New 240sx box

[KTMrida4life 10+ year member]

This isn't going to be short and I'm incredibly sorry.

I have a 95 Nissan 240sx. Tiny 2 door sports car. About a month ago, I bought 4 SA 8s. One needs a recone, and if anyone has seen my other thread, 2 of the others might as well.. we will see. I had RAM designs do me a box for 3 of them since the 4th one wouldnt fit because of the slot port. I have built the biggest box possible OUTSIDE of my trunk that will still fit into my trunk. It 1.8 cu ft with a slot port tuned to 33 hz. But I want to fit the 4th SA8, and heres where it gets a bit tricky.

So Im going to need a new box. Heres the old box design.

Heres a crappy drawing of my trunk specs (yes, its tiny)

And heres that box in my trunk as of right now. Only difference is right now the box is flipped the opposite way (subs and port facing drivers seat) at the very very back of my trunk (towards bumper)

And heres a video of what it sounds like as of right now..



It sounds good until I hit about 36 volume and at that point things start rattling so bad it sounds awful. Before then there is no noise that can be heard from the drivers seat. My rear deck flexes because of all the air trying to make it from trunk --> car... even with my rear seat folded down it just seems inefficient. I cant fit a 4th order, no way. Battery in trunk as well as amps.

Heres what I want to do and what I need help with as well as opinions, since this is what I want to do and what may not be best.. I want to build another box, almost to the same dimensions as the one I have now. I cant go bigger.. it will not fit in my trunk. I want to use external aero ports. I think 2 4" aeroports will work good. Cant do bigger because port will be too long.. I want to stay around the 30-33hz tuning. Im at 33hz now and its fantastic but I could stand to have a bit more lows, but only if its doable.. I may not be able to make the ports long enough for lower tuning to happen. Ill do some measuring and find out tomorrow.

Heres the kinda tricky part and Im not even sure if its doable or how it would sound, but I know it would look cool if I can pull it off and still look clean. I know if I were moving more air from trunk --> car I would be getting less rattles from my rear deck (maybe staying clipped in?) and it should be a bit louder. I cant seal off my trunk because of its odd shapes and trunk hinges as well as trunk springs. I CANT do any sort of blowthrough my seats because all they do is fold down is a unit. Driving around with them folded down is stupid.

However.. has anyone ever seen someone cut a hole in their rear seat (I'll buy another rear seat for this, Im not modifying mine) and put aeroports flush with the cover which runs back to the box in the trunk? Im not even sure how it would sound, but it *should* be the same as doing a blowthrough with aero ports, just look cleaner.

 

Thats my idea. I want the box at the very rear of the trunk like it is now, all 4 subs facing drivers seat, and them seperated in the middle by the aeroport. I dont know if its OK for an aero and the subs to be on the same face of the box, nor do I know what size/how long of an aero to use, or tuning.. which is why Im asking here. I do know that the port will probably be around 20-26" long max. I'll measure tomorrow and see how long I can get it AND if this is even possible! My trunk opening is FRIGGIN tiny and Im not sure if theres even enough space for 2 4" aeros! Im praying there is.. could someone measure the OD of a flared 4" aeroport for me? Is it something like 5"? I may have to put them next to each other, and even then.. not sure if its possible. I'll do some measuring tomorrow.

Heres a crappy photoshop picture for what I want to do

But I may have to do it like this.

Will this sound good? Loud? Bad? Terrible idea? Just trying to figure out how to fit these 4 8s in my trunk, without building a bigger box, or building a box in my trunk, AND at the same time getting more bass from trunk --> cabin. Opinions? Thoughts? Thanks all, hopefully you read this far. lol

If anyone thinks theres a better way to achieve what I want, speak up! I really need to stick with 8s so I dont lose a ton of cash. I want louder in the car and less bass stuck inside my trunk!

Click to read more...

 

[subzero 5,000+ posts]

why not go through the rear deck? Take the rea speakers out, maybe cut a hole in the rear dash somewhere. I was told by many, that air transfer is very inportant when loading in the trunk. You want as much air as possible to transfer from trunk to cabin and back. You also want to deaden everything as much as possible,

Maybe Ram can design a box with a side fire port.? I used to have one and it sounded awesome. got down real low.

I bet if you found a way to get more air transfer, it would get louder and less rattles.

My old neighbor had the same car, he took the rear speakers out and it sounded way better.

Adding ports might screw up the whole tuning on the output as well as ruin your interior. and looks tacky. post pics of the whole car, inside and out. with more light.

 

[KTMrida4life 10+ year member]

why not go through the rear deck? Take the rea speakers out, maybe cut a hole in the rear dash somewhere. I was told by many, that air transfer is very inportant when loading in the trunk. You want as much air as possible to transfer from trunk to cabin and back. You also want to deaden everything as much as possible,
Maybe Ram can design a box with a side fire port.? I used to have one and it sounded awesome. got down real low.

I bet if you found a way to get more air transfer, it would get louder and less rattles.

My old neighbor had the same car, he took the rear speakers out and it sounded way better.

Adding ports might screw up the whole tuning on the output as well as ruin your interior. and looks tacky. post pics of the whole car, inside and out. with more light.

I thought about the side port. It would still have to be an external aeroport, I cant fit any bigger of a box in my trunk. Not an inch an any dimension.

Also in that video if you watched it, my rear speakers are out. So even with the 2 6.5" holes in my rear deck, and my rear seat down, Im getting more boom in my trunk than in the car. Im getting so many rattles its ridiculous. My rear deck is deadened with AT 60mil, and I have some foam on it. My whole trunk is deadened as well.

Porting through my rear deck with PVC would work, sure.. but my rear deck would flop around like a dead fish even more. Thats why I thought of going through the seat.

As for the tackiness.. I would paint the aeroports grey probably. Or have someone cover them in grey sub box carpet or something so they didnt stick out.

 

[subzero 5,000+ posts]

I thought about the side port. It would still have to be an external aeroport, I cant fit any bigger of a box in my trunk. Not an inch an any dimension.
Also in that video if you watched it, my rear speakers are out. So even with the 2 6.5" holes in my rear deck, and my rear seat down, Im getting more boom in my trunk than in the car. Im getting so many rattles its ridiculous. My rear deck is deadened with AT 60mil, and I have some foam on it. My whole trunk is deadened as well.

Porting through my rear deck with PVC would work, sure.. but my rear deck would flop around like a dead fish even more. Thats why I thought of going through the seat.

As for the tackiness.. I would paint the aeroports grey probably. Or have someone cover them in grey sub box carpet or something so they didnt stick out.

Even if you put the areo ports in the seat, that would not benefit too much, port have to be tunned too. might drasticaly change the tunning.

What I saw from watching the video, is that I think your box is too wide. and the car has that cabin trunk half wall, That might also be interferring with the ait transfer. and I also see you have amps in the way too. What I would do is either shrink the box or re design, relocate the amps and battery to the rear part of the trunk. Maybe try a forward fire position. youd be surprised, using less subs might get louder in a smaller box too.

 

[KTMrida4life 10+ year member]

Even if you put the areo ports in the seat, that would not benefit too much, port have to be tunned too. might drasticaly change the tunning.
What I saw from watching the video, is that I think your box is too wide. and the car has that cabin trunk half wall, That might also be interferring with the ait transfer. and I also see you have amps in the way too. What I would do is either shrink the box or re design, relocate the amps and battery to the rear part of the trunk. Maybe try a forward fire position. youd be surprised, using less subs might get louder in a smaller box too.

Today for giggles I may try to put the box inside the car in my rear seat to see how it sounds. Ill post back

 

[KTMrida4life 10+ year member]

Put it in my rear seat facing me.

Heres what I noticed. Rear deck doesnt rattle obviously like this... only thing rattling are my doors on certain freqs. The SQ is amazing. My subs are NOT blown if anyone saw my other thread, they are fine! They sound awesome.

But... it doesnt seem as loud? Someone explain this to me.

 

[pro-rabbit 5,000+ posts]

Put it in my rear seat facing me.
Heres what I noticed. Rear deck doesnt rattle obviously like this... only thing rattling are my doors on certain freqs. The SQ is amazing. My subs are NOT blown if anyone saw my other thread, they are fine! They sound awesome.

But... it doesnt seem as loud? Someone explain this to me.

Loading and how the enclosure was designed. I'm sure RAM did not plan to have it sitting in the back seat lol.

 

[audiobaun 5,000+ posts]

Well, not sure what model of 240 you have, but I have a 90, and I had a pair of tens in there, with seperate boxes @1.6cuft, ported, and had them firing up with port towards front drivers seat.Sounded just fine to me.Although, i deadened the floor well at the hatch, and i also made a false floor out of 3/4 plywood, and covered it with carpeting.Most of the time i had to leave the seats down, and crack the windows approx 2in to get the best out of the sound it seemed.Yet i had to seal off my rear speakers with baffels as the subs were damaging them also.I ended up replacing 2 sets do to this.Most of the vibration was from the hatch cover in my car, so i took it out.You know, with the Mean Machine 99, on a pair of 1000rms tens, i mean..things vibrate, but it did sound pretty good set up that way.I dont have anything set up in there anylonger, but i will say that car was the hardest to get the wiring set up than any vehicle i have ever owned.Using the baffels On the rear speakers really helped out tramendiously for the nonsense vibration, as well as protecting the rears, and air escaping slowed down too.You can always keep your seats down and do a baffell/wall setup and that way, you can keep your rear seats?? Just a suggestion?Not sure if any of this may have helped, or made any sense, but just my experience of this type of car.

 

[audiobaun 5,000+ posts]

95model..//content.invisioncic.com/y282845/emoticons/eek.gif.771b7a90cf45cabdc554ff1121c21c4a.gif sorry

 

[audiobaun 5,000+ posts]

Its kind of hard to make mistakes with designing boxes these days with using cad programs with the specs that the subs call for, and @the hertz required, rather than back in the day using tape measure ect.Maybe those 8s just dont sound that great in that car??Ive had a pair of 12s that didnt sound as great as a pair of tens, and it was all due to the airspace of the vehicle, that I assumed?Everything was made to specs, but the tens just sounded so much better.Same brand, and pretty much same rms power/hertz.Have you tried to go sealed???

 

[KTMrida4life 10+ year member]

Its kind of hard to make mistakes with designing boxes these days with using cad programs with the specs that the subs call for, and @the hertz required, rather than back in the day using tape measure ect.Maybe those 8s just dont sound that great in that car??Ive had a pair of 12s that didnt sound as great as a pair of tens, and it was all due to the airspace of the vehicle, that I assumed?Everything was made to specs, but the tens just sounded so much better.Same brand, and pretty much same rms power/hertz.Have you tried to go sealed???

Cant do sealed with these 8s I dont think. Motor force is too high from what I've read...

My old Kenwood 10s were in a sealed box on 500W RMS and they sounded good but no where near this loud SPL wise..

I did some more driving around, and I was wrong.. its way louder in my rear seat. It sounds amazing. No rattles except for my door panels and its loud as crap...

Now if theres just a way to put it back in my trunk and it still sound good, AND add a 4th SA 8. I cant leave it in my back seat.....

 

[audiobaun 5,000+ posts]

Cant do sealed with these 8s I dont think. Motor force is too high from what I've read...
My old Kenwood 10s were in a sealed box on 500W RMS and they sounded good.

I did some more driving around, and I was wrong.. its way louder in my rear seat. It sounds amazing. No rattles except for my door panels and its loud as crap...

Now if theres just a way to put it back in my trunk and it still sound good, AND add a 4th SA 8. I cant leave it in my back seat.....

Ya, i wouldnt leave those exposed either man.May have to rip all the panels off, and start deading the entire vehicle??Till you like it?

 

[audiobaun 5,000+ posts]

Have you looked at taking/unbolting the top of the back seats, and building a baffel/wall for the subs?That would work, and you could get them all in there, and still be able to bolt the seats back if you never decide to sell the car?? Just a suggestion, and cover the face of the subs with some dark speaker cloth to help from exposure?

 

[KTMrida4life 10+ year member]

Have you looked at taking/unbolting the top of the back seats, and building a baffel/wall for the subs?That would work, and you could get them all in there, and still be able to bolt the seats back if you never decide to sell the car?? Just a suggestion, and cover the face of the subs with some dark speaker cloth to help from exposure?

Not sure I understand, but this will give you an understanding of how tiny that opening is.

I can almost gurantee all 4 8s wont fit across there. That would be at least 34" or so, and that opening is probably 28". There would be no room for a port either.. the 3 I have MIGHT fit, but there still wouldnt be enough room left for a port. Pretty sure, but Ill check anyway. The left side is taller than the right if anyone noticed.. by a few inches. Its not an illusion. Thats the access for the fuel pump in the gas tank.. actually went in there not too long ago to fix my fuel gauge. Drifted around a corner and got stuck on empty. lol

I drove around with the subs in my rear seat all day because it was amazing how good they sounded. Earlier though I had to take 2 of my friends somewhere.. 1 in my front passenger seat.. and the other, in my trunk. LOL. I wasn't moving my box and he was fine with riding in the trunk. He said even in the trunk it was loud.

Im going to figure this out.. just a matter of how. I also think I can run more power to the 8s. Heres my goals...

- Figure out a way to fit all 4 SA 8s in trunk, ported box.

- External aeroport(s) that I can tune..

- More power. Sell my Lanzar and get 2 1500W amps, either MBQs or AP 1500s.

- Seal off trunk.. this is confused on. If someone could further explain this, that would be awesome. Would you want to seal off in front of the box at your trunk opening or what? For this to work, do your woofers & port have to be right up against your back seat as well as your box? Need help on this to see if its even doable in my trunk

 

[KTMrida4life 10+ year member]

Ok new question.

I really want to fit a 4th order box for all 4 SA 8s in my trunk. Keep in mind I would also have to fit my amps somewhere as well as my battery. The battery should be able to fit beside the box if I make the box not quite as wide. The amps will be tricky to find a place for.

Anyway.. has anyone here ever built a box inside their trunk? Im thinking thats the only way the 4th order would fit. Just want some info on how you did it. I understand how to build a box, but how do I secure the top on it if I cant get a nailgun (or screwdriver, whatever) between the box + rear deck?