Bad Sound Occurring When Sending Audio To Second Monitor?

I hooked up a second monitor to my computer yesterday and I'm really disapointed in the sound quality coming thru. The video is coming thru perfect. This is my set up...1) windows 7 home, MSI p67a-c43 motherboard with integrated audio- realtek ALC892, nvidea gtx 550 TI. I have my regular computer speakers attached to the 1/2" speaker connection port (green) on the computer.2) The TV (second monitor) is a vizio E320vl . I have tried changing all of the audio settings on the TV ( like sound filters and pcm/dolby digital settings that are on the tv to try and correct the problem to no avail. There are a number of hdmi ports on the TV, and one of the hdmi ports (the one it is plugged into) does have rca audio ports next to the hdmi connection, but the audio is being sent via the hdmi and these are not being used.

3) The video card has 2 dvi ports and 1 mini hdmi. My regular computer monitor is being hooked up to the dvi port. and BOTH the audio and video to the second monitor is sent to the 2 nd monitor using the mini hdmi. I am using an hdmi extension because of the distance from the computer (about 16 feet from the computer)Here is what is happening with the audio- while I am getting audio to the 2nd tv ( by changing the playback devices default switch to the second monitor that displays in the computer sound settings, the audio sounds very different from what it should. The best way to describe it is almost like very tinny sounding... almost like listening to it thru a can Music sounds really bad. There is no static or noticable distortion, just sounds bad in comparison to what comes out of my very cheap computer speakers