Sundown X18 v4

1.549,00€

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Subwoofer

Packaging unit

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Wiring Wizard & Port Calculator

Use our wiring assistant for easy speaker and subwoofer connections! The correct connection is important for your amplifier! Low-impedance operation can damage the amplifier! The datasheet shows you which connection each amplifier is designed for!

Our port calculator shows you the tuning characteristics of your enclosure! The net volume is always particularly important here; calculate the subwoofer’s actual resonant chamber volume beforehand to get the correct result. The net volume is calculated by subtracting all dead spaces and is crucial for enclosure design.

The Sundown Audio X18 v4 is an uncompromisingly designed 18-inch subwoofer for high-performance car audio systems that require powerful low-frequency response, high sound pressure levels, and exceptional mechanical durability. With a power handling capacity of 3,000 watts RMS and a linear cone excursion of 30 mm Xmax, the X18 v4 moves enormous volumes of air, making it ideal for performance-oriented bass and SPL setups.

The solid motor structure, with a diameter of approximately 235 mm, combined with the high-performance voice coil, ensures precise control of the diaphragm’s movement. The robust design really comes into its own, especially at low frequencies and high power levels. The X18 v4 is available in versions with 2 × 1 ohm or 2 × 2 ohm voice coils, allowing for flexible pairing with high-power mono power amplifiers.

For standard use, a large bass-reflex enclosure is particularly recommended. Sundown specifies a net volume of approximately 198 liters for this, tuned to 32 Hz. This makes the X18 v4 an excellent choice for systems that require not only high volume but also massive low-frequency bass and palpable impact.

Technical Specifications

Manufacturer: Sundown Audio
Model: X18 v4 / X-18 v.4
Series: X Series v4
Subwoofer size: 18" / 46 cm
RMS Power Handling: 3,000 watts
Peak power: 6,000 watts
Voice Coils: Dual Voice Coil
Impedance options: 2 × 1 ohm (D1) or 2 × 2 ohms (D2)
Xmax: 30 mm
Outer diameter: approx. 467.9 mm
Installation diameter: approx. 423.9 mm
Installation depth: approx. 381 mm
Motor diameter: approx. 235 mm
Subwoofer displacement: approx. 7.93 liters

Thiele-Small parameters – D1 / 2 × 1 ohm

Re: 2.05 ohms
Fs: 25.87 Hz
Volume: 93.67 liters
Qes: 0.63
Qms: 4.13
Qts: 0.54
BL: 19.74 N/A
Mms: 737.81 g
Cms: 51.28 µm/N
Sensitivity: 86 dB (1 W / 1 m)
Xmax: 30 mm

Thiele-Small parameters – D2 / 2 × 2 ohms

Re: 3.74 ohms
Fs: 25.58 Hz
Volume: 93.67 liters
Qes: 0.55
Qms: 4.03
Qts: 0.84
BL: 26.8 N/A
Mms: 656.74 g
Cms: 58.9 µm/N
Sensitivity: 87 dB (1 W / 1 m)
Xmax: 30 mm

Recommended Enclosure: Bass Reflex

Recommended net volume: approx. 198 liters / 7.0 ft³
Recommended tuning frequency: 32 Hz
Recommended port area: approx. 723 cm² / 112 in²
Enclosed housing: Not recommended by the manufacturer for this size

Recommendation for a 4th-Order Bandpass Filter

Enclosed chamber: approx. 85 liters / 3.0 ft³
Bass reflex chamber: approx. 255 liters / 9.0 ft³
Port area: approx. 1,161 cm² / 180 in²
Port length: approx. 203 mm / 8"

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Frequently asked questions about the Sundown X18 v4 subwoofer

How much power does the Sundown X18 v4 require for optimum performance?

The Sundown X18 v4 is rated at 3,000 watts RMS and delivers a peak power output of up to 6,000 watts, making it ideal for high-powered SPL and everyday set-ups.

What size enclosure does the 18-inch subwoofer require?

The X18 v4 is optimised for ported enclosures. A volume of around 198 litres (approx. 7.0 cu ft) with a recommended port tuning frequency of 32 Hz ensures maximum performance.

How low does the Sundown X18 v4 go in terms of Hz?

The subwoofer easily reaches frequencies below 20 Hz and still delivers a noticeable sound pressure level even at 15–18 Hz. Its precise low-frequency reproduction makes it the top choice for car audio enthusiasts.

Can I run two X18 v4 subwoofers in parallel?

Yes, a dual configuration is possible and doubles the cone area for even more bass. Make sure you check the resulting total impedance in ohms and that your power amplifier can deliver the necessary power.

What is the maximum excursion of the Sundown?

The X18 v4 offers an impressive high excursion of over 30 mm on one side. This extreme range of movement enables tremendous sound pressure at low frequencies with astonishingly low distortion.

What makes the Sundown Audio X18’s motor structure so special?

The solid 190mm magnet and the optimised voice coil ensure precise control even under peak loads. The advanced motor design guarantees minimal distortion even at extreme volume levels.

How long does the X18 v4 last under continuous use?

When installed correctly and with adequate ventilation, the Sundown is designed for years of continuous operation. Its robust construction, using high-quality materials, makes it a reliable choice for discerning bass enthusiasts.

Sundown X18 v4 - Here's what our expert has to say

The Sundown X18 v4 proves that true bass power only makes an impression when it remains under control – and that’s exactly what it’s built for.