just remember...w7 does require an appropriate air suspension enclosure which a trunk is unable to provide...almost like a cars exhaust requiring to have back pressure to run optimally...without the air suspensuion required...your driver will suffer do to it being pushed well beyond its mechanical limits do to extreme over excursion...sooo...when you destroy your poor w7's spider or seperate the surround from the cone.....dont come on here and flame JL because you're bein a fuckin douchebag..catch my drift?

-Jason

Sorry if i have offended anyone in advance...

 

JL 8w7 manual shows you how to put the sub in a BOX. Also has recommendations for the correct amp. Link to manual http://mobile.jlaudio.com/pdfs/7720.pdf


SEALED ENCLOSURE:
Recommended Net Volume: 0.875 cu. ft. (24.8 ltrs.)
Fc: 46.0 Hz F3: 41.3 Hz Qtc: 0.797
Front Baffle Thickness: 0.75 in. (19 mm)
Wall Thickness: 0.75 in. (19 mm)

PORTED ENCLOSURE:
Recommended Net Volume: 1.0 cu. ft. (28.3 ltrs.)
Recommended Port Tuning: 32 Hz
Port Type: “Slot” ports are recommended. See information above.
The port recommendations listed above are derived through actual
tests and measurements (not computer simulations).
Front Baffle Thickness: 0.75 in. (19 mm)
Wall Thickness: 0.75 in. (19 mm)


It even includes a SAFETY NOTICE!

It is absolutely essential that the completed subwoofer enclosure is mounted firmly to the vehicle with heavy steel bolts (1/2 inch diameter) and large steel washers on both sides of the bolts. This will reduce the likelihood of occupant injury in the event of a collision or sudden deceleration.

 

I say let him do it. I have been installing car audio since i was in my teens and one thing I have learned is some ppl need to make their own mistakes until they listen to the voice(s) of reason. Everyone knows that this is not an IB sud with the exception of the OP, but its his car/cash so lets just see what happens

 

***edit***

 

Keep in mind this is the same guy who a while back started a thread asking if the 07-08 suspension was stiffer than 04-06. When several of us told him the opposite was true, even provided a link to the Acura website clearly stating the 04-06 was stiffer, he still disputed it and said we didn't know what we we're talking about.

I don't know why he asks questions when he knows it all.

 

^^^ that is exactly why I'm glad vBulletin has an "ignore user" function built in. I have, and will continue to make use of it as needed.

 

I did not know the history. Ill STFU now

 

I honestly really don't know too much about car audio, so I can't say too much, but if I had multiple AZ members telling me not to do it, I probably wouldn't. I wouldn't try to prove them wrong and act like I'm talking about. Do what you want man, chop up your car, but why don't you actually put some facts and research behind your ideas before telling everybody that it can and will be done with no problems. Just put that 8W7 in a damn box.

 

na. dont want a box. Thanks for your input though. I think I will just install a sub in the exisiting hole. No need to carry around a custom box in the trunk. There is already a mounting place in the rear deck. And it will sound damn good. Have you seen those hi performance 6.5" subs that JL makes? wow. This thing is going to hit hard, especially with a JL 8w3 or 8w7. =)

 

Well I respect your push to do something that others say can't be done, but I can't say I would take that risk with my car. Good luck and let us know how it goes.

 

thanx. The worst that can happen is I will install a box. So nothing is wasted. But I doubt I will install another box because if I can stand the factory mediocre 8" sub with a factory amp, then I already know the JL will finish me off fine. (as long as the rear deck is stable enough)

 

Chad..

i hope god eats your baby...skull fux your head...while shoving a pineapple up your pee-hole...

let us all bow to you because you're the man when it comes to car audio...

-Jason

lol

 

You read my mind.

 

God does not have sex like you dirty boy. And I have no kids. And you're right; I am pretty good with audio.. all EE's think for themselves.

 

You need to learn to think before you can think for yourself.

 

This is a hypothetical question. What if you made a custom box that would be wider rather than deeper. Mount it to the underside of the trunk deck and sealed it to the trunk deck thus sealing in the air surrounding the sub. Would that work? I am not sticking up for chad because i am all for using a speaker in a box. But, and i say BUTT, I too want to not have to use a custom box like I have currently that takes up the space it does. There was another thread somewhere where a guy was making the fiberglass boxes that are custom molded to the trunk corners for like $350. That looked sweet as hell but I am not sure how they sound.

 

fiberglass is too flimsy unless its like an inch thick. It won't sound good. A standalone box needs to be ridged. And if you were successful at mounting a box under the rear deck, all it would do is just reduce the amount of air space behind the speaker. - essentially the same thing as putting the speaker in a box. True, the speaker would be more "in the cabin".. but still the air space behind the speaker would be fewer cubic inches or cubic feet. So, when you reduce the "area" behind the speaker, the speaker is tuned to a higher freqency. That is why most people that make speaker boxes try to enlarge the boxes as much as possible. and for that reason, I think the trunk, acting like a box because of the speaker being mounted in the rear deck, will sound just as good as a ported box, if not better. And also you have to consider the value added from the speaker being inside the cabin and not lodged in the trunk..

 

fiberglass can also cause an echo without extra insulation. I built a box once out of fiberlgass about 10 years ago for lightweight, and it was way too thin and rattled so bad that it was worthless. So, you need at least real thick fiberglass and by that time, it may weight more than MDF board. So, nothing gained actually. Plus it may acho more.

 

Honestly, the only thing that comes to mind is fucking idiot.

Go read a book and educate yourself. You're the laughing stock of this board and you don't even know it.

 

I'm all for a box if it really does provide a better enclosure than what a factory car has structure to provide. I have owned 9 Camaro's and Trans Am's and most of them had a bass box. In fact I have 2 - 12"w3v2 in a square box sitting in my garage right now. And they work perfect. But if I can put an 8w7 in the rear deck, then I think the volume would be more focused in the cabin than in the trunk. And as I already stated, I won't have to carry around a heavy box in the trunk, just to have it penetrate the back seat and other structure before it reaches my ear. Nevertheless, Any loss from an 8" woofer, as a result from downsizing from a 12, may realize a gain from having a w7 vs. a w3, -AND- having the speaker located in the cabin rather than in the trunk, which is more distant at best.

Also, I don't mind you laughing at me. I expect resistance. Science is great. And I say let it be true if it is really true. So, If a box sounds better than what I will try, then so be it.

But here is a challenge: If a speaker sounds good in a box, then we need to ask “why?”. Does the speaker really know that it is sitting in a box vs. the rear deck of a car? -No- A speaker doesn't think. The department head of my college at OSU said to me, "if a bird is sitting out back taking a Sh**, then you need to ask why." Therefore I say, lets not walk the way of others just because the masses seem to go that way. For wide is the gate and broad is the road that leads to destruction, and many enter through it.

And if you know where I got that last sentence from, then I'll send you a cookie.

 

You are an electrical engineer and you dont understand the things that ppl are telling you?

 

I laughed my fucking ass off.....

 

hahaha...that was the idea...

-Jason

 

Would you like to retract or modify your statement now that you have the "infinite baffle" setup? haha "IB" setups use the trunk like a box.

(See, I'm like the government. I come back yeeeaaarrss later when you don't suspect it. Then I slap the handcuffs on ya)

 

An 8" that will fit in the stock location will never be as good as just about anything else whether it's a sealed box, ported, bandpass, or IB with more cone area.

 

Just giving you a hard time. But I do agree. I found a used 8" Jl sub. I think it's a w3. I may try it. Or if I can find a w6 I may do the IB. I am avoiding putting 2 12's as an IB setup. I have a big box in the back right now. and it's soo heavy my car sits noticeably lower back there. Plus it sounds muffled. I knew it would from the beginning but I listened to.other people and did it anyway since I got the box for like 35 bux at an outdoor market. But its a new box. It's built with the right shape and size but it rattles. At least I think that particular noise is coming from the joints of the box. But anyways, doesn't matter, it still sounds muffled. So either I will put a single w6 as an IB or put a light weight sub in the rear deck and insulate it to the max. Rear deck rattle against the back glass. I still have not fixed that yet. But I will when I pull the seat again.

 

Actually one other possibility. Install that mild 8 inch sub and also install a single larger woofer in the IB method. That way you get a more sharper bass hit from the 8 but a more surrounding bass with the IB in the trunk.

 

Size doesn't determine sharpness, only enclosure does. A 15 will be just as sharp as an 8.

 

I disagree. I've heard too many speakers on display and side by side on the same amp and the same HU. The professionals that sell stereos for decades will tell you that 8's always hit a little.faster and sharper but don't usually go as low. I think a sealed enclosure will make a 15 pop faster but what's the point in that? Meaning why buy a 15 and put it in a sealed box that requires more power and you get less sound out of it. I never understood sealed boxes. Pointless for any use I have.

 

The "professionals" don't know what they're talking about. This is a myth that refuses to die. Research over at DIYMA and you'll find all the evidence you need by some very well known people in the industry, some of which build some of the popular subs and you'll see that enclosure is the only thing that determines the "quickness" or "punch" of a sub.

You can have an 8 that goes super low and you can have a 15 that's super tight and punchy. The ones in my trunk are extremely sharp, punchy, and they go low. Truly the best of all worlds. The problem with the small subs is they can't move enough air to go low with authority. You can have a 3" play 20hz but it's not going to be very loud.

An 8 can't hit faster, absolutely impossible. If you have two subs playing a 60hz tone. Both at 5mm excursion, how can one be "faster" if they're moving the same distance and switching directions at the same rate? If one is quicker than the other, it will no longer be playing 60hz.

I'm not debating this, it's fact.

 

I'm talking about speakers with the same specs, same model and brand. Like comparing an 8 inch w3 to a 12 inch w3. You can't compare a w3 to a w7 or something along those lines. That's not even in the same ballpark.

 

FWIW, I have an 08 TL and a 01 SS Camaro. The SS has the subthump 10' box with a series 1 Rockford driver. I can actually make the bass painful in that car. Sealed box.....250 watts of cheapee amp bridged power. The car is a drag car so I didn't care to waste major dollars on the tunes.

After living with the tunes in the TL for a few months, I started playing with the system. I changed out to drivers for 2 ohm JBLs... and got much better sound. I debated the box rear deck thing, and finally went rear deck with the slim mount Pioneer. All of this is driven by Alpine amps. I dynomated the crap out of the rear deck and the install is done VERY well. The sub is what it is. I got better output by not sealing the metal deck underneath, and stuffing poly around the outer edge of that sub hole.

After 3 months of listening to it, I just ordered this:

http://www.audiointegrations.net/cat...75/8253904.htm

I have a Pioneer 12inch DVC sub that I will drop into it. Is it in the trunk? Yes. Will it out perform the 8inch in the deck? No doubt. I tried to get the 8 to hammer too, but JL, MTX, etc....its all the same. There is no substitute for a box if you really want to drive your system loud. Skip the drama and buy 1 sub instead of two!

 

Ok well just imagine how much painful it would be if you had that 10 in a ported box. Haha

Anyway my issue is not really with the box itself, ported or not.. even though it's heavy, my ass is dragging and my car is slower, and I get worse gas mileage and plus it sounds muffled coming through the back seat. I have own 9 f-body's and I know they are perfect for sound because there are no barriers between your ears and the woofers. So I already know. TLs stink for efficiency. Whatever. I'm mobile. Going into a store. Lata.

 

There's no substitute for a ported box if you want loud. If we're talking sealed, all they do is knock down efficiency. The box makes it power hungry and acts like a mechanical high pass filter when you're much better off using an electronic highpass and keeping efficiency way up. Since the TL is infinite baffle friendly, I would do IB or ported and skip the sealed box. IB gets just as loud as sealed while requiring half or less power for the same output plus it usually sounds better.

The less excursion you have, the better it will sound. This means running larger and/or multiple subs. If you just want a little fill, it's not an issue. If you want to turn it up moderately loud with very low distortion and non linearity, lots of cone area is the way to go.

With lots of cone are, efficiency goes up. With no air spring of a sealed box, efficiency goes waaay up. That's why 90w is all it takes to make the roof buckle with my 15s. They usually see under 10w for moderate listening and with all of the cone area you can't even see them move.

Couple all of that with efficient class D amps and the whole system gets very loud yet requires no wiring upgrades.
I'm talking the same exact subs as well. I've run my 12W6s in several sized sealed boxes along with bandpass, ported, and infinite baffle. Each has it's advantages but when talking sealed, the larger sealed boxes easily had the best SQ and lower power requirements. In a small sealed box they would not dig deep and sounded boomy. In infinite baffle (a very large box) they had low end, high end, they had everything.

Enclosure determines how they will sound. Displacement determines how loud they can play in a sealed box and IB.

An 8 can dig to 20hz but it won't have much output due to a lack of displacement. However, a 15 or a bunch of 8" subs in a large enclosure will have good tight bass and play low with authority.

 

Less excursion = less vibrations for your ear. Which won't sound better. Why do u think the w7's are so deep and the rubber/ foam roll on the top edge is so huge? Excursion = good. That's why sealed boxes are so inefficient. The woofer is stymied! Subsequently that is why sealed boxes do play quicker beats more effectively because the woofer is under a lot of resistance from a sealed box that won't let it move so much. And I don't have time to read the rest of your post. Sorry.

 

You don't listen. More cone area means less excursion is required which is a good thing. More cone area is always better than more excursion. So for the SAME DISPLACEMENT and the SAME SPL more cone area means less excursion is required.

You do have time to read the rest of my post and you did. You just don't understand it yet.

 

I know enclosures greatly effect the way speaker sou.es but you are diverting. That is not the subject. I said 8" subs hit faster and stop quicker, therefore they respond faster...innately. forget about the box for a moment.

 

That's wrong, though.

 

No, they don't. Theres no such thing as "quicker". A higher MMS is countered bt a higher Bl. Or like the 15s I use, the MMS (moving mass) is as low as most 10s. The air spring of a box greatly outweighs the weight of the cone. This is a myth that has been debunked for many years. I could have chosen any sub I wanted but I chose a pair of 15s for my sound quality system. 8s would have been cheaper but they would sound like shit.

 

I also am not saying an 8 sounds better. I think 10's and 12's sound better. But you missed what I said in the beginning. I want to play parts of the music that I am missing from having the woofer muffled behind the seat. That's all. I would still want install the IB setup. But for cheapness, I would just use one of my 12" w3's and take out at least 3/4 of the weight in the trunk. Plus that box slides around on that plastic tarp thing I got from Acura. I almost like the carpet better. Strange I did that. Oh well.