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    PURIFI PTT4.0PR-NF2-01 Long Stroke Passive Radiator with Ultra Low Distortion

    € 82,60€ 99,95 >10 In stock: delivery time 1-4 business days
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    Product description

    The PTT4.0PR is a 4” high-performance passive radiator featuring PURIFI ’s research based technologies, including the Natural Surround and a cone made from a proprietary fibre mix.



    • A whole new take on passive radiator design
    • PURIFI ’s Natural Surround
    • Bimax spider
    • High linear excursion limit
    • Tunable mass
    • Engineered and manufactured in Denmark


    Product Details

    PURIFI PTT4.0PR Passive Radiator 


    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 passive radiators from PURIFI are the most high-end passive radiators available at SoundImports.


    The challenge 

    Loudspeaker drivers are known to add a large, if not the largest, amount of distortion on 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 passive radiator design

    PURIFI developed mathematical models for the suspension, cone and surround. These models allowed for the optimization of different distortion mechanism separately. The result makes that the PTT6.5PR is a perfect passive radiator to accompany the PTT4.0W04 in a size efficient enclosure. Looking for a passive radiator the accompany the larger PTT6.5W04 or PTT6.5W08? Take a look at the PTT6.5PR


    The mechanism


    Low surround radiation distortion

    Reduces harmonic and intermodulation distortion caused by surround



    Q: Why is this surround odd shaped?

    A: This is the PURIFI Natural Surround. Conventional surrounds 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 complex sound wave. We are told that the Natural Surround is also called ‘wormy’ by insiders.


    Article number
    Woofer Series
    Woofer Type
    Passive radiator
    Nominal Diameter
    Power Handling (RMS)
    Power Handling (max)
    Continuous Program Power
    Impedance (Z)
    Frequency Response
    Voice Coil Diameter
    Magnet Weight
    DC Resistance (Re)
    Voice Coil Inductance (Le)
    Resonant Frequency (Fs)
    24 Hz
    Mechanical Q (Qms)
    Electromagnetic Q (Qes)
    Diaphragm Mass Inc. Airload (Mms)
    Moving Mass Of Diaphragm (Mmd)
    Mechanical Compliance of Suspension (Cms)
    1.41 mm/N
    Surface Area of Cone (Sd)
    57 cm²
    Volume of Displacement (Vd)
    79.8 cm³
    BL Product (BL)
    Compliance Equivalent Volume (Vas)
    6.4 liter
    Maximum Linear Excursion (Xmax)
    14 mm
    Driver's Mechanical Losses (Rms)
    Cone / Diaphragm Material
    Proprietary Fibre Mix
    Surround Material
    Nitrile rubber
    Voice Coil Wire Material
    Voice Coil Former
    Dual Voice Coil
    Basket / Frame Material
    Aluminum alloy diecast
    Magnet Material
    Overall Outside Diameter
    125 mm
    Overall Depth
    39.5 mm
    Baffle Cutout Diameter
    100 mm
    Bolt Circle Diameter
    115 mm
    # Mounting Holes
    Mounting Hole Diameter
    4.2 mm
    Sealed Volume
    Sealed F3
    Vented Volume
    Vented F3


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    PTT4.0PR-NF2-01 Long Stroke Passive Radiator with Ultra Low Distortion
    € 82,60
    € 99,95
    PTT4.0PR-NF2-01 Long Stroke Passive Radiator with Ultra Low Distortion
    PTT4.0PR-NF2-01 (PTT4.0WPR)
    >10 In stock: delivery time 1-4 business days
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