The answer is probably both, but which one contributes more to sound quality? Why? Are there other things to consider?

Good speakers (or good headphones).

If you want surround sound, cheap sound cards or in-built sound devices might not have all the plugs - so in that case you'd have to buy a decent card ;)

I once read that 90% of your budget should be spent on speakers.

The main difference between a cheap, built-in sound card and an expensive adapter sound card is that the cheap one will leech more juice out of your CPU - not much difference in sound quality. The good ones have a chip that will process sound and thus take that load off the CPU.

Good speakers definitely. You can probably use them also for a stereo or surround sound system for DVDs, and as long as the sound card has the connectors to take advantage of the speakers.

Two sound cards won't have much difference in sound quality, but probably better performance and less strain on CPUs.

Speakers are almost always more important.


But first we must ask, what is this for?

Is it a home PC that will be used for Word and EMail? A medium quality gaming rig in the front room? A home theater style setup? An audio developer or music director?


Integrated sound cards are just fine for many applications.

Sound cards are less of an issue than they were when they came out in the 80's and 90's. Back then a 16-bit "CD quality" sampling rate meant expensive hardware, you were more likely to get 22KHz stereo. Today's cheap integrated cards are often able to handle 7.1 at 96KHz with great quality. Those cards are more than sufficient for listening to music, games or blu-ray. High end cards today have incredible hardware, far beyond what is necessary for home use.

However, if you are involved in complex audio processing rather than listening, then the high-end cards are for you. Very few applications need this type of thing, and you need to know you need it. If you need to ask if you need that quality, then the answer is no.


Having speakers that match the intended use is much more important.

Having free speakers that whine, hiss, or pop may not be a problem for office or home computer use.

Good stereo headphones for personal use will cost you about $50 (more if you want headsets for voice chat). Professional studio headphones with dual layer diaphragms will set you back a few hundred dollars.

A home theater audio setup can cost several thousand or tens-of-thousands of dollars in high quality speakers. You will want professionals to measure the space and choose the correct speaker type and position. They may include some sound baffles to help improve the experience.

A professional studio audio setup will cost several hundred thousand dollars. If you need to meet the professional guidelines for recording studios it can cost several million dollars. They will include not just a full range of speakers but also physical changes to the walls, flooring, and ceiling for audio insulation and a range of baffles to control the sound.

Speakers

Get yourself a quality sound card with some nice EMI shielding, and some canal phones.

1)Errr...music? [smile]
2) Speakers
3) USB sound card with nice final amplifier

If your sound card has a digital output, then 100% of your quality will come from your speakers. However, I've had some motherboard-integrated analog sound outputs (for headphones and speakers) that had horrendous amounts of static noise. Buying a $15 used SoundBlaster on eBay made 100x difference. I couldn't imagine it getting much better than that.