GMC S15 Speaker Size
Speaker size, type, and location chart for GMC S15 models from 1982 to 1990 production years.
As an Amazon Associate, we may earn a commission from purchases made through links marked. Read more in our disclaimer.
Behind Seat Speaker
| Years | Type | Size (inch) |
|---|---|---|
| 1990 | Full-Range | 4x10 |
Dashboard Speaker
| Years | Type | Size (inch) |
|---|---|---|
| 1982 - 1990 | Full-Range | 4x6 |
Rear Speaker
| Years | Type | Size (inch) |
|---|---|---|
| 1986 - 1989 | Full-Range | 4x10 |
Rear Door Panel Speaker
| Years | Type | Size (inch) |
|---|---|---|
| 1982 - 1985 | Full-Range | 6x9 |
GMC S15 Speaker FAQ
What speakers should I replace first in my GMC S15?
Replace the dashboard 4 x 6 speakers first. They handle most of your mid-range frequencies and vocals. These typically run around 20-40 watts RMS and sit right in your line of sight. The dashboard location means they're doing the heavy lifting for clarity. Rear speakers can wait - they're mainly for fill and bass support. Dashboard upgrade gives you the biggest improvement for your dollar.
Can I install component speakers in the rear door panels of my GMC S15?
Yes, the rear door panels support component speakers from 1982-1985. You'll need 6 x 9 components with crossovers rated around 4-8 ohms. Mount the tweeters in the upper door panel or A-pillar. The woofers drop right into the existing 6 x 9 opening. Component separation gives you better imaging than coaxials. Just verify your amplifier can handle the crossover load - some factory radios struggle with complex impedance curves.
Why did GMC S15 switch from 6 x 9 to 4 x 10 rear speakers?
Cost and space constraints. The 4 x 10 speakers starting in 1986 were cheaper to manufacture and fit better in the revised interior design. 6 x 9 speakers technically move more air - roughly 15% more cone area. But 4 x 10s can still push decent bass if you get quality ones rated 30+ watts RMS. The frequency response might favor mids over deep bass. Really depends on what you're trying to achieve with your GMC S15 sound system.
What's the power handling difference between dashboard and rear speakers in GMC S15?
Dashboard 4 x 6 speakers typically handle 15-35 watts RMS, while rear speakers can take 25-50 watts RMS regardless of size. The larger cone area of 6 x 9 or 4 x 10 rears means better power distribution. Dashboard speakers work harder though - they're closer to your ears and need efficiency over raw power. Look for 88+ dB sensitivity in dashboard replacements. Rear speakers can be less efficient since you're pushing more watts anyway.
Should I upgrade the behind-seat speakers in my 1990 GMC S15?
Maybe not priority one. Those 4 x 10 behind-seat speakers mainly provide rear fill. The positioning means they're firing into the rear window and bouncing around. Better to focus on dashboard and door speakers first. If you do upgrade them, choose full-range speakers with strong midrange around 200-2000 Hz. Component speakers back there are overkill. The GMC S15 cabin is small enough that front speakers can carry most of the load.