Jerry Harvey, the founder of (and genius behind) Jerry Harvey Audio has this to say about the Layla: "The Layla is the first earpiece I've designed to be a reference/mastering IEM. Most IEMs I design have a live rock and roll tuning with a little more emphasis on the lows and low mids, accurate but warm. The Layla bass response when turned down is perfectly flat and when fully turned up has +13db of boost at 60Hz.
The Layla also has the most sophisticated crossover network ever put into a IEM. The shape of all crossover filters are all 4th order. This crossover circuit combined with the Freqphase waveguide and new proprietary quad drivers deliver a audio quality that will truly put you at the mix position in the recording studio whether it's hearing exactly what the mixer/producer and band wanted you to hear, mixing your own tracks or performing live."