Do you mean the 4” speakers. If so. Yes. I replaced them as well. Everything is focal utopia for speakers. Except the Raven subs
Up front
Utopia TBM tweets
utopia 3.5 mids
Utopia 6.5 mid bass
differential rear fill. Utopia 3.5 mids.
I did eliminate the center channel
Most people who are doing what you are, would be possibly replacing the DSP amp and using the stock 8s for mid bass duty. It’s not perfect in any way. But doable
I’ve done 2 iterations now. A single GB10 in the trunk corner. Ported.
And 2 Raven 12s sealed pointing backwards
The ported held its own but a little sloppy at times. The winner is the 12s location. Which is basically the original sub location
I’ve done this 2 times now. Once w 3 JL VXI amps. Optical
And once w helix amps. X3
both times using the sdmi25 from helix. I live in PA in the states. Check out resonix sound solutions. He’s a helix dealer and will get you one
I am not familiar w those amps. I know a guy on here did the mobridge amp/DSP and it was a huge headache for him. He and both use helix amps now. W the sdmi25 It gives you exactly what you need. Buy once cry once. Just go for it.
You can use cat litter. Packing peanuts. Etc. that’s to get really exact volume. I would also sound deaden the inside really well. Check out resonix. Top dawg in the sound deadening game.
I definitely understand what you’re trying to do. Definitely curious how the stock mid/subs would react in a proper port tuned enclosure. I can see if I still have the old boxes. I am not sure if I do. I removed mine
One method is, go ahead and seal the box all up. And use cat litter...
You definitely do not wanna even consider using the stock box. It’s really not worth your effort.
In the audio world, our stock Supra box would be considered along the lines of an AP enclosure. Aperiodic membrane I believe it’s spelled.
AP when done correct is very effective, however it’s...
I’m an audio nerd from way back. So I wanted one last ultimate SQ setup in my life. The Supra is a great platform for audio. Once you get the speaker locations changed. Lol
You can build an enclosure either on top of yours, or remove yours. I’ve done both now. This one is after removing the old box completely. Don’t try and reuse your box in any capacity, you will be disappointed
Good luck. It’s doable