Proline X PO 10-S DF RSW sealed down-fire enclosure, 30 inches wide by 4.75 inches tall, feet add 1.75 inches. Optimized for Alpine RS-W.

Proline X PO 10-S DF RSW sealed down-fire enclosure, front baffle with a single flush-mount cutout, 30 by 15 inches. Optimized for Alpine RS-W.

Proline X PO 10-S DF RSW sealed down-fire enclosure, end panel with recessed terminal cup, 4.75 inches deep by 15 inches tall. Optimized for Alpine RS-W.

Proline X

Performance Optimized Down Fire Sealed 10" Enclosure | Alpine RSW10

Q: How is this enclosure only 4.75 inches tall?

The neodymium motor. Most shallow subwoofers use a ferrite magnet, which is a large slug of material sitting behind the cone that both occupies internal volume and adds to the driver's overall depth. The Alpine RS-W10 uses a high-grade neodymium magnet instead, which delivers the same motor force from a far smaller structure. Alpine publishes a displacement of just 0.04 cubic feet for this driver, less than half what a typical 10 inch shallow displaces. Almost all of the cabinet volume is usable air, so a 0.50 cubic foot net enclosure fits inside a 4.75 inch tall box.

Q: Why 0.50 cubic feet when Alpine's range goes up to 1.0?

Because height is the whole point of this cabinet. 0.50 net is Alpine's own small-volume sealed recommendation and they publish an F3 of 32 Hz there. Going larger does help: Alpine lists 30 Hz at 0.75 net and 28 Hz at 1.00 net. But each step up adds cabinet height, and this enclosure exists to fit under seats where nothing else in the line will go. If your install has room for a 1.0 cubic foot box, you likely have room for a conventional subwoofer rather than a shallow one.

Q: Should I choose the RS-W10D2 or the RS-W10D4?

Both fit this cabinet identically and both carry the same 600 watt RMS rating, 20mm Xmax and neodymium motor. The difference is the load they present to your amplifier. The RS-W10D2 has dual 2 ohm coils, giving a 1 ohm load in parallel or 4 ohms in series. The RS-W10D4 has dual 4 ohm coils, giving 2 ohms in parallel or 8 ohms in series. Choose whichever produces a load your amplifier is stable and efficient at. Alpine's application guide ships with the driver and diagrams every option.

Q: How much excursion does this driver actually have?

20mm of one-way linear excursion and 54mm of peak-to-peak mechanical travel. That is a genuinely high figure for a shallow-mount 10, where many competing drivers offer half as much. Alpine pairs it with their DD Linear dual magnetic gap, which is designed to keep distortion low while the cone is operating out at those excursion levels rather than only near rest.

Q: Where is the terminal cup located on a down fire enclosure?

Side mounted. Every Proline X Performance Optimized enclosure uses a side mounted terminal cup regardless of alignment, whether standard, wedge, or down fire. On this cabinet that keeps the connection fully accessible with the enclosure in its installed position, since the baffle faces the floor. The cup is our Proline X ABS and carbon fiber composite unit, recessed, with stainless hardware, copper ring terminals, and pre-wired 12 gauge OFC.

Q: Why are the corners square instead of radiused?

Down Fire cabinets are built with square corners as a series standard. The 3 inch top down corner radius used on other Proline X alignments does not apply here. A down fire box is a low, wide platform that sits flat against a floor or under a seat, and square corners maximize usable internal volume for a given footprint while keeping the cabinet stable on its mounting surface.

Q: How is this enclosure built?

V-groove and dado joinery, CNC-cut on ShopSabre routers from Langboard Elite MDF. Every panel joint is a machined interlocking groove that mechanically locks the panels before adhesive is applied, which is what keeps the cabinet airtight under sustained pressure cycling. The front baffle is a double layer at 1.5 inches, two bonded 3/4 inch sheets. That matters especially on a cabinet only 4.75 inches tall, where short panel spans leave little room for bracing geometry and the baffle carries more of the structural load. Perimeter cross-bracing and pre-installed polyfill complete the build. Assembled and inspected in Tullahoma, Tennessee.

Q: Is the Alpine RS-W10 subwoofer included with this enclosure?

No. This listing is for the enclosure only. Bring your own Alpine RS-W10D2 or RS-W10D4. The cutout and mounting depth are direct fit for either version.

SKU: PO 10-S DF RSW

QUICK SPECS

Alignment: 0.50 cu ft net, Alpine's small-volume sealed target with a published F3 of 32 Hz. Qtc 1.49 / Fc 47 Hz / F3 32.9 Hz (D2), Qtc 1.94 / Fc 50 Hz / F3 34.1 Hz (D4)
Driver: Alpine RS-W10D2 (DVC 2Ω) or RS-W10D4 (DVC 4Ω), 600W RMS / 1800W peak, 20mm Xmax, 0.04 cu ft displacement, neodymium motor
Power: 500 to 600 watts RMS recommended; the thermal rating is reached before the 20mm travel limit, and a 25 Hz subsonic buys about 1 percent more
Build: Proline X V-groove and dado joinery, double-layer 1.5" front baffle, perimeter cross-brace, 12g OFC side-mounted terminal cup
Cabinet: 30"W x 15"D x 4.75"H in down fire position, square corners, no standoffs, among the shortest enclosures in the Down Fire line

Shipping Included No freight charges at checkout. What you see is what you pay.

Built in Tennessee CNC cut from 3/4" Langboard Elite MDF. V-groove and dado joinery.

Advanced Terminal Cup Built in-house. ABS/Carbon Fiber. Stainless steel hardware. Copper ring terminals.

$ 249.99

In Stock and Ready to Ship

Financing available. Choose Shop Pay Installments at checkout.

Performance Optimized Down Fire Sealed 10" Enclosure | Alpine RSW10

$ 249.99

Enclosure Type Sealed

External Dimensions 30" W x 15" D x 4.75" H (measured in down fire position)

Gross Volume 0.56 cu ft

Net Volume 0.50 cu ft

Weight 30 lbs

Front Panel Thickness 1.5"

INSTALLER'S TAKE

This is the shortest cabinet we build in the Down Fire line. 4.75 inches. If you have measured your under-seat space and everything else in the series is an inch too tall, this is the one that goes in.

Neodymium is the reason it works. Every other shallow in this series carries a ferrite slug behind the cone that eats internal volume and adds height. The RS-W10 does not. Alpine publishes 0.04 cubic feet of displacement, which is less than half what most 10 inch shallows displace, so almost all of the cabinet volume is usable air. That is what lets a 0.50 net box come in under 5 inches tall.

The driver itself is not a compromise. 600 watts RMS, 20mm of one-way linear excursion, 54mm of peak-to-peak mechanical travel, and a 4 inch high-temp voice coil. Twenty millimeters of Xmax on a shallow 10 is a real number - most drivers in this category run half that. The DD Linear dual magnetic gap is Alpine's approach to keeping distortion down when the cone is actually using that excursion, and the motor cooling fins and vented former handle the thermal side.

On volume: 0.50 net is Alpine's own small-volume recommendation and they publish 32 Hz F3 there. Their range runs to 1.0 cubic feet, and 0.75 gets you 30 Hz while 1.0 gets 28 Hz. Real gains, but each step costs cabinet height, and on a driver whose entire reason for existing is fitting where nothing else fits, trading height for 2 Hz defeats the purpose. If you have the clearance for a 0.75 or 1.0 net box, you probably have the clearance for a driver that is not a shallow.

Dual voice coil in either 2 ohm or 4 ohm. Set your final impedance at the driver. Alpine's application guide in the box covers every wiring option for both versions. Target 500 to 600 watts RMS.

Product Details

Proline X Performance Optimized Down Fire 10" Sealed

Cut and tuned for the Alpine RS-W10 Shallow

V-Groove and DadoLangboard Elite MDF0.50 cu ft NetShortest In The Line

0.50cu ft net

1.49system Qtc, D2

32.9-34.1 HzF3 rolloff

4.75 incabinet height

Performance, Performance Optimized, and Micro

Proline X builds three tiers of Down Fire enclosure. The difference is not finish or materials, it is whether the cabinet was designed for a category or for a driver, and how much of the fitting work is already done for you.

	Performance	Performance Optimized	Micro Series
Fitment	Universal. Accepts any subwoofer that clears the published cutout and mounting depth.	Woofer specific. Cut for one named subwoofer, with cutout, mounting depth, magnet clearance and displacement drawn in CAD from that driver.	Woofer specific. Cut for one named subwoofer.
Footprint	Sized to the driver diameter. 24.5 by 13.5 inches on the 10 inch.	Shared 30 by 15 inch platform on most builds, with cabinet height as the variable. A few drivers need a wider or deeper platform.	Compact per driver footprint. 21.5 by 14.5 inches on the 10 inch.
Front baffle	Single, 3/4 inch.	Double, 1.5 inch, outer layer machined as a flush recess.	Double, 1.5 inch.
Driver mounting	Solid flange. You drill your own mounting holes.	8/32 threaded inserts, stainless machine screws included.	8/32 threaded inserts, stainless machine screws included.
Joinery	V-groove and dado, CNC cut.	V-groove and dado, CNC cut, perimeter cross brace.	Stack fab, dowel reinforced.
Published alignment	Modeled Qtc profiles across a range of drivers. No single response curve.	A real predicted Qtc and F3 for that exact driver, calculated from its own Thiele-Small parameters.	Target alignment described in the listing.
Carpet	Gray standard, black optional.	Plush black.	Plush black.
Warranty	1 year limited.	1 year limited.	2 years.

Feet ship with every tier, uninstalled on purpose. Mount them where your floor wants them for a down fire install, or leave them off and run the cabinet front firing or up firing. The orientation is yours to choose.

This page is a Performance Optimized enclosure. The airspace, the cutout and the cabinet height all come from the Alpine RS-W10's own published numbers. A Performance box fits your subwoofer. A Performance Optimized box was built for it.

Built Around the Alpine RS-W10

Nothing about this cabinet is generic. The baffle is bored to the RS-W10's 9-5/8 inch, 243mm cutout, and the internal height is set by a driver that displaces only 0.04 cubic feet, the smallest published displacement of any driver in the Down Fire series. That is what puts the finished cabinet at 4.75 inches tall on a 30 by 15 inch footprint, the shortest enclosure in the line. If you have measured your under seat space and everything else in the series is an inch too tall, this is the one that goes in.

The driver ships as the RS-W10D2, dual 2 ohm, or the RS-W10D4, dual 4 ohm. Both are rated 600 watts RMS and 1800 watts peak, with 20mm of one way linear excursion and 54mm of peak to peak mechanical travel across 380 cm² of cone area. The motor is a high-grade neodymium design driving a 4 inch high-temperature USA-wound voice coil, with Alpine's DD Linear dual magnetic gap holding distortion down when the cone is actually using that excursion, a vented coil former for airflow, and motor cooling fins that pull heat off the coil. The frame is die-cast aluminum with a black anodized threaded rear mounting frame and an aluminum dust cap.

Neodymium is why the cabinet can be this short. There is no ferrite slug behind the cone eating internal air and adding height, so nearly all of the machined cavity is usable volume. Free air resonance is 30.0 Hz, and the motor's efficiency bandwidth product sits at 18.7 to 27.0 depending on coil, well inside the range that calls for a sealed load rather than a ported one.

Net Volume, Not Gross

We build this cabinet at 0.50 cubic feet net out of a 0.539 cubic foot gross cavity. That is Alpine's own small-volume sealed target, and Alpine publishes an F3 of 32 Hz at this volume.

True net, not marketing net. Internal volume is calculated from the machined cavity dimensions and the driver's published displacement, not estimated from external dimensions minus wall thickness.

The two coil variants do not load the same box the same way, so both are worth stating. The Dual 2-Ohm has a Qts of 0.950 and a 20.64 litre Vas; in 0.50 cubic feet it lands at Qtc 1.49, resonance lifted to 47 Hz, half power at 32.9 Hz. The Dual 4-Ohm has a Qts of 1.190 and a 23.35 litre Vas; it lands at Qtc 1.94, resonance at 50 Hz, half power at 34.1 Hz. Both figures are anechoic, taken before any cabin gain.

Alpine's published sealed range runs 0.45 to 1.0 cubic feet, and larger volumes do reach lower: 0.75 net gives 30 Hz, 1.00 net gives 28 Hz. We build 0.50 because it is what holds the cabinet at 4.75 inches. A down fire enclosure that no longer fits under a seat has given up the thing that makes it worth building. Firing down into the floor, the sealed rolloff meets rising cabin gain below 60 Hz, and in-car response extends well below the published figure.

Down Fire Construction

Cut with V-groove and dado joinery on our ShopSabre routers from Langboard Elite 3/4 inch MDF. Every panel joint is a machined interlocking groove that mechanically locks before adhesive is applied, which keeps the cabinet airtight under sustained pressure cycling. A perimeter cross-brace ties the long spans together on a 30 inch wide panel. Corners are square on Down Fire cabinets.

Double Baffle, Flush Recess

The front baffle is 1.5 inches, two bonded 3/4 inch sheets, with the outer layer machined as a flush recess so the driver bolts to the inner layer. That recovers 3/4 inch of internal clearance. Mounting is into 8/32 threaded inserts with stainless machine screws included.

Side-Mounted Terminal Cup

Proline X ABS and carbon fiber composite cup with stainless hardware, pre-wired in 12 gauge OFC. Side mounted so it stays accessible with the baffle facing the floor. One cup, and both coil variants are dual voice coil, so final impedance is set at the driver.

Shortest In The Line

30 in W x 15 in D x 4.75 in H, measured in the down fire position, with no standoffs under the cabinet. Nothing else in the Down Fire series comes in under 5 inches. Polyfill is pre-installed and the shell is wrapped in plush black carpet.

Power and Warranty

Alpine rates the RS-W10 at 600 watts RMS and 1800 watts peak. Target 500 to 600 watts RMS on the amplifier. In this specific volume the cone does not run out of travel first: it reaches its 20.0mm one way limit somewhere between 998 and 1011 watts depending on which coil you have, which is above what the driver can absorb thermally, so the voice coil gives up before the suspension does.

A subsonic filter at 25 Hz, 24 dB per octave, stops the cone wasting travel below the passband and moves that same 20.0mm limit out to roughly 1005 to 1028 watts. That is about 1 percent more amplifier for the price of one filter setting, and it is cheap insurance either way.

Both versions are dual voice coil, so you set your final impedance at the driver, and Alpine's application guide covers every wiring option for each. The enclosure carries a 1 year limited warranty. Bring your own RS-W10D2 or RS-W10D4; the driver is purchased separately.

Cut for the Driver, Not the Catalog

This cabinet exists because one driver's published numbers said 0.50 cubic feet and 4.75 inches. Machined on our ShopSabre routers and built one at a time in Tullahoma, Tennessee.

Specifications

Series	Proline X Performance Optimized Down Fire
Compatible Driver	Alpine RS-W10D2 (DVC 2Ω) or RS-W10D4 (DVC 4Ω)
Enclosure Type	Sealed \| Down Fire Geometry \| Floor-Coupled
Firing Direction	Down Firing, Driver Fires Toward Floor
External Width	30 Inches
External Depth	15 Inches
External Height	4.75 Inches
Dimension Reference	All External Dimensions Measured In Down Fire Position
Internal Volume (Gross)	0.539 Cubic Feet
Internal Volume (Net After Displacement)	0.50 Cubic Feet
Alpine Published Sealed Range	0.45 - 1.0 Cubic Feet
Alpine Alternate Alignments	0.75 ft³ = 30 Hz \| 1.00 ft³ = 28 Hz
Published F3 At This Volume	32 Hz (Alpine Small-Volume Sealed Spec)
System Qtc	1.49 (D2) \| 1.94 (D4)
Predicted Fc	47 Hz (D2) \| 50 Hz (D4)
Predicted F3	32.9 Hz (D2) \| 34.1 Hz (D4)
Driver Fs	30.00 Hz (Free-Air Resonance)
Driver Qts	0.950 (D2) \| 1.190 (D4)
Driver Vas	20.64 L (D2) \| 23.35 L (D4)
Driver Cone Area (Sd)	380 cm²
Driver Xmax (One-Way)	20mm
Driver Xmech (Peak-to-Peak)	54mm
Driver Power Handling	600 Watts RMS / 1800 Watts Peak
Driver Voice Coil	4 Inch, High-Temp USA Wire
Driver Motor	High-Grade Neodymium, DD Linear Dual Magnetic Gap
Driver Displacement	0.04 Cubic Feet (Published by Alpine)
Mounting Depth	Direct Fit
Woofer Opening	9-5/8 Inches / 243mm (Alpine Spec)
Standoffs	Not Used On This Model
Material	Langboard Elite 3/4" MDF
Construction	ShopSabre CNC / Perimeter Cross-Brace
Joinery	V-Groove and Dado (CNC-Cut)
Panel Thickness	3/4 Inch
Front Baffle Construction	Double-Layer 1.5" MDF (Two 3/4" Sheets Bonded)
Corner Profile	Square (Down Fire Series Standard)
Driver Mounting	8/32 Threaded Inserts \| Stainless Steel Machine Screws Included
Voice Coil Configuration	Dual Voice Coil, Final Impedance Set At The Driver
Terminal Cup	Proline X ABS/Carbon Fiber Composite \| Side Mounted \| 12g OFC Pre-Wired
Internal Wiring	12 Gauge OFC, Pre-Wired
Damping	Polyfill Pre-Installed
Recommended Power	500-600 Watts RMS (Alpine Rated: 600W RMS)
Carpet Finish	Plush Black
Weight	26 lb
Bundle Options	Enclosure Only (Bring Your Own RS-W10D2 or RS-W10D4)
Warranty	1-Year Limited (Enclosure)
Built In	Tullahoma, Tennessee, USA

Performance Graphs

Net airspace

0.50

cu ft per chamber

System Qtc

1.49–1.94

sealed

Half power

32.9–34.1

Hz · F3

Xmax at

998

W RMS · no filter

With 25 Hz subsonic

1005

W RMS · +1%

Amplifier

500–600

W RMS recommended

This enclosure holds 0.50 cu ft net per chamber. In it the Alpine RS-W10D2 runs a system Qtc of 1.49–1.94 with half power at 32.9–34.1 Hz, and the cone reaches its 20.0 mm travel limit at 998 W, above the driver’s 600 W thermal rating, so heat stops you before travel does. Run a subsonic filter at 25 Hz and that becomes 1005 W — +7 W, or 1 percent more power for the same 20.0 mm of travel.

01Is it a sealed driver?

Efficiency bandwidth product places the motor before anything else is decided.

EBP = Fs ÷ Qes = 18.7–27.0

D2 · EBP 27.0D4 · EBP 18.7

EBP under 50 means a motor that wants a sealed load. The RS-W10D2 sits at 18.7–27.0, inside that band, which is why this is a sealed build rather than a ported one.

02What the box does to it

0.50 cu ft against a 20.6 L Vas.

α = Vas ÷ Vb = 1.46 · Fc = Fs√(α+1) = 47–50 Hz · Qtc = 1.49–1.94

D2 · Qtc 1.49, Fc 47 Hz, F3 32.9 HzD4 · Qtc 1.94, Fc 50 Hz, F3 34.1 Hz

The box lifts resonance from 30.0 Hz free-air to 47–50 Hz and half power lands at 32.9–34.1 Hz, anechoic, before any cabin gain. This enclosure ships without a driver, so both coil variants the maker offers are plotted. They do not load the same box the same way.

03The watts that reach Xmax (in this enclosure)

Travel scales with the square root of power, so there is one wattage that puts the cone exactly on 20.0 mm — and a bigger one once a subsonic filter stops it wasting travel below the passband.

P_Xmax = 998–1011 W unfiltered → 1005–1028 W with a 25 Hz subsonic

D2 · 1011 W, no filterD4 · 998 W, no filterD2 · 1028 W with subsonic at 25 Hz, 24 dB/octD4 · 1005 W with subsonic at 25 Hz, 24 dB/octXmax 20.0 mm one-way

Every trace touches the limit and no further, because each is drawn at the exact power that puts that coil on 20.0 mm. Unfiltered that is 998 W, reached first at 47 Hz. It sits above the 600 W the driver can take thermally, so the voice coil gives up before the suspension does. The dashed traces are the same driver behind a subsonic filter at 25 Hz, 24 dB/oct: stopping the cone wasting travel below the passband lets it take 1005 W before hitting the same 20.0 mm. That is 1 percent more amplifier for the price of one filter setting.

Param	Value	Unit	Note
Fs	30.00	Hz	free-air resonance
Qts	0.950 / 1.190		D2 / D4
Vas	20.64 / 23.35	L	equivalent compliance
Sd	380.0	cm²	effective piston area
Xmax	20	mm	one-way linear travel
Pe	600	W	continuous RMS
SPL	78.9	dB	1 W / 1 m, derived from T/S

Driver parameters as published by Alpine R-Series Shallow application guide. Curves computed against this enclosure’s actual net airspace.

Materials

Material

Built From a Spec Sheet, Not a Sales Sheet

Every Proline X Performance Series enclosure is CNC-cut from Langboard Elite MDF, 3/4" (18mm) panels produced to published mill specifications. Most enclosure manufacturers source generic MDF without published data. We can tell you the internal bond rating, the modulus of elasticity, the modulus of rupture, and the face and edge screw holding strength for every panel in this enclosure, because we chose the material based on those numbers, not on price or availability.

Langboard Elite is produced in the United States. The specifications below are pulled directly from Langboard's published mill data and are verifiable. This is the same panel stock used in our full Proline X lineup.

Specifications

Langboard Elite MDF: Published Mill Data

Property	Value	Why It Matters
Panel Stock	Langboard Elite MDF	Named, verifiable panel source, not generic "high-density MDF"
Thickness	3/4" (18mm)	Industry standard for subwoofer enclosures; panels below this flex under pressure
Density	48.5 lbs/ft³	Higher density = less porosity, better screw retention, reduced resonance
Internal Bond	200 psi	Measures resistance to delamination under sustained internal pressure. The most enclosure-relevant spec on this sheet
Modulus of Rupture (MOR)	4,200 psi	Bending strength before the panel breaks, relevant for larger unsupported baffle spans
Modulus of Elasticity (MOE)	410,000 psi	Stiffness under load; higher MOE means less panel flex under bass pressure, less resonance
Face Screw Holding	325 lbs	How firmly the panel surface holds a screw; critical for baffle joint integrity over time
Edge Screw Holding	250 lbs	Panel edge retention, relevant for every joint that isn't face-to-face

Internal Bond

200 psi: The Number That Actually Matters for Enclosures

The internal bond rating measures how well the MDF panel resists delamination under sustained pressure applied perpendicular to the face. In a subwoofer enclosure, every bass transient generates a pressure pulse that pushes outward on every panel simultaneously. A panel that begins to delaminate internally loses stiffness gradually. The symptoms are slow: a box that starts to sound softer, less defined, less punchy over months of use. 200 psi internal bond is the spec that determines how long this enclosure holds its acoustic integrity under daily use at real power levels.

Stiffness

410,000 psi MOE: Less Flex, Less Resonance

The modulus of elasticity measures panel stiffness, its resistance to bending under load. A stiffer panel flexes less under the pressure generated by a high-excursion driver at volume. Panel flex is a source of acoustic coloration: the panel itself begins to radiate sound at its own resonant frequency, adding distortion to the output. 410,000 psi stiffness combined with V-groove and dado joinery means the panels stay rigid and the bracing controls resonance at the structure level, not the panel level. The bass you hear comes from the driver, not the box.

Screw Holding

325 lb Face / 250 lb Edge: Joints That Stay Locked

Screw holding strength determines how firmly the panel grips a fastener at the face and at the edge. This matters most at the baffle joint, where the front panel meets the side panels and where the driver is mounted. A panel with low screw holding strength allows fasteners to loosen over time under vibration, leading to air gaps at the joint and loss of acoustic seal. 325 lb face screw holding strength means the baffle hardware stays put. Combined with dado joinery and adhesive, the front panel on a Proline X Performance Series enclosure is not going anywhere.

Sourcing

Named Panel Stock: Not "Premium MDF"

The phrase "premium MDF" or "high-density MDF" appears on marketing copy for enclosures across every price point, from $40 to $400. It is not a specification. It is a description with no defined standard. Langboard Elite is a named, sourced, mill-documented product with published data. We name it in our copy because naming it holds us accountable to the spec. You can look up Langboard Elite independently, verify the numbers on this page, and confirm you are getting what we say you are getting. That is the point.

Why Proline X?

Most enclosures are built to a price point. Proline X is built to a spec. Every box starts with published-data MDF, gets CNC-cut to exact internal volume, and is assembled by hand in our Tennessee facility. The difference shows up in the measurements, and in how the box holds up two years into daily use.

CNC-Cut to Spec

Panels are machine-cut on ShopSabre CNC routers and joined with V-groove and dado joinery. Consistent geometry, no hand-cut variance, no gaps at the joints.