This 6.5" is a member of the ultra low distortion extended-stroke woofer family from PURIFI. The driver incorporates the easily recognizable PURIFI NeutralSurround suspension and ultra-linear motor system PURIFI PureDrive technology working in concert to elevate performance to a whole new level despite of it’s compact size.
The PTT6.5X04-NFA-01 features:
Vibroacoustic optimized cone and dust cap in proprietary paper fiber mix
Negligible Force Factor Modulation (FFM) and Surround Radiation Distortion (SRD)
Ultra Low Magnetic Hysteresis Distortion (MHD)
"Real" long-stroke performance with distortion remaining low over full excursion
Uncompromised midrange performance
Designed and manufactured in Denmark
Specifications
General Specifications
Type
Extended Woofer
Size
6.5in
Nominal impedance
4Ω
Cone material
Proprietary Fiber Mix
Linear excursion, Xlin
±9.8mm
Maximum mechanical excursion, Xmax
±14.5mm
Motor efficiency factor, Beta
17.7 (N/A)^2/Ω
Efficiency Bandwidth Product, EBP
111.1Hz
Long term maximum power
250W
Rated noise power, 100h
80W
Electrical & Acoustical Parameter
DC resistance
3.7Ω
Minimum impedance above resonance, Zmin
4.2Ω
Frequency for minimum impedance, fmin
268Hz
Maximum impedance, Zo
78Ω
Voice Coil inductance @ 1kHz 0mm, Le
0.38mH
SPL @ 2.83Vrms/1m, 300-800Hz
88.7dB
SPL @ 1W/1m, 300-800Hz
85.9dB
Thiele/Small Paramters
Resonance frequency, fs
30Hz
Mechanical Q factor, Qms
5.8
Electrical Q factor, Qes
0.28
Total Q factor, Qts
0.27
Equivalent volume, Vas
25.9L
Effective piston area, Sd
132.7cm2
Effective piston diameter, D
13.0cm
Force factor, Bl
8.1N/A
Mechanical resistance, Rms
0.88kg/s
Moving mass, Mms
26.7g
Suspension compliance, Cms
1.04mm/N
Typical Box Tunings
Typical corner frequency, sealed B2 alignment
78.6Hz
Box volume, sealed B2 alignment
4.4L
Typical corner frequency, bass reflex PTT alignment