Sorry for taking so long to reply (Internet was knocked out) My splitter works fine, before applying it for this I used it for my blu-ray player. a link to it is here-> http://www.amazon.com/Sewell-Powered-Splitter-Certified-Up-1080p/dp/B003B4O7NS/ref=sr_1_1?ie=UTF8&qid=1377629271&sr=8-1&keywords=sewell+hdmi+splitter
My monitor does have speakers built in, there's an audio-in-jack in the back. I used my 360 audio dongle I use to use my headset with my system to try and get sound that way but it didnt work and I found my speakers aren't the best.
However, after reading the user manual of the splitter it say in the last section- "If the maximum resolution of the two displays supported is not the same, the splitter will display at the lower of the two resolutions" Now, if the splitter can do that is it possible that it can also detect that no audio is being carried to one of the outputs so it restricts the audio to the other source? So yes it,could be the splitter. Under normal use, it performs fine but for my adapted use it doesn't fully work. Im suspecting thats what happened in my case.