Infiniti I35 Speaker Size

Front Door Panel Speaker

Rear Door Panel Speaker

Rear Deck Lid Speaker

A-Pillar Speaker

Infiniti I35 Speaker FAQ

Which speakers should I upgrade first in my Infiniti I35 for the biggest sound improvement?

Start with the front 6.5 inch door speakers. These handle most of your music's midrange and vocals - replacing them typically gives you 70% of the total sound improvement you'll notice. The factory speakers probably can't handle more than 15-20 watts RMS anyway. Look for speakers rated around 50-75 watts RMS with 4-ohm impedance. The rear 6.5 inch speakers come next, but honestly? You might not even need to touch them if the fronts sound good enough.

Should I go with component or coaxial speakers for my Infiniti I35?

Component speakers will sound better... if you're willing to deal with the installation complexity. Your I35 already has separate 1 inch tweeters in the front doors, so components make sense there. You'd replace both the tweeter and the 6.5 inch woofer. Coaxials are simpler - everything's built into one speaker. For the rear doors, coaxials probably make more sense since you're not sitting back there critically listening. The frequency response difference between good coaxials and components isn't as dramatic as people claim.

Can I install 8 inch subwoofers in my Infiniti I35 rear deck?

The rear deck already fits 8 inch speakers, but calling them "subwoofers" is... optimistic. They're more like full-range speakers that happen to be 8 inches. Real subwoofers need proper enclosures and amplification. If you want actual bass extension below 50Hz, you'll need a dedicated subwoofer system. Those rear deck speakers might handle frequencies down to 80-100Hz at best. They'll give you some low-end punch for rock music, but won't reproduce true sub-bass.

Do the tweeters in my Infiniti I35 need to match the door speakers?

Depends on your setup approach. If you're installing component speakers, the tweeter and woofer need to be from the same manufacturer - they're designed to work together with matching crossover points around 3-4kHz. But if you're keeping coaxial speakers in the doors, you might want to disconnect those separate tweeters entirely. Having two tweeters playing the same frequencies creates phase issues and weird imaging. The A-pillar tweeters from the early model year actually positioned better for soundstage anyway.

What's the difference between the rear speaker sizes in different Infiniti I35 model years?

Earlier models used 5.25 inch rear speakers, later ones got 6.5 inch. The 6.5 inch speakers will move more air and handle lower frequencies better - probably down to around 70Hz compared to 90Hz for the smaller ones. But here's the thing: rear fill doesn't need to be perfect. You're mainly filling in the soundstage, not creating it. Either size works fine as long as you're not overpowering them. Keep rear speaker levels about 6-8dB lower than fronts for proper imaging.