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  • Customization makes for a perfect fit


  • Very basic beyond fitting specialization

Isolation in headphones is super important, and in all honesty, not where it needs to be in most headphones for listening on a subway or on the street. Though headphone companies go to great lengths to provide active noise canceling (ANC) and unique tip designs for in-ears, these solutions are not as effective as they're billed. That's a huge problem when you consider that turning up your volume means increasing the overall pressure on your delicate inner ear. In most cases, you're either actively risking harm to your long-term hearing when plopping on some cans and drowning out the world, or making an enormous sacrifice in audio quality due to a physiological response called auditory masking.

...You're either risking harm to your hearing, or making an enormous sacrifice in audio quality due to auditory masking.

Though in-ears typically have some of the best isolation, they also have the difficulty of relying on a tip that's shaped slightly different from your outer ear canal. This basically means they either fall out, or put pressure on a very sensitive part of your body just to stay in place. Custom ear molds are the holy grail of isolation because they provide user-tailored fit. These in-ears also have the benefit of being extremely comfortable for in-ears, since they're guaranteed to fit perfectly every single time.

Unfortunately, custom-molded in-ears are ludicrously expensive. Because they require one or more $400+ visits to an audiologist to cast, the whole process stacks huge purchases on top of each other, and the end result doesn't necessarily last long. Though there are a few "budget" options that use this means of isolation, they still require the visits to the audiologist, making even the cheapest of these headphones (around $300) set you back close to a grand after everything is said and done. Up until now, even the budget custom ear molds for hearing aids and in-ear phones were literally worth their weight in gold.


This custom mold was made in 6 minutes, and could be re-molded just as quickly.

Last year, startup DeciBullz invented a product to play alchemist to the headphone industry. Using a user-pliable thermoplastic, DeciBullz' premiere product allows anybody with water, in-ears and a microwave to set their own re-castable custom in-ear molds in as little as 6 minutes and $15. That's a huge deal.

Instead of paying north of $1,000 for some of the most delicate pieces of electronics you can buy, you're dropping a pittance for a premium feature. The mold I made on the floor dropped the din of excited press and exhibitors enough to allow me to listen to my music at the same volume as I would at my desk. For those keeping score at home, the noise was north of 75dB at the show, meaning my frantic and seemingly-endless presence there probably put me close to the threshold of potential harm to my hearing. Not cool.

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Up until now, custom ear molds for hearing aids and in-ear phones were literally worth their weight in gold.

In any case, DeciBullz debuted a new product at 2014 International CES—their own entry-level in-ears with their custom molds. Though $49 dollar in-ears are almost as entry-level as you get, the isolation, comfort, and extreme value this product provides is very unique. Even if you're accustomed to listening to $100+ cans out in the wild, you may be surprised just how much a super-high level of isolation matters when you listen to your tunes in a noisy environment. Even relatively cheap headphones that isolate well will sound leagues better on the subway than ultra-premium headphones.

Setup is involved, but very forgiving to mistakes. Once you open the box, you'll find the thermoplastic molds, in-ears, and silicone tips. You prepare the molds much like mouthguards: Drop the molds in a bowl of water and microwave them for 2 minutes. After drying them off, clip them to the nozzle of the in-ears, install the appropriately-sized sleeve, and put them in your ears the way you'd like them to fit. Don't worry, you can always re-mold if the fit isn't perfect. After 4 minutes it hardens, and you're done: You have the most affordable custom-molded in-ear monitors money can buy.

Like I said before, the sound quality won't floor you if you're used to high-end headphones in a silent environment, but the first implementation of affordable DIY custom-molding is important.

If the graph readouts and test results shared with me are correct, these puppies have a consumer-friendly sound with emphasis that mimics how humans hear the world. My experience mirrored this, but again, more tests are necessary—I'm not our testing robot HATS, after all.

If these interest you, they're available for pre-order on the DeciBullz website for $49. Considering the barrier in price they just broke, even enthusiasts will want to give DeciBullz' custom ear molds a look to compare to their own.

Meet the tester

Chris Thomas

Chris Thomas

Staff Writer, Imaging


A seasoned writer and professional photographer, Chris reviews cameras, headphones, smartphones, laptops, and lenses. Educated in Political Science and Linguistics, Chris can often be found building a robot army, snowboarding, or getting ink.

See all of Chris Thomas's reviews

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