Voicing
At this point in the design, the Sunfire is an amplifier that can deliver high current as well as voltage, delivering both simultaneously for tremendous output power, and runs cold. However, the design is not yet complete. The amplifier needs to he voiced. Voicing of an amplifier is the last 5% in its design (potentially the most time consuming) and is where the art of amplifier design is truly based. It is accomplished by altering the values of resistors and capacitors in various parts of the circuit, and then listening to the effect that a particular value has. When I voice an amplifier, I first use a female vocalist so that she can be accurately located in an acoustic area between the speakers, and in such a way that a believable halo of space surrounds her in three dimensions. Also, I fine tune the amp so that her voice is soft, musical, lyrical, and has a great deal of believability. (Not too much to ask, right!?)
After I finish the female voicing, I work on the male voice using baritones to get the chestiness that is a prominent feature here. When that part of the amplifier voicing is completed, I go to the symphony. I have in my head a template of what a symphony orchestra should sound like. I close my eyes and fit the sound of that symphony orchestra in my head, to the sound that my amplifier is making through the loudspeakers. (Baked fresh Salmon and a nice glass of Chenin Blanc, followed by the Seattle Symphony under the stars. Ahhh ... that's got it.) In the case of the Sunfire, after finishing the human voices, I found that the symphony orchestra locked in, and I had only minor adjustments to make, sort of like getting the flesh tones correct on a color television receiver, once that is done, all the other colors often lock in with very little further effort.