Down4Sound D4S-NFO1 RCA Noise Filter

Many in-stock orders ship within 1-2 business days, but timing varies by item. Custom, built-to-order, oversized, special-order and supplier-direct products may need extra processing time. Free shipping applies to qualifying orders over $99 in the contiguous US. Approved returns may be subject to a restocking fee.

Most products are covered by the manufacturer's warranty against defects. Damage from over-powering or improper installation isn't covered — we'll help coordinate any valid claim.

Tell us your vehicle, subwoofers and electrical setup and our team will help you match the right gear. Reach out before you buy.