Splitting comms

[dkkim73]

Hi All, 

I've been wondering about something (general to aviation): 

How would it work to split comm radios across your Right and Left headset channels? 

I recall when working with USAF Combat Controllers (who do a combination of terminal attack control, extreme ATC, field surveys, comms support, and general armed bada**ery) that they would often split radios across their R and L ears. They would potentially be working a bunch of channels in a concurrent way to coordinate stacks of aircraft above them. Practically, the Peltor tactical headsets had a separate mono plug on each muff. 

A few times, I've been listening to ATIS/AWOS etc and ATC on different comm radios and, if the volumes aren't perfect, it's not very clear or efficient. I was looking at the stereo function on my headset (I've got a stereo plug in the left seat and mono in the other 3 positions). The Garmin audio panel (GMA347 I think) has a Comm1/2 split function where the Right front seater gets comm 2 and the Left seat comm 1. I was thinking of cobbling together some adapters (or fabricating something with a switch) such that I could bring the audio from the LF position (set to mono) to one ear and the audio from the RF position (mono) to the L and R channels of my headset. I'd probably have to figure out how to split the mic output (depends on impedance probably, whether or not I can use a naïve Y-connector) and figure out the PTT issue. I might guess the copilot yoke PTT switch separately keys Comm 2 in that situation but I'd have to verify that from wiring diagrams or a function check. 

Do I have to do this? Of course not. But it might be nice esp. for single pilot ops. 

IIRC auditory pathways crossover early in the brain, bilateral, at least for reflexes, but overall the brain does seem to spatially localize and contextualize audio quite well, using other integrative functions to model the environment. Practically, even in a crowded room the spatial localization helps us keep track of different things. I figure it might be a nice tool here. 

Any thoughts much appreciated. @EricJ since I used "aviation" and "impedance" in the same post. @Pinecone and @Ragsf15e since they know part of this world well... sorry if I missed other attack or ground people (CCT/JTAC) here. 

DK

 

 

 

[warren.huisman]

A couple years ago PS Engineering had a demo of one of their audio panels which features this. It was amazing to listen to the difference in comprehension when in this mode listening to two different inputs such as ATIS in one and ATC in the other. It’s a feature I plan to get when I update my audio panel.


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[N201MKTurbo]

I have this audio panel. The PMA450C. They are not completely isolated. I believe they are using DSP to change the spacial position of the different sources. I’ve found that it is better for identifying which source you are hearing, more than making them more intelligible. 
 

[dkkim73]

That kind of spatial processing looks amazing. Given it's a G1000 plane I don't think I can swap the audio panel. I wonder if it might be possible to finesse something post-panel, via downstream or parallel inputs. 

This would be a superset of the case of just splitting Comm 1 and 2 into L and R channels. 

 

[LANCECASPER]

It would be great if PS Engineering would come up with a slide-in replacement for the GMA 1347 in all G1000 airplanes that includes multiple Bluetooth inputs, IntelliAudio, etc. Are you listening Mark . . . lol?  @Mscheuer

[Ragsf15e]

3 hours ago, dkkim73 said:

Hi All, 

I've been wondering about something (general to aviation): 

How would it work to split comm radios across your Right and Left headset channels? 

I recall when working with USAF Combat Controllers (who do a combination of terminal attack control, extreme ATC, field surveys, comms support, and general armed bada**ery) that they would often split radios across their R and L ears. They would potentially be working a bunch of channels in a concurrent way to coordinate stacks of aircraft above them. Practically, the Peltor tactical headsets had a separate mono plug on each muff. 

A few times, I've been listening to ATIS/AWOS etc and ATC on different comm radios and, if the volumes aren't perfect, it's not very clear or efficient. I was looking at the stereo function on my headset (I've got a stereo plug in the left seat and mono in the other 3 positions). The Garmin audio panel (GMA347 I think) has a Comm1/2 split function where the Right front seater gets comm 2 and the Left seat comm 1. I was thinking of cobbling together some adapters (or fabricating something with a switch) such that I could bring the audio from the LF position (set to mono) to one ear and the audio from the RF position (mono) to the L and R channels of my headset. I'd probably have to figure out how to split the mic output (depends on impedance probably, whether or not I can use a naïve Y-connector) and figure out the PTT issue. I might guess the copilot yoke PTT switch separately keys Comm 2 in that situation but I'd have to verify that from wiring diagrams or a function check. 

Do I have to do this? Of course not. But it might be nice esp. for single pilot ops. 

IIRC auditory pathways crossover early in the brain, bilateral, at least for reflexes, but overall the brain does seem to spatially localize and contextualize audio quite well, using other integrative functions to model the environment. Practically, even in a crowded room the spatial localization helps us keep track of different things. I figure it might be a nice tool here. 

Any thoughts much appreciated. @EricJ since I used "aviation" and "impedance" in the same post. @Pinecone and @Ragsf15e since they know part of this world well... sorry if I missed other attack or ground people (CCT/JTAC) here. 

DK

 

 

 

Ha!  You got the wrong guy on this one.  ~5 years into my USAF career I had an acoustic neroma removed from my right auditory nerve.  It wasn’t fun, and I am completely deaf in my right ear.  Luckily, it didn’t impact my flying (other than 6 months for recovery) and I was also a JTAC as well (sort of cool but not Combat Controller cool).  So stereo audio is a thing I remember from high school but it’s something I avoid now.

In the F-15, we normally had two radios on at once (one for inter-formation, one for everyone else).  The “audio panel” was crap, so the normal technique was to have the volume slightly lower on the formation comm.  After a while, your brain could differentiate pretty well, but granted, it’s not perfect.  Luckily for me, that technique was still valid with my loss of stereo hearing.

As a JTAC, we didn’t have the cool headsets and gear like CCT, so we just cranked up the important ones and had like 4 radios blaring at us.  It wasn’t great.

Now, my airplane has a remote Garmin audio panel with 3D audio.  It’s similar to the PMA in that each person will sound like they are coming from wherever they are sitting.  It also separates the two radios into a “10 oclock” and a “2 oclock” so you can tell them apart.  Someone else will have to tell us if all that stuff works well because I have it all turned off!

The other “modern” technique I’ve seen is muting or partially muting the #2 radio when #1 is receiving.  It seems very useful to me for say getting atis while monitoring center, but it needs to be a “partial” mute or it’s just annoying when you hear all of atis and it mutes every time they say the identifier.  This is the one I like best but that’s likely because of my hearing limitations.  I suspect the stereo system is pretty awesome.  Unfortunately it doesn’t sound like the g1000 can accommodate an audio panel upgrade?

 

[good2eat]

I have the 450B - the IntelliAudio is quite useful for me.  I split it with Comm 1 in my left ear and Comm 2 in my right.

[EricJ]

I use my 450B to split the channels as well, and it doesn't take much to be able to separate the two coms.    Mine is on a setting for kind of low-level separation and it still works well.

 

[Mscheuer]

On 11/15/2025 at 3:56 PM, LANCECASPER said:

It would be great if PS Engineering would come up with a slide-in replacement for the GMA 1347 in all G1000 airplanes that includes multiple Bluetooth inputs, IntelliAudio, etc. Are you listening Mark . . . lol?  @Mscheuer

Well, we had asked GARMIN if they would give us permission to use their protocol to communicates between our audio panel and the G1000. In fact, it was Dale Klapmeier who set up the meeting (during Cirrus Grand Opening here in Knoxville) with GARMIN. Unfortunately they decided not give us permission. Without that, it would not been prudent for us to invest in that product, GARMIN would have every right to change the protocol.  I'm not saying they would, but they would have every right to do so. I have a world of respect for GARMIN, they have done remarkable things for us GA pilots, but it would have been great if they had said yes! 

[N201MKTurbo]

1 hour ago, Mscheuer said:

Well, we had asked GARMIN if they would give us permission to use their protocol to communicates between our audio panel and the G1000. In fact, it was Dale Klapmeier who set up the meeting (during Cirrus Grand Opening here in Knoxville) with GARMIN. Unfortunately they decided not give us permission. Without that, it would not been prudent for us to invest in that product, GARMIN would have every right to change the protocol.  I'm not saying they would, but they would have every right to do so. I have a world of respect for GARMIN, they have done remarkable things for us GA pilots, but it would have been great if they had said yes! 

So, they change their protocol, and you update your firmware. I’m not sure what the legality of the gap in functionality would be.

[Pinecone]

On 11/15/2025 at 6:02 PM, Ragsf15e said:

In the F-15, we normally had two radios on at once (one for inter-formation, one for everyone else).  The “audio panel” was crap, so the normal technique was to have the volume slightly lower on the formation comm.  After a while, your brain could differentiate pretty well, but granted, it’s not perfect.  Luckily for me, that technique was still valid with my loss of stereo hearing.

In the Hog, we just didn't say much on the formation comm.

I have the PSE 450B and the spacially split audio is great.

[dkkim73]

56 minutes ago, Pinecone said:

In the Hog, we just didn't say much on the formation comm.

 

I assume you couldn't hear anything over the main speed brake. I think it's a GAU something-or-other...

[dkkim73]

On 11/15/2025 at 4:02 PM, Ragsf15e said:

Ha!  You got the wrong guy on this one.  ~5 years into my USAF career I had an acoustic neroma removed from my right auditory nerve.  It wasn’t fun, and I am completely deaf in my right ear.  Luckily, it didn’t impact my flying (other than 6 months for recovery) and I was also a JTAC as well (sort of cool but not Combat Controller cool).  So stereo audio is a thing I remember from high school but it’s something I avoid now.

This is actually oddly interesting to me as I recall helping a CCT with otologic issues when I was a flight doc (I caught an odd diagnosis actually, and the insight from going out with them on training ops was very contributory). 

Did you do the JTAC qual as part of being an attack pilot, liaison, etc? 

[dkkim73]

6 hours ago, Mscheuer said:

Well, we had asked GARMIN if they would give us permission to use their protocol to communicates between our audio panel and the G1000. In fact, it was Dale Klapmeier who set up the meeting (during Cirrus Grand Opening here in Knoxville) with GARMIN. Unfortunately they decided not give us permission. Without that, it would not been prudent for us to invest in that product, GARMIN would have every right to change the protocol.  I'm not saying they would, but they would have every right to do so. I have a world of respect for GARMIN, they have done remarkable things for us GA pilots, but it would have been great if they had said yes! 

@Mscheuer Interesting. I can see why that might be problematic. Posturally even if not technically. 

I suppose the whole fact that there is a communication protocol means it's a different beast. 

Too bad. I think there's room in the ecosystem for both. And I really like what I read about the capabilities of the PS Engineering units. Looks like a lot of thoughtful and clever features that work backwards and forwards in design terms. 

 

[Ragsf15e]

13 minutes ago, dkkim73 said:

This is actually oddly interesting to me as I recall helping a CCT with otologic issues when I was a flight doc (I caught an odd diagnosis actually, and the insight from going out with them on training ops was very contributory). 

Did you do the JTAC qual as part of being an attack pilot, liaison, etc? 

Yeah, back then pretty much all fighter/bomber pilots had to do a tour doing something else- teaching pilot training, fighter lead in training, air liaison officer, etc.  I got a choice gig being a liaison for the 25th ID in Hawaii! Then I realized that they were going to be in Afghanistan for ~18 months of my 2 year tour on Hawaii.  So my 2 years in Hawaii turned into ~8 months in Afghanistan and 16 months in Hawaii.  So yeah, I was a liaison officer between Air Force and army as a jtac. My next tour was in the F-15E and I was back in Afghanistan flying over the exact same outposts I’d been living in a year earlier!  Good times.  But a standard JTAC doesn’t do the crazy stuff those cct guys do!

[Pinecone]

On 12/11/2025 at 9:06 PM, dkkim73 said:

I assume you couldn't hear anything over the main speed brake. I think it's a GAU something-or-other...

GAU-8A.  Yeah, when firing the gun, you only heard it.

[McMooney]

On 11/15/2025 at 1:54 PM, N201MKTurbo said:

I have this audio panel. The PMA450C. They are not completely isolated. I believe they are using DSP to change the spacial position of the different sources. I’ve found that it is better for identifying which source you are hearing, more than making them more intelligible. 
 

works great in my pma 8000g, really easy to listen to multiple conversations