but it picked up interference and noises because it was an internal sound card...
It may have picked up interference and noises, but that was
NOT because it was an "internal" sound card. Interference and unwanted noise is caused by something
faulty, either with the card itself, or something near the card. It could have been a bad solder joint, a bad cable, a loose connection, faulty shielding on some component, damaged slot, a "difference in potentials", or a bad ground.
Would it be smart to consider an EXTERNAL sound card to avoid interference
Without knowing the source of the interference, there is no way of answering that. If the source was, for example, coming the refrigerator in your kitchen, having an internal card that sits inside your metal computer case may help block that interference. An external sound device (along with all the external audio connections) may be more exposed to noise and interference from external sources.
But if the source of the interference is a faulty motherboard component, an external card might help. But since even an external card connects to the motherboard, interference may still be a problem. So again, without knowing the source of that noise/interference, there is no way in telling if an external card will help with that.
I recommend you first, check your wall outlets. Every home and every computer user should have access to a
AC Outlet Tester to ensure your outlet is properly wired
and grounded. Poor grounding is a major cause of unwanted noise and interference!
I recommend a tester with a GFCI (ground fault circuit interrupt) indicator as it can be used to test bathroom and kitchen outlets (outlets near water) too. These testers can be found for your type and voltage outlet, foreign or domestic, (like
this one for the UK) at most home improvement stores, or even the electrical department at Wal-Mart. Use it to test all the outlets in the home and if a fault is shown, have it fixed by a qualified electrician.
I got into audiophile quality audio reproduction long before I got into computers. And I got into computers in 1975! My first pair of quality speakers (which I still have) where the
Acoustic Research AR-3a's. Mighty-Lu-Bu is right that most motherboard sound is lacking. But the better boards do include better quality sound. But
of course, over all quality depends on many factors, including the sound source (original recording), compression, amplification, transmission (cables), speakers, and your own ears.
You cannot expect "true" audiophile quality sound from headphones or a sound card that costs $150 - not when you consider when a pair of decent
B&W bookshelf speakers cost $6000/pair! Note the stands are $1000 extra! And of course, then you need a quality amp/receiver to run them!
I am just saying, keep your expectations and perspectives in line.
As for difference in potentials, that is a common source of audio noise that is typically easy to render. Because every wall outlet is a slightly different distance back to the service panel and to Earth ground, there can be a "difference in potential" between the two grounds in two different outlets. This can cause interference (and noise) when two devices are powered through two different wall outlets.
This is pretty easy to fix or avoid completely. First, ensure the wall outlets are wired properly. Then, if possible, power all your computer equipment (PC, external sound card, monitors, powered speakers) are all powered through the same wall outlet. If not possible, use a small 22AWG connecting wire to "strap" all the devices together. For example, connect one end of the wire to a screw securing the PC's power supply to the case, and the other end of the wire to a screw in the subwoofer's chassis. Then connect a wire from the external sound card to one of those other devices. This puts all the grounds on all the devices at the same potential. A good thing.