Problem with audio output to portable speaker via usb-c dongle to aux connection - OnePlus 6t

[matus398]

I'm at my wit's end trying to find a solution online, so I thought I'd join this community. Thank you in advance!

So I have a OnePlus 6t that I absolutely love. No bootloaders or jailbreaking or hacking, and all software and apps are fully updated. I want to use it to play music at my desk at work, so I bought a Tribit Maxsound Plus portable speaker. But it's not working!

For reason's I won't go in to, I can't use Bluetooth, so I have an aux cable plugged in to the back of the speaker and then plugged in to a USB-C-to-Aux dongle, and then in to my phone. I am getting no audio output to the speaker. Here are things I have tried to troubleshoot and that I know to be true to narrow down the list of problems:

- The phone plays music just fine from its onboard speakers with no other accessories attached
- The phone recognizes that a dongle is plugged in as a headset by showing me the headset icon at the top
- The music player on my phone shows that the audio track is playing, even though no sound is coming from the Tribit speaker when I use the USB-C-to-Aux dongle and aux cable
- The Tribit speaker does work fine when music is played from a different phone with a 3.5mm aux output
- The USB-C-to-Aux dongle does work on my phone when I plug in regular, 3.5mm wired headphones into the dongle
- Audio plays fine from my phone when using USB-C headphones
- I've checked to make sure all of the connections are firm and all of the wires and dongles are working in other instances.
- I've tried switching out dongles and wires for other examples, including the dongle that came with the phone.

It is my understanding that a passive USB-C-to-Aux dongle should work on the 6t because it has an onboard DAC. So I don't think it's a question of having a passive, analog dongle instead of an active, digital dongle.

Through process of elimination, I think I can claim that the phone, the USB-C port on the phone, the dongle, the aux cable, the speaker, and the aux port on the speaker all work. So it's most likely not a hardware problem. But for some reason the speaker is not picking up any audio signal with this certain combination of connections.

Any ideas? Is my logic sound? Am I crazy? Thank you in advance!

Dave

P.S. - I know there will be an urge to tell me to just use Bluetooth. I promise that I can't for "reasons" and I'd rather not muddy the thread with that topic. Thanks!

P.P.S. - If I say or type the word "Dongle" one more time I am going to lose it.

 

[Rukbat]

Your logic and troubleshooting technique are sound.

Check the headphones - are there 3 connections on the plug (tip, ring and shell) or 4 (tip, 2 rings and shell)? If it's 4, you'll need a cable with 4 connections on each end. (See https://www.cablechick.com.au/blog/understanding-trrs-and-audio-jacks/ for a simple explanation of the mess.)

About the only other thing that comes to mind is an impedance mismatch that, for some reason, makes the combination not work. And the only troubleshooting I can think of to test that, short of butchering the speaker, is to get a headphone splitter and plug in both the headphones and the speaker at the same time, to see if that makes the speaker work. If it does, the speaker input is high impedance, but the phone needs a lower impedance loas on it to make audio come out of the dongle. (And that would take butchering the cable, at least, to add resistors across each audio lead and ground (47 ohms each ought to do it).

 

[Mike Dee]

I'm at my wit's end trying to find a solution online, so I thought I'd join this community. Thank you in advance!

So I have a OnePlus 6t that I absolutely love. No bootloaders or jailbreaking or hacking, and all software and apps are fully updated. I want to use it to play music at my desk at work, so I bought a Tribit Maxsound Plus portable speaker. But it's not working!

For reason's I won't go in to, I can't use Bluetooth, so I have an aux cable plugged in to the back of the speaker and then plugged in to a USB-C-to-Aux dongle, and then in to my phone. I am getting no audio output to the speaker. Here are things I have tried to troubleshoot and that I know to be true to narrow down the list of problems:

- The phone plays music just fine from its onboard speakers with no other accessories attached
- The phone recognizes that a dongle is plugged in as a headset by showing me the headset icon at the top
- The music player on my phone shows that the audio track is playing, even though no sound is coming from the Tribit speaker when I use the USB-C-to-Aux dongle and aux cable
- The Tribit speaker does work fine when music is played from a different phone with a 3.5mm aux output
- The USB-C-to-Aux dongle does work on my phone when I plug in regular, 3.5mm wired headphones into the dongle
- Audio plays fine from my phone when using USB-C headphones
- I've checked to make sure all of the connections are firm and all of the wires and dongles are working in other instances.
- I've tried switching out dongles and wires for other examples, including the dongle that came with the phone.

It is my understanding that a passive USB-C-to-Aux dongle should work on the 6t because it has an onboard DAC. So I don't think it's a question of having a passive, analog dongle instead of an active, digital dongle.

Through process of elimination, I think I can claim that the phone, the USB-C port on the phone, the dongle, the aux cable, the speaker, and the aux port on the speaker all work. So it's most likely not a hardware problem. But for some reason the speaker is not picking up any audio signal with this certain combination of connections.

Any ideas? Is my logic sound? Am I crazy? Thank you in advance!

Dave

P.S. - I know there will be an urge to tell me to just use Bluetooth. I promise that I can't for "reasons" and I'd rather not muddy the thread with that topic. Thanks!

P.P.S. - If I say or type the word "Dongle" one more time I am going to lose it.

Based on your trouble shooting steps it can't be software. You have verified output at the dongle so something has to be wrong between the dongle and the speaker input. Have you tried the whole setup on something besides the speaker like another speaker or line input into a car?

 

[matus398]

Thank you Rukbat and Mike Dee for your thoughtful responses! Much appreciated.

I looked at the aux cables I've been trying to use, they are all TRS, Tip Ring Shell (awesome website by the way, definitely learned something today).

I tried the setup in my car as well, same exact problem. For some reason this combo of cables is stopping the signal from getting from the phone to the speaker. Weird!

Could it have something to do with the phone registering the dongle as "Headphones" (hence the headphone icon), but the speaker (and car) not really being headphones?

 

[Mike Dee]

Thank you Rukbat and Mike Dee for your thoughtful responses! Much appreciated.

I looked at the aux cables I've been trying to use, they are all TRS, Tip Ring Shell (awesome website by the way, definitely learned something today).

I tried the setup in my car as well, same exact problem. For some reason this combo of cables is stopping the signal from getting from the phone to the speaker. Weird!

Could it have something to do with the phone registering the dongle as "Headphones" (hence the headphone icon), but the speaker (and car) not really being headphones?

The only devices I know that distinguishes between high, mid and low impedance equipment is LG models with the Quad DAC. You would still get sound even if it didn't match impedance properly.

I would try a different cable if you haven't done so.