(click on picture to zoom)
Left: SB15MFC30-4
Right: SB15NRXC30-4
Here’s a new set of measurements!
This time I’ve tested a pair of SB Acoustics 4Ω mid-woofers. The main difference between the two drivers is the cone material used. The SB15MFC30-4 uses a mineral filled Polypropylene (PP) cone and the SB15NRXC30-4 uses a coated Papyrus fiber cone.
They both share all other features like the same type of chassis, voice-coil, surround and motor system etc.
They are more alike than different in its measurement performance and it will be interesting to see if they subjectively sounds different from each other.
Detailed measurement data:
SB Acoustics SB15MFC30-4
SB Acoustics SB15NRXC30-4
SB15MFC30-4 vs. SB15NRXC30-4 comparison:
Build quality and looks:
At a first glance they both look confusingly similar to each other. The SB15MFC30-4 with its Polypropylene cone is slightly darker and shiny in its color compared to the coated structure of the SB15NRXC30-4.
They both have an impressive build quality with a high performance/price ratio.
Impedance:
(click on picture to zoom)
Green = SB15MFC30-4
Blue = SB15NRXC30-4
They have almost identical impedance plots besides the difference in the impedance peak of the resonance frequency (Fs).
Frequency:
(click on picture to zoom)
Left: On-axis
Right: 15deg off-axis
Blue = SB15MFC30-4
Red = SB15NRXC30-4
They have almost the same frequency response in the mid-range. The PP cone of the SB15MFC30-4 rolls of a bit earlier than the SB15NRXC30-4, but they both have a very extended frequency response.
Distortion:
(click on picture to zoom)
95dB @ 1m
Left = SB15MFC30-4
Right = SB15NRXC30-4
The SB15MFC30-4 has slightly higher odd-order distortion, but they are both good performers in this price class. When a proper cross-over design is in place, the difference should be negligible.
Summary:
These two mid-woofers are more alike than different from each other and it will be interesting to see how they sonically differ.
Based on the measurements performance I consider both these mid-woofer to be of high value and with a high performance/price ratio.