Can I use a TRRS headphone cable in the 6400M headphone TRS jack?

Mike N2YBB

Brian Denley KB1VBF

I would avoid it and see if Bose has an adaptor to convert to TRS.  I say that only because there are several wirings for TRRS that have the ground in different locations.  Unless another Flex owner has already tried it.  Anyone?

henrylance

I agree

Tim - W4TME

TRRS will not work.  That is for phones and tablets.  You will need an adapter to split out the headphones and mic and connect that to the appropriate 1.8" TRS connectors on the back of the radio.

Chris WX7V

Tim - I believe this should work, right? Its TRRS to TRS. I'd expect the back of the 6400M would accept the Phone and MIC.

https://www.amazon.com/gp/product/B07HXY9LV8/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1

Chris WX7V

I can confirm this aftermarket MIC boom works with my Bose QC25. The package also includes the TRRS splitter to separate out the MIC and PHONEs.

Even then you can’t just plug in the MIC into the back of the Flexradio, you have to enable BIAS and wire your own TRS adapter for the MIC into the back of the Flexradio using this circuit published by Dale K4DG. When you solder make sure TIP from the radio connected to TIP and RING on the MIC, and short RING/SLEEVE from the radio to sleeve on the MIC:

Dales original post has a lot of good detail. The circuit also works with the KOSS SB45 headset with integrated MIC boom.

https://community.flexradio.com/discussion/comment/20586161