AMX240 Audio Panel - AMX240 and Bose Aviation X issue

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AMX240 and Bose Aviation X issue

Printed From: Avidyne
Category: Avidyne General
Forum Name: AMX240 Audio Panel
Forum Description: Topics on the Avidyne AMX240 Audio Panel
URL: https://avidynelive.com/forum_posts.asp?TID=815
Printed Date: 26 Mar 2026 at 4:27pm
Software Version: Web Wiz Forums 12.07 - https://www.webwizforums.com

Topic: AMX240 and Bose Aviation X issue

Posted By: gherb
Subject: AMX240 and Bose Aviation X issue
Date Posted: 18 Sep 2015 at 6:59am

Not sure yet if this is a wiring issue of a compatibility issue. I am thinking its the former. I recently had installed the AMX240 to accompany my IFD540. Strangely two different pairs of Bose Aviation X headsets on the pilot side only hear faint audio from both com radios. They work fine on the co-pilot side. Bose A20's work fine on both sides. My older Lightspeed 30G works fine on both sides.

Has anyone heard of any compatibility issues with this model headset? The installer is an hour flight away so they have not been able to get into the troubleshooting yet.

Thanks.

Replies:

Posted By: gherb
Date Posted: 18 Sep 2015 at 7:00am

Airplane is C172M with 14V electrical, if that helps.

Posted By: Gring
Date Posted: 18 Sep 2015 at 7:30am

Did you check the headphone settings, mono vs stereo? There may be dip switches to set.

Posted By: gherb
Date Posted: 18 Sep 2015 at 9:04am

Thanks and I will try that. I talked to one person at Bose tech support and he suggested that if set to mono and being used on a audio panel with stereo sound, it would simply behave as mono. My dipswitch was set to mono on my X headset, so I've changed it to stereo and will definitely see if that makes a difference.

Posted By: tony
Date Posted: 21 Sep 2015 at 3:20pm

If your shop did a clean install, they should have wired up both jacks (pilot and copilot) as stereo. if it was a slide in, then who knows?

Posted By: gherb
Date Posted: 24 Sep 2015 at 7:59am

It was a clean install and all the wiring is supposed to be new. When I changed the dipswitch to stereo its louder but audio is only in one ear. We swapped out the IFD540 with another one, and then swapped out with a Garmin GNS530 and problem is still there. Odd how Only the Bose X, and only in the pilot side.

I think now its either the audio panel or the wiring. I am not finding anything online about compatibility issues with this headset and audio panel.

Posted By: DavidBunin
Date Posted: 26 Sep 2015 at 2:56pm

Look behind the jack (might need a mirror) and see if anything is touching that shouldn't be. Space behind jack panels is always a little tight.

Posted By: lolsen94
Date Posted: 15 Jan 2016 at 7:55am

I just had the AMX240 put in along with new IFD540 and IFD440. I was getting a random, every 30 seconds or so, squelch sound. I decided to start the elimination process by unplugging my Bose headset on the right seat, and sure enough the problem went away. I decided to buy new Bose A20s since my headsets were sold old, and sure enough, problem solved so far. Not 100% sure, but the headset had something wrong with them. Oddly enough, they work with my old Garmin avionics just fine. With the new Bose A20s, much clearer also.

Posted By: MysticCobra
Date Posted: 16 Jan 2016 at 4:04am

The headset may not have had anything wrong; they may have just been picking up enough noise in the mic to break squelch. I had a similar experience in that on one flight where I was occasionally hearing something that sounded like engine noise.

I eventually realized the co-pilot pair of Halos had been left plugged in and on top of the glareshield, and the mic was up near the windscreen. Every once in a while I'd do something that brought the mic in contact with the glass and it was enough to break squelch and transmit the noise.

Posted By: n7ifr
Date Posted: 16 Jan 2016 at 5:11am

I had same intermittent squelch-break with my AMX240 and Co-pilot Bose-X headset. It usually broke squelch when in "chop" or when mic. was too near air-vent.

Now that I am using the PMA450, so far no squelch break (no oversensitive VOX) with same co-pilot headset -

BTW, Thank you Steve Jacobson for facilitating my audio panel exchange... I am now a happy camper with dual 540's, 340, and MLB (and PMA450), and look forward to finally doing some serious Hangar-Flying to figure out BT KB integration.

Tom Wolf

Posted By: dpcraig
Date Posted: 09 Feb 2016 at 3:52am

I have a cirrus sr22 and will be installing a 440/540 and remote transponder combo. While doing that was contemplating making an audio panel change at the same time. After reading the forum the AMX 240 appears to have some problems? Can anyone provide some detail on the issues they are having and are the fixed yet? I see Tom went with the PMA 450 and returned his AMX 240?

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dpcraig

Posted By: AviJake
Date Posted: 09 Feb 2016 at 3:57am

"Problems" seems to be an overstatement in my opinion. The AMX240 does not auto mute the 2nd frequency when you are using the Monitor function, by design. Most of us who use the 240 don't care and actually prefer it that way but some folks really want that feature.

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Steve Jacobson
sjacobson@avidyne.com

Posted By: dpcraig
Date Posted: 09 Feb 2016 at 4:01am

Thanks Steve, i'm just trying to interpret what I am reading on the forum The issues seem to be with Bose headsets and volume control. I would rather have an all Avidyne panel but want to make sure i'm not in for some issues on the audio side.

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dpcraig

Posted By: AviJake
Date Posted: 09 Feb 2016 at 4:03am

It seems very isolated to a few folks. I fly with Bose headsets and the 240 and haven't experienced anything like that in the 3 years I've been doing so.

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Steve Jacobson
sjacobson@avidyne.com

Posted By: n7ifr
Date Posted: 09 Feb 2016 at 6:25am

Now that the dust has settled on this thread issue (for me), here is my experience using both AMX240 vs PMA450 audio panels -

The Avidyne AMX240 unit wins for simplicity and the KISS principle. That is worth a lot.

. AMX has Easy 1-button ops to Monitor Stby Comm1 or Comm2; multi-button push on PMA450 to set up.

. AMX has individual volume control for pilot & co-pilot, PMA lumps pilot/co-pilot together, with separate PAX control (as with AMX).

. Auto-Mute only with PMA unit. Very nice feature when "active" Comm not too busy - very convenient, while listening to non-x'mit Comm (usually Comm-2), mutes Comm-2 Active when Comm1 active channel is talking.

. PMA has separate individual volume control of Comm Stby channels (beyond 540/440 audio stby Vol control) - very useful to put desired Stby channel at decreased volume.

So, other than very nice, useful feature of Auto-mute on PMA, AMX is more user friendly - fewer button pushes. Once custom configured, not much need to play with either in flight.

Tom

Posted By: dpcraig
Date Posted: 09 Feb 2016 at 8:35am

Thanks Tom, I think the KISS principle is the overriding factor for me...Thanks for sharing!

Dan

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dpcraig

Posted By: tony
Date Posted: 10 Feb 2016 at 4:42am

I have never had any issues with my 240 audio panel and I'm happy with my choice. Its simple and intuitive.

Posted By: gherb
Date Posted: 01 Dec 2016 at 8:39am

Sorry I had not followed up on my original post, but just came across this thread and here is my update. It turns out the installer had bent a pin in the harness during the install. Straightening the pin resolved two issues:

1. The Bose headset and all headsets now transmit and receive normal volume.

2. Audio from the audio input on the co-pilot side (audio that patches to the rear of the panel) is now normal volume on both sides.

I usually fly with my Lightspeed Zulu 2 headset, while my front seat pax will use my Bose X headset. Recently I swapped headsets with my fiance and flew with the Bose. I did find its max volume was useable, but a bit lower than I was accustomed, requiring me to turn up the volume on my IFD 540 some. However I am sending my Bose headsets to them for a clean and check, and I suspect I have an issue with my headset cable, and the dipswitches, so I don' think its an issue with the audio panel.

Thanks for the help on this. My only lingering issue with the AMX240 is the backlight doesn't get bright enough to read the buttons in daylight. The IFD540 buttons are much brighter. I have been told there could be some issues with the rheostat compatibilty with older C172's (mine is a 1976 172M), so it may be a matter of getting a newer rheostat, or a change in how its wired. I am a bit annoyed that my installer returned the plane to me with both these issues, but I imagine this backlight/rheostat issue is because I am flying an antique.

Posted By: LulaNord
Date Posted: 31 Mar 2017 at 9:52am

Hi...I have had my Bose A20 headset for about two years and probably around 200 hours. Recently, I have noticed that I get some annoying static if I touch/move the cord during flight, especially near the plugs. Now the audio is cutting in and out through out the flight whether the cord/plugs are touched or not almost causing me to miss radio calls. Obviously, this is an issue that I will need to resolve before flying with this headset again. I though it was an issue with my head phone jacks on the plane but I tried another headset there and found no issues. I tried the Bose on a different jack and the problem followed the headset so I know its an issue with the headset and not the plane.

So my question is has any one dealt with getting their A20's repaired under warranty? How did you get the process started? How long did it take? Did Bose just send you a refurb unit or did they repair and return your same headset?

http://www.7pcb.com/Prototype-PCB-Assembly.php" rel="nofollow - prototype printed circuit board assembly

Posted By: lolsen94
Date Posted: 03 Sep 2017 at 7:26am

I am having the same issue. If I put the Bose switches on Stereo, only the left side of the Bose headset works. If I put the switch on mono, both sides of the Bose headsets work. I am guessing not stereo. Help!!

Posted By: lolsen94
Date Posted: 05 Sep 2017 at 6:55am

I was having issues with the right side of my Bose headset getting sound in the "stereo" DIP switch setting. Right before sending it in to be looked at, I checked the male end of the 3.5MM cord where it plugs in and found that it was the problem. Put the other end of the cord in and it resolved the problem.