Boston computer speakers - Model BA735. Problem connecting to computer

[thewaz]

I'm not sure if this is the right forum for this but maybe someone can help me out

I bought a set of Boston BA735 computer speakers at a yard sale. They came without the audio cable. On the back of the sub-woofer is a standard RCA female connection labelled DIGITAL IN. After a bit of reading, I found out that the computer must supply a digital signal to the speakers.

My notebook is an Acer 5742 running Windows 7 Home Premium -- 64 Bit. The only information supplied about the Acer audio is that it is Realtek High Definition Audio and it has high-definition audio support.

My notebook has an HDMI OUT port and a standard headphone port. I tried connecting an RCA cable to the sub and used an RCA to mini plug adapter to plug into the headphone jack but got no sound. I suspect that it is not a digital signal from the headphone connection but am not sure about that.

The HDMI out should provide a digital audio signal. Is it possible to use (or even get?) an HDMI cable with an RCA male end that will plug into the Digital Audio in on the speakers that will make them work?

Any help would be greatly appreciated

The Waz