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RFIRE15

Time to plan for the show car....

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Ok guys... here is what will be my spring project!!

I have a 2k3 Grand prix GTP... nice size trunk, though i'd like to have as much of it left as possible.

Here is what I am thinking:

2 15" Magnum D2's

2 PG Tantrum 1200.1's

Sealing off the trunk and facing the speakers and port into the cabin. I will have to customize a way for my whole back seat to fold down, but i'm sure that will be managable.

I figure I'll have to build this box inside my trunk to get it to fit.

What I'm looking for out of you guys :) is some pointers. As some of you know, I'm still somewhat of a n00b when it comes to the big stuff.... but I still want it all!! I'd like to compete with this if at all possible, but that isn't the main priority. She is going to be a show car(30+ shows this year), So i would like to use some plexi on the back of the box (viewable from the trunk) to see that sexy ass of the sub's.

questions...

-What will the minimum size encloser (volume) that I will need to get these things to pound.. and what should I tune it to.

-What kind of electircal upgrades would i have to do... I have a price on an upgraded alt. from that guy Dom if i need it. I will be pulling 2400+watts with those 2 amps. Maybe another battery in the trunk, i dunno. I know i have to do the "big 3"

-Should I Dynamat the whole car?

-Wiring... I have 0 guage going to the trunk now.. with a 200amp circuit breaker under the hood.. will I need another circuit breaker?

Anyway.. most important thing is the box design for the subs (hense why its in this section). Any and all tips are welcome!!! :)

And maybe i can talk aaron into giving me a hand or 2 when i start on this ordeal B)

Thanks guys!!!!!!!!

PS.. I'd also be interested in some SI components.. if they are as good as some of the guys say they are. I was eyeing up some focal utopias.. but if they are comparable, i'd like to keep some things uniform.. and hell, maybe nick could cut me a deal ;)

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Well, everyone's pretty much in the same boat as far as enclosures are concerned. Until we all get our drivers, we really don't know what is going to work "best." Also, everyone's taste is different, so what I like, you may not. I would suggest starting out with the reccommended enclosures and going from there. Also, every install will be different and different designs don't have the same results in every car.

Dampening, while not always a necessity is a great idea none-the-less. I highly reccommend it for the simple reason of decreased road noise.

As far as the elctrical system is concerned, I am not familiar with the charging system in the Grand Prix, but I would suggest larger primary wires and an extra battery to start out with and go from there.

And last but not least, beeing a nooB, be careful who and what you listen to on the net. There are a lot of "experts" on the net and not everyone will lead you in the right direction. Do your homework and research and get your hands on as much as you can. Experience will become your friend. This is a very good forum and I myself hold everyone here in high regards and we have some very knowledgeable people here to help, so if you need it we are here.

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If you upgrade your wiring, upgrade the big 3 - alternator to battery, battery to ground, and battery to starter. Spend the extra money and get your alternator beefed up. I highly suggest looking around for an alt thats been built by Dominic Iragi? (I have no clue how to spell his name)

If you deaden your vehicle, go to your local hardware or home improvement store and buy Peel-n-Seal. It is a material that used in roofs that works just like "Dynamat" but costs about 1/5'th as much. It's $1 per square foot. I would use that on all the horizontal surfaces. For verticle surfaces like your doors and the sides of your trunk (and anything like the underside of your trunk lid) I would look around for RAAMAT deadening material on the internet. RAAMAT is extremely sticky and will perform better on surfaces that are tougher to adhere to. I also strongly recommend buying a heat gun and lightly heating up all of your deadening as you are installing it. Just heat it up a little bit and then use something like the opposite end of a screw driver to rub the back of the deadening material onto your floor, door, or trunk lid.

After listening to this Magnum 15, I strongly recommend placing it in a sealed enclosure...unless you just totally want to loose your hearing. ;) If you're after that sort of thing, however, by all means knock yourself out.

You won't need another fuse/circuit breaker. The one you have is just fine.

I would go 2 cubes sealed stuffed 50/50 with fiberglass insulation and polyfil. If you do port them you will need 8 cubic feet after port displacement for two 15's tuned to ~28 Hz. You can go smaller, but your tuning frequency will rise in anything smaller than 4 cubes each.

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Not to hijack the thread or anything, but Nick, what is the driver displacement of the MAG15? I haven't been able to design my enclosures yet cuz I haven't found it anywhere. Also, when you are using poly and insulation, how much of each are you using is said enclosure and what exact fiberglass (R value) insulation are you using?

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The fiberglas insulation that we use is just regular home insulation (Owens Corning). We typically go down the isle of our local hardware store and look for the small rolls (~$7 or so), or grab a big jumbo roll that you see outside houses when they're being built for larger enclosures (like the Esprit's we just got done with).

The 15 might displace ~0.15 cubes. The Magnum 12's technically displace 0.07 cubes, but we tell customers to account for 0.1 cubes just to be safe. I'll get you an exact number soon.

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An upgraded alt is always a great idea - the bigger the better. I have a 200 amp alternator in my 67 mustang, alongside a yellow top battery, and I still get the slightest bit of dimming when the bass is pounding. Which is a lot better than having my HU flash in tune to the music if I run the car of a charger :)

Same goes for the big three wiring upgrades - just make sure that you get a very clean ground connection from the battery, sand off some paint on the chassis if you have to.

As far as sound deadening goes, I would recommend Ant's products over at secondskinaudio.com - I covered the firewall, the inside of the doors, the entire floor and the space behind the back seat leading into the trunk with his stuff & noticed a huge decrease in noise. Next up is the headliner which'll receive a couple of layers too. He also hands out a mighty 40% discount for people who hang out on the caraudio.com or caraudioforum.com forums which rocks. And, yeah, a heat gun (or hair dryer) is a great tool to have around when applying dampening materials.

Lastly ... I've said this before - I'll say it again: the SI components are sweeeeett, and make a fine pairing with the magnums.

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hey Mcschmidt, do you have pics of that sweet ass install? :slayer:

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Thanks for the info guys!! I'm sure i'll pick some of your brains as i get things started :)

one other question... i see some ports are thinner then others, while keeping the same over volume...

is there any advantage with making a port big enough to fit my arm through lol... or is the volume of the port the only thing that matters?

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Just waiting for the sun to come out here in SF, and then I'll take some picts - it looks insane :)

awsome, I love your car

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Alright!!! Another Stang freak!!!! :slayer:

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my father used to have a '64 red Convertable :(

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one other question... i see some ports are thinner then others, while keeping the same over volume...

is there any advantage with making a port big enough to fit my arm through lol... or is the volume of the port the only thing that matters?

Port area is generally determined by the total displacement capability of the sub.

Area is what matters with a port, but you're always making a sacrifice when increasing area. For any given enclosure, an increase in port area means an increase in length and thus, an increase in total volume and depth. To compensate for this increase in volume of the port, your box volume must be increased and the length of the port must also be taken into account as well. That's where "snaking" or bending the port comes into play.

9 times out of 10, you want to make the port as large as possible, within reason. Too large of a port will have just as much an ill-effect on a sub as too small of a port. For all-out spl purposes, you'll see many competitors with as much as 100% Sd for their port area. That means as much surface area of their ports as they have of their subs. For prictical purposes, however, it is generally ok to use just enough port area to nullify port noise associated with ports that are too small, but efficiency may be somewhat sacrificed if going with a smaller port.

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