Three Drivers, One Cabinet

Triple 8 Inch Subwoofer Boxes

Triple 8 inch subwoofer boxes, CNC-cut in Tullahoma, Tennessee.

Triple 8 inch subwoofer box built by Proline X in Tullahoma, Tennessee

Three Drivers, One Cabinet

A triple 8 is the shallow-and-wide answer. Three eights give you about the same cone area as two tens, in a cabinet that stays short enough front to back for a regular cab or a low trunk floor.

Every cabinet on this page is sealed and holds three 8 inch drivers, each in its own chamber behind a bonded full-height divider. The driver-matched cabinets are cut from the parameters the driver's maker publishes, and the universal cabinets take any set that clears their cutout and mounting depth. Each listing states the net volume for the whole cabinet and the figure per chamber, which is what one driver actually works into.

Sealed triple 8 inch cabinets, wedge and standard front-firing, 29, 32 or 40 inches wide.

Cut, assembled and finished in Tullahoma, Tennessee. Shipping included.

Driver-matched cabinets are cut from the parameters each driver's maker publishes. Enclosure only unless the listing says loaded.

Shop the Lineup

←
→

Every Triple 8 Inch Build, Side by Side

The series decides the build standard and the warranty term. Prices are the lowest in stock in each series today.

Triple 8 inch cabinets by series, 12 November 2026.
SeriesChambersShapesFitWarrantyFrom
Performance OptimizedA sealed chamber per driverWedgeDriver-matched1 year limited$359.99
Performance (universal)A sealed chamber per driverStandard front-firingUniversal1 year limited$199.99

Every cabinet is Langboard Elite MDF, carpeted, with an ABS or carbon fibre terminal cup.

Why Three Drivers

Cone area is the point

The reason to run three drivers instead of two is total cone area in a fixed amount of width. Three eights give you about the same cone area as two tens, and they do it with smaller moving masses, which start and stop faster than one large cone covering the same area.

A chamber each, not a shared box

Multi-driver sealed builds here follow one standing design rule: the cabinet is split by bonded full-height dividers so each driver gets its own sealed volume and its own polyfill. Drivers sharing one chamber work against each other's compression, and with three of them that interaction compounds. Separate chambers remove it, which is why the alignment printed on the listing is the alignment in each chamber rather than an average across the box.

One terminal cup, every driver in parallel

The cabinet carries a single terminal cup pre-wired in 12 gauge OFC to every driver position, and those positions are in parallel inside the box. That is worth knowing before you buy: all three drivers have to be the same model at the same impedance, and the final load is settled by how you wire each driver's own coils. The numbers are below.

Built as a wedge because that is where the width is

The rear panel sits flat against the cab wall or trunk bulkhead and the baffle rakes back to follow the lean of the seat. That is the one place in most vehicles with enough uninterrupted width for three drivers, which is why nearly every cabinet on this page is cut that way.

How to Choose a Triple 8 Inch Box

Start from the driver and buy a matched set

Most of these cabinets are cut to one named driver. Match the model and the coil on the listing, and run three of the same driver at the same impedance. The chambers are identical and the positions are paralleled inside the cabinet, so a different driver in one of them gets neither the volume it wants nor the same share of the power.

Work out the final impedance before you buy the amplifier

Because the cabinet parallels the driver positions, what is left to decide is how each driver's own coils are wired, and that gives two loads rather than the usual three. Three dual 4 ohm drivers land on 2.67 ohms with each driver's coils in series, or 0.67 ohms with them in parallel. Dual 2 ohm drivers land on 1.33 ohms or 0.33 ohms the same way. Neither usable figure is the familiar 1 or 2 ohms, which is the one real catch with an odd driver count: 2.67 ohms wants an amplifier stable at 2, and 1.33 ohms wants one stable at 1. Check the rating before you commit to the box. Calculate impedance for multiple subwoofers does the arithmetic for any set, and what 1 ohm stable means explains why the lowest reachable figure is not always the one to wire for.

Read the per-chamber volume, not the total

The total net volume tells you how big the cabinet is. The per-chamber figure tells you what each driver is working into, and that is the number that decides how the box sounds. Both are on every listing.

Sealed is the whole page

Every triple and quad cabinet we cut is sealed. At three drivers the port volume a vented box needs stops fitting in the space that made the high driver count attractive in the first place. If ported is what you want, it is a two driver or single driver build: the ported page has every vented cabinet.

Or step down a count

The dual 8 inch page and the single 8 inch page cover the same drivers in narrower cabinets.

Will a Triple 8 Fit?

Measure the width first, every time

These are built on 3 platforms, 29, 32 or 40 inches wide, and every listing prints its full external dimensions. Width is the constraint at this driver count, not depth or height. Measure the narrowest point of the opening, at seat-back height rather than along the floor, then work down the page from the platform that fits.

Behind a truck seat

The wedges are cut for the space between the seat backs and the rear wall of a cab. How to measure for a wedge box behind a truck seat walks through the three measurements that matter, and which box fits your cab covers the common cabs by name.

If the width is not there

Two drivers in the same size need less of it. The dual 8 inch page has the same build standards in a narrower cabinet.

The Triple 8 Inch Range at a Glance

Performance Optimized (a sealed chamber per driver): wedge, cut for Alpine, Arc Audio, AudioControl, DD Audio, Dayton Audio, Image Dynamics and more. From $359.99.

Performance (universal) (a sealed chamber per driver): standard front-firing, universal fit. From $199.99.

Pricing across the page runs from $199.99 to $559.99, shipping included. The cabinets sit on a small number of platforms 29, 32 or 40 inches wide, and every listing prints its full external dimensions. Browse the full lineup above.

Driver-matched

Performance Optimized triples

Triple 8 inch·From $359.99

Sealed, a chamber per driver. Wedge, cut to a named driver.

1 year limited warranty on Performance Optimized

Universal

Performance (universal) triples

Triple 8 inch·From $199.99

Sealed, a chamber per driver. Standard front-firing, universal cutout.

1 year limited warranty on Performance (universal)

Construction and chamber layout are stated on each product page.

Triple 8 Inch Subwoofer Box Questions

Do the three drivers share one chamber?

No. Every cabinet on this page splits the volume with bonded full-height dividers, so each driver gets its own sealed air space and its own polyfill. The listing states the total net volume and the figure per chamber.

Is the net volume per driver or for the whole box?

The headline figure is for the whole cabinet. Each listing also gives the per-chamber volume, which is what one driver is working into and the number the alignment was solved from.

How wide is a triple 8 inch box?

They are built on 3 platforms, 29, 32 or 40 inches wide, and every listing prints its full external dimensions. Width is the constraint at this driver count, so measure the narrowest point of the opening first.

What impedance will three subwoofers give me?

The cabinet wires every driver position in parallel to one terminal cup, so the choice is each driver's own coils. Three dual 4 ohm drivers reach 2.67 ohms with the coils in series or 0.67 ohms with them in parallel; dual 2 ohm drivers reach 1.33 ohms or 0.33 ohms. Match the final load to the amplifier's minimum stable impedance rather than chasing the lowest figure. Calculate impedance for multiple subwoofers works through any set.

Can I run different subwoofers in one cabinet?

No. Run three of the same model at the same impedance. Each chamber is cut to one driver's parameters, and because the positions are paralleled inside the cabinet a different driver in one of them changes the load for the whole set.

Are there ported triple 8 inch boxes?

Not from us. At three drivers the extra volume a port needs no longer fits in the space that made the high driver count worth doing. Vented builds are single and dual cabinets, on the ported page.

Is a triple 8 better than two tens?

They move close to the same air. Three eights spread it over more motors with less moving mass on each, which starts and stops faster and shares the heat; Two tens get there with fewer drivers to buy, mount and wire, and a simpler final impedance. What will physically go in the space usually settles it. The dual subwoofer setup guide covers the trade in detail.

Last updated November 12, 2026