Introduction
sE Electronics built its name on microphones. The KLS 150 is its first pair of headphones, and it doesn't play it safe. Instead of another closed-back with one fixed tuning, sE has put a mechanical Bass Control inside each earcup. Open or close a set of ports and the low end comes up or down, with no DSP, batteries or app involved.
The rest is a working engineer's checklist. There's a custom 40 mm driver tuned for controlled, readable bass and dual-shell earcups for isolation on loud stages and low bleed into open mics. Memory foam and leatherette pads are made for long days, and glass-fibre reinforced parts and a locking detachable cable are made for the road. Interchangeable earcup covers sit over the Bass Control, so your setting doesn't move when the headphones get thrown in a bag.
Where it doesn't stretch: the box has a straight 3 m cable and a drawstring pouch. sE says coiled cables, velour pads and a carry case will follow as optional extras.
Watch It in Action
sE Electronics' official introduction to the KLS 150:
Key Features & Benefits
- One pair, several tunings: the acoustic Bass Control lets you set a neutral reference for mixing or add weight for a cue mix, right at the earcup.
- Bass you can make decisions with: the custom 40 mm heavy-duty driver keeps the low end controlled and low in distortion, so mixes translate.
- Keep the stage out and the click in: dual-shell closed earcups give strong passive isolation and keep headphone bleed out of your mics.
- Your setting stays put: interchangeable earcup covers protect the Bass Control from knocks, and laser-etched markers bring you back to the same fit.
- Wear them all day: pressure-relieving memory foam and leatherette pads seal well without clamping.
- Built to travel: 335 g, foldable, 90° swivelling earcups for one-ear monitoring, spring steel and a locking detachable cable.
- Plugs into anything: 6.35 mm screw-on and USB-C adapters are both in the box.
Real-World Reactions
sE gave early pairs to working engineers and drummers. A few of their reactions, from sE's KLS 150 page:
“I can't believe it no one came up with this before! Most times I want the truth and sometimes I want some fun. sE gave us a fun knob right on the drivers!”
Drew Thornton, FOH/monitor engineer (Teddy Swims, Billie Eilish, Finneas)
“Being able to dial the low end up or down mechanically, with no DSP, batteries or electronics in the way, is seriously clever.”
Virgil Donati, drummer, composer and producer
“For my mixes, I need to hear the truth, not something that simply flatters my ears. The KLS 150 gives me the detail and honesty I need to find problems, make better decisions, and ultimately build better mixes.”
Patrick “Paddi” Krause, monitor/FOH engineer (Ghost, Toto, In Flames, Mastodon)
These are launch testimonials, not independent reviews. Still, they point at the same thing we noticed on paper: a closed-back built for people who spend their day monitoring, with a bass control that's actually useful rather than a gimmick.
Gallery
Every angle in one place. Click any shot to open it full size.
Who It's For
- FOH and monitor engineers who need isolation on loud stages
- Producers and mix engineers who want a closed-back reference with adjustable low end
- Drummers and tracking musicians who need a punchy cue mix without bleed into the mics
Who should look elsewhere:
- Anyone mixing mostly in a quiet room who prefers an open-back sound. The Beyerdynamic DT 990 Pro X is the open-back alternative.
- DJs who want a coiled cable and a hard case in the box today. Those extras aren't included.
Quick Specs
- Type: closed-back, over-ear (circumaural)
- Driver: custom 40 mm heavy-duty dynamic, neodymium magnet
- Frequency range: 12 Hz–28 kHz
- Impedance: 39 Ω
- Sensitivity: 98 dB
- Max input power: 1,600 mW
- Cable: 3 m straight, detachable, locking connector
- Dimensions (L × W × H): 166 × 83 × 200 mm
- Weight: 335 g
Pros & Cons
✅ Pros:
- Acoustic Bass Control gives you several tunings in one pair
- Strong isolation for stages and tracking rooms
- Light, foldable and built for touring
- USB-C and 6.35 mm adapters in the box
⚠️ Cons:
- Only a straight cable in the box, no coiled option yet
- Soft pouch rather than a hard case
Where to Buy
The sE Electronics KLS 150 is available at Soundium for €179, with a 3-year warranty.
- Free pickup shipping on orders over €149
- Free courier shipping on orders over €299
- Secure checkout and interest-free payments
- Support from people who actually know the gear
Get the sE Electronics KLS 150 from Soundium
Final Thoughts
A first headphone from a microphone company could easily have been a safe rebadge. The KLS 150 isn't. The mechanical Bass Control solves a real problem (one pair for mixing, tracking and the stage), and at €179 it sits right where most working engineers shop for their daily closed-back.
Still Unsure?
Tell us what you're monitoring and where, and we'll help you choose. Get in touch with the Soundium team.