Primarily for general aviation discussion, but other aviation topics are also welcome.
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By timjenner
#1770656
Hi,

Can anyone suggest the best way to add an auxiliary audio input into an existing headset? This is to allow my daughter to listen to music while in the back of the aircraft, so I don't want it through the intercom etc. She currently has a Pilot PA-51 Children's headset, though if anyone has a solution which will also work with ANR converted DC 13.4s that would be great as she'll use them once she's big enough (or I find a smaller headband to fit).

I presume you can't just wire an input jack to the speakers in parallel and a simple passive mixer made from resistors would drop the audio levels - so what's actually inside a passive nom-ANR headset with an aux input?

Many thanks,
Tim
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By Lerk
#1770659
Depending on the intercom system, you might find that you end up with it backfeeding to all headsets anyway.
I had a play with trying to connect pilotaware audio into the headset lead and found this - in that case it was an unintentional bonus.
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By timjenner
#1770664
That's interesting. Apart from the back feed did simply wiring the input to the speakers work? My shareoplane has a pretty new Garmin GMA 340 audio panel and I feed Skydemon audio through the "Music 1" input which works fine. There's also a "Music 2" input which almost does what I want! Unfortunately according to the manual the only way to use Music 2 for passengers is to switch to crew isolate mode - tempting though that is with a chatty 5 year old, I do need to be able to talk to and hear her!
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By PaulSS
#1770677
Similar to Sean's suggestion, you could always have BT wireless earbuds and then just use BT to pipe the music from the device.

A small mixer could quite easily be built using an LM386 amp and one those rectangular 9v batteries. A couple of potentiometers and you've got volume control for music and intercom.

This is one I experimented with for three inputs and a 12v supply but it can be easily modified:

Image

Edited to add: Genghis's suggestion looks a LOT easier :D
User avatar
By Lerk
#1770710
By timjenner - Tue May 19, 2020 8:18 am
That's interesting. Apart from the back feed did simply wiring the input to the speakers work? My shareoplane has a pretty new Garmin GMA 340 audio panel and I feed Skydemon audio through the "Music 1" input which works fine. There's also a "Music 2" input which almost does what I want! Unfortunately according to the manual the only way to use Music 2 for passengers is to switch to crew isolate mode - tempting though that is with a chatty 5 year old, I do need to be able to talk to and hear her!


I was trying to come up with a plug and play solution and happened to have a 1/4" splitter cable laying around.
Your audio panel is a million miles away from the avionics fit I tried with though!
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By timjenner
#1770719
Thanks for the suggestions. The only review for the Marv Golden cable said it dropped the volume too much which suggests it might just be a passive cable. Flight Store do one which looks identical and that has a bad review too!

Ear buds sounds like a good option, but dependant on my daughter actually leaving them in. She's never tried in ear headphones so might give that a try.

Don't mind building a mixer (ugh, yet another battery to remember to charge!), but wonder if something like this might do the trick with less hassle? https://www.ebay.co.uk/itm/223902864338

Cheers,
Tim
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By matthew_w100
#1770772
PaulSS wrote:Similar to Sean's suggestion, you could always have BT wireless earbuds and then just use BT to pipe the music from the device.

A small mixer could quite easily be built using an LM386 amp and one those rectangular 9v batteries. A couple of potentiometers and you've got volume control for music and intercom.

This is one I experimented with for three inputs and a 12v supply but it can be easily modified:


Me being thick, can you explain why what looks to me to be the left channel on the two stereo inputs has an additional 1k resistor in line? Won't it make that channel quieter in the mix?
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By timjenner
#1770788
matthew_w100 wrote:PaulSS wrote:
Similar to Sean's suggestion, you could always have BT wireless earbuds and then just use BT to pipe the music from the device.

A small mixer could quite easily be built using an LM386 amp and one those rectangular 9v batteries. A couple of potentiometers and you've got volume control for music and intercom.

This is one I experimented with for three inputs and a 12v supply but it can be easily modified:


Me being thick, can you explain why what looks to me to be the left channel on the two stereo inputs has an additional 1k resistor in line? Won't it make that channel quieter in the mix?


I'm no expert but I think it's half of a passive mixer, so yes one channel would be quieter. Adding another matching resistor to the other channel should do it, basically converting to mono which is then fed to the amp.
#1770798
timjenner wrote:Thanks for the suggestions. The only review for the Marv Golden cable said it dropped the volume too much which suggests it might just be a passive cable. Flight Store do one which looks identical and that has a bad review too!

Ear buds sounds like a good option, but dependant on my daughter actually leaving them in. She's never tried in ear headphones so might give that a try.

Don't mind building a mixer (ugh, yet another battery to remember to charge!), but wonder if something like this might do the trick with less hassle? https://www.ebay.co.uk/itm/223902864338

Cheers,
Tim


It got lost but I had one connecting my Garmin Aera into a headset, and the volume was not loud, but more than adequately audible. That was from Marv Golden.

You don't actually want it to be too loud, as you still want said child to hear what the pilot says if they have something important to say.

G
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By timjenner
#1770803
Genghis the Engineer wrote:
It got lost but I had one connecting my Garmin Aera into a headset, and the volume was not loud, but more than adequately audible. That was from Marv Golden.

You don't actually want it to be too loud, as you still want said child to hear what the pilot says if they have something important to say.

G


Thanks, that's interesting. As you say, certainly don't want it drowning everything else out - to be honest it's more to keep her interested/alert and reduce chatter so really more like background music. No idea if it will work but in the car she talks a lot less when there's something she likes on the radio (and there is less "are we nearly there yet?").
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By PaulSS
#1770825
@matthew_w100 I'd love to help you but I am doubly thick when it comes to resistors and stuff. I plagiarised the design from a similar one I'd seen, so I can't explain why there are any resistors at all :oops: I can say that I made it and hooked up various inputs into the mixer and it did work when fed to an external speaker. I never installed it into the aircraft nor connected it to the radio aux in as I simplified everything with Bluetooth. I did install a resistor on the top circuit (the one without a resistor) on the advice of the MGL guru but I still don't know why :D