How to Fit a 5.25" Speaker in a 4" Location
1990-1994 Lexus LS400
How do you fit a larger speaker in a 4" location? You mod! Lexus LS's have custom speaker boxes in the doors for 4" speakers. This makes it tough to install larger speakers, but it can be done. Here's how I fit 5.25" component speakers in my doors.
- 5.25" speakers
- Paper, pencil
- Sealant, silcone caulk
1) Remove the door panel, tweeter, and speaker box. The speaker box is held on the door by 4 bolts and the tweeter by 2 screws. There should be another plastic tab for a bolt on the lower left but mine broke off.
2) Remove the factory speaker.
3) Remove the back of the speaker box.
4) Get rid of the port, wiring, and crossover. Cut the brown wire at the terminal ends, it will be used later. Pull the brown wire through to the outside of the box. Cut the green wire at the top on the inside of the box.
5) Plan how your speaker will fit. Make a template for the speaker opening and draw an outline of it on the top of the speaker box. Plan this out carefully, you only get one shot!
6) Take out the Dremel and cut. Believe it or not this was the good cut. As you can see I had to do a little fine tuning at the bottom since the speaker needs to be flush.
7) Put the box back together and place a wire in for the woofer. I used the hole where the brown wire used to go through.
8) Connect the speaker and screw it in. Seal up the holes and around the speaker. I used this putty stuff, but silicone would probably be a better choice. The brown wire is what comes from the amp. You now have a sealed woofer.
9) You may or may not need to do this. I needed to take out the Dremel again to remove the raised areas of the grill on the back of the door panel. The panel wouldn't fit back on with the larger speakers without doing this. There isn't much room behind the door panel.
10) Here's where I mounted the crossover. I had to cut out a little bit of foam to make it work. You can also see the trimmed speaker grill in this pic.
11) Mount the tweeter. I used the factory tweeter bracket flipped over and screwed the tweeter into that. The tweeter cover just barely fit over this with some modification. It's not as perfect as I would like, but it does fit over the tweeter.
Back of the factory tweeter cover.
12) Remove the metal piece.
13) Remove the plastic grid.
14) Bolt the speaker box back in and wire everything up. Test to make sure everything works before you put the door panel back on.
Here's how nice the speaker lines up.
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