Car audio experts... need some sub advice

[CorsePerVita]

So here's the dealio... I want to make as stealthy of a setup as possible in my car. But the problem is... I have limited room. The storage area is quite small, and the reviews I've seen of boxes in there are drowned out far too much.

Some people have done custom sub enclosures that replace the passenger seat in the rear (and I MIGHT be okay with that, on one seat).

Apparently this fits under the seat:
http://www.kenwoodusa.com/Car_Entertainment/Subwoofers/Powered_Subwoofers/KSC-SW10

However, I LOVE electronica, dubstep, and the system in my 944 would rattle and shake your kidneys but had nice enough speakers that the entire system was very well balanced and just sounded awesome.

The speakers in the doors and rears I'm installing are JL and sound awesome. However, it lacks a nice sub to really kick.

I did see one setup where someone fabricated a box out of fiberglass that fit flush behind the driver's seat near the back seats, I am somewhat open to this idea but know nothing about making a sub box, and definitely wouldn't know where to start with a fiberglass box.

There is also a box enclosure that takes up the whole rear up by the rear seats, and it's nice, but, you give up the back seat entirely, no one can sit then. Somewhat looks stealthy, isn't too bad.

I sort of like the idea of one of the rear seats being removed and a box in the shape of the seat in it's place, didn't look bad.

http://i225.photobucket.com/albums/dd58/koihoshi/911/DSC_0059.jpg

http://i225.photobucket.com/albums/dd58/koihoshi/911/DSC_0057.jpg

http://i225.photobucket.com/albums/dd58/koihoshi/911/DSC_0056.jpg

the interior is damn near immaculate, no rips or tears, so i want to keep it original, if i remove one of the rear seats it can always be glued back in professionally so that's not really a big deal. I just don't want to cut and entirely bork my interior for a sub.

Ideas?

[CorsePerVita]

Errr i guess this should be in misc projects, brainfart, sorry.

[crenn]

For a custom sound system, I recommend these:

http://www.queenslandsafety.com.au/images/hearing_protection/Bilsom%20Leightning%20L.3.jpg

[CorsePerVita]

Hard to beat that at home :P

[OvRiDe]

I would look at the rear deck or the side panels next to the rear seats. The side panels usually have some airspace hiding in there. You could remove the original panels and create custom boxes using fiberglass. A bit of upholstery work and they could look pretty stock, and you would still have the originals to revert it back later. The rear deck could be a good spot as well, but it might be pretty obvious that they are there so it could be a security issue.

[jdbnsn]

Well, I do have experience with this situation. I used to have a 93' Celica convertible and wanted a bassy system in so I had to compromise. I gave up the trunk and built a box that took up most of it. It was a horizontal box though so I could still use the trunk for smaller things to lay on top of it. It was a mix of fiberglass (which I didn't do myself, I had a friend who did fiberglass do it for me, we have a tutorial by Franklin in the forums if you want to learn). The box's airspace came from the wheel-well where the spare tire was supposed to be, lol, so there is always a compromise, but the airspace came out to just a bit more than the recommended for those subs. Pics below. It actually did sound phenomenal, so facing the subs upward thus far has sounded better than any other arrangement I have tried, I recommend that route if you are giving up space anyway, that way you keep your backseats and your system is invisible. You will lose alot of bass no matter what you do though because of the convertible top, but the fiberglass and wood combination box is really the way to go if you want to make up for it, the combination of flexible fiberglass which worked a little like a passive radiator and the rigid double layered MDF top makes for a perfect enclosure for crisp sounding thunder. Another thing you can consider is high-end treble, separated mid range, and use some fairly small subs that can be mounted in your rear side panels (you will need to build small enclosures for them though, done this too and it works pretty well), I would recommend Morels for the large/mid range, they are power hungry but they are devils. Look into adding an EpiCenter pre-amp to the midrange speakers to fine tune your mids, it is a fantastic device and works wonders. Then, you can skip the subs and use bass shakers (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=299-028) instead. In a convertible, since you will lose much of the bass at highers speeds anyway, these make a great space saving solution and actually improve your sound since it's not your ears that make the bass experience anyway these things trick your mind and in the end it ends up sounding just as good. I was surprised actually when I first heard a system that used these, just like any other high bass stereo than boomed along. You mount them under the seats so once again, invisible/concealed and you don't need to give up any room in the car. I would not recommend building a large box in the backseat. For one, your car looks tacky, two you lose seating, three your stuff is right out in the open just begging to be stolen, four your sound sucks because placing subs that close to you always sounds distorted. The bass coming from your stereo has more to do with the enclosure and the room you're in than the actual subs, the resonance from reflecting off surfaces and the flexibility of the enclosure are like a fine tuning mechanism and it's hard enough to get it just right with all that space to work with, but when you eliminate all of it and try to rely just on the subs placed behind your head, you will regret it.

http://www.thebestcasescenario.com/jdbnsn/car/subwoofer%20box.jpg

http://www.thebestcasescenario.com/jdbnsn/car/subwoofer%20box2.jpg

http://www.thebestcasescenario.com/jdbnsn/car/subwoofer%20box3.jpg

[jdbnsn]

BTW, is that a Porsche?

[BuzzKillington]

Have a center console made and have the sub out the back towards the rear seats?

[CorsePerVita]

THANK YOU for all the advice guys!


I would look at the rear deck or the side panels next to the rear seats. The side panels usually have some airspace hiding in there. You could remove the original panels and create custom boxes using fiberglass. A bit of upholstery work and they could look pretty stock, and you would still have the originals to revert it back later. The rear deck could be a good spot as well, but it might be pretty obvious that they are there so it could be a security issue.

Not sure how much room is in the side panels. I'll take a look and see if there is much. The rear deck is housing my other speakers, but, there is enough room under there I might be able to do something, there is actually decent room under the rear deck. A guy at the local audio shop I get my stuff from said that he's seen people raise the decks on them, the way he explained it sounded kind of ugly and would make it harder to see out the back. But something /under/ it may be an option. I can measure and find out.


Well, I do have experience with this situation. I used to have a 93' Celica convertible and wanted a bassy system in so I had to compromise. I gave up the trunk and built a box that took up most of it. It was a horizontal box though so I could still use the trunk for smaller things to lay on top of it. It was a mix of fiberglass (which I didn't do myself, I had a friend who did fiberglass do it for me, we have a tutorial by Franklin in the forums if you want to learn). The box's airspace came from the wheel-well where the spare tire was supposed to be, lol, so there is always a compromise, but the airspace came out to just a bit more than the recommended for those subs. Pics below. It actually did sound phenomenal, so facing the subs upward thus far has sounded better than any other arrangement I have tried, I recommend that route if you are giving up space anyway, that way you keep your backseats and your system is invisible. You will lose alot of bass no matter what you do though because of the convertible top, but the fiberglass and wood combination box is really the way to go if you want to make up for it, the combination of flexible fiberglass which worked a little like a passive radiator and the rigid double layered MDF top makes for a perfect enclosure for crisp sounding thunder. Another thing you can consider is high-end treble, separated mid range, and use some fairly small subs that can be mounted in your rear side panels (you will need to build small enclosures for them though, done this too and it works pretty well), I would recommend Morels for the large/mid range, they are power hungry but they are devils. Look into adding an EpiCenter pre-amp to the midrange speakers to fine tune your mids, it is a fantastic device and works wonders. Then, you can skip the subs and use bass shakers (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=299-028) instead. In a convertible, since you will lose much of the bass at highers speeds anyway, these make a great space saving solution and actually improve your sound since it's not your ears that make the bass experience anyway these things trick your mind and in the end it ends up sounding just as good. I was surprised actually when I first heard a system that used these, just like any other high bass stereo than boomed along. You mount them under the seats so once again, invisible/concealed and you don't need to give up any room in the car. I would not recommend building a large box in the backseat. For one, your car looks tacky, two you lose seating, three your stuff is right out in the open just begging to be stolen, four your sound sucks because placing subs that close to you always sounds distorted. The bass coming from your stereo has more to do with the enclosure and the room you're in than the actual subs, the resonance from reflecting off surfaces and the flexibility of the enclosure are like a fine tuning mechanism and it's hard enough to get it just right with all that space to work with, but when you eliminate all of it and try to rely just on the subs placed behind your head, you will regret it.



I like the idea, your pics are great. I hadn't considered the spare well. In fact, I have yet to see anyone actually make a box in the spare tire well and there IS a good bit of space in there. After looking at your pics if I removed the spare well I might be able to fit something in there. I'll take it out in a little bit and snag some pictures and see if I can get some second opinions. The boxes I saw were small, bulky boxes that were pushed up against the storage area, they didn't really look that great and took up a big bit of space. I think with your idea of the trunk and taking out the spare tire area I could probably still keep some storage space.

I like your bass shaker idea too. That's a good point that most crazy bass is felt and not heard. The other thing is with those I may be able to get away with a SMALL sub and those to compliment it since those appear to be pretty small and easy to hide from looking at them. I had never heard of those before, I'm open to the idea. I'm assuming those would be best mounted under the seats.


BTW, is that a Porsche?

Yes, it's my 82' 911 SC.


Have a center console made and have the sub out the back towards the rear seats?

Do you have an example? Are you talking like a bazooka style? There isn't much space inbetween the seats. I know it looks roomy in the pictures, but once you get in the car and look around it's quite small lol.

[jdbnsn]

Ah, the porche is a rear engine car then right? The spare well in the front. Some cars has the spare under the vehicle and not in the trunk is why I ask, not sure about the porche. I googled it but the results just said "you cannot afford to even look at this car" lol

Anyway, building a box in the spare well will only be useful if you use the fiberglass bass keep in mind. Any square box you try to squeeze in there will not likely sound well due to the corners bouncing off the vehicle when you drive and the box will not have enough contact with the frame of the car. Much of the bass you feel in the car is from the direct conduction of the vibe transmitted through the frame to your car seats. So you want as much of the box's surface area as you can get to be in contact with the frame and tightly fastened or even bolted down if possible. That is where the fiberglass proves most useful and it uses the full volumetric area of the well giving you the deepest bass for your buck out of a wheel well. It's not a difficult as you might think, after seeing it done I though "why in the hell didn't I just learn how to do this? You'll need to first line the well with a plastic sheet so the fiberglass doesn't adhere permanently to your porche and it's another layer of moisture barrier. Then get a big sheet of something cheap like peg-board or masonite and cut a hole in it about the same diameter or slightly smaller than the diameter of the wheel well. That is to make the top mounting rim for the fiberglass since you won't be putting your MDF in until later and your fiber glass won't dry into a nice flat ring at the top on it's own. then line the inner surface with the fiber fabric and mix up your resin and kind of quickly pour and paint it on while in a well ventilated garage and wearing a high quality respirator. once you have the resin thickly painted on the sheet place the MDF ring on the top and with your gloved fingers pry under the edges to press the sheet up against the bottom surface all around the circumference to ensure the fiberglass is tightly sealed against the ring and you won't have an airleak later when it drys. then just leave it alone and let it dry for the time recommended by the resin directions, trunk open in a well ventilated garage. Once it's dry all you have to do is add the MDF top. Add the first layer with the measured sub holes already cut and screw it down tighly to the masonite ring using counter-sunk holes and lots of them with fairly small wood screws. That sheet you see in mine is the first layer and unfortunatly when we did this I didn't take many pics of the whole process but you have several options. We figured out the wiring diagram based on a 4 ohm circuit on Rockford Fosgate's website which has a wiring diagram calculator and I recommend it, great tool. You can choose the desired ohms and it will show you how to wire the subs for that specific loop. we routed the sub holes before mounting it and then wired and fastened the subs in place before adding the next layer. This way we could add the next layer on top with the holes being the same size and the screws could not be accessed without removing the top later making the whole box somewhat theft proof without a lot of time and effort. Then pre-carpet the top layer so you can manage the inner edges of the sub holes more easily and then screw it down tightly to the bottom layer with larger wood screws. Then you are done. You end up with a very clean looking yet concealed and theft resistant whopper of a sub box that sounds amazing and you still have a little room on top for storage if you mount grills over the subs to avoid items rolling on top of the subs damaging them. Good luck with the project and show us pictures if you do this!

Jon

[OvRiDe]

The 911 is a tough nut to crack when it comes to subwoofers. The most common placement does seem to be the rear seat. The problem is you lose the use of the back seat. Of course that seat isn't THAT usable in the first place, unless you are about 4'2. Here is an example of a rear side panel.

http://forums.pelicanparts.com/uploads/114_1495.jpg
http://forums.pelicanparts.com/uploads/115_1502.jpg

Here is a pretty nice example of a rear seat replacement box.

http://i15.photobucket.com/albums/a357/nineballots/911%20interior/100_5756.jpg

There is a worklog on the build here..

http://fiberglassforums.com/build-pics/12433-porsche-911sc-build.html

I have been a member of the fiberglass forums for a while, it has a ton of information, tutorials, and examples of this kind of fiberglass work.

What ever you decide to do .. I want pics! :D

[BuzzKillington]

Search "Center console sub" in google images. Now that you mention it though, that does look like a pretty tight fit.

[CorsePerVita]

Thanks again guys. Looking at the pictures in OvRiDe's pics it looks like that's a nice setup but not sure how far I wanna go, that's pretty much an entire seat tear out.

That door panel looks freaking rad! So that's a sub enclosure?

I'm 5'10" and my wife is 5'8" so the seats pretty much sit pretty far forward so the idea of having it near the floor doesn't bug me too much, and the seat idea doesn't either.

Here's pics of the spare area. The actual area where the tire itself sits provides little space since it domes. However, just past that is a nice empty area up near the headlight. Sorry for the dirty pictures, I haven't cleaned out the storage area and waxed it since I bought it lol.

http://i225.photobucket.com/albums/dd58/koihoshi/911/sound/IMG_20110227_115455.jpg

http://i225.photobucket.com/albums/dd58/koihoshi/911/sound/IMG_20110227_115431.jpg

http://i225.photobucket.com/albums/dd58/koihoshi/911/sound/IMG_20110227_115338.jpg

[jdbnsn]

While the rear panels look great and would be a pretty good solution, they offer very little air space to accommodate subwoofers. They would be well suited for a pair of morel 8" mid-ranges though. Plus, sidepanels are very tough to work with, you are looking at a very involved process in just removing them much less rebuilding or fabricating new ones. The trunk space looks pretty small, I think it could be done but it would be limited and if there is no communication with the car interior you will lose a bit of the bass because having the box in the same chamber of the seating adds the pressure created when the subs are firing gives you alot of the sound effect. In my opinion, the bass shakers securely fastened under the seats is your best bet unless you are willing to take on a huge building operation.

[dr.walrus]

Your four options are, without losing the back seat

1. Custom rear parcel shelf box (http://www.caraudiocentre.co.uk/news/car-audio-centre/porsche-911-cutom-subwoofer-enclosure/)
2. Custom door panels (http://caraudiosecurity.com/shop/product_list/c_path/60_436_1038/spd/porsche.html)
3. Custom rear footwell box (http://www.caraudioinnovations.com/porsche1stload.htm)
4. Standard underseat sub (http://www.google.co.uk/search?q=under+seat+subwoofer)

That parcel shelf idea, if suitable for your model of 911 (i have no idea if that's the case), would produce the most and best sound without sacrificing any practicality.

If cash is limited? Underseat is your only viable option, unless you want to learn to fiberglass!

[Kordova]

This topic is right up my ally...

jdbnsn has this pretty well tied up with ideas and seems like his dipped his hand in this before ;)

Well Jon is defiantly right about air space, if you want a kick a$$ system its all about the box baby! Lol Coming from a competition back ground and hopefully becoming a autotech at a local audio shop soon, as my last trade wasn't nearly as fun as my hobby :)

So my thoughts on this might be a little crazy and out there but just hear me out... One go for the spare room you got, if your not willing to use your back seats for you box then defiantly go for the front of the car where you have the room.

Two: Possible port placement, not sure if you heard of this but if you're able to run the port under the dash/firewall to get that sound in the car it self, you'll be amazed at the out come. As long as you don't use crappy subs that distort it should be fine, along with to big of port. You may end up getting a muffled effect out of the port if its to big.

For the box, well with the amount of space your working like most have been suggesting fiberglass is probably the way you want to go. Also you don't necessarily have to make it perfect, reason for that is you can do a wrap in fabric making the over look great.

If you lean toward a custom mdf box bigger is always better, that is no lie when it comes to bass. There is only so much room you can work with and my experience build the biggest box possible.

I do really like the side panel boxes for mids or even 8" subs for the rear bass effect seeing how your bass is going to be up front if you choose that as your only option.

I really wish i had taken more time with my buddys 944 because all he wanted was a deck put in, which was easy as pie. But i never looked around on where or how he could put in a sub.

Hmmm, trying to picture this in my head to give you more ideas. :alien:

Trying to wrap my head around this one, its actually bugging me now. How much head room do you have up front? In order to stay away from fiberglass you gotta have enough room to have 1" 3/4" (box thickness) plus the 12" sub even if faced on a angle you might run into problems with clearance, I'm thinking back seat myself. But is that what you really want, to be completely honest my buddy had a 2+2 300zx and it was so pointless to have the back seats but if your willing to do some custom work it can look pretty sweet.

If you take some more pics with the storage area I might be able to come up with a design you could follow... No promises or anything but I could give you a good idea where to take it.

Kordova :think:

[msmrx57]

There are some newer subs (shallow mount) that don't require a lot of volume. However they are more expensive than traditional subs of the same performance level. I'm certainly not an expert but for what you're after they should provide enough punch without having to hack up the interior.

[jdbnsn]

I will tell you in my amateur opinion as someone who has built car systems less than 6-7 times and never professionally. If you don't have a great deal of experience doing this, go small. The under-the-seat subs sound like **** to be generous and since they are usually not attached to the frame but just bouncing around under the seat (unless you bolt them down of course) they add very little enhancement to your audio quality for the money. The smaller or flatter subs being mentioned are really not a new idea. Back when I was in high school they marketed "free-air" subs which supposedly didn't need a box at all, and consequently also sounded like ****. The distortion at any significantly gangster-impressing level was so bad the buyers lamented.

What Kordova said about the box size is quite true however, and there in lies the rub for you. My first proof of this was my friend in high school who build an enormous sub box in his hatch back Skyline and mounted two 6*9's and one 8" sub. We laughed at him, until he turned it on. There is a measured airspace/volume recommendation for all subs, the rockford fostgate site has a calculator for your dimensions if you choose to build your own (and it doesn't have to be a rectangular cubical structure either, kinda cool). What is not usually mentioned however is what is gained or lost by exceeding the recommended size and I haven't enough experience to say with certainty that it always sounds better to go bigger, but from the examples I've seen it does look that way. What I do know for sure is that if you go less than the recommended size, you lose quality, and it seems to be an exponential loss the smaller you go.

So that means for you to get really nice and crisp sounding bass in that car you are in for a major project, even for a skilled technician who does it daily he would be clearing his schedule for a few days. Taking out seats, side-panels without destroying them or losing any of the little plastic fasteners, working around seat belts, pulling up carpet, routing cables twice (the second time is after you've put it all together and realize you forgot the power lead), building the box, dreaming up ways to bolt it down without losing the seal or jacking up the MDF, taking it back out because you forgot to address moisture control and then bolting it back down, taking it out again because you forgot to hook the power lead back up. Then you turn it on and it doesn't work, trouble shooting for 6 hours with volt-meters and NASA grade electro-spasmaticoshygmomanometers until youo want to cry, then realizing the fuse that came with your power lead only works at low amperes, fixing that and still doesn't work because one of your 6 ground leads doesn't conduct through the waterproofing, and so on and so on. It's very rewarding to undertake and complete a project like this, but for the week and a half to two weeks you are working on it nearly all day with the finishing touches and vinyl or carpet coverings including the ripples you couldn't get out of the corners that keep you lying awake at night, your car in unusable and dismantled in piles of stuff that don't look so familiar when you go to put it back together. Don't forget the 5-10 extra pieces that you really don't think you've ever seen before and can't figure out where they went (maybe part of the lawn mower?)

The short cut ways like subs marketed to people who don't want to build a real box sound about like you'd expect any shortcut to, they sound like a short cut. Even if your front trunk is suitable for a fiberglass/MDF enclosure, I would still be sure you are ready for a true grit experience, and that would be alot easier than replacing the back seat and side panels with enclosures. But the fact of the matter is, that's a Porsche and it looks to be in pretty nice condition, I learned on old Hondas and they didn't always come out un-scathed. You risk major tears to the interior, dents when you are moving larger sheets in and out, or boxes, or dropping amps, etc. A Porsche does not have stock electrical system designed to support a large amplifier either, so consider a second battery, or adding a 1 farad capacitor (or both) or buying a new high output alternator to make up for the new demands. I don't know what your living situation is but if you are married, expect a pissed off wife because you are always in the shop making your avoidance of her obvious to the neighbors, if you live with your parents expect them to get sick of the mess you are making, if you are jobless expect the project to take at least 3 extra months of welfare check installments to make up for the extra fasteners and wire-harnesses, or waterproofing varnishes that you didn't think to add into your project budget. I don't want to discourage you from doing something creative by any means but I do want you to be aware of the scope of this undertaking and risks to your classic car.

If all of these bases are covered and you still want to roll up your sleeves to build a beast then go for it. But if you are looking for a reasonably good sounding system with maintaining the classiness and well kept look of your Porsche then I'd consider keeping it to highs, mids, and bass-shakers with maybe small subs if you can find a good place to mount their cute, tiny little boxes under the seats or behind the kick-panels. But you are not going to build a ground-pounder system in that car without a huge amount of effort and sacrifice to your marriage, parent-emancipation case, or SSI good-standing, not to mention your Porsche will have greatly diminished value due to the visible alterations that few others will appreciate, and don't forget the spare tire you have to have delivered to the site of your blow-out (mine did fit on top of my box just barely but watching me try to un-wedge it and extract it from the trunk was hysterical, yours won't fit so place it in a large box with packing peanuts and drop it off at FedEx to be held until notified). And in my humble opinion, those systems that show the subs out in the open look tacky anyway unless they are marketing devices for stereo companies.
Make sense?


EDIT: Oh, and not exactly related but a significant consideration before pouring blood, sweat, and tears into any car project is another risk. The first system I did really well was stolen out of my car within one month of finishing it. That was my first lesson in security measures, either bolt it down so that the manufacturer themselves couldn't take it out or make it plug'n play so it's easily removed by even an amateur thief (and let's face it, professional thieves are too busy in congress and wall street to worry about your car) because if you half-ass it then half of your interior goes with the system. The second well done system I did, the car was totaled within 6 months probably because I was too busy head banging to Judas Priest to watch the road. The third one was the Celica shown above and the car's radiator exploded in Philadelphia while I was in medical school which believe it or not, totaled the car (lol, piece of ****) so I spent half a day in the parking lot of the comfy-Philly August 99 degree heat with 380% humidity on a black-top parking lot in full view of my many homeboy 40oz beer swilling fellow tenement dwellers removing the components rather than pass them along to the sales lot. They now have a home in my current car seen here (http://www.thebestcasescenario.com/forum/showthread.php?t=15885). So just keep in mind that a work of art in a state of inertia carries certain inherent risks, and if you go to all that trouble just to watch it crushed it will break your heart.