SB Acoustics Lautsprecher SB26STC-C000-4 25 mm Tweeter
Its membrane of impregnated fabric is held by a wide, flat surround of the same material in the matte shimmering plastic front panel. It protrudes a few millimeters beyond the rounded recess, which serves both to guide the sound and to increase the level. Towards the edge, the front is also slightly flattened. With its geometry, the engineers were able to positively influence the omnidirectional behavior off-axis. The 1.2 mm high voice coil was wound on an unperforated aluminum carrier and connected to the solder lugs by thick strands. A construction of a very special kind is the drive system of the tweeter. It is not the combination of magnet ring and pole plates that is to be emphasized, rather it is the small things that betray the thoughtfulness of the designers. For example, the pole core is drilled through to lower the resonant frequency and closed at the back with a plastic chamber. To reduce reflections from this chamber, a "dome" was placed on the opening. A copper coating on the pole core also serves more than just optical purposes in the tweeter. The engineers do not need ferrofluid in the air gap; they do not rely on commercial thinking here either.
Features
- Copper cap for reduced voice coil inductance and minimum phase shift
- Non-reflective rear chamber with optimized damping for improved dynamics
- Flow optimized vented pole piece for optimum coupling to rear chamber
- Fine weave soft fabric dome for smooth frequency response
- Saturation controlled motor system for low distortion
- CCAW voice coil for low moving mass
- Long life silver lead wires
- Low resonance frequency
Specs
- Nominal Impedance 4 Ω
- DC resistance, Re 3.2 Ω
- Voice coil inductance, Le 0.04 mH
- Effective piston area, Sd 6.2 cm2
- Voice coil diameter 25.4 mm
- Voice coil height 1.3 mm
- Air gap height 2.5 mm
- Linear coil travel (p-p) 1.2 mm
- Moving mass incl. air, Mms 0.3 g
- Free air resonance, Fs 750 Hz
- Sensitivity (2.83 V / 1 m) 91.5 dB
- Mechanical Q-factor, Qms 3.0
- Electrical Q-factor, Qes 1.78
- Total Q-factor, Qts 1.12
- Force factor, Bl 1.6 Tm
- Rated power handling* 120 W
- Magnetic flux density 1.15 T
- Magnet weight 0.22 kg
- Net weight 0.53 kg
* IEC 268-5, high-pass Butterworth, 2600 Hz, 12 dB/oct