3hp in a trunk question

jellyfish420
10+ year member

i design boxes .......
well i just got my 3hp motor in today. i'll be sending it off for a recone in the next week or two, and i wanna get started on the box so when it gets back i can have everything ready to thow it in. i have 2 questions....

1) *personal experiance only* what is the best way to fire in a trunk car? i've always been a fan of sub/port back...but i've heard a few people say sub up port back. i don't know about this, so i wanna hear some opinions. (and i can't rip the back seat out, i have 3 kids)

2) i will have no t/s specs as this will be a custom driver, so i would like some opinions on box size/tuning. i've never had a driver of this magnitude, but i was gonna guess at around 4ft @ 38Hz.

car is a 94 grand prix 4dr and the 3hp is a 15.

 
I was told overwehlmingly that Sub Up is NOT the way to go in a trunk.. and was reccomended sub/port fire forward into cabin if possible...or sub/port towards rear taillights.. make sure there is a lil room over the top of the box when rearfiring so you dont seal your soundwaves off (read that last part on audioque.com)

 
I was told overwehlmingly that Sub Up is NOT the way to go in a trunk.. and was reccomended sub/port fire forward into cabin if possible...or sub/port towards rear taillights.. make sure there is a lil room over the top of the box when rearfiring so you dont seal your soundwaves off (read that last part on audioque.com)
right now i have sub/port up, and don't get me wrong its loud, but i think an 18 off 1000w is gonna be loud anyway i go. but w/ the 18 thats the only way i can go. other than that, i've ALWAY done sub/port back...but if there's a better way, by all means im game.

 
Man, I had the same post like 2 days ago wanting to run a 3518 in my trunk, in EXACTLY the same situation of sub up, port front or back.. I just decided to run a smaller size, but if you have the sub already just go subs up... or Angle it as much as possible

 
Sub and Port back is the way to go for your particular car.

Sub up Port back works ok if you absolutely have to due to space issues.

Sub and Port into the cabin is ideal but only if you have the trunk 100% completely sealed off from the cabin. Even if you build the box within a few inches of the width of the trunk, if the trunk is able to have air flow into it you will notice that you lose a lot of SPL in the low low notes and you have a very steep roll-off after a certain point. (around 50hz for me)

this is from experience

 
i have a hatch, i was told sub fired rear and port forward
in my hatch the best way....well was my wall //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif but the second best way was sub and port back. i had them about 3" away from the back wall was the loudest.

 
Activity
No one is currently typing a reply...
Old Thread: Please note, there have been no replies in this thread for over 3 years!
Content in this thread may no longer be relevant.
Perhaps it would be better to start a new thread instead.

About this thread

jellyfish420

10+ year member
i design boxes .......
Thread starter
jellyfish420
Joined
Location
STL ill side
Start date
Participants
Who Replied
Replies
9
Views
1,264
Last reply date
Last reply from
iamamp3pimp
IMG_20260516_193114554_HDR.jpg

sherbanater

    May 16, 2026
  • 0
  • 0
IMG_20260516_192955471_HDR.jpg

sherbanater

    May 16, 2026
  • 0
  • 0

New threads

Top