What size speakers are in a 1994 GMC Sierra?
In most 1994 GMC Sierras, the front doors typically house 6.5-inch speakers, while the rear door or cab panels often use 4x6-inch speakers. Exact sizes can vary by cab configuration and trim, so it’s best to verify for your specific truck if you’re upgrading. This article explains the typical layouts and how to confirm the precise sizes on your vehicle.
Overview of the factory speaker layout
GM trucks from this era used a combination of dash, door, and rear-panel speakers. The exact arrangement depends on whether the truck is a regular cab or extended cab, and on optional equipment. The following guide covers the common locations you’ll encounter when inspecting or upgrading factory speakers.
Common sizes by location
Before listing the sizes, here is a quick guide to where these sizes appear in the Sierra.
- Front doors: typically 6.5-inch (165 mm) speakers in most trims.
- Dash/center area: many 1994 GM trucks used a 4x6-inch (102x152 mm) speaker mounted in the dash or upper dash area; some models may rely on a separate tweeter or omit a dash speaker entirely.
- Rear doors or rear side panels: commonly 4x6-inch or 5x7-inch configurations, with some extended-cab layouts using larger rear speakers in certain setups.
Note: Configurations vary by cab style (Regular Cab vs Extended Cab) and trim level; dealer-installed options or aftermarket replacements can also alter the stock sizes. If you’re replacing stock speakers, verify by removing a panel or consulting documentation specific to your vehicle.
How to verify your vehicle's exact size
Because factory options and cab configurations varied across the 1994 model year, the most reliable method is to measure or check the documented specifications for your exact truck.
- Inspect the openings: measure the diameter of the speaker hole and the mounting depth to determine what size fits.
- Remove a speaker and check markings: look for size stamps on the magnet or frame (for example, 6.5", 4x6", etc.).
- Consult the service manual or VIN-based documentation: the exact trim and cab configuration will specify the original speaker sizes.
With the sizes confirmed, you can select aftermarket replacements that fit without modification beyond usual mounting considerations.
Summary
For a 1994 GMC Sierra, expect front-door speakers to be around 6.5 inches in most configurations, with rear locations typically using 4x6 inches, though some extended-cab or optioned trucks may differ. Always verify your specific truck’s sizes by measuring the openings or consulting the service data, especially if planning an upgrade. This approach ensures compatibility and preserves optimal sound quality.
