Final Audio Design Heaven V Aging

Disclaimer: This review is dedicated to the owner of the IEM, Vlad. Thanks to his contribution, my review on Final Audio Design products is continuing on. And of course, Inks takes credit for organizing this loan. You never fail to impress me, my dear friend.

After the commercial success of their BAM-driven Heaven series, Final Audio Design quickly revises the lineup once again. Unlike the predecessors, which are rear-vented, the new Heaven series models are featured with an unvented design.

The working principle of the new BAM technology is briefly described in 特開２０１２－１５５８０. The possible vented/unvented schemes have been proposed here, and it can be expected that many different variations are actually available for commercialization. Interestingly, this patent is not of the manufacturer themselves, but of Molex Incorporated, suggesting some kind of partnership between two companies, or perhaps an outsourcing of the product. As 高井金盛 san, who is the representative director at Final Audio Design, has been formerly employeed at Molex Incorporated, such analogy makes sense after all.

PRO: Improved frequency response linearity, even better than that of the top of the previous BAM series, FI-BA-SS.

CON: High distortion & inverted polarity, which are usual characteristics of the BAM-driven IEMs. In addition, bodily fluid from a normal usage causes oxidation of the brass housing, leaving gooey green residue underneath the ear sleeve. Users must pay attention to any possibilities of the residue getting into the driver.

ON SECOND THOUGHT #1: An overly shallow fit is not recommended for Heaven V Aging, as it may introduce a peak at 6~7 kHz.

ON SECOND THOUGHT #2: Adding a serial resistance to the IEM definitely makes the tonality closer to that of the diffuse-field reference, but the peaks at 6 kHz and 10 kHz are more emphasized in return. The bandwidth itself remains more or less the same.

ON SECOND THOUGHT #3: Unlike the previous BAM lineup, this new unvented design has higher acoustic output impedance. The most amount of attenuation a microfiber handkerchief can yield is only about 2 dB.

ON SECOND THOUGHT #4: Heaven V Aging comes with two types of ear sleeves, one with a bigger bore, and the other one with a smaller bore. As previously mentioned, a bore size smaller than that of the acoustic output nozzle of an IEM is utilized to increase the acoustic output impedance of the IEM due to the acoustic reverse horn effect. One good example of which such tuning is well utilized is the bore of Etymotic Research's gray triflange sleeves, as the thinner bore gathers high frequency resonances to the frequency range they are needed the most. Without doing a proper calculation in regards to in-ear acoustics, the reverse horn sleeves may reduce the overall frequency response bandwidth and introduce harshness to the system.

And the same analogy applies to Heaven V Aging- Above comparison indicates that the Final Audio Design has not given much attention to detail to bore acoustics at all: Unless deeper insertion depth than that of the reference plane is desired, users must stay away from the sleeves with a smaller bore size. They not only introduce harshness in the treble, but also cuts off the bandwidth.

ON SECOND THOUGHT #5: Surprisingly, Final Audio Design's Heaven V Aging loosely follows the Olive-Welti target without any modification applied. As their products have been all very funky, this new Heaven series is certainly a great step-up.