Frequently Asked Questions
What enclosure do I need for a Sundown 18-inch subwoofer?
The Sundown X-18 v.3 requires 5.0 to 6.0 cubic feet net for a ported enclosure tuned to 28-32 Hz. For the NS-18 v.5 (Nightshade), plan for 6.0 to 8.0 cubic feet. These enclosures are large — measure your vehicle before ordering. Wall-mounted builds are common for 18-inch competition setups.
Is an 18-inch subwoofer louder than a 15?
An 18-inch sub has approximately 44% more cone area than a 15-inch, producing 2-4 dB more output at the same power in comparable enclosures. The real advantage is low-frequency extension — an 18 moves significantly more air below 30 Hz, which is felt more than heard in SPL competition.