Home » Reviews » Earphones » Sennheiser IE800S – Fireflies in the Midnight Sky

Sennheiser IE800S – Fireflies in the Midnight Sky

DISCLAIMER: Sennheiser provided me with the IE800S in return for my honest opinion. I am not personally affiliated with the company in any way, nor do I receive any monetary rewards for a positive evaluation. I’d like to thank Sennheiser for their kindness and support. The review is as follows.

Sennheiser are bonafide industry legends. From headphones, to in-ear monitors, to microphones, to wireless systems, it’s impossible to ignore the legacy they’ve built on a global scale. The company is no stranger to innovation, which their monumental Orpheus systems will attest to. Their HD800S headphones have also proven their tact in remastering their greatest hits. But, nowhere are both qualities more clearly exemplified than in their flagship in-ear monitors: The IE800S. With refinements in driver tech, acoustics and damping, how does the IE800 successor measure up in today’s landscape?

Sennheiser IE800S

  • Driver count: One dynamic driver
  • Impedance: 16Ω
  • Sensitivity: 125dB @ 1Vrms
  • Key feature(s) (if any): Proprietary Extra Wide Band drivers; patented dual-chamber absorption system
  • Available form factor(s): Universal in-ear monitor
  • Price: $999.95
  • Website:

Packaging and Accessories

The IE800S arrives in a black box sleeved within high-resolution prints and metallic silver text embossed along the front. It’s a more commercial aesthetic than the more boutique custom IEMs I’ve reviewed recently, but it’s flawlessly executed nonetheless. The inner box is satin-grey with the Sennheiser logo on top – reminiscent of the cases that house their HD headphones. Underneath, the monitors are stored snugly within foam cut-outs, plus the leather case and accessories.

The leather case is a wonderful inclusion; showcasing the luxury and class befit of a $1000 price tag. It adopts a subtle aesthetic, which emphasises its exceptional construction – cut, stitched and engraved with precision. It comes equipped with a magnetic latch, a metal badge with a serial number and a solid foam insert. The insert has cut-outs and ridges for the earphones and cable, respectively. Although the solution is secure, some may find it cumbersome to wrap the cable around the entire enclosure in order to store them. An additional, compact zipper case would be ideal in this scenario.

Below the earphones and the case are the IE800S’s suite of accessories. These include a selection of foam and silicone tips, as well as termination options for the cable, which we’ll get into later. The tips are individually seated on a plastic card of sorts with lettering engraved to denote the tips’ sizes. This is a vast improvement in organisation over the cheap, plastic baggies I’ve seen with monitors in the past. This benefits security too, as you’re less likely to lose the tips when they’re securely seated like this. The tips all come equipped with wax guards too to maximise longevity and hygiene.

Cables and Build Quality

The IE800S maintains the original IE800’s semi-detachable cable system. Instead of the more common philosophy where the wire detaches completely from the monitor’s housing, the IE800S’s cord detaches at the Y-split in a 2.5mm plug. This can then be adapted into a wide range of terminations. Sennheiser has included three by default: 3.5mm single-ended, 2.5mm balanced and 4.4mm balanced. I appreciate the sentiment of at least a semblance of a swappable system, but I wish Sennheiser had committed to the more common ideology and separated the entire cable from the housing. This would allow further customisation, potentially removed a risk of failure and solved a few quirks the cable currently has.

An example would be length. The wires between the earphones and the Y-split are awfully short. The Y-split sort of sits at the neck rather then the chest when wearing them down. This design is infinitely more comfortable on-the-go with the cable running down the back. Another major issue is microphonics. The IE800S’s cable is terribly noisy. The slightest bit of contact with any part of the wire sends an irritating noise that disrupts the listening experience. The IE800S is best heard when stationary or with the included shirt clip to keep the cable still. In 2018-2019, these issues are disappointing oversights in my opinion. And again, these problems would’ve easily been solved with a fully detachable cable system.

But, with that said, I must give Sennheiser utmost praise when it comes to the earphone’s build quality. The matte-black ceramic housings are as robust as they are breathtakingly gorgeous. Although the in-ears are small, never once have they felt fragile, light or insubstantial. They truly look and feel like quality products, and I have no complaints whatsoever here. In terms of wearing comfort, they excel as well. They’ve maintained the original IE800’s self-adjusting system where they seat themselves in place no matter how deep you try to force them in. I’ve found this system to achieve a consistent fit with utmost security and comfort, so kudos to Sennheiser again here. With the silicone tips, isolation is perhaps not the best, but that’s to be expected with the acoustical technologies at hand. The Comply’s are best for noise isolation.

Dual-Chamber Absorber System

Aside from the refined XWB drivers, the IE800S also features Sennheiser’s patented dual-chamber absorber (D2CA) system. This was first introduced on the original IE800, then incorporated into Sennheiser’s acclaimed open-backed flagship HD800S. According to Sennheiser’s website: “This innovation overcomes the “masking effect”, where low-volume components of a sound are obscured by much louder sounds in a lower frequency range occurring at the same time.” In the next page, you’ll see some parallels between this quote and what I’ve written about the IE800S’s midrange. Although the lower-midrange harmonics are more reserved, they are resolved expertly well. I believe this has much to do with D2CA.





Church-boy by day and audio-obsessee by night, Daniel Lesmana’s world revolves around the rhythms and melodies we lovingly call: Music. When he’s not behind a console mixing live for a congregation of thousands, engineering records in a studio environment, or making noise behind a drum set, you’ll find him on his laptop analysing audio gear with fervor and glee. Now a specialist in custom IEMs, cables and full-sized headphones, he’s looking to bring his unique sensibilities - as both an enthusiast and a professional - into the reviewer’s space; a place where no man has gone before.


Leave a Reply

Your email address will not be published. Required fields are marked *

Recent posts