Trimming dash to fit 4" speakers?

[Sonnie]

Has anyone (or do you know of anyone) that has trimmed the mounting area in the dash to fit 4" speakers in a 2019-2020?

I'm thinking about trying it. I don't think much would have to be removed, and a Dremel should take care of it, being it's all plastic.

I'm also curious if anyone knows the crossover frequency of the dash speakers.

Of course I have no idea if it would help or make any difference, but it would be interesting to find out if it would.

 

[RichInMN]

4" won't allow the grills to re-seat over the top regardless of trimming underneath. There are also mounting depth and width restrictions, particularly with the passenger side air vents.

I have 4" plate Morels up there, but I cut the plates to 3 5/8"; even so the magnets just barely fit for depth and width. Even if the vents were cut or melted for more space, the windshield and/or dash would have to come out to install anything particularly beefy in there.

 

[RichInMN]

Also, the caps on the 3.5's I had were 2.2 microfarad, which is a 6db crossover at 9K... But with the HK sytyem you have different speakers (I started with base 6)

 

[Sonnie]

Hmmm... I looked at the left side and it appears only slight trimming is needed there... width and depth no issue at all, as the cut-out only has to be 3-5/8" inches for the Infinity 4032 speakers. Did not look at the cover, although I did make sure I would not get into any of the cover tab holes. However... I did not look at the right side dash. I'll check that out closer.

 

[Sonnie]

Checked out the right side of the dash... only 1.5" depth, unless I heat the vent as you suggested... it wouldn't take much, about 1/4-1/2".

I don't see an issue with the grill cover with these speakers, as everything will sit below the bottom of the cover. I might have to trim 1/8" off one small section on the edge of the speaker, but otherwise the width should work. HOWEVER, I think there are better options for 4" speakers from Parts Express that might work easier and not require quite as much work.

Or just keep it simple and stick with the 3.5"... lol... seems like it might be the most reasonable thing to do.