is there any difference in using a aux or usb connection and....

is there any point in using a dedicated audio sound card if you choose to use usb?

Not really, what makes the difference are the electronics involved in processing the signals, crucially important if you are dealing with analog sources.
Decent connectors and cables are definitely a must have, nothing fancy but try to stay away from the cheapest stuff.

USB audio cards are as good as internal ones as long as you avoid cheap stuff that may add some latency or have low end processors, but generally nowadays are usually good.
Help with portability and allow you to place the card ouside of the case where there may be a lot of electromagnetic noise.

If you have an external USB sound card with optical out (toslink) to a proper receiver to take advantage of it (and not using HDMI for sound), then yes, it's far better in terms of audio quality. Otherwise there's no real gain there.

However, other reasons is if you want less static interference, more options and connections (MIDI f.ex.), higher volume, adding remote control, and/or want a small audio lab.

With USB you simply get more options.

I've used my Sound Blaster Extigy for years and through the drivers I got the stereo-mix (option to record what's playing or going through the machine) on my laptop. Best thing is, I can still use it outside of the computer regardless if it's on or not, or if the drivers get too old.

One is analogue, the other is digital. How does that ultimately matter? It does, in many ways.

Analog signals are vulnerable to noise, whereas digital ones will correct themselves. Of course at some point your speakers will need an analogue signal to play back sound, but if this conversion happens down the line (for example some USB speakers include their own DAC into the subwoofer) there's less reasons to get signal degradation. Digital signals can also employ other tricks like compression, carry multi-channel data on the same wire etc.

In essence, having a speaker connected over USB when it has both USB and AUX will have the potential to improve your sound quality. If it's just a sound-card that then outputs an analogue signal anyway, it doesn't really matter, assuming they are comparable in quality. No, you don't need an internal sound card then, because whatever you connect via USB will do its own DAC.

You get what you pay for.

Onboard sound that comes with motherboards is what it is - a small chip surrounded by a bunch of noise and interference, vying for low latency high signal-to-noise output. It ranges in quality from 'is that you hissing??' to 'well, i guess you could call that music, i think' levels.

External soundcards or usb DACs are the best cheap upgrade to sound there is. Good headphones a close second, but really the two go hand in hand anyways.

Just try them with any decent headphones (I'm not talking 500euros+ either), and hear the difference.

And voila - the poor man's hifi. Or just improved sound gaming and watching netflix, too.

Ouch, sounds like you are talking from your own bad experience :). It's really gotten better in recent years and some motherboards pack high quality onboard sound cards with isolated circuitry and high SNR, quite comparable to entry level USB "hifi" audio cards.

I am, and things have certainly gotten better sure. But apart from some ultra special extra pricey gaming mobos, I haven't seen any decent offerings that are even remotely comparable to cheap headphone amps and usb dacs, whether it's SNR, frequency response or something like a 1/4 jack for some. Depending on headphones, you might need that extra oomph or ohms, too.

For the vast majority, a USB dac (even a cheap one) is more than worth the investment over an average 'gaming mobo chip', I would think.

I have one of these...

... and its frequency response is only marginally better than my onboard audio on this.

Sometimes better speakers/headphones are the wiser investment, if we are talking about your average gamer here.

To be fair, that looks like a 20 euro usb stick :)

Also, the best headphones aren't any use if your source is trash.

But do what sounds best, what's best for your ears and music, that's what I say. If it makes you happy, who can tell you otherwise.

average gamer, with an acquired taste.... , and a love for orchestral pieces ( which i prefer to listen to without a headset ) .....

The thing is, i'm getting a soundbar for my p.c. for my birthday , yay \o/ \o/

Not the most expensive of things, just a nice gesture the creative v2 something something ( no not the Katana soundbar )

thing is, i noticed with the headset i have that it works optimal if used via usb and not if i connect it to the soundcard, now with the soundcard ( creative ) i'm hoping that it will combine like water with the soundbar which is also creative but i have some worries in advance concerning the digital surround settings and more

it would be such a shame if the soundcard will end up like the worst piece of purchase i'd ever made .....

You did say even cheap ones, so I rose to the challenge :))... True, but when you're on a limited budget you want the best compromise you can afford. Fair enough, I'll rest my case. Just based on observations, I've noticed a lot more people are wowed by upgrades to their speakers/headphones, wherein only audiophiles will care much about (or notice differences in) source signal quality. I'm in the latter crowd, so I do get your point.

Until Bluetooth 5 came along, which I can put up with, I could not use wireless headsets as the signal compression artifacts were driving me nuts.

If you can use optical audio, sure. If it just connects to your PC/console via USB it won't matter, as it will bypass your soundcard anyway and you will see it as a separate audio device.

It's an interesting question, I would like to know the answer to it too.

My intuition is that an external sound card and thus DAC is completely unnecessary and maybe even a hindrance in that setup. A soundbar with USB or optical straight from mobo with pass-through will be more than fine, and then you skip the unnecessary middle step of a digital to analogue conversion. Let the soundbar do its thing.

But. If you want to use headphones too, then the usb dac would come in handy.

there are seperate ways of connecting, optical is possible, also the normal audio jacks and usb ... according to the site optical is only available for ps 4.

also, after a quick glance on the box it seems the AE-5 internal sound card does not support optical connections

Well, then you are stuck with USB as your best bet and your internal sound card won't matter in that setup anyway.

Soundbars will usually provide an analogue audio out, post internal amp anyway... so they become a USB DAC :).