The linear, self‑powered X‑400C offers similar sonic characteristics to the X‑800C subwoofer— low‑frequencies down to 20 Hz, clean, punchy transients, and excellent phase coherence—in a more compact cabinet that can be installed singly or as multiple units. 

The X‑400C comprises a single 18‑inch low‑frequency, long‑excursion cone driver housed in an optimally tuned, vented cabinet and powered by a single‑channel amplifier. On‑board processing includes driver protection circuitry, low‑pass filtering, and correction filters for flat phase and frequency responses. The Intelligent AC™ power supply provides automatic voltage selection, EMI filtering, soft current turn‑on, and surge suppression.