Dayton Audio ND91-8 3-1 - Manual (Page 6)

Linear Parameters
Symbol
Large +
Warm
Large +
Cold
Small
Signal
Unit Comment
Note:
for accurate small signal parameters, use LPM
module
Delta Tv = 39
0 0 K
increase of voice coil temperature during the
For accurate system modelling “Large + Cold” parameters are preferable to “Small Signal”
parameters because they more closely reflect the parameters in their typical operating range.
Tv-Ta measurement
Xprot 8.8 8.8 2.9 mm maximal voice coil excursion (limited by
protection system)
Re (Tv) 8.45 7.37 7.37 Ohm (imported) voice coil resistance considering
increase of voice coil temperature Tv
Le (X=0) 0.87 0.87 0.75 mH
voice coil inductance at the rest position of the
voice coil
L2 (X=0) 1.46 1.46 0.84 mH
para-inductance at the rest position due to the
effect of eddy current
R2 (X=0) 3.83 3.83 3.52 Ohm resistance at the rest position due to eddy currents
Cmes (X=0) 167 167 160 µF electrical capacitance representing moving mass
Lces (X=0) 66.02 66.02 32.69 mH
electrical inductance at the rest position
representing driver compliance
Res (X=0) 79.97 79.97 44.04 Ohm resistance at the rest position due to mechanical
losses
Qms (X=0,
Tv)
4.02 4.02 3.08 mechanical Q-factor considering Rms only
Qes (Tv) 0.37 0.32 0.46 electrical Q-factor considering Re (Tv) only
Qts (X=0,
Tv)
0.34 0.30 0.40 total Q-factor considering Re (Tv) and Rms only
fs 48.0 48.0 69.6 Hz driver resonance frequency
Mms 5.210 5.210 5.210 g
(imported) mechanical mass of driver diaphragm
assembly including voice-coil and air load
Rms (X=0) 0.391 0.391 0.739 kg/s mechanical resistance of total-driver losses
Cms (X=0) 2.11 2.11 1.00 mm/N mechanical compliance of driver suspension at the
rest position
Bl (X=0) 6.02 6.02 6.02 N/A (imported) force factor at the rest position (Bl
product)
Vas 2.7595 2.7595 1.3121 l equivalent air volume of suspension
N0 0.080 0.091 0.091 % reference efficiency (2Pi-sr radiation using Re)
Lm 81.2 81.8 81.8 dB characteristic sound pressure level
Sd 30.43 30.43 30.43 cm² diaphragm area