Sky High Car Audio subwoofers

Thiele/Small parameters of Sky High Car Audio subwoofers (6.5″–18″) and a recommended sealed and ported box for every model, in a free sub box calculator.

Size

Voice coils

Ω per coil

Qts

58 models

Model	Size	Voice coils	Fs, Hz	Qts	Vas, ft³	Xmax, in	RMS, W	Box, ft³ · Hz
6.5″ 8 models
BMX-6.5 D1	6.5″	dual 1 Ω	57.3	0.85	0.07	0.59	500	Sealed 0.18 Ported 0.35 · 43
BMX-6.5 D2	6.5″	dual 2 Ω	53.3	0.71	0.07	0.59	500	Sealed 0.18 Ported 0.35 · 43
FE-6.5 D2	6.5″	dual 2 Ω	51.3	0.80	0.08	0.43	300	Sealed 0.18 Ported 0.35 · 43
FE-6.5 D4	6.5″	dual 4 Ω	55.7	0.94	0.07	0.43	300	Sealed 0.18 Ported 0.35 · 43
FMX-6.5 D1	6.5″	dual 1 Ω	55.5	0.83	0.07	0.63	600	Sealed 0.21 Ported 0.35 · 43
FMX-6.5 D2	6.5″	dual 2 Ω	54	0.71	0.07	0.63	600	Sealed 0.21 Ported 0.35 · 43
FXB-6.5 D2	6.5″	dual 2 Ω	49.9	0.76	0.08	0.43	400	Sealed 0.18 Ported 0.35 · 43
FXB-6.5 D4	6.5″	dual 4 Ω	49.9	0.84	0.09	0.43	400	Sealed 0.18 Ported 0.35 · 43
8″ 8 models
BMX-8 D1	8″	dual 1 Ω	38	0.66	0.18	0.67	500	Sealed 0.35 Ported 0.46 · 41
BMX-8 D2	8″	dual 2 Ω	37.2	0.59	0.29	0.67	500	Sealed 0.35 Ported 0.46 · 41
FE-8 D2	8″	dual 2 Ω	48	0.80	0.17	0.55	400	Sealed 0.35 Ported 0.49 · 41
FE-8 D4	8″	dual 4 Ω	50.5	0.85	0.14	0.55	400	Sealed 0.28 Ported 0.49 · 41
FMX-8 D1	8″	dual 1 Ω	44.3	0.59	0.17	0.71	800	Sealed 0.35 Ported 0.46 · 41
FMX-8 D2	8″	dual 2 Ω	43.5	0.50	0.16	0.71	800	Sealed 0.35 Ported 0.46 · 42
FXB-8 D2	8″	dual 2 Ω	44.4	0.75	0.17	0.55	500	Sealed 0.35 Ported 0.49 · 41
FXB-8 D4	8″	dual 4 Ω	44.3	0.77	0.19	0.55	500	Sealed 0.39 Ported 0.49 · 41
10″ 8 models
BMX-10 D1 !	10″	dual 1 Ω	33.4	0.43	0.29	1.18	2,000	Sealed 0.62 Ported 0.60 · 37
BMX-10 D2	10″	dual 2 Ω	31.6	0.36	0.32	1.18	2,000	Sealed 0.60 Ported 1.31 · 35
FE-10 D2	10″	dual 2 Ω	37.9	0.69	0.50	0.59	700	Sealed 0.99 Ported 0.81 · 38
FE-10 D4	10″	dual 4 Ω	38.7	0.72	0.49	0.59	700	Sealed 0.99 Ported 0.81 · 38
FEX-10 D2	10″	dual 2 Ω	33.8	0.55	0.57	0.75	1,250	Sealed 0.49 Ported 0.81 · 45
FEX-10 D4	10″	dual 4 Ω	34.8	0.58	0.64	0.75	1,250	Sealed 0.71 Ported 0.81 · 38
FXB-10 D2	10″	dual 2 Ω	36.4	0.64	0.28	1.18	1,000	Sealed 0.51 Ported 0.81 · 38
FXB-10 D4	10″	dual 4 Ω	37.7	0.69	0.29	1.18	1,000	Sealed 0.60 Ported 0.81 · 38
12″ 12 models
BMX-12 D1	12″	dual 1 Ω	26	0.50	1.03	1.26	2,500	Sealed 0.74 Ported 1.13 · 34
BMX-12 D2	12″	dual 2 Ω	25.8	0.42	1.04	1.26	2,500	Sealed 0.74 Ported 1.13 · 34
FE-12 D2	12″	dual 2 Ω	29.8	0.68	2.62	0.59	700	Sealed 1.80 Ported 2.08 · 33
FE-12 D4	12″	dual 4 Ω	31.1	0.72	1.40	0.59	700	Sealed 1.80 Ported 1.27 · 34
FEX-12 D2	12″	dual 2 Ω	34.6	0.67	1.42	0.75	1,250	Sealed 1.80 Ported 1.27 · 34
FEX-12 D4	12″	dual 4 Ω	34.7	0.64	1.42	0.75	1,250	Sealed 1.80 Ported 1.27 · 34
FMX-12 D1	12″	dual 1 Ω	29.6	0.47	0.94	1.46	3,500	Sealed 0.92 Ported 1.13 · 33
FMX-12 D2	12″	dual 2 Ω	29.3	0.40	0.83	1.46	3,500	Sealed 0.92 Ported 1.13 · 32
FXB-12 D2	12″	dual 2 Ω	28.8	0.60	0.98	1.18	1,500	Sealed 1.24 Ported 1.31 · 32
FXB-12 D4	12″	dual 4 Ω	31.4	0.68	1.02	1.18	1,500	Sealed 1.87 Ported 1.31 · 34
FXXL-12 D1	12″	dual 1 Ω	34.3	0.48	0.68	1.42	5,000	Sealed 0.92 Ported 1.13 · 35
FXXL-12 D2	12″	dual 2 Ω	32.9	0.44	0.67	1.42	5,000	Sealed 0.92 Ported 1.13 · 35
15″ 12 models
BMX-15 D1	15″	dual 1 Ω	23.6	0.51	3.23	1.26	2,500	Sealed 2.15 Ported 2.58 · 30
BMX-15 D2	15″	dual 2 Ω	21.7	0.47	3.36	1.26	2,500	Sealed 1.80 Ported 2.68 · 30
FE-15 D2	15″	dual 2 Ω	30.2	0.88	2.92	0.59	700	Sealed 2.79 Ported 2.33 · 33
FE-15 D4	15″	dual 4 Ω	31.8	1.07	2.96	0.59	700	Sealed 2.79 Ported 2.37 · 34
FEX-15 D2	15″	dual 2 Ω	30.5	0.79	3.81	0.75	1,250	Sealed 2.93 Ported 3.04 · 33
FEX-15 D4	15″	dual 4 Ω	30.4	0.64	3.79	0.75	1,250	Sealed 2.93 Ported 3.04 · 33
FMX-15 D1	15″	dual 1 Ω	24	0.49	2.87	1.46	3,500	Sealed 1.77 Ported 2.30 · 30
FMX-15 D2	15″	dual 2 Ω	20.9	0.42	2.98	1.46	3,500	Sealed 1.48 Ported 2.40 · 30
FXB-15 D2	15″	dual 2 Ω	29.5	0.70	2.44	1.18	1,500	Sealed 2.86 Ported 2.01 · 32
FXB-15 D4	15″	dual 4 Ω	29.3	0.74	2.31	1.18	1,500	Sealed 2.86 Ported 2.01 · 32
FXXL-15 D1	15″	dual 1 Ω	31.2	0.57	2.22	1.42	5,000	Sealed 2.22 Ported 2.05 · 34
FXXL-15 D2	15″	dual 2 Ω	29.6	0.43	2.23	1.42	5,000	Sealed 1.48 Ported 2.05 · 33
18″ 10 models
BMX-18 D1	18″	dual 1 Ω	22.7	0.60	6.28	1.26	2,500	Sealed 4.45 Ported 5.01 · 30
BMX-18 D2	18″	dual 2 Ω	20.5	0.51	7.60	1.26	2,500	Sealed 4.45 Ported 5.76 · 30
FEX-18 D2	18″	dual 2 Ω	27.7	0.71	7.87	0.75	1,250	Sealed 4.34 Ported 5.62 · 30
FEX-18 D4	18″	dual 4 Ω	29.1	0.94	8.28	0.75	1,250	Sealed 4.34 Ported 5.62 · 32
FMX-18 D1	18″	dual 1 Ω	22.3	0.57	6.43	1.46	3,500	Sealed 4.45 Ported 5.16 · 30
FMX-18 D2	18″	dual 2 Ω	20.3	0.49	7.35	1.46	3,500	Sealed 4.45 Ported 5.76 · 30
FXB-18 D2	18″	dual 2 Ω	26.1	0.66	4.80	1.18	1,500	Sealed 4.27 Ported 3.85 · 30
FXB-18 D4	18″	dual 4 Ω	27.3	0.82	4.69	1.18	1,500	Sealed 4.31 Ported 3.74 · 30
FXXL-18 D1 !	18″	dual 1 Ω	26.1	0.62	3.67	1.42	5,000	Sealed 4.03 Ported 2.93 · 30
FXXL-18 D2	18″	dual 2 Ω	28.4	0.52	4.05	1.42	5,000	Sealed 2.97 Ported 3.25 · 31

Click a column header to sort. “!” means the model’s published specs don’t add up; details are on its page.

Qts: under 0.4 — ported 0.4–0.6 — either over 0.6 — sealed · “Box” — recommended sealed and ported net volume and ported tuning.