FiR Audio M4 Demo model

DIRECT BORE
Direct Bore is a Subset of Direct Aperture Acoustic, where the IEM’s balanced armature drivers are pointing directly to the earphone’s bore. A spout directing sound to the ear canal is a constant in classic BA driver designs. The drawback of this traditional design, however, is that it prevents sound from expanding naturally, resulting in muffling and distortion. FiR Audio’s Direct Treble driver offers a solution to this by removing the spout, widening the aperture on the driver and allowing more air through—negating any harshness or muffling and resulting in a more natural, organic sound. These Direct Treble drivers harmonise with the other Drivers within the chassis, giving the M Series a natural, organic signature as compared to its counterparts.

FiR Audio ATOM module.
Also known as the Air Transferring Open Module, is a pressure release system developed by Bogdan Belonozhko following experimentation with a variety of nano-thin membranes and foam materials. FiR’s ATOM has a significantly reduced filter size, allowing its IEMs to be less affected by air volume within the module while allowing for a positive effect on sound presentation, widening the soundstage while helping to alleviate listener fatigue.