Seas H1397-04 (27TAFNC/D) 1 inch Aluminum Dome Tweeter

  • Tuesday, Jan 1, 2013

Up for test is the SEAS Prestige H1397 1” Aluminum Dome Tweeter.

A commonly used tweeter in the car audio world and home audio world due to its compact size (outer diameter is only 53mm; approximately 2 inches) and relatively low cost.

Thiele-Small Parameters and Impedance

Electrical Parameters
Re 3.03 Ohm electrical voice coil resistance at DC
Krm 0.001 Ohm WRIGHT inductance model
Erm 0.53 WRIGHT inductance model
Kxm 0.0002 Ohm WRIGHT inductance model
Exm 0.83 WRIGHT inductance model
Cmes 246 µF electrical capacitance representing moving mass
Lces 0.07 mH electrical inductance representing driver compliance
Res 1.05 Ohm resistance due to mechanical losses
fs 1212.6 Hz driver resonance frequency
Loss factors
Qtp 1.479 total Q-factor considering all losses
Qms 1.974 mechanical Q-factor of driver in free air considering Rms only
Qes 5.68 electrical Q-factor of driver in free air considering Re only
Qts 1.465 total Q-factor considering Re and Rms only
Sd 7.5 cm² diaphragm area
Magnitude of electric impedance Z(f)

Frequency Response

2.83v/1m, Nearfield and farfield merged at 1300hz.

Harmonic Distortion

Mic placed in the nearfield and measurements performed at an SPL equal to a farfield level of 90dB/1m.

Output increased to represent 96dB/1m.

Bottom line:

  • Small and very compact.
  • $42 price tag (as of this writing) is attractive.
  • Measured Sensitivity is ~ 85dB on-axis.
  • Very nice off-axis performance, though be mindful of the on-axis rise. Likely a good candidate if a compact tweeter and 30 degrees off-axis aiming is called for.
  • Well controlled high frequency dispersion.
  • High THD below 2khz.
  • Increasing THD above 5khz at 96dB output relative to 1m.
  • Crossed at 2.5 kHz with an electrical LR4, this driver should be able to provide some decent output levels.

Overall, what I'm seeing here is a very compact, well-performing, low-cost tweeter.


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