Coax Input - Low bass compared to Direct 6ch

[Kai]

hi guys, i bought the logitech z-5500 sound system couple of months ago and i was told it would sound way better if i connected them via coax instead of the current Direct 6ch i was using before. (which was supplied with the speakers when i first bought them)

Now it is true, coax does sound quite better in some ways plus sound comes out of all 5 speakers in equal volume instead of before with 6ch where it came out of rear speakers not as loud as center,left and right.
But, there is one complaint, now the bass is way feinter than before..
Not bass from the speakers, the bass from the speakers is fine, but the massive 12" subwoofer has really low bass, its no where near as powerful as before.

Im using the same EQ settings as before and havnt changed any other soundcard settings so why the decrease in bass? ithought coaxial input/output was meant to be better :(
Does anyone know? or have the same problem?

OH and, i have the Asus xonar d2 soundcard.

 

[Ferg]

I have that set - I only use the coax from a media player - do you have an optical link that you could make use of?

Its likely because the coax is a digital link (as opposed to the direct link) the speaker system will be doing the decoding itself as when using the direct option the on board sound will be boosting it itself - have you tried boosting the bass level on the speakers manually? - I'm constantly adjusting it.

If you get a movie with a DTS soundtrack and switch to it on the digital link you'll see a much better low end.

I have found that the best for me is when listening to normal stereo music I use the direct using my on board sound to adjust levels - and for movies i have powerdvd set to use the optical link - for true digital sound reproduction.

 

[RHochstenbach]

I need to add something to this. When playing 5.1 audio, the Z5500 displays the DD Digital logo. Then you have 5.1. When you play stereo audio, it does not use all speakers to play the music. In that case, press the Effect button to use either Stereo X2 or DD Logic II Music. When using the last effect, the stereo gets upscaled to 5.1 and also results in a more powerful bass. You won't really get a better sound when using Coax. The three analog plugs work just fine. But use the effect button to use either Stereo X2 or Logic II Music when playing stereo audio, and 6ch direct when playing 5.1 audio.