Stereo?

[Gilliland]

I was trying to use my Mogul today to drive my car stereo's aux input. I had to connect the supplied adapter to the USB port, then a 2.5mm to 3.5mm headphone adapter to that, then a 3.5mm patch cable to the car stereo input. Kludgy, but all the connections worked.

Nonetheless, only the right channel was activated. I thought that maybe I had a bad connection, but I did some testing and found that the problem goes all the way back to the HTC-supplied adapter (USB to 2.5mm). If I plugged in my HTC headphones directly into the USB port, I got full stereo. But if I used the HTC supplied adapter to a pair of headphones with a 2.5mm plug, only the right channel came through.

So there are two possibilities: 1) The HTC-supplied adapter is defective, or 2) there is something in the hardware, software, or connection that deliberately sends just one channel through that connection.

Anyone know? Is there a setting somewhere to fix this?

[storino03]

You're probably using the headset connection.

--James

[Gilliland]

I suppose the obvious response is: Of course I'm using the headset connection - there IS no other connection on the Mogul. So feel free to elaborate.

A quick look through the manual suggests that this adapter is supposed to transfer a stereo signal, so it appears that the most likely scenario is that the supplied adapter is defective.

[budney]

What device did you have before? I think it may be your 2.5mm to 3.5mm adapter that dose not work with the supplied adapter for the Mogul.

[prototypedc]

it is the adapter but its not defective and it is stereo. im not sure how to explain it but it has some thing to do wit how the contacts are lined up in the adapter,

you can tell what i mean if you use a stereo headset that was made for a cell phone with a 2.5mm plug with the contact for a mic you will hear stereo sound,

but if you use (most if not all) 2.5mm to 3.5mm adapter with out a mic contact you will only receive mono sound,
{do to the lining up of the contacts in the adapter}

[Destructor]

I'm guessing your 2.5mm to 3.5mm adapter is bunk. Either that or it doesn't want to play right with the HTC cabling.

Buy this. It's nice and small, and it offers not only a standard 3.5mm plug (and yes, I've plugged in headsets into it and it outputs stereo), but your standard USB plug too.

Works great on the Mogul, and you can't go wrong with the price.

http://www.semsons.com/2miusband3st.html

[dishe]

There is a KNOWN INCOMPATIBILITY with many 2.5 -> 3.5 adapters- I find it funny that it didn't even occur to you to consider THAT part of your connection!
This was the same way on the HTC Wizard and Tornado, and afaik all HTC phones that had a 2.5mm plug. It only worked with "True" 2.5mm stereo adaptors, and not 2.5mm adaptors made for phones, since phones usually made the first pin channel the mic instead (real stereo uses the first 2 channels for L+R, phones use Mic+Right, and stereo phones use Mic+Right+Left).

What you can do is pull the adaptor out just slightly, essentially skipping the first contact inside, and you'll hear full stereo sound! Problem is that this is a flimsy connection and will probably not stay connected.

Pick up a regular stereo (non-phone type) 2.5 -> 3.5 adapter from Radio Shack for $5, or get a Sony BT2500 a2dp stereo head unit like I did for truly wireless music... Bluetooth stereo is a lot cheaper than it used to be, and I can keep my phone in my pocket while the music comes out of the car speakers!

[Gilliland]

Originally Posted by dishe

There is a KNOWN INCOMPATIBILITY with many 2.5 -> 3.5 adapters- I find it funny that it didn't even occur to you to consider THAT part of your connection!

Since all of you have raised this issue, let me make it clear that I DID, in fact, explore the entire signal path. I took a normal pair of 2.5mm cellphone headphones and plugged them into the HTC-supplied adapter. The result was that only the right channel worked. So here's the score:

Mogul to HTCadapter to adapter to cable to car stereo - right channel only
Mogul to HTCadapter to adapter to 3.5mm headphones - right channel only
Mogul to HTCadapter to Seidio 2.5mm headphones - right channel only
Mogul to HTC-supplied headphones - full stereo.

That's why I conclude that the HTC-supplied adapter is defective.

To answer Budney's question, my 2.5 to 3.5 adapter worked fine with my Treo, and to answer Dishe's remark, it DID come from Radio Shack. I also have one from TreoCentral, which I'd try if I could just find the darn thing. <g>

Destructor, thanks for the product pointer. It would be nice to have an adapter that goes straight to the 3.5mm socket. I'll still bug Sprint about replacing the HTC one.

Edit: I just found my TreoCentral 2.5 to 3.5 adapter and tested it. Same result, right channel only.

[budney]

the reason both of your adapters don't work are because the Treo has a slightly different plug. both of my adapters that work on my treo will not work with my 6700and mogul while my adapter that I had for my 6700 works perfectly with my mogul.

[Gilliland]

Originally Posted by budney

the reason both of your adapters don't work are because the Treo has a slightly different plug. both of my adapters that work on my treo will not work with my 6700and mogul while my adapter that I had for my 6700 works perfectly with my mogul.

Then why don't my 2.5mm Seidio headphones work? The only adapter they go through is the HTC-supplied USB adapter. The Treo adapters aren't even in the picture.

If your Treo adapters don't work, then it sounds like your adapter is broken as well. That is a possibility that I've considered - the HTC adapter may be broken by design. If that's the case, then swapping it won't do me a whole lot of good. It sounds like HTC may have done something decidedly non-standard with respect to normal 2.5mm cellphone headphones.