What size speakers are in the 2003 IS300?
The 2003 Lexus IS300 offered two main audio configurations, and speaker sizes varied by package. In the base setup, you’ll typically find 6.5-inch front speakers and 5.25-inch rear speakers; the JBL Premium Audio package upgrades the rear to 6.5 inches and adds an 8-inch subwoofer in the trunk.
To understand what you’re dealing with, the exact sizes depend on whether your car has the standard audio or the optional JBL Premium/Monsoon system. Below, you’ll find a breakdown of typical sizes for each configuration, along with notes on tweeters and subwoofers.
Speaker sizes by trim
Before listing the sizes, note that exact measurements can vary by market and production specifics. The following reflects common US-spec configurations for the 2003 IS300.
Base / standard audio
Common sizes you would expect with the standard system are:
- Front door speakers: 6.5 inches
- Rear door speakers: 5.25 inches
- Tweeters: approximately 0.5–1 inch in the A-pillar or dash area
- Subwoofer: not included in the base package
Conclusion: The base system uses smaller rear speakers and does not include a dedicated subwoofer, which is often a consideration for those planning upgrades.
JBL Premium Audio (Monsoon)
For the JBL Premium Audio package, the sizes typically expand in the rear and add bass amplification, including:
- Front door speakers: 6.5 inches
- Rear door speakers: 6.5 inches
- Tweeters: approximately 0.5–1 inch in the A-pillar or dash area
- Subwoofer: 8 inches, located in the trunk
Conclusion: The JBL upgrade standardizes rear speakers at 6.5 inches and provides an 8-inch trunk subwoofer for deeper bass, resulting in a fuller overall sound profile.
Additional notes and upgrade considerations
When replacing or upgrading speakers, confirm the exact sizes for your specific vehicle by removing a door panel or consulting the factory service manual. Some aftermarket options may require adapters or crossovers to fit the IS300’s mounting locations and electrical connectors. If you’re chasing a particular sound profile, consider a full component upgrade (separate woofer, midrange, and tweeters) to preserve tonal balance.
Summary
The 2003 IS300’s speaker sizes depend on the audio package. The base system uses 6.5-inch front speakers and 5.25-inch rear speakers with no subwoofer, while the JBL Premium Audio package uses 6.5-inch rear speakers and adds an 8-inch subwoofer in the trunk, with 6.5-inch fronts and standard tweeter placements in both configurations. Always verify exact measurements for your exact vehicle, as trims and markets can differ.
