That particular sub says it can work as a free air, so in theory it could be mounted in a door. However, I think you will have your work cut out for you getting a true 8" sub in the door. The door speakers I mounted were 2.54" deep, and that was too deep for the doors. The sub you mentioned is 2 5/8, so a little deeper. I needed a mounting ring to push them out nearly a half inch. With a 6.5" speaker, that was ok because it fit inside the door panel's speaker shroud.Jeff, nice write up. I just posted a question to another member Boxster build (here) but I realized it's from 2012.
Question for you, I have a 987 Boxster with janky aftermarket setup and it sounds like crap. I want to add more bass but don't want to tackle an external sub...do you think a shallow depth 8" sub in the lower door would sound decent? like a pioneer 2002D2 or 2002LD2. The car would have a 3-say setup (8" bass, 4" mid, 1" dash tweeter) only thing purchased so far is an Alpine PDX-V9 amp and Alpine 2-din aftermarket head unit that came with the car.
- Can I adapter my way out of this? I could only find 1 reference of 8" that required cutting the opening larger. This person used a slightly wider version of the pioneer 8". I'm hoping a newer sub/adapter can solve this.
- Is the sound improvement worth it? or is the 3-way only setup the limiting factor, 8" vs. 6.5"/6.75" has diminishing returns..stick to plug-n-play? I don't mind the hard work.
Then it gets a little more interesting. I googled the Pioneer, and they don't give detailed line drawings with measurements. What's the full external diameter of the speaker mounting ring? The Bose you're replacing is 7.9". The pioneer could be 8", or 8" could refer to the speaker face, with a 9" or more surround. Assuming you fabricate a mounting plate, and figure out how to attach it, without touching the other door speaker, you'd then need to trim material from the inside of the door panel to get it back on. You need to figure out the thickness of the speaker mounting plate and maximum "grill protrusion", to make sure it fits without anything rubbing, even at max speaker excursion. I'm a little skeptical, but it may be possible to make it fit.
Would the end result be worth it? No idea... no experience with that Pioneer speaker. My gut is that because they market it as a driver for sealed OR free air, it probably performs much better in a sealed enclosure. But who knows...