I'll split the audio performance analysis into two parts - gaming and music. Even though the headset produces the same sound regardless of what it's being used for, you won't necessarily look for the same things while annihilating your virtual opponents as you will when listening to your favorite tunes.
Gaming
First thing that needs to be said is that the tuning of the 40-milimeter audio drivers built into the Arctis 5 is neutral. They call them the S1 Speaker Drivers and point out that they're the same ones as in their most expensive headset (that would be the $340 Siberia 840, I suppose).
Unlike many of its competitors, SteelSeries successfully fought off the urge to make a headset with an annoyingly bloated bass and nothing else happening in the rest of the sound spectrum. Instead, they went down the same road as a manufacturer of proper hi-fi headphones. What that means is you'll get a very balanced, well-rounded sound signature, one that has something to offer in the entire frequency range.
When playing games, that translates into precision. Every single sound, be it a gunshot, someone reloading their gun, shouts of your enemies or something else, is perfectly crisp and clear - and easy to locate in the virtual 3D world surrounding you. As far as spatial positioning goes, the Arctis 5 is up there with the best of them. Recently I've been playing a lot of PlayerUnknown's Battlegrounds, a third-person/first-person "battle royale", essentially a Hunger Games kind of a shooter where a death means game over - there's no respawning. The ability to hear the footsteps of your enemies and pinpoint their exact location is what effectively decides if you'll win or lose. Let's just say I won the very first PUBG match I played with the Arctis 5 on my head. The spatial positioning is so good that you can sit in a house and accurately rotate your camera as your enemy walks around it, never losing track of him or wondering where he went. For a closed-back gaming headset, that's quite a feat. But that's what you get when you tune the audio drivers the right way instead of just focusing on nothing but the bass.
Since the bass isn't overdone, some may find the explosions, car crashes and such to sound a bit boring. Events like that definitely won't shake your head or ferociously slam your ears, so if that's what you're after, you'll be better off with a different (cheaper!) gaming headset. With the Arctis 5, it's all about precision and refinement. Also, let's not forget that there's a system-wide equalizer offered within the SteelSeries Engine 3 software, which you can utilize to tune the bass the way you find preferable.
The passive noise isolation is great. With the ear cushions being marketed as "airy", I was a bit worried that they're going to leak a lot of sound into their surroundings, but they don't. At all.
Music
My experience is that people usually run into the dilemma of whether they should buy a gaming headset or a pair of headphones that will be better for music. They think they have to choose between gaming and music performance. With many gaming headsets that is indeed true because they go for excitement and drama while gaming and ruin the music performance in the process, where you also need subtlety, rich dynamics, and a presentation that's going to stay as faithful to the source as possible.
Not so with the Arctis 5. I have a strong feeling SteelSeries wanted to make a great pair of headphones first and foremost to only then perform the necessary tweaks to turn it into a fantastic gaming headset. Like I already said, the tuning of the audio drivers is natural, equally focusing on all parts of the sound spectrum. This is why you'll get a rhythmical, accurate sound you'd normally expect from a pair of $150 hi-fi headphones. Hell, I heard many of them from the $200 and $300 price brackets that sounded worse than the Arctis 5.
I truly enjoyed listening to a wide range of music genres on these, be it electronic music, hip-hop, indie folk, string-heavy classical pieces with complex dynamics, or my usual lineup of death and black metal… I want to say songs, but I'm not sure everyone would agree. The built-in drivers can keep up with fast drums, guitars, male and female vocals of all ranges and everything else you throw at them.
What I'm trying to say is - don't think of the Arctis 5 as nothing but a gaming headset. You're also buying and getting a great pair of headphones for your music listening sessions.
Should you buy a separate DAC/headphone amp to get even more from the Arctis 5? I wouldn't bother. Do keep in mind that this is a USB headset, which means it already comes with its own sound card, and a good one at that, at least when it comes down to sound reproduction (microphone performance is a slightly different story - check out the next page of the review). I liked the sound of the Arctis 5 more when it was connected to its own sound card than when I connected it to the FiiO X5, which is a $300 FLAC player that can be used as a USB DAC/amp.
Yes, the overall sound presentation did improve even more when I combined it with the Audiolab M-DAC, but that's a $600 device you definitely won't be buying to drive a $100 gaming headset. What the M-DAC did show me though is that the Arctis 5 can handle extreme volumes, ones that go far beyond the range of its own built-in volume dial, with no distortion.
7.1 Surround Sound
The Arctis 5 supports 7.1 Surround Sound and the DTS Headphone:X technology, which should, in theory, make the sound "bigger" and convince your ears that it's coming from a grand total of eight different speakers, rather than just the two. Activating surround sound comes down to pressing a single button in the SteelSeries Engine 3 software. You can also pick between a few audio presets (Game, Movie, Music) once you activate surround sound.
My advice is - don't. It completely ruins the overall audio presentation and removes pretty much everything I love about the sound of this headset. Suddenly, gunfire sounds like you're hitting a metal bucket with a spoon, and vocals sound like they're coming from the bottom of a well. At the same time, the surround didn't help me with in-game spatial positioning at all. If anything, it caused a feeling of paranoia as I suddenly had a feeling that enemies were coming from all sides at once.
Put the DTS Headphone:X 7.1 switch into its "Off" position and forget it ever existed.