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Proline X PO 12-S DF RSS315HF sealed down fire enclosure, front panel on 1.75 inch feet, 30 by 10.9 inches.
Proline X PO 12-S DF RSS315HF sealed down fire enclosure, end panel with recessed terminal cup, 15 by 10.9 inches.

Performance Optimized · Datasheet

Dayton Audio Reference RSS315HF Box: Sealed 12" Down Fire Enclosure Single 12" Sealed enclosure

Net volume
1.75 cu ft after the brace and the driver displacement
Max mounting depth
5.75 in required, 4.38 in clearance above the motor
External dimensions
30.00 in W × 10.88 in in the down fire position H × 15.00 in D
Front baffle
1.5 in double baffle, outer layer machined as a flush recess
Buy at Audio IntensityFactory-direct, ships from Tullahoma
Dayton Audio Reference RSS315HFBuy at Audio Intensity
  • Alignment: 1.75 cu ft net, Qtc 0.64 to 0.77, F3 44.3 Hz on the RSS315HF-4 (single 4 ohm) and 35.2 Hz on the RSS315HFA-8 (single 8 ohm)
  • Driver: Dayton Audio Reference RSS315HF (RSS315HF-4 (single 4 ohm) and RSS315HFA-8 (single 8 ohm)), 400 W RMS, 14.3 mm Xmax, 5.75 in mounting depth
  • Standoffs: Included, 1.75 in, shipped uninstalled. Installed height near 12.63 in
  • Cabinet: 30.00"W x 15.00"D x 10.88"H in down fire position, excludes standoffs, square corners

Spec of record

Technical specifications

SpecificationValue
SeriesProline X Performance Optimized Down Fire
Compatible DriverDayton Audio Reference RSS315HF (RSS315HF-4 (single 4 ohm) and RSS315HFA-8 (single 8 ohm)), quantity 1. Direct fit
ConfigurationSingle 12 inch, sealed down fire
Mounting PositionTrunk or cargo floor, baffle facing down on standoffs
Firing DirectionDownward. Feet ship uninstalled, so front or up firing is also possible
External Width30.00 in
External Depth15.00 in
External Height10.88 in in the down fire position, excludes standoffs
Installed Height12.63 in including the 1.75 in standoff
Internal Volume, Gross1.85 cu ft
Internal Volume, Net Acoustic1.75 cu ft after the brace and the driver displacement
Height Set ByAirspace; clearance alone would allow a lower cabinet
Driver Mounting Depth5.75 in required, 4.38 in clearance above the motor
Floor Slot0.77 times the cone area at the 1.75 in standoff
Alignment, RSS315HF-4 (single 4 ohm)Qtc 0.640, fc 39.7 Hz, F3 44.3 Hz anechoic
Alignment, RSS315HFA-8 (single 8 ohm)Qtc 0.774, fc 38.2 Hz, F3 35.2 Hz anechoic
Woofer Opening11.10 in, cut for Dayton's frame
Frame Outer Diameter12.36 in
Bolt Circle11.61 in, Dayton spec; threaded inserts pre-installed
Driver Displacement0.092 cu ft, estimated; Dayton publishes none
RSS315HF-4 (single 4 ohm) Fs / Qts / Qes / Qms / Vas24.2 Hz / 0.39 / 0.45 / 2.83 / 84.1 L
RSS315HFA-8 (single 8 ohm) Fs / Qts / Qes / Qms / Vas22.2 Hz / 0.45 / 0.54 / 2.5 / 97.2 L
Driver Sd515 cm2, Dayton spec
Xmax14.3 mm, one-way, as Dayton publish it
Driver Power Handling400 W RMS
Wiring OptionsDayton sells the RSS315HF as RSS315HF-4 (single 4 ohm) and RSS315HFA-8 (single 8 ohm): the RSS315HF-4 (single 4 ohm) is a single 4 ohm coil, a 4 ohm load; the RSS315HFA-8 (single 8 ohm) is a single 8 ohm coil, an 8 ohm load. A parallel load at or under 1 ohm needs an amplifier rated for it.
Parameter SourceDayton Audio spec sheet
MaterialLangboard Elite MDF
ConstructionCNC cut, V-groove and dado joinery, square corners
Panel Thickness0.75 in
Front Baffle1.5 in double baffle, outer layer machined as a flush recess
Internal BracingWindowed brace, dadoed to the shell
Driver MountingThreaded inserts pre-installed at Dayton's bolt circle; stainless machine screws included
Terminal CupsOne Proline X ABS and carbon fiber composite, side mounted, pre wired 12 gauge OFC
StandoffsIncluded, 1.75 in, shipped uninstalled
DampingLight polyfill wall lining, does not alter acoustic volume
CarpetPlush black
Shipping Weight45 lb
Warranty1 Year Limited
Built InTullahoma, Tennessee

Modelled response

Performance in this enclosure

Net airspace
1.75
cu ft
System Qtc
0.64–0.77
sealed
Half power
35.2–44.3
Hz · F3
Xmax at
251
W RMS · no filter
With 25 Hz subsonic
365
W RMS · +45%
Amplifier
400
W RMS recommended
This enclosure holds 1.75 cu ft net . In it the Dayton Audio RSS315HF runs a system Qtc of 0.64–0.77 with half power at 35.2–44.3 Hz, and the cone reaches its 14.3 mm travel limit at 251 W, below the driver’s 400 W thermal rating, so travel is what stops you here, not heat. Run a subsonic filter at 25 Hz and that becomes 365 W — +114 W, or 45 percent more power for the same 14.3 mm of travel.

01Is it a sealed driver?

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

EBP = Fs ÷ Qes = 41.1–53.8
SEALED 0–50 TRANSITION 50–100 PORTED 100–150 0 50 100 150 RSS315HF-4 53.8 RSS315HFA-8 41.1
RSS315HF-4 · EBP 53.8RSS315HFA-8 · EBP 41.1
The RSS315HF straddles the boundary at 41.1–53.8 depending on coil — part sealed-band, part transition. Either way it takes a sealed load happily; the coil you run shifts the alignment more than it shifts this verdict.

02What the box does to it

1.75 cu ft against an 84.1 L Vas.

α = Vas ÷ Vb = 1.70  ·  Fc = Fs√(α+1) = 38–40 Hz  ·  Qtc = 0.64–0.77
20 30 50 70 100 150 200 +6 +0 -6 -12 -18 -24 FREQUENCY · Hz LEVEL · dB −3 dB
RSS315HF-4 · Qtc 0.64, Fc 40 Hz, F3 44.3 HzRSS315HFA-8 · Qtc 0.77, Fc 38 Hz, F3 35.2 Hz
The box lifts resonance from 22.2–24.2 Hz free-air to 38–40 Hz and half power lands at 35.2–44.3 Hz, anechoic, before any cabin gain. Parameters are Dayton Audio’s own spec sheet for each coil plotted. Driver displacement is not published and is estimated. Only the coils this listing carries are plotted; the other version falls outside a well-behaved sealed alignment in this cabinet.

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 14.3 mm — and a bigger one once a subsonic filter stops it wasting travel below the passband.

PXmax = 251–269 W unfiltered  →  365–442 W with a 25 Hz subsonic
20 30 50 70 100 150 200 0 4 8 12 16 FREQUENCY · Hz CONE TRAVEL · mm PAST LINEAR TRAVEL · Xmax 14.3 mm 251 W reaches Xmax here
RSS315HF-4 · 269 W, no filterRSS315HFA-8 · 251 W, no filterRSS315HF-4 · 442 W with subsonic at 25 Hz, 24 dB/octRSS315HFA-8 · 365 W with subsonic at 25 Hz, 24 dB/octXmax 14.3 mm one-way
Every trace touches the limit and no further, because each is drawn at the exact power that puts that coil on 14.3 mm. Unfiltered that is 251 W, reached first at 20 Hz. It sits under the 400 W the driver can take thermally, so the enclosure sets the ceiling, not the voice coil. 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 365 W before hitting the same 14.3 mm. That is 45 percent more amplifier for the price of one filter setting.
ParamValueUnitNote
Fs24.20 / 22.20Hzfree-air resonance
Qts0.390 / 0.450RSS315HF-4 / RSS315HFA-8
Vas84.10 / 97.20Lequivalent compliance
Sd514.7 / 506.7cm²effective piston area
Xmax14.3mmone-way, as Dayton publish it
Pe400Wcontinuous RMS
SPL86.1dB1 W / 1 m, derived from T/S

Driver parameters as published by Dayton Audio spec sheet. Curves computed against this enclosure’s actual net airspace.

From the shop floor

Installer's take

1.75 cubic feet: Qtc 0.640 on the RSS315HF-4 (single 4 ohm) and Qtc 0.774 on the RSS315HFA-8 (single 8 ohm), F3 44.3 Hz on the RSS315HF-4 (single 4 ohm) and 35.2 Hz on the RSS315HFA-8 (single 8 ohm).

Measure the installed height, not the cabinet height: 10.88 tall on its own, 12.63 with the standoffs on the 30 by 15 footprint.

Floor slot is 0.77 times the cone area at the 1.75 standoff, under the 1.0 I like. For hard use, taller feet or front firing.

Dayton's spec sheet holds together on every check I run. Displacement is the one figure they do not give, so it is estimated.

Inserts are pressed at Dayton's bolt circle, so the driver bolts straight in. Sealed, so leave the polyfill as it is and run it at 400 watts or under per driver.

Before you order

Questions

Does this fit the Dayton Audio Reference RSS315HF, and will any other 12 inch fit?

The Reference RSS315HF, yes, in both coil versions. The baffle is cut to 11.10 in for Dayton's 12.36 in frame. The 5.75 inch motor clears the cabinet with 4.38 inch to spare.

Any other 12, no. The airspace is engineered around the Reference RSS315HF's own Qts and Vas, and a different woofer that happened to drop into the hole would not see the alignment printed on this page.

Why 1.75 cubic feet, and what alignment does it target?

1.75 cubic feet net on Dayton's published figures: the RSS315HF-4 (single 4 ohm) reads Qtc 0.640 with resonance at 39.7 Hz and half power at 44.3 Hz, and the RSS315HFA-8 (single 8 ohm) reads Qtc 0.774 with resonance at 38.2 Hz and half power at 35.2 Hz. One cabinet serves both coils, built to the volume that keeps both closest to maximally flat. That is spread either side of maximally flat: the lower-Q coil a little drier, the higher-Q coil a little punchier.

Cabinet gain in a vehicle lifts the bottom end further, so in the car this reads deeper than the anechoic figures.

What amplifier power should I run, and how should I wire it?

Dayton rates the Reference RSS315HF at 400 watts RMS, so target 280 to 400 watts RMS at the final load.

Dayton sells the RSS315HF as RSS315HF-4 (single 4 ohm) and RSS315HFA-8 (single 8 ohm): the RSS315HF-4 (single 4 ohm) is a single 4 ohm coil, a 4 ohm load; the RSS315HFA-8 (single 8 ohm) is a single 8 ohm coil, an 8 ohm load. A parallel load at or under 1 ohm needs an amplifier rated for it. Confirm your amplifier's minimum stable impedance first.

How tall is this once the standoffs are on?

The cabinet is 10.88 inches tall measured in the down fire position, and that figure excludes the standoffs. The standoffs hold 1.75 inches under the baffle, so plan your space around a finished stack of roughly 12.63 inches.

The footprint is the standard Performance Optimized down fire platform, 30.00 inches wide by 15.00 deep. Height is the only dimension solved to the driver.

Why is the front baffle double-layered?

The baffle is two bonded 3/4 inch sheets, 1.5 inches through. A single 3/4 inch panel flexes under the pressure a 12 inch woofer puts on it at 400 watts, which smears output and works the driver loose over time; the second layer stiffens the face and gives the mounting hardware twice the material to bite.

The outer layer is machined as a flush recess to Dayton's 12.36 inch frame, so the driver bolts to the inner layer.

What is the expected low-frequency extension?

Anechoic F3 is 44.3 Hz on the RSS315HF-4 (single 4 ohm) and 35.2 Hz on the RSS315HFA-8 (single 8 ohm). The lower-Q coil rolls off gently with F3 above fc; the higher-Q coil carries a small lift near resonance.

Those figures exclude cabin gain. In a car the cabin's transfer function adds real output below 50 Hz, so in-vehicle response runs deeper than the numbers above.

Do I need to add polyfill or damping?

No. Polyfill is already installed as a light wall lining to control internal reflections, and the quantity is chosen so it does not change the acoustic volume.

Do not add more. Packing a sealed box with fill makes it behave as though it were larger, which walks the alignment away from the 1.75 cubic feet this cabinet was built to.

Is the driver included, and are the threaded inserts installed?

No driver. This is an enclosure only. You receive the cabinet finished in plush black carpet, one side-mounted pre-wired terminal cup, the polyfill lining already in place, the standoffs, and stainless machine screws, with the threaded inserts already pressed.

The inserts are pressed at the shop on Dayton's published bolt circle for the Reference RSS315HF, so the driver bolts straight in. The Dayton Audio Reference RSS315HF is purchased separately, and the cabinet is cut direct fit to it, not a general purpose 12 inch box.

Same series, same size

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