Our employee is happy to help you find the right product
Dedicated midrange driver with enhanced efficiency. Negligible force factor modulation. Ultra-low magnetic hysteresis distortion. Utilizes PURIFI’s neutral surround technology.
Highlights
The PTT6.5M04-NFA-01 has been optimized for Midrange use and achieves higher sensitivity as compared to the X- and W- versions of PTT6.5 product family. Furthermore, the M-version has a slight redesign chassis. Please observe the 2D drawings in the datasheet. The driver achieves astounding performance with ultra-clean distortion specifications.
PURIFI is a fresh company that designs and manufactures extremely 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 performances degrading aspects for both amplifiers and transducers. Thanks to this understanding the PTT6.5W08-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 (PTT6.5M08-NFA-01), and a 6,5" passive radiator available.
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 to a large degree.
PURIFI developed mathematical models for the motor system, suspension, cone, and surround. These models allowed for the optimization of each distortion mechanism separately. This systematic approach reduced all distortions mechanisms and keeps intermodulation distortion low. The result makes that the PTT6.5M04-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.
The mechanism | Improvement |
Low force factor modulation | Current through the voice coil is not distorted by cone movement. Gives undistorted midrange regardless of the excursion |
Constant force factor over excursion - Bl(x) | Prevents amplitude devotions of midrange output during the large excursion (sometimes called ‘burbling’) |
Low surround radiation distortion | Reduces harmonic and intermodulation distortion caused by surround |
Low magnetic hysteria distortion | Reduces harmonic and intermodulation distortion caused by magnetic traces left by the previous cycle |
Q: Should I go with this 4 ohm or with the 8-ohm version?
A: Both woofers have similar distortion performance and the T/S parameters are alike. The 4 ohm coils of this PTT6.5W04-NFA-01 allow more current to flow on a similar drive voltage. This gives higher sensitivity and is preferred in most applications. If you have an amplifier that is not comfortable with low impedance loads or has specific requirements, such as parallel woofers, the PTT6.5M08-NFA-01 might be more favorable.
Q: Why is this surround odd-shaped?
A: This is the PURIFI Natural Surround. Conventional surroundings create distortion as they deform. The shape of the Natural Surround reduces cone edge resonances and distortion. It might be odd-looking, but form follows function here. A more detailed look shows that the surround actually represents a complex sound wave. We are told that the Natural Surround is also called ‘wormy’ by insiders.
Show more
Show more
Home audio 
Audio components 
Crossover components 
Test & measurement 
DIY kits 
Accessories 
New products 
Speakers
Amplifiers
DAC converters
DSP modules
Streamers
Turntables
Woofers
Tweeters
Exciters
Bass shakers
Plate amplifiers
Amplifier modules
Single board computers
Assembled crossovers
Printed Circuit Boards (PCB)
Capacitors
Resistors
Coils
Circuit Breakers
Crossover tools
Screw terminals
Acoustic measurements
Electric measurements
Sound level meters
DIY amplifier kits
DIY component packs
DIY speaker kit
DIY subwoofer kits
DIY bluetooth speaker
DIY electronics kits
Binding posts
Cabinet Hardware
Cables
Connectors
Speaker cabinets
Electromechanics
Power supplies
Speaker repair
Workshop & tools
Amplifier accessories
Stands & mounts
Gift voucher
Books
New products
Speakers
Amplifiers
DAC converters
DSP modules
Streamers
Turntables
Woofers
Tweeters
Exciters
Bass shakers
Plate amplifiers
Amplifier modules
Single board computers
Assembled crossovers
Printed Circuit Boards (PCB)
Capacitors
Resistors
Coils
Circuit Breakers
Crossover tools
Screw terminals
Acoustic measurements
Electric measurements
Sound level meters
DIY amplifier kits
DIY component packs
DIY speaker kit
DIY subwoofer kits
DIY bluetooth speaker
DIY electronics kits
Binding posts
Cabinet Hardware
Cables
Connectors
Speaker cabinets
Electromechanics
Power supplies
Speaker repair
Workshop & tools
Amplifier accessories
Stands & mounts
Gift voucher
Books
New products
