I bought one of these recently.

https://store.davidclark.com/dc-pro-x2-series

During use on an aircraft there is sidetone--hearing yourself in your ear when you speak.

I get perfect sidetone when: a)speaking to the other person in the cockpit, b)using the PA, c)speaking to the pushback crew below.
However, when doing the most common thing, talking on the radio, the sidetone is immensely muted and of low volume.

I called DC to ask them, and the gentleman on the phone instantly said it was the aircraft. However, after speaking with a friend who has the exact headset I learned his produces perfect sidetone in every condition.

So the question is: What kind of things happen during sidetone generation that would be different between transmitting on a VHF radio versus an inter-cockpit intercom? Could it have anything to do with the wattage of the radio?

I'm out of my element on this; any insight would be appreciated.

 

I do believe the sidetone is produced by the audio processing in the aircraft - it's not a direct function of the headset. Can you try the unit on a different aircraft or try a different headset in the aircraft with the issues?

 

I do believe the sidetone is produced by the audio processing in the aircraft - it's not a direct function of the headset. Can you try the unit on a different aircraft or try a different headset in the aircraft with the issues?

Actually I tried it on three or four different aircraft. A friend used his on one or two with no problems.

Can the sidetone from Transmittting on the VHF be of lower power than the intercom?

 

Actually I tried it on three or four different aircraft.

So, you tested YOUR headset in other aircraft ?
And what was the result ?
A) Your headset works perfectly in other aircraft or
B) Your headset has the same problem in other aircraft

A friend used his on one or two with no problems.

Your friend tested HIS headset in YOUR aircraft ?
And what was the result ?
A) His headset works perfectly in your aircraft or
B) His headset exhibits the same sidetalk problem in your aircraft

Answering the above two questions should tell you if the problem is in your headset or in your aircraft.

 

So, you tested YOUR headset in other aircraft ?
And what was the result ?
A) Your headset works perfectly in other aircraft or
B) Your headset has the same problem in other aircraft


Your friend tested HIS headset in YOUR aircraft ?
And what was the result ?
A) His headset works perfectly in your aircraft or
B) His headset exhibits the same sidetalk problem in your aircraft

Answering the above two questions should tell you if the problem is in your headset or in your aircraft.

There is no discernible difference in aircraft. We have a couple hundred of them.

My headset muted the side tone in any aircraft tried. My results were the same. His results were the same—only polarized from mine. Leads me to a defective headset though DC was rather aggressive when I suggested that.

 

Thirtywest,
Looks like we're working on multiple, similar projects. Would you mind shooting me an email? <SNIP>
Take care.

Moderators note : removed email to avoid spam

 

the answer might be embedded in here https://en.wikipedia.org/wiki/Telephone_hybrid somewhere.

 

The equipment the headset connects to (see the hybrid above) produces the sidetone. If the headphones also produced sidetone then they would add (too loud) or subtract (cancel) which might be the problem with yours. Maybe yours has active noise reduction that also cancels sidetone.