The top 4 things I've learned improving the sound system in my Forester... 🔊

Just wanted to share this to anyone else interested. I am not an expert, nor am I an audiophile. I've just spent a ridiculous amount of time understanding how to maximize the sound quality in my 2019 forester in my own spare time and research and testing this all myself.

• The most dramatic difference in listening experience was switching out the front corner dash speakers to what are called "3.5in coaxial midrange/tweeter speakers". The factory tweeter speakers in the dash are very poor quality. And instead of switching out the dash speakers with just upgraded tweeters (only producing very high frequencies of 3,000hz and above) if you put in the coaxial midrange+tweeter speakers, you get the entire wide frequency spectrum from a low 200hz to 20,000hz hitting your ears straight on from the dash. If you don't do this, the door speakers will be producing the midrange and you will barely hear it because it's projecting at your feet, rather than high up at your ears like the dash speakers are. Once I made this change, my jaw dropped when I heard the difference. And on our last road trip, my gf kept saying how much better the music sounded.
• Subaru Forester's front door speakers accommodate 6x9in speakers, which imho is definitely something worth utilizing. 6x9in speakers are larger and have something like 30% more cone area than 6.5in speakers, and generally can produce more bass/midbass (all things being equal). In my personal experience, having used both sized speakers in my forester, the 6x9in speakers made a huge difference.
• There's no reason to change or upgrade the rear door speakers if you don't change the factory headunit. The factory head unit is supplying only like 20% of the volume that is given to the front door speakers. If you upgrade the rear speakers, you will not hear a difference because there is barely any volume that can come out of them. Test yourself by adjusting the fader 100% to the front and then 100% to the back.
• Other than speakers, the most limiting factor is the factory head unit. Even the Harmon Kardon upgrade is using the same low quality 2-volt 7-watt preamp as the base trim, but just with a small external amp added to minimize the faults and deficiencies of the factory head unit. Source signal is the same.

There's more personal learnings I could share, but these are the top things that I felt could be most applicable to any Subaru Forester owner, and are things I wish I knew when I first got my car 5 years ago.

3.5in coaxial midrange+tweeter speaker in dash. Fits without any modification.