This has been tried before, this is my latest attempt and educating people on PC audio do's and donts, and clearing up a lot of myths surrounding the subject. Out of arrogance i'm going to sticky this, because i think its worth it. Dedicated vs Onboard + Analogue sound quality Spoiler This is an age old debate, and a good point to start. The short version is this: onboard sound has most of the features of high end cards these days. you get EAX 2.0, 5.1 and 7.1 sound, dolby digital encoding (and DTS) on some motherboards, and even HDMI audio built into some onboard VGA. The only real area they differ is analogue audio quality. If you have high end speakers or good headphones, you WILL hear a sound difference. Just so you know, a budget dedicated card (for example, those budget X-fi cards) can often sound just as bad as onboard. do your research before 'upgrading' Analogue Vs digital Spoiler Expanding on above, digital audio (usually via HDMI or SPDIF) does NOT differ in quality between sound cards. it relies 100% on the decoder in your speakers or amplifier, to determine how good it sounds. If you use digital audio for stereo, or your onboard has dolby digital or DTS encoding capabilities, dont bother with a dedicated card. To answer a question asked in another thread, analogue can sound better than digital, if the DAC's in the sound card are better than the DAC's in your digital receiver. You'd have to test that, but usually you'd not notice a difference except on extremely high end speakers. As Frederik S says here, the only time digital should vary at all from one sound card to another, is if its incredibly bad quality, or just broken. DDL/DTS encoding as stated above, these are technologies to let you get 5.1 audio over a single digital cable (optical or RCA connections using SPDIF), instead of the normal limit of 2.0 audio. Not all cards have this, but lately even onboard solutions can. So yes, in this case onboard can in fact do something cheap dedicated cards cannot. SPDIF vs HDMI Spoiler SPDIF is an older method of getting 5.1 sound over a connection originally designed for stereo (2 channel) audio only. It uses compression to do this, but helps you bypass the digital to analogue conversion process in your sound card. Most older home cinema speakers/receivers use this, so its a good way to use those speakers on PC. SPDIF only allows stereo or an encoded stream - which really means stereo or encoded (Compressed) 5.1 only. HDMI is a new cable you should all be familiar with, that uses both video and audio on the one cable. I havent got personal experience with HDMI receivers i cant cover that perfectly, but i can say this: Without a receiver with a HDMI input, you are stuck at stereo. The HDMI specs do not allow you to send the audio to your TV or monitor, and output it back out of the TV as SPDIF. If you think it does, test it yourself. You'll find out it doesnt work. (thanks DRM!) Basically, you need to have the HDMI source go like this PC -> Audio receiver -> TV, or you're stuck at stereo from the TV speakers, just like SPDIF. The main advantage of HDMI over toslink is one less cable (well, its not really since you have to add a second one once you add a receiver), and upto 8 channels of un-compressed audio. It WILL sound better, with really high end speakers. How to setup 5.1 sound Spoiler First of all, make sure your sound card software, AND windows is set to 5.1. Here is how to setup your sound card in windows: its really simple, but some sound card software does NOT change this in windows, and can cause weird behaviour. make sure they match up. here is my auzentechs Cmedia based software (Realtek is very similar, and not worth showing) In this image you can see the 'input' and output are seperate. if i had input to stereo but output to 5.1, this would give me stereo sound, spread out over my speakers. For example, i would hear an MP3 played back, play out of all speakers. If i set it properly to 5.1 (6 channel) on both as below: Then audio only comes out where its supposed to. MP3's are only stereo, so the sound will only come out of my front left and front right speakers (and probably the sub too, due to bass redirection) Creative soundcards have a CMSS3D option that does the same as what i said above with the upmixing - its BAD. yes it gives your MP3's that surround feel, but it destroys positional audio in games. ever wondered why you can never tell where enemies are firing from, even with 5.1? thats why. When it comes to true positional surround sound, you do not want ANY upmixing. period. If you are setting up digital audio for surround sound, its pretty much the same, heres a screenshot of my realtek onboard and auzentech set up to use it. Note how the realtek treats it as a seperate sound source/soundcard, while the auzentech/cmedia disables the analogue outputs to do it (notice how its greyed out - but i still had to select 5.1 input at the top) When selecting your sound card in windows, apps or games it can vary based on what i said above. If i wanted windows to use the digital on my auzentech, i have to set it to come out the analogue outputs because that stream is being encoded and moved to the optical port - whereas on the realtek its treated as an entirely different sound card, and therefore you need to choose the optical output Positional audio Vs Surround sound Spoiler This does need to be briefly mentioned, even though it is touched upon in the other sections: Surround sound is kind of misleading, as any sound that surrounds you is surround sound. This could be 5.1 surround sound, upmixed stereo sound, or even virtual surround sound. TRUE surround sound is positional audio, where each output device (Speaker, subwoofer, etc) has its own dedicated sound stream. Front left only plays audio that is to your front left, and so on. A good example of this is with movies, how voices only come from the center speaker unless they are trying to make it sound like someone is 'behind' you, or to the side. Fake surround sound Spoiler As shown in my Cmedia/auzentech screenshot above, virtual surround sound exists. Basically, it gets 6 (or more) channels of audio, and then mixes it back into a stereo stream using audio effects to make you think there is more than just two speakers. Kind of how like muffling a sound can make it seem further away, only more advanced. This is fine in many cases, if you only have stereo inputs to your device (speakers or headphones - but if you have true multi channel inputs, for gods sake use true surround sound and not this fake crap. EAX in the modern gaming world Spoiler Some people seem to think EAX is all important, fancy, and required for all sorts of sound features like positional audio, reverb effects, audio occlusion and surround sound in general. None of this is true. EAX may have added those features in on top of Directsound3D, but it is not the only way to do so, and the death of EAX will not stop those features from existing in games today. The only reason people think these features were tied in, was smart marketing on creatives part - they DISABLED all those features on soundcards that didnt support EAX, just to make it seem like EAX did more than it really did. A good analogy there would be games designed for Nvidia graphics that dont allow anyone on ATI/AMD or intel graphics to go above 800x600 resolution. We wouldnt accept that there, which is why no one liked it in the audio market, and creatives monopoly got toppled. And a bonus: 16 bit audio vs 24 bit read this to see that some people think 24 bit audio aint worth it. arguments abound on this one. Sticking your audio straight to 24 bit in the windows control panel may not actually give you better audio, test it and see for yourself.