Overview:
The SB Acoustics Satori MW13P-8 is an 8Ω 5″ mid-woofer from SB Acoustics. The mid-range has a 30.5mm voice-coil with a 10.0mm (p-p) linear coil travel. It’s fitted with an extende copper sleeve on the pole piece for reduced distortion.
Key features:
- Vented aerodynamic cast aluminium chassis for optimum strength and low compression.
- Proprietary cone material with EGYPTIAN PAPYRUS™ fibres made in-house.
- Soft low damping rubber surround for optimum transient response.
- Advanced BIMAX spider for improved linearity.
- Powerful optimized low distortion neodymium motor system.
- Non-conducting fibre glass voice coil former for minimum damping.
- Extended copper sleeve on pole piece for low inductance and reduced distortion.
- CCAW voice coil for reduced moving mass.
- Long life silver lead wires attached 180° apart for improved stability.
- Vented pole piece and coil former for reduced compression.
- High piston to chassis diameter ratio.
- Gasket and bolt hole protrusions for reduced coupling to speaker cabinet.
SB Acoustics Spec sheet: 5in SATORI MW13P-8
T/S Parameters:
(Click on picture to zoom)
Left: T/S parameters measured using “added” mass method in horizontal position.
Right: T/S parameters measured using “known” mass method in vertical position.
The drivers where burnt-in for 3 hours at 6 Volts using a 41Hz tone and then cooled off before measuring.
Impedance:
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Left: Free-air impedance driver sample #1 vs. sample #2.
Right: Close-up of free-air impedance driver sample #1 vs. sample #2.
Some wrinkles in the impedance plot are visible at ~1.3kHz and ~7.5kHz. The wrinkle at 1.3kHz is the cone edge resonance and 7.5kHz is the cone break-up frequency.
Frequency:
Frequency measurement conditions:
The mid-woofer is measured mounted on a baffle in a 11 liter closed enclosure with the following conditions:
Baffle size (WxH): 27×106cm. No baffle edge round-over.
Driver position: Mounted on center-line with driver unit center 24cm from the top of the baffle.
Mic position: 1m distance, on mid-woofer axis.
Smoothing: No smoothing applied. Measurement valid down to 275Hz.
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Left: Frequency response on-axis (Blue=sample #1, Red=sample #2).
Right: Frequency response 15deg off-axis (Blue=sample #1, Red=sample #2).
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Smooth frequency response up to 4.5kHz. Rising frequency response above 4.5kHz. A dip in the frequency response ~1.3kHz due to the cone edge resonance.
4kHz is about the highest suitable cross-over frequency for this mid-woofer.
Distortion:
Measurement setup:
- Mid-range near-field measurement at 12cm
- Frequency Range Mid-woofer: 200-20000Hz
- Baffle size WxH: 27×106cm
- Equipment: Steinberg UR12
The distortion measurements are done in near-field and the amplifier output level was adjusted for each driver so that the fundamental is 90dB and 95dB at 1m. This setting simulates medium-high to high listening levels.
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90dB @ 1m
Left = Sample #1
Right = Sample #2
(click on picture to zoom)
95dB @ 1m
Left = Sample #1
Right = Sample #2
The Satori MW13P-8 mid-woofer is overall a very low distortion driver. The resonance issue shown in the impedance plot around 1.3kHz is shown here as a spike of second order distortion.