Angle of attack the wing becomes more pronounced, leading to a reduction in the rate of increase of the lift coefficient. The figure shows a typical curve for a cambered straight wing. A symmetrical wing has zero lift at 0 degrees angle of attack. The lift curve is also influenced by the wing shape, including its airfoil section and wing planform. A swept wing has a lower, flatter curve with a higher critical angle. The critical angle of attack is the angle of attack which produces maximum lift coefficient. This is also called the "stall angle of attack". Below the critical angle of
P-90 rather than subtract the signal between the coils; thus, the impedance can be lower, avoiding overwinding to obtain sufficient output. There is less signal cancellation. Sonically these sit somewhere between a true P-90 and a stacked pickup. They don't chime but they aren't nasal or lifeless either. They are ideal candidates for overdriven sounds where loss of sparkle is less important than avoiding hum amplification. These type of pickups have the same appearance of P-90s. The new generation Zero-Hum P-90 Hx by Kinman strives to have a P-90 sound and appearance, but is far more complex, with 202 individual parts.