# Some sub advice please: for a Grand Marquis



## Lanson (Jan 9, 2007)

I'm working on a friend's very large Grand Marquis, and I've got a basic system plan figured out so far. We've got Phoenix Gold Octane amps for the front stage and subs, the 15.0:1 for sub amp, and 4.0:2 for fronts. This means the sub(s) must be at 2ohm final for the best output from the amp.

I need ideas for capable, yet cost efficient subs. I have lots of depth, and available airspace volume in this vehicle, so space isn't a premium. I need something that will play rock, rap, and some older jazz, etc. fairly well. Clean and tight is my friend's request, but with sufficient bottom end. We are fully deadening the car w/ Raamat and ensolite, so no rattles here.

So far, my research has put me on a few different subs, most notably the dB500 from TC sounds, in a 12" size. I need to know more about this sub, though. How is its SQ? Is it snappy? Does it play as good as its response graph shows? How about noise extraneous from the bass output? Distortion? etc. 

Other subs we've been considering are TC Sounds 1000, Eclipse SW7000, 7200, and 8000 (like mine), Fi Audio beginning line 12's, and DIYMA's. Nothing wrong w/ the DIYMA , but I'd like to try something that can play loud in the lower freq's. The trunk is HUGE on these cars, and we'll have the trunk vented to the cabin in two locations, to let the bass waves affect the interior properly.

Any other ideas? Options I haven't considered? I'm up for just about anything. Our budget is no more then $250, and I'd like to have 2 subs for that, or more.

Available power will be either 1000W RMS @ 2ohms or a pair of amps for double that @ 2 ohms each.

Thanks guys!


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## chad (Jun 30, 2005)

Me smells some 18's in the trunk! Do you have enough DC power on tap to give 1-2KW for the subs alone?

Chad


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## bassfromspace (Jun 28, 2016)

chad said:


> Me smells some 18's in the trunk! Do you have enough DC power on tap to give 1-2KW for the subs alone?
> 
> Chad


2 18's would be a cinch in that car.


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## unpredictableacts (Aug 16, 2006)

audioques!!!


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## 89grand (Nov 23, 2006)

I just finished my install in my 2006 Crown Victoria (Ford version of the Grand Marquis). I'm running 1 Diyma 12 in a .85 total sealed box, so about .7 with the sub installed powered by a JBL GTO600.1 and I find the output more than enough, 2 of these would pound pretty hard I would imagine. These cars do have huge trunks, but I wanted to maintain as much of the trunk as possible so I went with the Diyma and I'm glad I did.

I have the a/d/s 5.25 midbasses installed in the factory door locations and the tweeters installed in the sail panels. I may move the tweeters to the A-pillars though for less reflections off the dash. The a/d/s speakers are bi-amped with a JBL GTO 75.4. I built a 2 story amp rack to house both amps under the rear deck towards the drivers side next to the spare tire. It's a good place since it's not really a useable area anyway.

For having only 5 speakers and not really that much power, this system gets very loud, more than loud enough for me and I like music loud. I removed the rear speakers and the factory sound deading from a 6" hole in the rear deck next to the drivers side factory speaker. That hole is for a factory "subwoofer" option. So I have 3 openings in the rear deck, the two stock 6x8's and I get plenty of bass in the cabin.

I need to deaden the trunk and rear deck as it vibrates pretty good when turned up fairly loud.

The power wire is very easy to run down the passenger side as there is some plastic conduit like stuff for some factory wires. I ran a 4 gauge wire in there with no problem. On the passenger side firewall is a large factory grommet type thing that I cut a small slit in to run the wire through. Running the 3 sets of RCA's on the other hand was a *****. There's no room under the dash to get your hands in there. Run the RCA's from the radio opening then back to the trunk to save yourself the grief that I went through trying to do it the other way around.

If you have any questions let me know since I just finished working on basically the exact same car.


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## B&K (Sep 20, 2005)

How about the Mach 5 MJ-18, I'd love to run an 18 but would need a car like the Marquis.


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## Lanson (Jan 9, 2007)

I suggested 18's to him, but he felt (probably incorrectly) that they may be too slow. I don't agree. Afterall, the great R. Clark Grand National had a pair of them.

We have about 1000W RMS (Octane 15.0:1) planned to go in. We might be able to stuff another identical amp in there as well. He's not a basshead, he just wants clear, clean, deep, and convincing bass. He really likes what I have picked out for my system, and since he's got WAAAY more room that I do, I figured I'd make his system significantly more potent then mine. 

What 18's would fit the budget? I've allocated ~4.5 cubes of space for the box's volume, which is the amount of room in a tub within the trunk. That way I can make a false floor for him, and he'll still have a trunk. The box's height is about 8-9", width near 43", and length 28". This will be a sealed box. I want all the low end extension I can get here. Ported is fine and dandy, but in this case, I want to see how low we can go sealed. Fast and accurate, as well.

If not 18's in that, then 15's or 12's. I'd like to hear your opinions, since this will be one of the first times I've had this much space to use. I'm so used to .65 cu ft, or .75. This 4+ is something I'm not sure how to handle! LOL. 

So, what would you do? Don't forget the budget of $250 ish. We also need a 2ohm final load.


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## savagebee (Sep 12, 2006)

the mach 5 stuff should work pretty well....
edesign 19os (Ive got two) work pretty well, but for 2 of them you're over budget
Ive heard a lot of good things about the fi audio 18"s as well (the q I believe)

there's some options for ya..

(my 18"s are very tight and snappy... just get them in a good box and itll be great)


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## Lanson (Jan 9, 2007)

So, running a pair of MJ-18's in sealed boxes w/ about 500W each should be a snappy, clean setup? Like I said, I'm new to large subs. I know that the greater surface area of the cone will yeild us some impressive efficiency, but I'm concerned about sloppiness. This system isn't about loud as she'll go, but more about clean, smooth, and punchy. Sealed is the only way I'll design a sub for a car, to avoid a huge peak at cabin gain Freq's.

so, any more ideas? If I align the MJ-18's at .707 Q, think i'll get what I want?


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## chad (Jun 30, 2005)

Big drivers aren't "slow." It's a very common misconception.

Chad


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## quality_sound (Dec 25, 2005)

Every time I tell someone that it's the midbasses that sound "fast" they make the same face as your avatar.


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## Lanson (Jan 9, 2007)

OK, well based on what I've seen and what you're suggesting, we should go w/ a pair of MJ-18's, sealed box @ .707


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## chad (Jun 30, 2005)

fourthmeal said:


> OK, well based on what I've seen and what you're suggesting, we should go w/ a pair of MJ-18's, sealed box @ .707


SQ or kidney lithotripsy?


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## Cancerkazoo (Jul 21, 2006)

fourthmeal said:


> OK, well based on what I've seen and what you're suggesting, we should go w/ a pair of MJ-18's, sealed box @ .707


Do you have room for IB? If you do, pair that with a nice set of 8" mid bass for lots of trunk space and good sound.


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## chad (Jun 30, 2005)

Cancerkazoo said:


> Do you have room for IB? If you do, pair that with a nice set of 8" mid bass for lots of trunk space and good sound.


Yup that.... or... Vent them at 35-40 cycles in a nice big box and have fun with it  


Chad


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## Lanson (Jan 9, 2007)

Allow me to be clear in this car's design intentions.

Sound Quality is first. Having fun by turning up the bass knob is a plus but not necessary nor considered judging quality. It has to play loud enough to impress the owner (my friend), and stay clean and pure playing rock, metal, pop, rap, etc.

That means we want something that produces lively, believable musical bass. It can't be muddy, distorted, resonant, or anything else that us audio guys would abstain from in the first place. The ONLY reason why 10's and 12's aren't going right in this car immediately is the fact that this car has sooo much room to spare (and the owner, my friend, doesn't care about using some of it), that I figured I'd ask if bigger is indeed better.

I only want to use sealed for this app. Porting in a car is silly due to the natural cabin gain of the car itself. IB is out for this one, due to location.

We've got 4.5-5 cubes of airspace or so, more if necessary, less if not. About 1000W total power to a pair of *<insert your suggestion here> *.

The rest of the system will be simple. We have a leftover pair of DEI Comps. They are the Neo set they made a couple years ago. Not horrible, IMO. The main trouble with the Grand Marquis is the doors. There is a 5x7 in the door, but the opening for sound is a mere palm-sized hole. This means no amount of quality driver will be heard correctly. The tweeters will be installed in the sail panels, and I'll integrate them eventually.

We are ordering the subs tomorrow morning based on suggestions, so please let me know if we are on the right path. *The Sound Quality w/ SPL potential path*.

Would you go with:

MJ-18's x 2
MAW-15's x 2
TC Sounds dB500 x 2
Another suggestion?


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## bassfromspace (Jun 28, 2016)

fourthmeal said:


> Allow me to be clear in this car's design intentions.
> 
> Sound Quality is first. Having fun by turning up the bass knob is a plus but not necessary nor considered judging quality. It has to play loud enough to impress the owner (my friend), and stay clean and pure playing rock, metal, pop, rap, etc.
> 
> ...


If you're going for SQ, I'd upgrade the front stage asap. Those comps won't keep up with a pair of 18's. It seem's like you guys are on a budget. Have you thought aobut trying to build the system one piece at a time? 18's are gonna require a mininum of 8's up front for a good blend between the subs and the frontstage. That's an absolute must.


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## 89grand (Nov 23, 2006)

I pretty much agree with the above post. 

The door speaker locations do have a rather small grille. I'm running a 5.25" in there and it's about as big as you can go and still get most of the speakers output through the grille. Anything larger will just be firing into the door panel. An 8" is nearly impossible unless you want to get all crazy with fiberglass enclosures in the bottom of the door panel.

I think 18's are over kill and unnecessary to achieve nice loud bass, especially when you're pretty much limited to 5.25" speakers up front. I have 1 Diyma 12 in my trunk it gets quite loud, 2 would be very loud. I know these cars have huge trunks, but I didn't really see any reason to use a lot of space if you don't have to.


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## B&K (Sep 20, 2005)

When I recommended the MJ-18, I really just meant one.


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## Lanson (Jan 9, 2007)

Hmmm...well the front stage will be done again later. I'm working on his budget, which is $500. He's already compensated me for my work to be done to the car, so thats a max $500 for the subs, amp, install materials, and whatever else. Less is better, because that $500 is better spent in other things.

When the rear is done, I'm going to start work on a front stage (probably in 3 months), using the front of the door instead of behind it. The door panel is just way too bad of a design to expect great things out of it. For now though, it will have to do.

Now then, getting back to it, if not 18's, then what? Give me a usable suggestion that I can take to him. The only reason 18's came up is that they will be efficient, and they fit. WinISD wants just 1.8 cu. ft. per sub in a sealed box to achieve ~.707 Qtc. We have that, and a LOT more. We'd need to run a 2ohm final load, so 2 subs was the solution there. 

Ok, if not 18's (and why not, now that you know what the plan is) what then? If no good reason can be given (like sloppy, or dull, or distorted sound), then we're going with them. Or at least the 15's


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## ArcL100 (Jun 17, 2005)

fourthmeal said:


> The trunk is HUGE on these cars, and we'll have the trunk vented to the cabin in two locations, to let the bass waves affect the interior properly.


Eh, like a huge bandpass? That's a no-no.

-aaron


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## Lanson (Jan 9, 2007)

no, not bandpass. The car's trunk air must meet w/ the car's cabin air. So I'm going to open up the trunk to the cabin. No tubes or chambers, just perforation and ventilation.


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## chad (Jun 30, 2005)

fourthmeal said:


> Hmmm...well the front stage will be done again later. I'm working on his budget, which is $500. He's already compensated me for my work to be done to the car, so thats a max $500 for the subs, amp, install materials, and whatever else. Less is better, because that $500 is better spent in other things.
> 
> When the rear is done, I'm going to start work on a front stage (probably in 3 months), using the front of the door instead of behind it. The door panel is just way too bad of a design to expect great things out of it. For now though, it will have to do.
> 
> ...


You are cracking me up man!  

It's an SQ rig.......... BUT WE ARE DOING SUBS FIRST!!!!!!!!    

Many systems that start this way never get the front stage finished.

Chad


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## Lanson (Jan 9, 2007)

<sigh>

Dude all I'm trying to say is I want subs that sound musical and are accurate. 

Thus the question, are the MJ-18's that kind of sub? Honestly, I gotta tell ya, you guys aren't helping here. Its a new brand for me, and I've not gone with a sub that large before. But I figured some of you have, so hence the request for advice.

I have to order a pair of subs by today, so rather then chuckling about the front stage (which will require far more effort and time then I have to devote to this car at the present time), how about suggesting some options? I know what to do with 12's, and 10's. Its the 15's and 18's that have me perplexed.

Fair enough? If it were my car, then yes, I'd do the front stage too. But, just like customers come in to an audio shop and plunk down their money, stating they want good bass first...well thats what we're going to do. Also, I want to hear these DEI neo comps before I judge them as bad speakers.


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## bassfromspace (Jun 28, 2016)

fourthmeal said:


> <sigh>
> 
> Dude all I'm trying to say is I want subs that sound musical and are accurate.
> 
> ...


I think we've given you very good advice. Several people have already said that 18's can sound just as good as any other size sub. Maybe you don't want to believe that. We're also saying that no matter how good of a sub you get, it's gonna sound like cow dung if your substage and front stage don't blend and that's the case especially with a sub the size of an 18. That has been said already as well. We're really giving you some damn good advice.
You just have to take it.

We know you're helping a friend out with his setup. I understand the part about people coming in and wanting to plunk down big money for huge bass. You're job at this point would be to educate your friend. If he's stuck on 18's, you really need to convince him to do his front stage first. If he's serious about SQ as you've pointed out, his system will sound like pure ass with 18's and 6.5's up front. You've said it yourself that he wants musical and accurate sound and he won't get that with the setup you're looking at now.

89grand has already given you a suggestion in terms of a 12 with good output and he has real world experience with your type vehicle. Listen to the man. If your friend is on a budget, I'd seriously look at doing a pair of DIYMA's as they're cheaper than shid and he could get a pair for under 3 bills. That should put him in bass heaven. TCSounds is also running some good deals on subs that are both musical and get loud.

In this case, your buddy's budget is holding him back. Try and squeeze more loot out of him or at least lead him to some product suggestions that will help him get the sound he's wanting to get in one big swoop. It's like Hoffman's Iron Law and your friend would be hard pressed to get his cake and eat it too in this case.

Good Luck


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## chad (Jun 30, 2005)

fourthmeal said:


> <sigh>
> 
> Dude all I'm trying to say is I want subs that sound musical and are accurate.
> 
> Thus the question, are the MJ-18's that kind of sub? Honestly, I gotta tell ya, you guys aren't helping here. Its a new brand for me, and I've not gone with a sub that large before. But I figured some of you have, so hence the request for advice.


I have run large diameter drivers in a car (pro or proish) drivers IB with excellent results, there should be NO FEAR of a larger driver. I had a Caddy Eldo circa 1982 with 2 JBL1500GTi's in there IB, 120 blazing watts to each. It sounded GREAT! The eldo is about the same size car as the Grand M, it was not boomy, was awesome SQ wise in that you could literally feel the bass drum being primed and then just ruputre in classical pieces. There was no unecessary boom, it was there and gone if need be. Bass guitar was great, no one note was emphasized, right on down the scale smooth as silk. 

Now, mechanical power handling is limited in this app, the cone has no control being applied to it other than the amplifier and it's suspension. If you get nutty with it and plow a KW into it you may be reconing drivers. 

We don't KNOW your friend, I like the music you listed, so does my wife. I do sound for rock concerts and am used to having no less than 20KW and no less than 8 very efficient 18's planted under my ass every weekend in smallish rock clubs. Music styles have ABSOLUTELY no correlation to listening HABITS. I'm a little rougher on subs than my wife if that's any question.

No one can tell you what to do, it's up to you to take our options and fit them to your friends personality. It's not a race, you are not defusing a bom, you're building a car stereo.


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## Cancerkazoo (Jul 21, 2006)

fourthmeal said:


> <sigh>
> 
> Dude all I'm trying to say is I want subs that sound musical and are accurate.
> 
> ...


I have 2 eD 19Ov.2s in 6cu ft powered by a Memphis 1100watt amp. It sounds good SQ wise. I am going to install them IB in my 95 Caprice but have no reference at the moment to how they sound IB.

From what I hear the mid bass is more important in an 18" IB install as the high end suffers a little more from the enclosure (trunk), but has awesome low end extension.

Another idea is 4 IB 12"s behind the seat, they should had a little better upper bass than the 18"s so you may be able to get buy with a nice 6.5 - 7 inch mid bass if you can't fit the 8".


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## JasonH (Oct 27, 2005)

Here's a review on the MJ-18 http://video.snoopdan.com/reviews/mach5.htm

I always wanted to remake the rear deck of my Grand Marq to hold 3 or 4 8's.


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