Thus began YG’s extensive use of machined parts made from high-quality aluminum billet. Machined aluminum provides several advantages as a cabinet and cone-membrane material: good strength-to-weight ratio, relatively high resistance to environmental factors such as corrosion and high temperature (helpful when machining friction heats the stock), and the ability to be machined into a wide variety of custom shapes to very precise tolerances. It also has relatively good resonance damping characteristics when properly constructed. YG uses mostly aircraft grade 6061-T651 billet and some ballistic-grade aluminum for key parts like the tweeter waveguide. I have visited the YG factory outside of Denver in Arvada. Everyone at YG is very focused on delivering high-quality products, and the CNC machines at work are truly impressive. Each “BilletCore” driver cone takes hours to mill on a five-axis CNC milling and turning machine from Germany called Gildemeister CTX Beta 1250 TC. Many parts are machined to within 0.0008" tolerances (20 microns). Which brings me to the subject of the Kipod’s price: $38,800. Given the engineering, parts-quality (capacitors and inductors are top-drawer Mundorf), raw material costs, the nearly obsessive lengths YG goes to manufacture and deliver a high-performing product, and the high level of its overall performance, the asking price is justified.
The current Kipod II Passive incorporates many advances over the model previously reviewed in TAS by Robert Harley in Issue 199. First, the Kipod Studio Robert reviewed had an adjustable, on-board Class-D bass amplifier to power the woofer in the bass module, making the speaker system semi-active. The model in this review is fully passive. (YG is moving toward all-passive configurations, although customers can still get semi-active versions in all models except the Carmel.) Second, the former model used Scan-Speak midrange and woofer drivers with standard cones. The current Kipod uses YG-machined aluminum cones integrated with some Scan-Speak supplied parts. Third, the previous Kipod used a Scan-Speak ring-radiator tweeter. The current tweeter is a YG “ForgeCore” unit with an in-house-machined motor assembly and a proprietary YG soft-dome membrane. (Some of the more standard tweeter parts, like the back lid, are from Scan-Speak.) Fourth, the Kipod reviewed in Issue 199 did not have a high-pass filter on the midrange unit so some bass content below the midrange driver’s bandwidth could apparently cause the speaker to sound stressed at higher volume levels. The current Passive model has a “Signature” crossover package that applies not only a high-pass filter on the midrange driver (expanding the loudspeaker’s dynamic range) but also includes some components to improve the out-of-passband phase-matching between the midrange and woofer. This now brings YG’s DualCoherent technology to both crossover regions, which was not possible in the semi-active configuration.
Fifth, the earlier model had high-quality OEM inductors. The current model uses in-house wound “ToroAir” toroidal inductors, which YG says reduce distortion and, more notably, cross-talk between drivers. Sixth, the two sealed (air-suspension) cabinet modules have been further optimized to reduce resonances; the tweeter waveguide has been improved; and the external cabinet screws have been replaced by internal joiners. The two modules of the earlier version of the Kipod weighed a combined 104 pounds; the current Kipod II Passive weighs 122 pounds.
The only other speaker I had available that came close to overlapping the Kipod’s frequency and dynamic range was the very nice sounding Aerial 7T [$9850, Issue 218], a ported, bass-reflex design. The Aerial 7T seemed much easier to drive, had fuller bass in its low register, but did not extend quite as low in the bass as the Kipod.