Ported box size for 3 10" subs
3 10" subs usually want 3–4.8 ft³ net (85–136 L) in a ported box. Your sub’s manual wins: if it gives a volume, build to that.
Example: 3.9 ft³ (110.4 L) net in 3/4" MDF is a box 38 5/16" × 13" × 22" outside (width × height × depth), with a 4 3/4" × 11 1/2" slot port 30 3/4" long for 32 Hz. The port takes 1.12 ft³ (31.9 L), already counted in that size.
The 30 3/4" port is longer than the box is deep inside (20 1/2"): fold it into an L along the side or the back.
Example box for 3.9 ft³ (110.4 L) net
Example box for 3.9 ft³ (110.4 L) net| What | Size |
|---|
| Outside (W × H × D) | 38 5/16" × 13" × 22" (974 × 330 × 559 mm) |
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| Inside (W × H × D) | 36 13/16" × 11 1/2" × 20 1/2" |
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| Gross volume | 5.02 ft³ (142.3 L) |
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| Slot port | 4 3/4" wide × 11 1/2" tall (54.6 sq in) |
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| Port length | 30 3/4" (781 mm) for 32 Hz |
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| Port takes up | 1.12 ft³ (31.9 L) |
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| Net volume | 3.9 ft³ (110.4 L) |
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Cut sheet for the example box (3/4" MDF)
Cut sheet for the example box (3/4" MDF)| Piece | Qty | Size |
|---|
| Front (baffle) | 1 | 38 5/16" × 13" |
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| Back | 1 | 38 5/16" × 13" |
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| Top and bottom | 2 | 38 5/16" × 20 1/2" |
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| Sides | 2 | 11 1/2" × 20 1/2" |
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Same slot port at other tunings
Same slot port at other tunings| Tuning | Slot length |
|---|
| 30 Hz | 35 13/16" (910 mm) |
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| 32 Hz | 30 3/4" (781 mm) |
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| 34 Hz | 26 9/16" (674 mm) |
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| 36 Hz | 23" (585 mm) |
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Typical net volume for 10" subs
Typical net volume for 10" subs| Subs | Sealed | Ported |
|---|
| 1 | 0.6–1 ft³ | 1–1.6 ft³ |
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| 2 | 1.2–2 ft³ | 2–3.2 ft³ |
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| 3 | 1.8–3 ft³ | 3–4.8 ft³ |
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| 4 | 2.4–4 ft³ | 4–6.4 ft³ |
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Before you cut
Take off the sub’s own displacement (in its manual, often 0.05 to 0.2 ft³ per sub) and any bracing: the box calculator does that and redoes the width.
Measure the space twice, including the angle of the seat back in a truck cab. A wedge box often fits where a rectangle doesn’t.
Volume ranges are common starting points for car subs, not a standard. The example uses the middle of the range, 3/4" MDF, and for ported boxes a slot port of 14 sq in per ft³ tuned to 32 Hz along the full inside height.
Other box sizes for 10" subs
Frequently asked questions
What size ported box for 3 10" subs?
3 10" subs usually want 3–4.8 ft³ net (85–136 L) in a ported box. Your sub’s manual wins: if it gives a volume, build to that.
What are the dimensions of a ported box for 3 10" subs?
Example: 3.9 ft³ (110.4 L) net in 3/4" MDF is a box 38 5/16" × 13" × 22" outside (width × height × depth), with a 4 3/4" × 11 1/2" slot port 30 3/4" long for 32 Hz. The port takes 1.12 ft³ (31.9 L), already counted in that size.
What should a ported box for 3 10" subs be tuned to?
Most daily boxes are tuned between 30 and 36 Hz. Lower goes deeper and needs a longer port; higher hits harder up top. Your sub’s manual may suggest a tuning.