexp works great, but as soon as I start talking and past the threshold the background noise passes as well. Try using the sonar mixer by SteelSeries and you will see what I am mean. They have a very nice AI noise reducer that works well as well the Sunsdr software as reference. My buddy can turn on a drill and I won't hear it. He uses the SUNSDR radio/software and it works pretty cool.

It is a useful request and allowing NR2 on TX would help in noisy situations. DEXP won’t help high levels of room noise. The SunSDR TX noise reduction works well. If you have the Blue USB microphone with their tools it will also work well.

Doug

w3ub wrote:It is a useful request and allowing NR2 on TX would help in noisy situations. DEXP won’t help high levels of room noise. The SunSDR TX noise reduction works well. If you have the Blue USB microphone with their tools it will also work well.

Doug

I currently use the Behringer bigfoot. It only has an asio4all driver which I just discovered on their website. I was considering going to an audio interface so that I can use some of the noise management included in Potato/Sonar etc.
The DEXP settings are as follows. That has worked ok for me

n2gq wrote:I currently use the Behringer bigfoot. It only has an asio4all driver which I just discovered on their website.

ASIO4ALL is an ASIO wrapper around WDM.

"In addition to what Scott advises above: a strongly cardioid dynamic mic, with "variable-d" characteristics (or equivalent) will go a long way in taming down a noisy shack (like mine)."


Wow variable-d is interesting. Thanks I never knew.

You can use any number of other solutions to acomplish this, not sure I want resources spent implementing something like this natively in Thetis.

Look at NVIDIA Broadcast, or any other number of solutions.

rdwing wrote:You can use any number of other solutions to acomplish this, not sure I want resources spent implementing something like this natively in Thetis.

Look at NVIDIA Broadcast, or any other number of solutions.

What resources are you referring to? Computer?

n2gq wrote:

rdwing wrote:You can use any number of other solutions to acomplish this, not sure I want resources spent implementing something like this natively in Thetis.

Look at NVIDIA Broadcast, or any other number of solutions.

What resources are you referring to? Computer?

Development resources

rdwing wrote:

n2gq wrote:

rdwing wrote:You can use any number of other solutions to acomplish this, not sure I want resources spent implementing something like this natively in Thetis.

Look at NVIDIA Broadcast, or any other number of solutions.

What resources are you referring to? Computer?

Development resources

Yes, I understand. I know it's a lot of work but, hey you never know they might have some energy to include someday. My buddy uses Nvidia broadcast and I was using sonar for some time. But some like sticking to the K.I.S.S. principle.

I am using an EV RE27 mike with a foam pop filter and work about 1 - 3 inches and talk in a normal voice. It helped my shack fan noise quite a lot. No breath noise and of course with that mike no proximity problems.

Off topic - I have been using that mike thru a shure low impedance to high impedance matching transformer to my KWM2 and S Line and get excellent reports. Great mike.

73

Bill, WA2DVU
Cape May

WA2DVU wrote:I am using an EV RE27 mike with a foam pop filter and work about 1 - 3 inches and talk in a normal voice. It helped my shack fan noise quite a lot. No breath noise and of course with that mike no proximity problems.

Off topic - I have been using that mike thru a shure low impedance to high impedance matching transformer to my KWM2 and S Line and get excellent reports. Great mike.

73

Bill, WA2DVU
Cape May

The noise in the shack comes from my amp. It's emitting a high pitch whine. I have removed the blower fan and placed a silicone gasket under the blower. It dampened it a lot and the blower doesn't resonate the cabinet anymore. I use a standard 3300128 Radio shack dynamic mic. I was also using an electret mic which picked way more noise but that modulated a lot better. I am now going thru an audio interface, so I have not plugged the electret there because I need to step down voltage. Looking to pick up a vxlr plus or pro for the step down. The ev 27 seems like the go to mic for lots of people. Scott mentioned the design here and it was interesting how it is tuned for the proximity effect. I always talk into the mic about 3 or 4 inches.