SM35CX

The Autotek SM35CX is a pair of 3.5-inch 2-way coaxial car speakers built as a direct replacement for tired factory dash and pillar speakers. Each speaker handles 75W RMS and 150W peak at 4 ohms, with 88dB sensitivity that lets a factory head unit push them to usable volume before you add an amplifier.

A 1-inch Neo Mylar soft dome tweeter reproduces highs without the harshness common in small paper-cone factory speakers, and an Alpha-Cellulose poly cone keeps midrange and upper bass present while staying light enough to respond quickly. A passive Butterworth crossover with a 6dB internal network hands frequencies from the cone to the tweeter at 6kHz, so vocals stay in one place instead of splitting between drivers.

Build details matter in a door or dash location. The UV and moisture resistant rubber surround holds up to sun and humidity, high temperature adhesive keeps the cone and surround bonded under hard use, a pure copper voice coil on a Kapton former sheds heat, and an anti-resonant stamped steel basket keeps the frame from ringing.

Mounting specs are 3.41-inch cut-out, 3.41-inch outside diameter and 1.5-inch depth, which suits the shallow openings 3.5-inch speakers usually live in. Grilles are not included since these speakers typically install behind a factory panel. Frequency response runs 80Hz to 20kHz. Use spade connectors or solder directly for the best connection.