Step 1 — Start With the Subwoofer
The sub sets every other decision: how much power you need, how big the box is, and how hard the electrical has to work. Pick by cone area and output goal first. Bigger cones move more air per stroke — but cost you enclosure volume and amperage. If you have not chosen a driver yet, start with our size guides for the 10-, 12-, 15-, and 18-inch classes.
Step 2 — Match the Amplifier
Two numbers decide the match: power and impedance.
Power comes in two ranges with two different purposes:
- Recommended Power Sweet Spot — 80–100% of sub RMS: an amplifier in this band, set on a clean, unclipped signal, delivers full output without cooking the voice coil. This is the target.
- Safe Compatibility Envelope — 75–150% of sub RMS: the wider band that will physically drive the sub. Headroom builders can live here with disciplined gain structure — more clean power is safer than less dirty power (a clipped 1,000-watt signal carries more heating duty than a clean 1,200-watt one). It is a compatibility range, not a recommendation.
Impedance — match the sub's wired load to the amplifier's stable rating. Coil choice drives it: a DVC 2-ohm sub wired in parallel presents 1 ohm, in series 4 ohms; run two of them and the math changes again (two DVC2 in parallel = 0.5 ohm). Pick the coil — D1, D2, or D4 — for the amplifier you own. Mismatching the load by a step roughly halves your rated power.
Step 3 — Build the Electrical Backbone
This is the step most people skip and then blame the subwoofer. An amplifier is a current machine: at realistic Class-D efficiency on a 12-volt rail, every 1,000 W RMS pulls on the order of 100 amps at full tilt. Plan the electrical before the amp ships.
- The Big 3 — upgrade the alternator-to-battery, battery-to-chassis, and engine-to-chassis ground to 1/0 AWG OFC.
- Alternator — a high-output unit for anything at or above ~2,000 W RMS. Stock alternators top out around 130–150 A with the vehicle's own loads already on them.
- Storage — a supplemental AGM or LTO (lithium-titanate) battery to hold voltage under sustained load.
- The test that matters — voltage at the amplifier under load. Below ~12.5 V, your electrical system is the bottleneck, not your subwoofer.
Step 4 — Get the Enclosure Right
The box is part of the spec, not an afterthought. Net (not external) volume, adequate port area, and tuning — commonly ~32–34 Hz for a daily ported build — determine whether the sub performs as published. Sealed is tight and compact; ported is louder and lower but larger. Match the box to the driver using the per-size specs on the product pages and our inch-class guides.
Step 5 — Tune It (Don't Skip This)
A correctly paired system tuned badly sounds worse than a modest one tuned well. Sensible starting points:
- Gain — set to the sub's clean limit by ear or scope, never to max. Gain is not a volume knob.
- Low-pass filter — around 80 Hz is a typical starting point for a subwoofer channel.
- Subsonic filter — set near your enclosure's tuning frequency to protect the driver below it.
- Bass boost — off or minimal. It is the fastest way to clip an amplifier and cook a coil.
A subwoofer is one component of a system — the amplifier, the electrical, the box, and the tune decide whether you hear what you paid for. Build the whole chain, not just the loudest single part.
