1999 GMC Sierra 1500 Speaker Sizes

The 1999 GMC Sierra 1500 factory audio system features specific mounting locations that accept various components, where the front door panel accommodates a 6.5 inch speaker size as well as 6.75 inch units, while the rear door panel, c-pillar, and d-pillar accommodate 4x6 inch speakers. Full-range and midbass units serve as viable replacement and upgrade options for these locations.

Specific details regarding locations, speaker sizes, and types are outlined in the compatibility chart.

Speaker Details by Location
Location Size Type Notes
C-Pillar 4x6 Full-Range
  • Complex interior disassembly
  • Professional installation recommended
  • Low replacement priority
  • Replacement difficulty: high
D-Pillar 4x6 Full-Range
  • Extremely difficult access
  • Professional service only
  • Low replacement priority
  • Replacement difficulty: high
Front Door Panel 6.75 Midbass / Full-Range
  • Standard installation
  • High replacement priority
  • Replacement difficulty: low
Front Door Panel 6.5 Midbass / Full-Range
  • Standard installation
  • High replacement priority
  • Replacement difficulty: low
Rear Door Panel 4x6 Full-Range
  • Standard installation
  • Medium replacement priority
  • Replacement difficulty: low

1999 GMC Sierra 1500 Speaker Replacement Summary

5 total positions
3 easy to replace
2 high priority
2 professional only

Replacement difficulty:

Low: 3 Medium: 0 High: 2

Replacement priority:

High: 2 Medium: 1 Low: 2

1999 GMC Sierra 1500 Radio Slot Size (DIN)

DIN Type Size (inch) Size (mm) Notes
Single DIN or Double DIN 7"×2" or 7"×4" 180×50 or 180×100 Vehicle supports both radio sizes
  • Always measure the slot before purchasing a new radio
  • Check slot depth - it may vary

Additional Notes

  • The front door panels in the 1999 GMC Sierra 1500 accommodate either 6.5 inch or 6.75 inch speakers, with both sizes supporting midbass or full-range configurations, which could provide flexibility when selecting replacement components for the primary listening position.
  • Full-range speakers are specified for the C-pillar, D-pillar, and rear door panel locations, all using the 4x6 inch format, suggesting these positions typically handle broader frequency reproduction without dedicated tweeters or woofers.
  • The front door locations may benefit from prioritization during upgrades, as they accept larger cone areas compared to the 4x6 inch openings found in the rear and pillar positions, potentially offering greater bass response and overall output capability.
  • Component speaker systems with separate midbass drivers might be installed in the front doors of the 1999 GMC Sierra 1500, given the midbass compatibility notation, which would allow for dedicated frequency handling and possible crossover integration.
  • The radio openings support both single DIN and double DIN head units, which could influence speaker system planning if amplification or advanced signal processing capabilities are considered during audio system modifications.
  • The 4x6 inch format across multiple rear locations suggests a factory approach emphasizing spatial distribution rather than concentrated output, which aftermarket installations might address differently depending on listening preferences.