The GF-1 from 1991 came to be known as an active speaker encapsulating an active crossover and a drive amplifier directly connected one-to-one with all speaker units. It was the culmination of the Yamaha HiFi speaker technology. It was designed with a two-part configuration (140 cm tall and 150 kg total) with the upper half housing a three-way speaker element and the lower half a YST superwoofer element. Its four drive amplifiers and active crossover units per channel were attached as four independent modules to the back of the superwoofer, and with a massive external power supply that itself weighed 25kg supplying each of the four amplifier modules with independent power it was a truly heavy piece of equipment. The crossover slope and cutoff frequency were completely fixed and could not be adjusted from the outside in any way, with only fine adjustments of up to ±2.5dB to each module’s input level available to the user. From this it can be seen that the developers intended the system to be perfectly tuned and did not intend the balance to be changed easily.
The 3 cm tweeter and 8 cm midrange were of course made of pure beryllium, but rather than using the vacuum deposition process of the past it went as far as using a forged beryllium dome developed for and used in only this model. Its pair of large and small woofers (27 cm bass and 30 cm YST sub-bass) likewise used a Kevlar cone and forged beryllium cap specific to this model, and the magnet utilized a voice coil with reduced diameter and dendritic crystal aluminum-nickel to lighten the motion of the diaphragm system. The tweeter and midrange magnets were also composed of dendritic crystal aluminum-nickel. The gold deposition method was performed on each unit’s diaphragm in an effort to damp the slight squeal of beryllium and produce uniform tone across all units. Overall it was built like it was meant to be the crowning glory, and if there was just one thing left undone it would probably be that it was not possible to use a forged beryllium woofer cone. As Yamaha’s speaker development changed course for a new era of focus on the home theater, the GF-1 put a period at the end of the pure beryllium development story that had played out since the NS-1000M.
In 1992 a dedicated 100W/ch Class A power amplifier, the GFD-1, with external power supply was introduced to complement the GF-1 loudspeaker. It featured a 6-position source selector and a 23-position rotary attenuator. It's construction made possible to be used with any passive loudspeaker not just the Active GF-1.
