640 kbps versus 1.5 mpbs and Energy Encore Speakers...??

[andsoitgoes]

Okay - So I've got some ancient Energy Encore speakers that have done me well for going on about 8 years now. I like them, they're great -and I don't have the money to change/upgrade

I have a non-HDMI (audio) receiver and can only do optical out.

I'm picky, but I'm financially strapped. Is it worth buying a new HDMI audio capable receiver to push 1.5 mpbs sound to my 8 year old speakers?

Or would the difference be marginal in comparison to the cost increase? I like good sound, don't get me wrong - but I'm interested in knowing if there is a HUGE difference.

I hope I posted this in the right forum. I just want to do the best to get the MOST out of what I already have.

And I'm assuming there's no way that I could convert the HDMI to send the audio portion into the 7.1 analog signals, is there? ( I have inputs for that on my receiver )

Nick