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If you want a rugged, over-ear monitoring headphone you can wear for hours on end and repair rather than replace, choose Sennheiser HD 25; if you need a low-profile, in-ear monitor that seals out stage and street noise with a swappable cable, choose CTM CE110. Those two sentences are the whole article compressed into one line, and everything below is me showing my work.
• Sennheiser HD 25 — biggest strength: a genuinely tough, repairable over-ear design with 70-ohm dynamic drivers, a detachable single-sided cable, and a rotatable capsule for single-ear listening. In my opinion this is the more versatile tool of the two.
• Sennheiser HD 25 — biggest trade-off: it's an over-ear headphone, so it doesn't disappear into a pocket, and its sound isolation depends on the earcup seal rather than a deep in-ear fit.
• CTM CE110 — biggest strength: a 10mm titanium-coated dynamic driver in a true in-ear shell with a 2-pin detachable oxygen-free copper cable and three sizes of foam and silicone tips. That's a lot of fit and cable flexibility in a tiny package.
• CTM CE110 — biggest trade-off: its listed frequency response tops out at 14.5 kHz, which is narrower than the HD 25's 22 kHz top end, and small in-ears are simply easier to lose.
• Who each pick is for: choose the HD 25 for long sessions at a desk, in a booth, or behind a mixer; choose the CE110 if you need something that stays put and seals out the room while you move around.
The HD 25 is built around a simple idea: make a headphone that survives the job. Sennheiser gives it lightweight aluminium voice coils, which is the design choice behind its high sensitivity — that means it reaches loud levels without needing a lot of help from whatever it's plugged into. The driver is dynamic, impedance is rated at 70 ohm, and the frequency range runs from 16 Hz to 22,000 Hz. That 16 Hz low end is the headline number here; it tells you the design is meant to reproduce deep bass content, which is exactly what you want when you're cueing a track or checking low-frequency detail.
Two features stand out for real-world use. First, the detachable, single-sided cable: one cable on one side means less tangling and less chance of snagging, and if the cable ever fails you're looking at replacing a cable rather than a headphone. Second, the rotatable capsule, which lets you swing one earcup out of the way for single-ear listening — handy if you're monitoring a mix while still hearing the room, or holding a conversation mid-session.
Who should skip it: if you want something that vanishes into a jacket pocket, this isn't it. It's over-ear, it's wired, and it's a full-size object. If your priority is maximum passive isolation from a deep in-ear seal, you'll get more of that from the CE110.
CTM CE110: Who It's For
The CE110 takes the opposite approach: get everything small, seal it in your ear, and make the wear parts replaceable. Clear Tune Monitors builds it around a single 10mm titanium-coated dynamic driver using titanium-coated PEEK material, and the pitch is fast, clear reference audio across the spectrum. Impedance is 32 ohm and the frequency range is listed at 20 Hz to 14.5 kHz, with a sensitivity figure of 115 dB-SPL at 1 mW — high sensitivity, so again, these are easy to drive from a phone or a small interface.
The fit story is where this thing earns its keep. You get two tip materials, foam and silicone, in three sizes each: small, medium, and large. That's six combinations to work with, and the payoff is a secure seal. CTM quotes -26 dB of passive noise isolation, which is the number to focus on if you play loud rooms or commute — that's noise blocked by the physical tip, not by electronics. The cable is a 2-pin detachable design, quad-braided from over 320 strands of 99.99% oxygen-free copper, which addresses the single most common failure point of any wired in-ear: the cable, not the driver.
Who should buy it: performers and commuters. Anyone who's had an in-ear yanked out mid-song, or who needs the room to fade down so they can hear detail. The company describes these as tested by musicians on and off stage and engineered to stay in during movement — treat that as their design intent rather than something I can verify, but the tip assortment and detachable cable are consistent with that goal. The included protective case is a sensible touch for something this small.
Who should skip it: if you dislike things inside your ears, no tip size will fix that. And if you want the widest listed top-end extension, the HD 25's 22 kHz ceiling is higher than the CE110's 14.5 kHz.
• Best for long listening sessions → Sennheiser HD 25. Over-ear, described as very lightweight and comfortable for extended use, with improved headband joints.
• Best for blocking out a loud room → CTM CE110. -26 dB of passive isolation from the tip seal, versus an earcup seal on the HD 25.
• Best for durability and repairability → CTM CE110 on the cable, HD 25 on the whole unit. The CE110's cable is user-detachable via 2-pin; the HD 25's cable is also detachable, and its single-sided design reduces snag points.
• Best for single-ear monitoring → Sennheiser HD 25. The rotatable capsule is a feature the CE110 simply doesn't have.
• Best for portability → CTM CE110. In-ear shells and a protective case versus a full-size over-ear with a separate nylon carry case and holder.
• Best for low-frequency extension on paper → Sennheiser HD 25. 16 Hz versus 20 Hz at the bottom of the range.
• Best for fitting a wide range of ear shapes → CTM CE110. Foam and silicone tips in three sizes each.
• Best for hands-on control → CTM CE110. It lists media controls with a remote, where the HD 25 uses touch control.
One thing I won't do is hand you a number for either. Check the current price on Amazon before you commit, because that's the one variable that can flip this decision for a lot of buyers.
If I had to pick one for myself, I'd take the Sennheiser HD 25. In my opinion it's the more complete tool: it works at a desk, in a booth, and behind a mixer, it handles high sound pressure levels, the cable is replaceable, and the rotatable capsule gives you an option the CE110 can't match. The CE110 is the better choice if your job happens in loud rooms or on the move — I'd recommend it without hesitation to a gigging musician or a commuter who wants isolation and a swappable cable. But for one headphone to cover the most ground, the HD 25 wins it for me.
FAQ
On paper, the CTM CE110. CTM states -26 dB of passive noise isolation from the tip seal, and it ships with foam and silicone tips in three sizes. The HD 25 relies on its earcup seal, and the specs list sound isolation as its noise-control approach rather than a dB figure.
Yes. The CE110 uses a 2-pin detachable cable, quad-braided from over 320 strands of 99.99% oxygen-free copper. The HD 25 also has a detachable cable, but it's a single-sided design rather than 2-pin.
Both are efficient. The HD 25 uses lightweight aluminium voice coils for high sensitivity at 70 ohm. The CE110 is rated 115 dB-SPL at 1 mW at 32 ohm. Either should reach usable volume from a normal headphone output.
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