Review: 64 Audio Tia Fourté – Pushing Boundaries

64 Audio Tia Fourté

Disclaimer: The tia Fourté by 64 Audio was provided by the manufacturer for this review. 64 Audio is not a site advertiser and is not affiliated with Headfonia. Many thanks for the opportunity and generosity.

About 64 Audio

This is my third 64 Audio review now, and I hope you don’t get annoyed by the same introduction to the brand each time, but I feel it tells exactly who 64 Audio is and what they do. So here it goes one more time.

64 Audio is a US based company that specializes in making custom and universal in ear monitors, they also dipped their toes into making studio/live belt packs. As you can find out in the interview we did with them last year, 64 Audio started out as 1964 Ears and has renamed themselves. Their core is the Belonozhko brothers who all manage different departments. They have been around for almost eight years already, and have started out because of a project their founder, Vitaliy, has been working on – an in ear monitor for his wife. This project later on became what we know today as 64 Audio.

They are also one of the few companies that bring out one technology after another. They have introduced tiatm (Tubeless In-ear Audio), apextm (Air-Pressure Exchange) and LIDtm (Linear Impedance Design).

You can consider tiatm as some sort of hat-less balanced armature driver that fulfills its job in a special acoustic-chamber and doesn’t put out sound via a regular tube and dampener system. This way the treble frequency response is more extended and the resonances of the tube are eliminated, giving a more enjoyable listening experience.

apex is an interchangeable system that drastically reduces the pneumatic pressure on the eardrum, which can be found on regular custom IEM designs, and therefore enhances the safety of your hearing.

LIDtm is a new technology by 64 Audio that was introduced with the A/U12t and tiatm Trió. It is responsible for an almost flat impedance curve of the IEM, enabling it to be completely unaffected by varying output impedance of sources. This comes in very handy for touring musicians, producers and audiophiles that connect their IEMs to an array of different gear. LIDtm and its impedance behavior enable the monitors to always sound the very best, no matter the source it is connected to.

64 Audio also is one of the few companies that 3D prints your custom IEMs. It works like this: you take your regular impressions at your trusted audiologist, send them to 64 Audio, they scan them with their hardware, edit the scan to make it printable as a custom in ear and then 3D print them.

64 Audio also closely works with many professional and award winning musicians and artists such as Alessia Cara, Seal, Bon Jovi and Beyoncé. This definitely says a lot about their reputation.

64 Audio Tia Fourté

64 Audio tiatm Fourté

About tia Fourté

The tia Fourté is one of two models by 64 Audio that is solely available in universal form. The reason for this is, that the Tia models use specific acoustic chambers in which each driver performs. Getting each of these chambers packed into a custom shell is a near impossible trait. Imagine the process that would be necessary to get it done. The chambers need to have one exact size and shape and need to be at the optimum position to ensure the drivers sound like they should. Maybe this would be possible for some moulds, but certainly could not be offered for any ear-shape. So while I think it’s too bad they can’t offer it, I completely see and understand why. If you really want the superior comfort of custom shells, why not get a custom tip made by a third party? It’s a solution, maybe not the best, but a way around.

The Fourté was officially launched in November 2016 and currently resides at the absolute top of 64 Audio’s list of products. With only four drivers it is proof that the driver wars are long over and that you can create an outstanding and unique product without going full bonkers about the number of drivers implemented. The Fourté uses a ten millimeter dynamic driver for lows, a single tiatm mid-driver, one upper-mids BA driver and a single tiatm high-driver. That’s it. All drivers reside in 64 Audio’s patent pending tia system with carefully positioned chambers in which the speakers work. 64 Audio got rid of all tubes and dampers in the Fourté. I don’t know if any other company is doing that at the moment. It’s great to see manufacturers thinking out of the box and create something new in order to unleash a new sound.

64 Audio Tia Fourté

64 Audio tiatm Fourté

Fourté uses a four way passive crossover and a single bore design. The drivers are protected by an aluminium mesh, so don’t fear any earwax or debris falling in. An internal apex M20 module is installed to take down ambient noise by 20 decibels while offering reduced pneumatic pressure. It also ensures a proper phase response by switching from pressure-based to velocity-based amplitude. With 114 dB sensitivity per Milliwatt and only 10 Ohms the tiatm Fourté is pretty easy to drive. You shouldn’t run into problems driving this little gem. Under typical use the Fourté has a measured frequency response of 5Hz to 22kHz. I don’t know the dB variances for it. When asked, 64 Audio confirmed that there is no audible benefit of burn-in for the tiatm Fourté.

Due to the complicated build process and the number of orders 64 Audio is facing for Fourté, there is a waiting time of six to seven weeks to receive them.

tiatm Fourté sells for an eye-watering price of 3599 US Dollars. On rare occasions 64 Audio also offers them with slight visual blemishes at a lower price in their B-stock sales. Make sure to check that part of their website on a regular basis, as they usually sell within the shortest of time.

More about the Fourté on Page 2

Review: 64 Audio Tia Fourté – Pushing Boundaries
4.7 (94.88%) 121 votes


A daytime code monkey with a passion for audio and his kids, Linus tends to look at gear with a technical approach, trying to understand why certain things sound the way they do. When there is no music around, Linus goes the extra mile and annoys the hell out of his colleagues with low level beatboxing.


    • Reply May 30, 2018

      Robert Horton

      Who makes custom tips for these

      • Reply May 30, 2018


        I’d try the ususal suspects: Snugs or Custom Art
        But I think you would also have to send in your Fourté then.

    • Reply June 3, 2018


      Great review but I think the big question is how them compare to the mighty electrostatic KSE1500?

      • Reply June 4, 2018


        Hi Matt,
        thanks for your comment.
        That truly would be an interesting comparison. If I ever get the chance to audition the KSE1500 for a longer period (no show conditions), I will add them to the list here, but untill then, I will not be able to compare the Fourté to the Shure, sorry.

    • Reply June 9, 2018


      If you have a chance, check out the VE Erlkönig, I would say this a the ultimate end game iem. A perfect marriage between technicality and musicality.

      • Reply June 9, 2018


        Hi Clarence,

        thanks for your impressions on the Erlkönig. I think Lieven might be going to check it out. Not sure though. If he will, I might send/give him the Fourté for comparison. That will sure be an interesting fight 😉

        Cheers and have a great weekend!

    • Reply June 18, 2018

      Charles Ma

      Really appreciate this review of the 64Audio Tia Fourte. I currently have a Sony NW-WM1Z and I would like to be able to connect the Tia Fourte to the NW-WM1Z via the 4.4mm balanced jack. Would you recommend some cables for this setup? Any price range is fine for me. Thanks again.

      • Reply June 19, 2018


        I’m currently using the Tia Fourte with 1Z, Leonidas and foam tips. It’s a wonderful combo, with the Leonidas adding some dynamics throughout the spectrum that you don’t quite get with stock cable.

    • Reply June 18, 2018


      Hi Charles,
      thanks for your comment.

      It all depends on how you want to change the signature of Fourté?

      If you want to keep the key-signature but push it a bit further on technicalities, give the Bespoke Ares II 8 wire of Effect Audio a go.

      If you want to push Fourté to its very limits, take a look at the Effect Audio Leonidas or Gold Plated Silver Exo (plusSound).

      If you want to give Fourté a more mainstream tuning and take down those highs, check out the Tri-Copper of plusSound, I have it in the X8 version and it does wonders to it.

      I expect that the PWaudio 1960s 2wire also works really well with the Fourté, unfortunately mine is currently in for repair services, therefore I can’t say much about it.
      Two other cables I’m really interested in are the two Janus variants (D and B), when the review comes, I will include the Fourté in the pairings section.

    Leave a Reply

    This site uses Akismet to reduce spam. Learn how your comment data is processed.