Which should I use?

[Jsheth]

I have a Phillips MX 5600D surround set without HDMI compatibility
And I use my HDMI-ed PS3 slim as my main entertainment setup (DVDs/Blus)

What I used to do was keep HDMI video while pluging the standards to my sound set but I was thinking that it could sound better with my reg TV speakers in HDMI quality

I cant even mount the rear speakers or even keep them behind me, I have to keep them jumbled up by the TV

What do you think I should do to get the best possible audio?
I dont have money too shell out to get a surround so thats no option...

Here are the tec specs for the surround set I have


Home theater system with 5-disc DVD/CD player, 4 satellite speakers, 1 center speaker, Twin Sub bass pipes, and 600 watts total system power
Dolby Digital and DTS 5.1-channel surround decoding for discrete, enveloping DVD surround sound
40 FM/AM radio presets, progressive-scan video output for high-definition and HD-ready TVs
Audio inputs for 2 additional components; all necessary speaker cables and interconnects included
Receiver/DVD: 17 x 4 x 15; satellites: 3 x 11 x 3; center speaker: 17 x 3 x 3; sats/bass pipes: 4 x 39 x 4 inches (W x H x D)
Technical Details
Brand Name: Philips
Model: MX5600
Output Wattage: 600
Component Type: Home theater system
Surround Sound Effects: Matrix Surround, Virtual Surround Mode
DVD Type: DVD changer
Built In Decoder: MPEG, Dolby Digital, DTS decoder
Remote Control Description: Universal remote control
Coaxial Digital Input: Yes
Audio Input: None
Coaxial Digital Output: Yes
Headphones Jack: Yes
Tuner Technology: Digital
Radio Bands Supported: AM/FM