CARSFM
Turn it up — car audio and in-car entertainment, speakers, amps and subwoofers, tuning and installs, and the calculators every enthusiast needs.
From designing a subwoofer box and matching an amp to your speakers to wiring the right impedance, sizing your power cable, dialing in an SPL target, and setting a crossover, CarsFM pairs free hands-on car-audio calculators with practical guides and a richly illustrated museum. Build smarter, turn it up.
Car Audio Tools & Calculators
Free tools for every install — subwoofer box calculator, amplifier power (RMS) calculator, speaker impedance calculator, amplifier wire gauge calculator, SPL loudness calculator, and crossover calculator.
Subwoofer Box Calculator
Design a sealed or ported enclosure — net internal volume for one or more subs, the vented-box port length that tunes a ported box to your target frequency, and external cabinet dimensions from your panel thickness
Amplifier Power (RMS) Calculator
Match an amp to your speakers by RMS — get a recommended amp power range with headroom, an under/matched/over verdict for an amp you're considering, and how power scales as impedance drops
Speaker Impedance Calculator
Total impedance for speakers or voice coils wired in series, parallel, or series-parallel — dual-voice-coil subs included — with a warning when the load falls below what most amps can safely drive
Amplifier Wire Gauge Calculator
Pick the right power and ground wire gauge (AWG) from your amp's RMS output or fuse rating and the run length — with the estimated current draw and a suggested inline fuse to protect the wire
SPL (Loudness) Calculator
Estimate how loud a speaker plays from its sensitivity, power, and your distance — sound pressure level in dB, with +3 dB per doubling of power and free-field distance loss, plus a real-world loudness reference
Crossover Calculator
Component values for a passive first- or second-order crossover — the high-pass capacitor for the tweeter and the low-pass inductor for the woofer — from your crossover frequency and driver impedance
Museum of Car Audio & Sound
Wander an immersive museum of car audio and the science of sound — the history of in-car listening from the car radio to the modern head unit, the anatomy of a system from amplifier to subwoofer, the speakers and enclosures that shape the sound, and the electronics that carry the signal, each in its own gallery, so you can get to know the story behind every component: how it works, what it does, and the part it plays in great sound on the road.
Tour the museum →From the Journal
Fresh guides on speakers and subwoofers, amplifiers and wiring, head units and stereo systems, soundproofing, and tuning, plus practical tips for planning, installing, and dialing in a system that sounds its best on the road.
Best Car Stereo Systems Tips and Strategies
Best Car Stereo Systems Tips and Strategies In today’s world of advanced automotive technology, upgrading your vehicle’s audio system can transform your driving experience from ordinary to extraordinary. Whether you’re…
Quick Car Audio Solutions Under 30 Minutes
Revving Up Your Ride: Essential Car Audio Tips for Music Lovers In today’s fast-paced world, car audio systems have evolved from simple AM/FM radios to high-fidelity entertainment hubs that can…
Car Audio Best Practices 2025
Car Audio Best Practices 2025 In an era where entertainment and connectivity define modern life, car audio systems have evolved far beyond simple AM/FM radios. Today’s automotive audio solutions blend…
Common Car Audio Mistakes to Avoid
Common Car Audio Mistakes to Avoid In today’s world, car audio systems are more advanced than ever before, offering features that rival home entertainment setups. However, despite these advancements, many…
Car Audio Step-by-Step Tutorial
Understanding Core Components of Car Audio Systems The foundation of any great car audio experience lies in its core components. At minimum, a functional system requires a head unit, speakers,…
Professional Car Audio: Advanced Techniques
Professional Car Audio: Advanced Techniques The world of car audio has evolved far beyond basic AM/FM radios. Today’s enthusiasts are pushing boundaries with high-fidelity sound systems that rival home theaters….
Keep Learning
Practical know-how on planning, installing, and tuning a car-audio system, plain-language explainers on impedance, amplifier power, wire gauge, and crossovers, and seasoned tips for first-time installers and veteran enthusiasts alike — everything you need to dig deeper and turn it up.
Visit the Learn hub →