Guides / Sound
Amps and subwoofers explained
An amp gives your speakers and sub the clean power they need to get loud without distorting. The sub and its box decide how deep and how "boomy" the bass is.
Amp type depends on the job: mono for a sub, 4-channel for speakers, 5-channel for both. Match the amp's RMS power to the sub or speaker RMS, not the peak numbers. Sealed box = tight, accurate bass. Ported box = louder, boomier.
What an amp does
It takes the small signal from your radio and boosts it to real, clean power. Look for the CTA-2006 power rating, the industry standard that measures RMS watts at 14.4V into 4 ohms at under 1% distortion, held for at least a minute, so you can compare brands honestly. It's voluntary, so reputable brands publish it. If a box only screams "peak watts," be skeptical.
Amp types
Mono (1-channel) for a subwoofer. 4-channel for four speakers, or two speakers plus a bridged sub. 5-channel does four speakers and a sub from one chassis.
RMS power matching
Match the amp's RMS output to the speaker or sub's RMS rating. Peak and "max" numbers are marketing.
Subwoofer sizes
Common are 8", 10", 12" and 15". Bigger generally moves more air and goes deeper, but the box matters as much as the size.
Sealed vs ported
A sealed box gives tight, accurate bass and is smaller. Great for rock, jazz, mixed music. A ported box is louder and deeper (boomier) and more efficient with power, great for hip-hop, rap and EDM, but it's bigger.
Impedance and voice coils, plain
Subs come in different ohm ratings and single or dual voice coils. Those just give me wiring options to match the amp so it makes the right power. I handle that.
Amp wiring kits
Use the right gauge wire for the amp's current (roughly 4-gauge for around 1,000W RMS, 1/0 for big systems), and choose OFC (oxygen-free copper) over CCA (copper-clad aluminum). CCA is cheaper but carries less current; you'd have to go up about two gauge sizes to match OFC. Too-thin or CCA wire is a common cause of a system that underperforms.
Line output converter (LOC)
If your factory radio has no preamp (RCA) outputs, an LOC taps the speaker wires and creates a signal an amp can use. That's how I add an amp while keeping the stock radio.
Dimming lights and the Big 3
If your headlights dim on bass hits, the electrical system is straining. The "Big 3" upgrade adds heavier cables in three spots (alternator to battery positive, battery to chassis ground, engine to chassis ground) to improve current flow. It helps on bigger systems. It's not needed for small ones.
| Box | Bass character | Size | Best for |
|---|---|---|---|
| Sealed | Tight, accurate | Smaller | Rock, mixed music, sound quality |
| Ported | Louder, boomy | Larger | Hip-hop, rap, EDM, max output |
What you'll need
Amp; sub + box (sealed or ported); amp wiring kit (OFC, correct gauge); LOC if no preamp outputs; possibly a Big 3 upgrade.
What it costs to install (labor only, parts separate)
Subwoofer: from $150 · 4-channel amp: from $180 · Full system (amp + sub + speakers): from $400 · Big 3: from $125
Your sub amp only powers the sub, so for better door-speaker sound you'd need a separate 4-channel amp. I can install everything together.
Common mistakes
- Matching peak watts instead of RMS (blown gear or weak sound).
- Cheap, thin CCA wiring choking a big amp.
- Wrong box type for your music (boomy when you wanted tight).
- Adding a big system without addressing dimming and the electrical side.
FAQ
Sealed or ported?
Sealed for tight and accurate, ported for loud and deep.
One amp for everything?
A 5-channel can, or separate amps for sub and speakers.
Do I need the Big 3?
Only on bigger systems or if your lights dim.
No RCA outputs on my radio. Can I still add an amp?
Yes, with a line output converter.
What I need from you: year, make, model; a trunk or cargo photo; the music you listen to; whether you already have gear; your city.
Related: Speakers: louder vs better · Component vs coaxial
Not sure what your car needs?
Text me your year, make, model and what you want done. I'll tell you what fits and what it costs.