Volume level when listening music through external speakers

[seb481]

So I plug my iPhone to my PC speakers at work every day to listen to the music.
I tried to change the volume level from the iPhone but I can't, it just doesn't change the volume level at all.
My IT guy told me that his iPhone will change the volume level.
Now today, I was listening at the music and all the sudden, no more sound. So i started playing with the volume level on the iPhone and all the sudden, the sound came back and I was able to increase or decrease the volume at will.
The song ended, next song starts playing and now I can't change the volume anymore. (unless I adjust the speakers volume!).
Anyone else has encountered this issue?

 

[Conan]

my speaker doesn't have the supported cord thing to work with iPhone or I would test it out and tell you. . the 3 ring cord thing...

 

[stevetim]

When I dock the iPhone with the charging stand, and use the OUT plug on the back to go into my home stereo, volume is controlled via the stereo only.

If I use the headphone jack without docking to the charging stand and plug my iPhone into the stereo, volume is controlled by either the iPhone or the stereo.

 

[seb481]

Sweet, thanks for your input