Model
Rockford Fosgate P1S4-15
Rating
DIAM
FS(Hz)
VAS(l)
QTS
PWR(W)
SPL(dB)
IMP(Ohm)
avb
+156 P-Bass
26 Oct 2021, 21:16
Enclosure
Vented, Vb: 253.5l, Fb: 19.1Hz
+156 P-Bass
26 Oct 2021, 23:04
Description
This closed box's Vb is the largest on which the driver reaches but not passes over its X-max at every frequency down to 10 Hz on RMS power using both computation models. This driver in this box will perform really good in car, because at low bass its transfer function is much higher than 0 dB with the SBL's stock 55 Hz / 12 dB cabin gain. Simple model shows that it is the loudest between 13 and 23 Hz, but complex model - which gives more cone excursion - shows that there is a peak around 24 and 25 Hz.
Enclosure
Closed, Vb: 115.8l
+156 P-Bass
17 Oct 2021, 14:26
Description
I heared this driver in real: it performs really good in closed box. So, first I determined a Vb with SBL which gived ideal RMS power handling + reaching Xmax at every frequency, and the box would have too big outer dimensions, so I simulated a Vb in WinISD to have the same power handling and Xmax rules, that gived way less Vb, so the box have now acceptable outer dimensions. BassBox6PRO gived for me even higher Vb like SBL. The box is tuneable using acoustic wool.
Enclosure
Closed, Vb: 71.4l
+156 P-Bass
17 Oct 2021, 16:58
Description
This vented box I simulated the same way using the same needs like the closed box before. The 3 simulators I used (SBL, WinISD, BassBox6PRO) gived the same exact result-differences like at closed box: WinISD box was the smallest which gived the the most acceptable outer dimensions. This sub will have outstandingly good group delay + tiny vent air velocity + goes below 20 Hz + in car will be around 6 dB louder compared to the closed.
Enclosure
Vented, Vb: 124.5l, Fb: 23.3Hz
Description
Using simple model I was looking for that lowest possible tuned highest Vb - lowest Fb combination which gives lower or equal F3 like Fb, and the driver just not overpasses it's X-max on RMS power higher like Fb. Using complex model I found a port area which gives clear graphs up to around 120 Hz. As bonuses, vent air velocity is less than 17 m/s, RMS power handling ability is way under 20 Hz, up from 26 Hz transfer function is in "+" without cabin gain, so this sub is useable even in exterior too.