Performance Optimized Series PO 15D-S GUS woofer enclosure by Proline, featuring a black frame with two circular cutouts showing beige acoustic panels inside, with dimension markings of 36 inches by 17.5 inches.Proline X PO 15D-S GUS sealed wedge enclosure, interior through the baffle opening showing the 1.5 inch mounting baffle and pre-wired leads. Optimized for ResoNix GUS.A dark gray wedge-shaped car audio woofer shown on a black background with measurement labels indicating 15 inches tall, 13.5 inches wide, and 8 inches top width.

Performance Optimized · Datasheet

Performance Optimized Wedge Sealed Dual 15" Enclosure | ResoNix GUS-15 Dual 15" Sealed enclosure

Net volume
2.70 cu ft total, 1.35 cu ft per driver after displacement
External dimensions
36 in W × 17.5 in at the seat face H × 16.5 in at the base D
Front baffle
1.5 in, double baffle
Buy at Audio Intensity
  • Driver: ResoNix GUS-15 x2, direct fit only
  • Net Acoustic: 1.35 cu ft per driver, 2.70 total
  • Alignment: Qtc 0.707, ResoNix target
  • Chambers: Dual, full divider
  • Position: Trunk mount, tall face against rear seat
  • Firing: Rearward. No down fire option
  • Footprint: 36 in W x 16.5 in D at the base
  • Terminal Cups: Two, one per chamber
  • Weight: 60 lb

Technical specifications

SpecificationValue
SeriesProline X Performance Optimized Wedge
Compatible DriverResoNix GUS-15, quantity 2. Direct fit, no other driver
ConfigurationDual 15 inch, dual chamber sealed wedge
Mounting PositionTrunk or cargo area, tall face against the rear seat back
Firing DirectionRearward into the trunk. Not a down fire design, no feet included
External Width36 in
External Height17.5 in at the seat face
External Depth16.5 in at the base, tapering to 10 in at the top
Internal Volume, Gross2.85 cu ft total, 1.425 cu ft per chamber
Internal Volume, Net Acoustic2.70 cu ft total, 1.35 cu ft per driver after displacement
Target AlignmentQtc 0.707, ResoNix published target
Driver Displacement0.072 cu ft each
Woofer Opening356.17mm direct fit, both positions
Min Front Clearance33mm, both drivers
MaterialLangboard Elite MDF
ConstructionCNC cut, dado and V groove joinery
Panel Thickness0.75 in
Front Baffle1.5 in, double baffle
Chamber DividerFull divider, no shared airspace
Driver Mounting8/32 threaded inserts, stainless machine screws included, both positions
Terminal CupsTwo Proline X ABS and carbon fiber composite, side mounted, one per chamber, independently pre wired
Internal Wiring12 gauge OFC
DampingLight polyfill wall lining, does not alter acoustic volume
CarpetDark gray trunk liner standard, plush black available
BadgeWoofer face mounted, lasered acrylic
Weight60 lb
Warranty1 Year Limited
Built InTullahoma, Tennessee

Performance in this enclosure

Net airspace
1.35
cu ft per chamber
System Qtc
0.69–0.70
sealed
Half power
32.2–35.6
Hz · F3
Xmax at
1590
W RMS · no filter
With 25 Hz subsonic
3025
W RMS · +90%
Amplifier
1500
W RMS recommended
This enclosure holds 1.35 cu ft net per chamber. In it the ResoNix GUS-15 runs a system Qtc of 0.69–0.70 with half power at 32.2–35.6 Hz, and the cone reaches its 25.0 mm travel limit at 1590 W, above the driver’s 1500 W thermal rating, so heat stops you before travel does. Run a subsonic filter at 25 Hz and that becomes 3025 W — +1435 W, or 90 percent more power for the same 25.0 mm of travel.

01Is it a sealed driver?

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

EBP = Fs ÷ Qes = 44.1–50.3
SEALED 0–50 TRANSITION 50–100 PORTED 100–150 0 50 100 150 D4 50.3 D2 44.1
D4 · EBP 50.3D2 · EBP 44.1
The GUS-15 straddles the boundary at 44.1–50.3 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

1.35 cu ft against a 117.5 L Vas.

α = Vas ÷ Vb = 3.07  ·  Fc = Fs√(α+1) = 32–35 Hz  ·  Qtc = 0.69–0.70
20 30 50 70 100 150 200 +6 +0 -6 -12 -18 -24 FREQUENCY · Hz LEVEL · dB −3 dB
D4 · Qtc 0.69, Fc 35 Hz, F3 35.6 HzD2 · Qtc 0.70, Fc 32 Hz, F3 32.2 Hz
The box lifts resonance from 17.1 Hz free-air to 32–35 Hz and half power lands at 32.2–35.6 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 25.0 mm — and a bigger one once a subsonic filter stops it wasting travel below the passband.

PXmax = 1590–1720 W unfiltered  →  3025–3057 W with a 25 Hz subsonic
20 30 50 70 100 150 200 0 8 16 24 FREQUENCY · Hz CONE TRAVEL · mm PAST LINEAR TRAVEL · Xmax 25.0 mm 1590 W reaches Xmax here
D4 · 1720 W, no filterD2 · 1590 W, no filterD4 · 3057 W with subsonic at 25 Hz, 24 dB/octD2 · 3025 W with subsonic at 25 Hz, 24 dB/octXmax 25.0 mm one-way
Every trace touches the limit and no further, because each is drawn at the exact power that puts that coil on 25.0 mm. Unfiltered that is 1590 W, reached first at 20 Hz. It sits above the 1500 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 3025 W before hitting the same 25.0 mm. That is 90 percent more amplifier for the price of one filter setting.
ParamValueUnitNote
Fs17.11Hzfree-air resonance
Qts0.340 / 0.310D4 / D2
Vas117.47 / 157.94Lequivalent compliance
Sd804.2cm²effective piston area
Xmax25mmone-way linear travel
Pe1500Wcontinuous RMS
SPL84.2dB1 W / 1 m, derived from T/S

Driver parameters as published by resonixsoundsolutions.com. Curves computed against this enclosure’s actual net airspace.

Installer's take

This is a direct fit cabinet cut for the ResoNix GUS-15, which changes the install in one important way. The baffle carries threaded inserts set to the GUS-15 bolt circle, so you are not drilling and you are not relying on wood screws. Bring the driver down square, start every fastener by hand before you drive any of them, and torque in a star pattern. Inserts hold torque across repeated removal far better than screws in MDF, which matters on a driver this size if it ever comes out for service or an impedance change.

It is a true dual chamber cabinet with a full divider, so each driver gets its own sealed 1.425 cubic feet and its own terminal cup. That has a practical consequence at install time. There is no cross chamber wiring, which means you are running two separate sets of leads and you are free to wire the two drivers to different channels or to a single amplifier as the impedance allows. It also means one driver under hard excursion is not modulating the air load the other one sees, so the pair stays predictable at high output rather than getting soft in the middle.

The wedge geometry is doing real work here. The cabinet is 10 inches deep at the top and 16.5 at the bottom, which lets it sit tight against a rear seat back or bulkhead instead of standing square in a cargo area, and keeps the baffle off parallel with the rear glass. At 36 inches wide and 60 pounds empty this is a two person lift once the drivers are in, so plan the tie down before it goes in the vehicle. An unsecured enclosure of this mass is a safety problem in a hard stop, not just a rattle.

Questions

Can this enclosure be run down firing?

No. This is a trunk mounted wedge and it works in one orientation only. The tall face sits flat against the back of the rear seat, the cabinet tapers away toward the trunk lid, and the drivers fire rearward into the trunk. There are no feet and no baffle clearance gap. If you need an enclosure that can run down fire, the Proline X Micro Series Dual 15 Sealed Enclosure Built for ResoNix GUS-15 is a square stack fab cabinet that ships with feet and works in either orientation.

Will a standard 15 inch subwoofer fit this enclosure?

No. The opening is cut direct fit to the ResoNix GUS-15 at 356.17mm, and the chamber depth and volume are both built around that driver. A standard 15 will not fit the opening and would not see the correct airspace even if it did. That is what Performance Optimized means on this line. The enclosure is designed backward from one driver rather than sized to a diameter class.

Why is the gross volume 2.85 cubic feet but the net acoustic volume 2.70?

Gross volume is the empty chamber. Net acoustic volume is what the driver actually loads into after its own body displaces air. Each GUS-15 displaces 0.072 cubic feet. Each chamber is built at 1.425 cubic feet gross, so after the driver goes in the working airspace is 1.353 cubic feet, which is ResoNix's published 1.35 target. Across two chambers that is 2.85 gross and 2.70 net acoustic. The net figure is the one to enter into a modeling program.

Is this a common chamber or dual chamber enclosure?

Dual chamber. A full divider separates the two 1.425 cubic foot chambers and there is no shared airspace between them. Each driver loads independently, so one cone's motion does not modulate the air load the other driver sees under hard excursion. There is also no internal cross chamber wiring, since each chamber has its own terminal cup.

Why does this enclosure have two terminal cups instead of one?

Each chamber has its own Proline X terminal cup, pre wired with 12 gauge OFC to its own driver, so the amplifier configuration is left to the installer rather than fixed inside the box. The two common approaches are a dedicated monoblock per driver, or a single high output amplifier bridged externally across both terminals. The dual amplifier path gives the cleanest channel separation and the most consistent damping at high SPL, which matters for competition and serious sound quality builds.

Why is this a wedge instead of a square cabinet?

The cabinet is 10 inches deep at the top and 16.5 inches at the bottom. That taper lets it sit tight against a rear seat back or bulkhead rather than standing square in the middle of a cargo area, which recovers usable space in a hatchback or SUV. It also means the baffle is not parallel to the rear glass, which helps with the standing waves you get when a large flat baffle faces a large flat window.

How much does this enclosure weigh and how should it be secured?

The cabinet is 36 inches wide and weighs 60 pounds empty, which makes it a two person lift once drivers are fitted. Plan the tie down before the enclosure goes into the vehicle. Two 15 inch drivers in 2.85 cubic feet will move an unsecured cabinet, and an enclosure of this mass loose in a cargo area is a safety issue in a hard stop rather than just a rattle. Use proper anchors rather than a single ratchet strap.

What is the warranty and where is the enclosure built?

This enclosure carries a 1 year limited warranty on craftsmanship and materials, which is the standard across the Performance and Performance Optimized lines. Micro Series and Professional Series enclosures carry 2 years. It is CNC cut and assembled to order in Tullahoma, Tennessee from Langboard Elite MDF, with a double thickness baffle, a full chamber divider, threaded inserts set to the ResoNix GUS-15 bolt circle, and dual Proline X terminal cups.

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