Improving the sound quality in your car doesn’t have to break the bank. If you’re looking to enhance the audio experience in your base GR86 model, replacing the factory speakers is a fantastic starting point. This guide details a step-by-step DIY speaker upgrade, focusing on affordable and effective solutions to dramatically improve your car’s sound system.
Enhancing the Front Stage: Dash Speaker Upgrade
The base GR86 comes with rudimentary 1” paper tweeters in the dash. These are often underwhelming, contributing minimally to the overall sound, especially when compared to the fuller sound produced by the door speakers. These stock tweeters are 4ohm and wired in parallel with the 4ohm door speakers, resulting in a 2ohm load for the head unit.
For a significant audio upgrade, consider replacing these dash tweeters with 4” coaxial speakers. The Polk DB402 coaxial speakers are an excellent choice. Featuring a 3/4” silk dome tweeter and a high sensitivity of 90db, they are perfectly suited for the lower wattage output of a factory head unit. A key advantage of the Polk DB402 is their drop-in readiness for many vehicles, including the GR86 with minor adjustments.
When installing, you’ll find the opening under the speaker grill in the dash accommodates a 3.5” cutout, suitable for smaller 4” or 3.5” speakers. The Polk DB402, with a 3.5” top mount width, fits this space well. Depth is limited to 1.75 inches, and these speakers are designed to just fit, resting against the ventilation ducts within the dash.
Installation is nearly a drop-in process, but requires slight modification to the 45-degree slope support and connection point, as the speaker basket arm might slightly interfere. Using a razor blade, carefully shave off about 1/8” to 1/4” of plastic. You’ll know you’ve removed enough when the speaker and dash holes align, allowing the speaker to sit flush with the dash’s molded curve.
For mounting, you’ll need U-clips. Interestingly, #10 U-clips from Harbor Freight are reported to be a perfect fit for this application, highlighting how affordable, readily available parts can be used in car audio upgrades. You will only need two out of the four mounting tabs/ears on the speaker – simply break or cut off the unneeded ones, as per the speaker’s design. A Metra harness, often included free from retailers like Crutchfield with speaker purchases, ensures a plug-and-play connection. Tuck any excess speaker wire adapter slack into the dash corner to prevent rattles. Adding a 3/8” foam strip around the opening under the factory grill, approximately 5” in diameter, can further enhance sound by reducing vibrations. The factory speaker grills can be easily pried off, as shown in numerous online video tutorials.
https://www.crutchfield.com/p_107DB402/Polk-Audio-DB-402.html
https://www.crutchfield.com/p_120728110/Metra-72-8110-Speaker-Wiring-Harness.html
https://www.harborfreight.com/170-piece-u-clip-and-screw-assortment-67588.html
Rear Speaker Transformation: From Weak to Powerful
The base GR86 rear speakers are a significant weak point in the factory audio system. They feature small 2.5” 6ohm paper speakers. Being 6ohm, their volume is notably lower than the front speakers which operate at a 2ohm load. Additionally, the rear speakers are high-pass filtered at the head unit, around 150-250Hz, further limiting their audio output.
The bracketry in the base GR86 differs from the premium model, which utilizes a 3.5” bracket from the previous generation. However, the mounting points remain the same. A popular approach is to acquire 3.5” speaker brackets from a previous generation Toyota 86 (model year 2019, for example) from online marketplaces like eBay. Discard the old speakers from these brackets and modify the brackets to accommodate 4” speakers, such as the Polk DB402 coaxial speakers used in the dash.
Modifying the previous generation brackets involves enlarging the opening, as it’s approximately 3.25” while the Polk 4” speakers require a 3.5” opening. Using a hacksaw and Dremel tool, carefully enlarge the bracket opening. The speaker basket arms will need clearance, but after modification, the speaker should fit flush against the bracket. Like the dash speakers, these Polk DB402s feature 3/4” silk dome tweeters, are 4ohm, and have a 90db sensitivity, ensuring a volume increase with the factory wattage.
Speaker adapters, often provided for free by retailers like Crutchfield, are available for the rear speakers and ensure proper wiring connections. It’s also beneficial to add foam around the speaker and trim the factory padding behind the rear panels to improve sound and reduce vibrations. YouTube tutorials offer excellent visual guidance on dismantling the rear seats and panels, which is generally straightforward. A helpful tip for panel removal is to use quick, firm tugs to pop them off, minimizing the risk of bending or warping the retainers and plastic panels compared to slow prying.
https://www.crutchfield.com/p_107DB402/Polk-Audio-DB-402.html
https://www.crutchfield.com/p_120728105/Metra-72-8105-Speaker-Wiring-Harnesses.html
Door Speaker Replacement: Adding Depth and Clarity
The base GR86 door speakers are 6.5” full-range paper cone speakers. These are also 4ohm and run in parallel with the dash speakers, contributing to the 2ohm total load. Replacing these door speakers offers another significant improvement to the overall audio quality.
Consider upgrading to Polk DB652 speakers. These 6.5” speakers feature silk dome tweeters and have a high sensitivity of 92db, making them well-suited for door placement and efficient with the factory head unit’s power. Metra speaker harnesses, often provided free by Crutchfield, ensure easy wiring. Scosche SAT6 brackets are also recommended for mounting.
With Scosche SAT6 brackets, space for additional baffling or sealing between the door and speaker, and speaker and bracket, is limited. To address this, a thin foam rubber layer applied to the speaker’s edge allows it to seal against the molded ring inside the door panel. For more clearance, you could opt for different brackets or trim the molded circle inside the door panel. After connecting the harness (which routes out the top), bundle any slack and tape it to the door plastic above the speaker, ensuring it’s out of the way and rattle-free.
Removing the door panels involves removing three screws and then carefully pulling the panel off. One screw is located behind the cover near the interior door lever. Pry off this cover starting near the manual lock switch to access the screw. The other two screws are under a cover in the recess of the door armrest/handle. Use a flathead screwdriver to pop off this thin panel to reveal and remove these two screws. Once the screws are removed, firmly and quickly tug on the panel to release the door clips. Start near the hinge area, then the bottom, and work your way up. Avoid slow prying to prevent warping the plastic. When reinstalling the panel, ensure all panel clips are attached to the door panel cover. Remove any clips left in the door frame and re-install them onto the panel as needed before re-attaching the door panel.
https://www.crutchfield.com/p_107DB652/Polk-Audio-DB-652.html
https://www.crutchfield.com/p_120728104/Metra-72-8104-Speaker-Wiring-Harnesses.html
https://www.crutchfield.com/S-8CFwqVFfRBT/p_142SAT6/Scosche-SAT6-Speaker-Mounting-Brackets.html
Conclusion: Affordable Audio Enhancement for Your GR86
Upgrading the speakers in your base GR86 model is a remarkably effective way to dramatically improve your car’s audio quality without extensive modifications or expense. By choosing efficient and sensitive speakers like the Polk DB series and utilizing readily available, budget-friendly tools and parts – even U-clips from Harbor Freight – you can achieve a significantly enhanced listening experience. This DIY project not only saves money compared to professional installations but also provides a satisfying and personalized upgrade to your vehicle’s sound system. Remember to always double-check compatibility with your specific vehicle year and model and consult resources like Crutchfield for guaranteed fit and free helpful accessories.
