Convertible Subwoofer Set Up - Thoughts/Pics?

TheOdessa · Jul 5, 2020

Hey all.

Can any of you guys post up your subwoofer enclosure set ups with specs and recommendations? I've been looking at upgrading mine but I wanted to get some ideas.

Being a convertible, I cannot fit a big box with the seats down like a coupe. I want some bass for when I cruise and some extra thump over what I have now. I currently have a single Alpine Type R 10" in a ported box (1.1CU/FT tuned to 34HZ) off a Rockford Prime 750.1 Class D amp. It's just not enough for me and the thump isn't there. I know being a Vert hinders the performance, along with a solid back seat, but there's got to be a way. I was debating running a dual sealed box set up with JL Audio 10TW3 slim subwoofers but before I dump almost $700 on subs I want to ensure this is a good upgrade.

Current audio specs:
Pioneer 7" in-dash screen
Entire car, literally besides the roof, sound deadened on all hard surfaces
Rockford 750.1 Class D mono block running sub
Rockford 400.4 Class D running highs
NVX 6.5" component system up front
NVX 6.5" component system in rear
All new speaker wire ran from amp to cross overs feeding components
Rockford RCA cables
Pure copper cables for power/ground
Big 3 Upgrade
System tuned with oscilloscope to prevent clipping
Alpine Type R 10" subwoofer
Custom built and tuned ported box - 1.1cu/ft tuned to 34HZ

TheOdessa · Jul 5, 2020

Seriously just thinking off the top of my head here and don't judge me for the noobness of this. I don't typically take routes like this on my build but I am brain storming. What if I cut (4) 3" diameter holes in the piece that divides the trunk to the interior cabin? I'd still have the rear seat to deal with, but perhaps bass can pass better through this solid interior piece better penetrating the cabin through the material behind the seats and the seats themselves?

I need my back seat due to my daughter so a rear seat delete isn't an option.

evilcw311 · Jul 5, 2020

TheOdessa said:
Seriously just thinking off the top of my head here and don't judge me for the noobness of this. I don't typically take routes like this on my build but I am brain storming. What if I cut (4) 3" diameter holes in the piece that divides the trunk to the interior cabin? I'd still have the rear seat to deal with, but perhaps bass can pass better through this solid interior piece better penetrating the cabin through the material behind the seats and the seats themselves?

I need my back seat due to my daughter so a rear seat delete isn't an option.

This would be attempting a free air setup which doesn’t work well enough in a coupe, more of less a vert. You need to look into a larger more powerful sub to make up for the loss of a hard top. Problem is your trunk is short in space as is. Last time I helped someone with a vert setup and we got decent bass we eliminated the spare and used that air space for 3 10”s. Best one we did was a 15” in the well.

Obviously this would mean your trunk is almost worthless and you no longer have a spare. Most of us with bigger wheels can’t use a spare anyways.

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TheOdessa · Jul 5, 2020

evilcw311 said:
This would be attempting a free air setup which doesn’t work well enough in a coupe, more of less a vert. You need to look into a larger more powerful sub to make up for the loss of a hard top. Problem is your trunk is short in space as is. Last time I helped someone with a vert setup and we got decent bass we eliminated the spare and used that air space for 3 10”s. Best one we did was a 15” in the well.

Obviously this would mean your trunk is almost worthless and you no longer have a spare. Most of us with bigger wheels can’t use a spare anyways.

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I appreciate it. That's what I've been reading is I need to make up for the hard tip is the only way. I used to do SPL comps over 10 years ago but I was dealing with a Ford Explorer. I had a 15" Magnum SI ported off a Hifonics 1200.1 and that thing slammed. Now that I'm older I dont want that kind of bass, but for what I have I feel like it's seriously lacking.

After doing researching I was looking at doing a dual-custom up firing setup. Dual sealed 12" Rockford P3 slim subs. This will give me 2x 12's, cleaner bass while utilizing the same amp and still having a trunk.

http://www.conceptenclosures.com/product-p/ce-94-04mustang.htm

https://www.amazon.com/dp/B000O3M0TM

I'd do poly fill in the enclosures. Subs are rated min .6/sealed, 1/optimum. .85 each prefab. This is what I'm leaning towards right now.

I don't have my spare anymore because of what you said - different tires/wheels. Just messing around with the idea of different set up and right now this is the best I can find without a ton of fab work. 2x 12's should def push more air even if the 12's are sealed and the 10 is ported.

TheOdessa · Jul 5, 2020

Also the holes would be for the bass to escape the trunk and get into the cabin. It'd still be in it's appropriate box. I never ran a subwoofer in free air. I'm just trying to allow bass to get from the trunk in the cabin.

A buddy of mine many years ago had a coupe new edge. With the rear seats down the bass was much louder then if the seats were up.

ttocs · Jul 5, 2020

how much do you use your back seat and when you do how much do you enjoy it? The 2nd part is a rhetorical question since no one over the age of 8 has ever enjoyed a ride back there, and no one in the front seat enjoyed them back there either. If you don't have kids ditch the seat and put them there and you will be much happier on the rare occasion when you might need to use the back seat you will find another way.

evilcw311 · Jul 5, 2020

ttocs said:
how much do you use your back seat and when you do how much do you enjoy it? The 2nd part is a rhetorical question since no one over the age of 8 has ever enjoyed a ride back there, and no one in the front seat enjoyed them back there either. If you don't have kids ditch the seat and put them there and you will be much happier on the rare occasion when you might need to use the back seat you will find another way.

Do they still sell the membrane material to put behind free air subs??? It kind of gave the sun an enclosure when one couldn’t be done.

If so he could put a board across the opening behind the back seats and then use the membrane to seal that area closest behind it. Sub would still pound a little when the seat is up but when his kid isn’t in the car he could drop the seat for more bass.

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dwcopple · Jul 5, 2020

Don't cut holes in the well liner.

evilcw311 · Jul 5, 2020

dwcopple said:
Don't cut holes in the well liner.

Do you have anymore of a applicable comment other than just “Don’t cut holes in the well liner”?!?!?

Something so short and vague isn’t exactly constructive. [emoji38]

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dwcopple · Jul 5, 2020

TheOdessa said:
What if I cut (4) 3" diameter holes in the piece that divides the trunk to the interior cabin? I'd still have the rear seat to deal with, but perhaps bass can pass better through this solid interior piece better penetrating the cabin through the material behind the seats and the seats themselves?

I was answering him ^^^

MyLittlePony · Jul 6, 2020

Edit - Didn’t see the part where you mentioned RSDs being out of the question. Sorry

This is what I did way back when:

Rear seat was basically useless anyway. Had to reinstall the seat in 2012 though when I had a kid. All of a sudden, that rear seat became practical. Who knew?

It might not be professional, but it got the job done. Was plenty good for what I needed it to do. I would like to know a better way, like mini subs in what could be in the extra Mach sound rear speaker grill. (Note: current set up has an all forward setting for when my daughter rides with me. No need for her to go deaf with a speaker right there)

MyLittlePony · Jul 6, 2020

ttocs said:
how much do you use your back seat and when you do how much do you enjoy it? The 2nd part is a rhetorical question since no one over the age of 8 has ever enjoyed a ride back there, and no one in the front seat enjoyed them back there either.

Part of the fun of having a rear seat delete is being able to tell people you can’t give them a ride. But as far as no one enjoying it back there, I once, regrettably gave a ride to two elderly people in need. Beggars can’t be choosers, but I do recall several teenaged chicks LOVING the back seat! As a matter of fact, no, they WERENT legal! There was only two seat belts back there. I always told my passengers that if they ever wanted to ride with me, they had to wear a seat belt, but if the capacity ever exceeded the limits, I gave exceptions. Although I don’t know how that cop let us go by with 4 in the back. You see, with a convertible, you basically have a truck. Tops down, you can pile all sort of shit in there! (Note: when that happened, we were only going 20mph the entire time. It was a school zone).

Anyway, for the bulk of the 98/99 school year, I seemed to be the only one with a license for some reason, so if they didn’t like the rear seat, they could either ride the bus home or walk. And honestly, one of them literally lived right across the street from the school, so no idea what her problem was. She had a good circle of friends though, so it was a win for me.

BillG · Jul 6, 2020

I'm watching this thread for ideas. My 95 needs a sub and an amp and I'm not sure how to do it get it to the trunk with top in the way.

dwcopple · Jul 6, 2020

The top doesn't impede on the actual trunk. I'm leaning towards an under-seat powered 8" sub personally.

ttocs · Jul 6, 2020

dwcopple said:
The top doesn't impede on the actual trunk. I'm leaning towards an under-seat powered 8" sub personally.

I am not aware of any subs that will fit under our seats. There is hardly space for french fries down there...

BillG · Jul 6, 2020

ttocs said:
I am not aware of any subs that will fit under our seats. There is hardly space for french fries down there...

Mines more like pine needles and leaves from top LOL

TrickVert · Jul 6, 2020

I mounted a 12" sub in my spare tire well, using that as a sealed enclosure. At the time, I calculated the volume, but no longer have the notes. I anchored the baffle board to to the bottom of the deck with screws, and to a 2x2 I secured across the back wall. At the time I cheaped out and used ice guard for sound-deadening. (The only "real" options then were expen$sive, so don't shoot me.) Attached are a few pics.

EDIT: Holy crap! Was it really 2006 when I did this????

With the trunk separator in place and an extra piece of carpet laid over the trunk floor, now you see it, now you don't'

Nothing aftermarket is visible. The wiring from the battery is spilt-loomed and the fuseholder is buried under the factory fuse block.

The head unit is a then-current Kenwood Excelon with a 180° flip face, and a Ford factory stereo is mounted above it to maintain the OEM look.

To mount the amp under the convertible top, I had hoses made to allow the hydraulic pump to be moved to one side.

ALSO EDIT: I know you only asked about the sub, but I couldn't help myself.

Badass2v · Jul 6, 2020

Badass2v · Jul 6, 2020

One ported. Box to the right an d a sealed. Box to the left. Nos bottle was being painted but. Built me a bomber seat with racing harness for my kid 2 12s and 2 6.5 subs