The PTT6.5W04-NFA-01 is the standard stroke 6.5" bass-midwoofer from the PURIFI woofer family. It incorporates similar breakthrough technology, but due to a reduced excursion limit the efficiency is improved over the PTT6.5X04-NFA-01 long stroke woofer.

Highlights:

A whole new take on driver design

PURIFI’s Natural Surround

Extreme low distortion over full excursion range 

Engineered and manufactured in Denmark

Excellent midrange performance

High power handling

Perfect balance between volume displacement and midrange efficiency

Product Details:

PURIFI PTT6.5W04-NFA-01 bass-midwoofer 

PURIFI is a fresh company that designs and manufactures extreme high performance transducers and amplifier modules. Don’t let the freshness fool you; Their leadership team consists out of some well-respected audio technology pioneers. PURIFI developed a deep understanding of many performance degrading aspects for both amplifiers and transducers. Thanks to this understanding the PTT6.5W04-NFA-01 is the most refined bass-mid woofer from our woofer category.

Besides this 4 ohm version there is also an 8 ohm version, a long stroke version (PTT6.5X04-NFA-01) and a 6,5" passive radatior available. Looking for similar performance, but something smaller? Take a look at the 4" PTT4.0W04.

The challenge 

Loudspeaker drivers are known to add a large, if not the largest, amount of distortion in an audio signal chain. Reducing this distortion is a challenge with the complication of fine-tuning to improve one part (e.g. harmonic distortion) often results in a degradation of  another part (e.g. intermodulation distortion). These distortions consist out of several separate distortion mechanisms. By carefully mapping and completely understanding these mechanisms, PURIFI succeeded in improving the overall performance by a large degree.

A whole new take on driver design

PURIFI developed mathematical models for the motor system, suspension, cone and surround. These models allowed for optimization of each distortion mechanism separately. This systematic approach reduced all distortions mechanisms and keeps intermodulation distortion low. The result makes that the PTT6.5W04-NFA-01 is a compact 6.5” driver that parallels or even surpasses  the bass performance of a low excursion, large surface driver, while it also excels in midrange performance.

Specifications:

Nominal Diameter: 6.5"

Power Handling (RMS): 250 watts

Continuous Program Power: 80 watts

Impedance (Z): 4 ohms

Sensitivity (SPL at 1m / 2.83V): 90.3 dB

Voice Coil Diameter: 39 mm

DC Resistance (Re): 3.7 ohms

Voice Coil Inductance (Le): 0.32 mH @ 1kHz

Resonant Frequency (Fs): 33 Hz

Mechanical Q (Qms): 6.3

Electromagnetic Q (Qes): 0.27

Total Q (Qts): 0.23

Diaphragm Mass Inc. Airload (Mms): 21.1g

Mechanical Compliance of Suspension (Cms): 1.10 mm/N

Surface Area of Cone (Sd): 132.7 cm2

Volume of Displacement (Vd): 78.3 cm3

BL Product (BL): 7.7

Compliance Equivalent Volume (Vas): 28.9 liter

Maximum Linear Excursion (Xmax): 5.9 mm

Driver's Mechanical Losses (Rms): 0.7 kg/s

Cone / Diaphragm Material: Proprietary Fibre Mix

Surround Material: Nitrile rubber

Voice Coil Wire Material: Aluminum

Voice Coil Former: Fiberglass

Basket / Frame Material: Aluminum alloy diecast

Magnet Material: Ferro-magnetic

Overall Outside Diameter: 176 mm

Overall Depth: 90.2 mm

Baffle Cutout Diameter: 145 mm

Bolt Circle Diameter: 166 mm

# Mounting Holes: 6

Mounting Hole Diameter: 5.1