Old JVC stereo system and Xonar D1 vs ALC888

[Hammer92]

Hello this is my first post on this forum I hope anyone Can help in resolving my problems. Last time sound from my computer isn't suprising me (current card is ALC888) so I'm preparing to buy sound card I guess it will be Xonar D1 or SB X-fi Gamer ( I dont know which is better). One problem is that I have old stereo system JVC MX-D301T with speakers SP-D301 Photo: http://kopochsalj.eniro.se/images/80...1_76425big.jpg and specs:
Speakers

Type 3- way, 3-speaker bass-reflex type
Woofer 16 cm (6-5/16 inches) cone ´ 1
Mid Range 5 cm (2 inches) cone ´ 1
Tweeter 2 cm (13/16 inches) dome ´ 1
Power Hardling Capacity 80 watts
Impedance 6 ohms
Frequecy Range 45 Hz - 20,000 Hz
Sound Pressure Level 90 dB/w ? m
Dimensions (W/H/D) 215 ´ 295 ´ 275 mm
(8-1/2 ´ 11-5/8 ´ 10-7/8 inches)
Mass 3.2 kg (7.1 lbs) each

I don't think it is bad system but I don't know something and I need advice so. Is it worth to buy Xonar D1 or X-fi Gamer to this stereo system ? Will I see a difference between onboard sound and Xonar ? A reason why I want to change sound card is that sound is boring and poor when I'm listening to music like Rock/Metal ore something similar to it. But please I need and subjective opinion. Generally I'm listening to music in MP3 format but sometimes I like to play games.Card must work correctly on Windows 7

I wanted to buy Genius SP-HF2000X speakers, and using ALC888 maybe it will take better effect than buying Xonar D1 ?

Btw. sorry for my language mistakes I'm not from english speaking country

[audionewbieyao]

Xonar D1 has significantly better SNR and THDN over a Xtreme Gamer, not to mention ALC888.

You JVC is old maybe but you should still be able hear the difference.

[Hammer92]

What about Genius SP-HF2000X+ALC888 ? Maybe it will be better idea ?