Purifi Audio PTT6.5M04-NFA-01

Discover the PTT6.5M04-NFA-01, a specially optimized midrange driver from the renowned provider Purifi Audio. This audio component presents a new dimension in driver development. The Danish-developed device stands out with impressively low distortion across the entire control range and high power handling. With PURIFI's Natural Surround technology and an efficient balance between volume shift and efficiency in the midrange range, this model really exudes perfection. Let yourself be convinced by the first-class performance of this midrange driver, whose quality can be felt in every detail.

• A completely new way of driver development
• PURIFI's Natural Surround
• Extremely low distortion across the entire control range 
• Developed and manufactured in Denmark
• Excellent midrange performance
• High resilience
• Perfect balance between volume shift and efficiency in the midrange

The challenge 

Speaker drivers are known to cause a large, if not the largest, amount of distortion in an audio signal chain. Reducing this distortion is challenging because fine-tuning to improve one part (e.g. harmonic distortion) often results in a deterioration of another part (e.g. intermodulation distortion). This distortion is composed of several separate distortion mechanisms. By carefully mapping and fully understanding these mechanisms, PURIFI has managed to improve overall performance to a great extent.

A completely new perspective on driver design

PURIFI developed mathematical models for the motor system, suspension, cone and surround. These models made it possible to optimize each distortion mechanism separately. This systematic approach reduces all distortion mechanisms and keeps intermodulation distortion low. The result is that the PTT6.5M04-NFA-01 is a compact 6.5-inch driver that matches or even exceeds the bass performance of a large-area, low-excursion driver, while also providing excellent midrange performance.

• The mechanism improvement modulation with low force factor
• improvement
• The current through the voice coil is not distorted by the membrane movement. Ensures an undistorted midrange regardless of the deflection
  
• Constant force factor over the deflection - Bl(x)
• Prevents amplitude deviations of the midrange output during large excursions (sometimes called "rumble")
• Low distortion due to surround radiation Low magnetic hysteria distortion
• Reduces harmonic and intermodulation distortion caused by the surround
• Reduces harmonic and intermodulation distortion caused by magnetic traces from the previous cycle

• nominal diameter 16.5 cm
• load capacity (QMW) 250 W
• Impedance (Z) 4 Ohms
• Sensitivity (SPL at 1m / 2.83V) 93.2 dB
• DC resistance (Re) 3.9 Ω
• Voice coil induction (Le) 0.26 mH
• resonance frequency (Fs) 55 Hz
• Mechanical quality (Qms) 4.2
• Electrical quality (Qes) 0.36
• Total quality (Qts) 0.33
• Moving mass (Mms) 17.8 g
• Suspension compliance (Cms) 0.47 mm/N
• Membrane area (Sd) 132.7 cm2
• Force Factor (BL) 8.1 N/A
• Equivalent volume (Vas) 11.7 L
• Maximum deflection (Xmax) 3.9 mm
• Driver's Mechanical Losses (Rms) 1.47 kg/s
• Cone / Diaphragm Material Proprietary Fiber Mix