. Dark_Ethereal • Mar 10, 2016, 6:42 AM
Ok so here's the deal:
An internal sound card contains a DAC. An external USB DAC is a DAC.
Sound cards used to offload sound processing tasks from the CPU to an dedicated processor on the card, but new versions of Windows basically broke this feature, plus new CPUs can easily deal with the task anyway, so that isn't really a thing to consider when comparing them...
That leaves us with:
The Real Differences between DACs and Soundcards
Bundled software solutions.
Signal Path and susceptibility to noise.
Target Market
Bundled Software
Sound cards tend to come with more bundled software with more features. A heck of a lot of these features you probably won't use.
There most important of these IMO are HRTF based surround virtualiztion solutions.
Head Related Transfer Functions are clever bits of maths that take a sound, and it's 3D position, and turns it into a 2 channel stereo output for headphones that accurately reproduces the 3D nature of sound using psychoacoustic magic.
This isn't snake oil. It's real audio engineering stuff.
Sound Cards often come with one of these solutions, as do the "gamer" targeted USB "mixamps" from companies like Astro.
Here are the names of some of these solutions:
CMSS-3D (on Creative cards)
SBX Pro Studio (on new creative cards)
Dolby Headphone (on many devices, such as Asus Xonar soundcards)
Razer Surrond (not tied to a card, but terrible IMO)
These solutions tend to be tied to a hardware product. You can't run them without the product (even though they don't need the hardware inside the product).
There are some paid solutions that don't require hardware I hear.
Audiophile targeted DACs don't tend to come with these things, but there are probably exceptions.
Signal Path and Interference
Here's the typical signal path for any computer audio solution:
Proccessor > Digital Signal > DAC > Analogue Signal > Amp > Strong Analogue Signal > Headphones
The important thing to note is that digital signals are very resistant to noise, because all they are is on and off pulses, so any noise can just be cleaned right up.
Analogue very easily corruptable by noise, but you can't drive headphones with a digital signal.
Internal soundcards
In an internal soundcard the digital signal is delivered to the DAC from the processor via PCI/PCIe, where it is converted inside the case, and sent to the rear IO ports.
That means the analogue signal spends some time inside the case, on a card connected to lots of electrical connections connected to other parts of the motherboard. It can be a noisy place in there, but a good card will have shielding around the card and will take steps to properly isolate noise... so that shouldn't really be an issue for the rear IO.
The REAL interference often comes when you connect the front IO panel to the soundcard through those nasty thin front IO cables that have no shielding, and you run them right past the back of the motherboard, in between a bunch of other cables, and past your hard drives (which generate magnetic fields on purpose!). If your internal soundcard sounds noisy, always try getting sound from the rear output before spending money!
External DACs
External DACs plug in via USB or S/PDIF (whether that's copper cable or fibre-optic). I'm pretty sure these both send basically the same audio data, just through different physical means.
They all transfer digital audio signals to the external DAC. That means that the audio signal has spent no time inside the case as an analogue signal, so there's much less opportunity for noise from your computer.
That said, DACs can still introduce hissing from their own hardware, if they haven't been properly engineered to avoid doing so.
So it may seem like DACs have a big advantage over noise compared to soundcards, but really it's just a theoretical difference. The noisiness of sound cards will vary between models and price points, and many of them are perfectly good enough to not bother spending extra money getting an external DAC.
Target Market
Sound Cards are marketed to gamers. Sound Card makers also make external DACs that are marketed to gamers (see Creative). DACs are often marketed to audiophiles.
What does that mean? Well gamers often aren't really discerning with their sound. They want something that they think will make them play better. They will pay something for it, but they won't really care to notice whether they got a sound that matches what they paid for (See all gaming headsets ever).
Audiophiles, however, do care about sound... but they are also willing to pay too much for good sound all too often, and when people pay too much, they often try to justify their purchase when they've been fleeced. Some audiophiles buy into snake oil.
You won't see soundcards and DACs marketed to gamers for over £200, because they won't pay that much. They may pay £50 for something they don't really need, and never really assess the quality of the product, but they're not going to pay big bucks.
Audiophiles, on the otherhand, don't seem to care about the concept of deminishing returns. You can bet your arse there is someone out there paying over £200 for a DAC, because he thinks it may make some tiiiiny difference to the sound, and he doesn't care how small the difference is. HE NEEDS IT!
That's not to say that there aren't price conscious audiophiles who look for a more reasonable value proposition. There totally are. It's just that there are also snake oil buyers and Snake oil sellers.
(I'm both a gamer and an Audiophile BTW).
Onboard audio honourable mention
There was once a time where soundcards were mandatory. Those times are over.
Quality onboard audio is here people. You might not need any of these things if your onboard sound is up to scratch.
Things may vary from board to board though. My on-board sound picks up hard-drive noise and is too quiet for my headphones, so I have a properly amped soundcard.
There's no point getting a fancy ass soundcard if you've got crappy headphones/speakers, and there's no point getting good headphones/speakers if you're running them on a crappy DAC+Amp setup.
u/alucard835 • Mar 10, 2016, 6:57 AM
If you're using any kind of higher quality headphones, a sound card will definitely benefit you. The Soundblaster Z sounds great and is a great value.
The benefit of a USB DAC is you can use it on a laptop, or on other machines you might use, giving you better sound quality wherever you go.
The choice is up to you. You may want to swing by /r/headphones too.