The Ollo Audio S5X are a pair of reference headphones with a neutral sound signature, designed for audiophiles as well as mixing and mastering engineers.

Final verdict
All things considered, the Ollo S5X are a good set of headphones. The response is mostly neutral, and the soundstage offers a lot of depth and openness. They’re comfortable, designed well, and built sustainably.
However, the recess in the upper-midrange and high-end isn’t great for professional work, at least in my opinion. I’m sure there are some folks out there that can come out with some excellent mixes and masters using the S5X, but not me.
Although, I’m more than happy to recommend them for any audiophiles looking for a new set of cans for casual listening.
What I like
- Good sub-bass extension.
- Fairly neutral frequency response.
- Great soundstage.
What I don’t like
- Recessed upper mids.
- Treble balance is a bit too warm for fully accurate listening.
Why you should trust this review

I’ve been producing and engineering for over 15 years.
During that time, I’ve had hands-on experience with a wide array of monitoring setups – from high-end monitors and studio headphones to crappy earbuds and repurposed car speakers.
I know how to stretch a budget, and I know when a piece of gear doesn’t perform up to its asking price.
This experience, along with years of problem-solving in a variety of recording environments, has taught me what gear is worth your investment – and what isn’t.
Sound quality 4.0
Overall, the S5X are a nice pair of semi-open-back headphones. The bass presentation is clean and accurate, the imaging is solid, and the total balance is fairly neutral.
The frequency response is 15 Hz to 22 kHz. They have an impedance of 50 ohms, so should be generally easy to drive, although some of you might require a headphone amp to get the best performance out of them.
There’s a slight dip in the upper-midrange, and I found the high-end to lean towards the warmer side. While neither of these things are bad per se, it does make the S5X a bit less accurate. The high-end in particular makes it somewhat difficult to do more detailed mixing and mastering.
In consideration of this, my opinion on their performance becomes a bit more subjective. I probably wouldn’t prefer to use these headphones to mix and master, but I’d be alright with having them for a pair of casual listening headphones.
Build and design 5.0
As far as I’m concerned, the build quality here is pretty great.
The design seems sturdy enough, the frame is made of stainless steel, the headband is adjustable, and the earcups are made out of American walnut. Not much more to say, I have no complaints.
Comfort 5.0
I found the earpads to be incredibly comfortable. They’re made out of artificial leather and velour combination, which I found to be pretty good at warding off sweat as opposed to most leather pads. The clamping force is comfortable, not too loose, but not too tight.

No quarrels with the stability. The adjustable headband locks into place while you’re wearing them. Plus, the cables are detachable, so I don’t have many worries about getting snagged on some gear when I’m mixing.
Isolation 3.0
Considering that these headphones are semi-open, most anybody in your proximity will be able to hear what it is that you’re listening to even at more modest volumes.
That being said, they do offer a solid deal of noise cancellation, at least more so than your average set of open-back or semi-open headphones. However, they weren’t designed with noise cancellation specifically in mind so I can’t recommend them for that purpose.
Accessories 4.0
The Ollo S5X headphones come with a 1/8 to 1/4-inch adapter as well as a carrying case. Replacement pads are also fairly easy to come across if you find the pads are too small for your ears.

Compared to other headphones
Here are a few alternatives to consider in comparison to the Ollo S5X.
Ollo S5X vs S4X
While this might be an obvious comparison, it’s an important one.
The S5X is the updated S4X, and so has a fair amount of improvements in the overall performance and design, i.e. better bass response, better balance, and better high-end as well.
Of course, the S4X is the cheaper option here.
Ollo S5X vs AKG K702
I would personally recommend the K702 over the S5X. They have a wider frequency response and better imaging.
They have a bit less low-end than the S5X, but I have never had much issue with this. However, you can’t really go wrong with either.
Ollo S5X vs Sennheiser HD 600
The HD 600 lack a little bit in the imaging department, but the soundstage is super-intimate and the frequency response is well-balanced. If you’re in the market, definitely give them your consideration.
Read the full Sennheiser HD 600 review
Who are the Ollo S5X headphones best suited for?
The Ollo S5X are well-suited for audiophiles and music nerds. I’m sure they can be used in professional settings as well, albeit they wouldn’t be my go-to pair.
See current price at: AmazonVideo demo
Watch this video by my colleague Fabio where he puts the Ollo Audio S5X headphones to the test.
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