Purifi Audio PTT5.25X08-NFA-01

With the innovative PTT5.25X08-NFA-01, Purifi Audio presents a highly developed midrange driver that scores with key technologies for optimal audio performance. This device, which is specially optimized for use in the midrange range, is characterized by improved efficiency and negligible modulation of the force factor. Advantages such as very low magnetic hysteresis distortion and Purifi's unique natural surround technology clearly set the PTT5.25X08-NFA-01 apart from the crowd. Due to the impressive long-throw performance, distortion remains minimal even at full excursion. This powerful product is manufactured by a visionary company from Denmark that understands what performance-reducing aspects really are and how to improve them. The PTT5.25X08-NFA-01 is therefore a testament to Purifi's commitment to sound quality and precision.

• Negligible force factor modulation and distortion due to bead radiation
• Low magnetic hysteresis distortion
• "Real" long-stroke performance: Distortion remains low over the entire stroke
• Unadulterated midrange performance
• Developed and manufactured in Denmark

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 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

• PTT NFA woofer series
• nominal diameter 13 cm
• load capacity (QMW) 250 W
• Sensitivity (SPL at 1m / 2.83V) 85.7 dB
• DC resistance (Re) 3.8 Ω
• resonance frequency (Fs) 29 Hz
• overall quality (Qts) 0.26
• Membrane area (Sd) 85 cm2
• equivalent volume (Vas) 13 L
• Maximum deflection (Xmax) 9.8 mm
• Cone / Diaphragm Material Proprietary Fiber Mix