Din

Im about to do a system in my car, I want to see some pics of subs in trunks to get some idea on how I want to do mine without takin up to much space.

PERRYinLA

I have not seen too many installs, but of the few I've seen, this is the best. Below is the link to the original discussion.

"marcman18 ", you da man! Any chance of us making a mold of this box, so we can cast a few dozen copies for our listening pleasure?

https://www.clublexus.com/forums/sho...threadid=21677

Lex Luthor

How 'bout amps?

lex400sc

Perry, that's a nice box and all, but it doesn't look like it has adequate air space for higher output subwoofers. My subs are midlevel in their capabilities, but they still require a minimum of 3 cubic feet per sub. I'm trying to do something similar in design, but slightly cornerloaded. The smallest standalone box I can put them in is this guy (this is only a temp. setup)...

PERRYinLA

I agree with you, lex400sc , that marcman18's 12" woofer looks like it might be a bit cramped in that box, but remember Din's original question- he did not want to take up too much space. Given that restriction, I think marcman18, and others such as SC300TURBO have the right idea.

I'm no Percy (I'm a Perry!), so just because I read the Crutchfield catalog each quarter, I'm not claiming to be an expert, but many of the 12" subs they sell have recommended box sizes of 1 cu. ft. or less. You are probably in a different league, and I'm certain your subs can stop a pacemaker, but even with the restricted real estate, I'll bet marcman18's 12" woofer sounds better than any free air 10" in the stock position.

Unfortunately, even marcman18's box makes the trunk too small for my golf clubs!
You really want to cry? Check out all the trunk room that LS400 owners have to play with:
https://www.clublexus.com/forums/sho...threadid=41467

lex400sc

Oops, I was a little quick to apply that sub box to my needs rather than Din's. Golf clubs... I'm just trying to regain use of my spare tire. My friend's GS has at least twice as much trunk space as our cars, which makes me bitter. He's doing all kinds of crazy stuff to his car including a 15 speaker Dolby/DTS 5.1 setup. All this while still fitting a full size 19x8.5 chrome spare.

1BomexLex

It is really hard to get alot of bass out of subwoofers in the trunk without sacrificing trunk room
our trunks are already very small as it is
unless you want to go all out on a custom enclosure
be ready to sacrifice a lot of room in the trunk

PERRYinLA

...or a very stupid one! I've started a thread in the Audio forum on this whole trunk vs. enclosure issue. Let's see what develops:

https://www.clublexus.com/forums/sho...threadid=41615

Here's the text of the first post, for those purists who never leave the sanctity of their beloved SC400/300 forum:

"How come the trunk can't be sealed to the point where it becomes the woofer box?"

One problem with the SC400/300 is how small the trunks are, and how putting any decent woofer enclosure takes up most of the trunk space. I started wondering why the trunk can't be sealed to the point where it acts as an enclosure.

I mean, I have seen many posts and photos of trunks being completely stripped for Dynamat and RAAMmat60 treatments. How come, at that point, the extra step is not taken to completely seal the trunk, making it airtight? Then the trunk becomes an enclosure, AND a trunk! It's the same principle as turning the spare tire well into an enclosure, only bigger!

I'm thinking this is not feasible due to the trunk lid never fully sealing well, given all the chassis flex involved. Similarly, the walls of the trunk are not stiff enough to be a good enclosure, even with matting. And gas fumes might pose a safety problem. You can forget about easily changing the tail light bulbs. Plus, if you parked your airtight trunk in the hot sun, the whole rear of your car might EXPLODE! (Oh wait- only the woofer(s) would blow, but in some audiophile's minds, that would be even MORE tragic!)

Well, I warned ya this might be a stupid question. Did I cover them all, or did I miss any even more obvious reasons why trunks are not used as enclosures?

lex400sc

Perry, the trunk would make a good front-firing--front-ported enclosure. As to a sealed enclosure, I think you pretty much answered you own question. If you sealed the trunk air-tight, you'd create a high pressure system in the trunk everytime you closed it (if you could close it). Opening and closing the trunk, traps more air than atmospheric level into the trunk and exerts additional outward pressure on the subwoofer cone. That also makes it harder for the cone itself to resonate (like pushing a car uphill). It'd be interesting to see the effects of wide temperature variance on it too. Say if you lived in the Mohave Desert in the summer-- 140-degrees at noon, 30-degrees at night. The woofer cone would probably invert outwards then blow the dustcap open. If you bought one of those 3000-watt RMS capable subs made out of a solid aluminum plate, that'd be even scarier!

SC300T

I used this type of setup on an old 89 Z24. Had two cheap 15" woofers on the rear deck with the trunk as the enclosure.

1. Performance to me was awesome
2. The sound was fat, deep and semi controlled.
3. I had no problem reaching a flat 15hz on the RTA with this setup, so it played deep very very well.
4. You'll never get the trunk totally sealed, but the goal is to seal it as well as possible. There will be always some leaks. Leaks into the passenger compartment will be most critical as these will directly affect the output of the sub. Leaks to the exterior will not be as critical.
5. If you're going for SQ with ultimate bass extension and not boom, this is a good solution. The total system "Q" will be extremely low.
6. The mounting surface and surrounding area must be EXTREMELY rigid. I used two layers of 3/4" mdf sandwiched on each side of the rear deck, and bolted the two pieces together. Caulking, foam and minimal expanding foam was used to seal as many nooks as possible.
7. Since you'll never seal it completely, the risk of blowing the dust caps off the woofers is very remote. I'd slam the trunk and the woofers would move a quarter inch or so... Not enough to worry about.

I think this would be an excellent solution for the SC300/400. You could even put the baffle board right behind the gas tank in the place of the cardboard panel that forms the front wall of the trunk area. There is some area for magnets on either side of the gas tank, so the woofers could face the trunk. There probably isn't room for two 15s in this configuration, but two 10s or 12s may fit nicely without giving up any of the already puny trunk area.

lex400sc

I've got two twelves and the problem with mounting on the rear dash is cutting through all that metal, otherwise I'd have done it already. It just seems like too much work. If I were to do that, I'd probably use dual free-airs at that point. I'm trying to sell the twelves as I hardly ever use them to their capabilities. That way I can buy a JL 10-inch IB4 and be done with the whole mess. Maybe dual IB4s?? I was referring to dustcaps being blown off by expanding air due to temperature change, but that is probably just as unrealistic. BTW, I installed an 8-inch free-air sub into an LS400 and it knocks amazingly hard for an 8. I mean really impressive.

--uzz30--

pic:

[img]ftp://nonez4:xzRcEMO@myfilelocker.comcast.net:21/myfilelocker/Lexus20sc2blue20trunk.jpg[/img]

lex400sc

Cleeaaaaan... That trunk would look even better with the JL grilles over them plus they'd protect the subs and make them look like 15s. They are kind of obnoxiously priced though, for grilles that is.

marcman18

Hey. I am the one with the lexus sub box made out of fiber glass. I am try to answer all your comments. There was someone that said that I cant fit a set of golf clubs..... well I will have to take a picture of the whole trunk. The subwoofer was engineered by myself. I took out the cellular phone assembly and shaved some of the steel bar that was back there. There is a lot of DEAD space behind that panel. I only lost about 2 inches of trunk space, and that is mostly for the sub to hit back and forth. There is exacly 1cubic ft of space for the sub. Notice the contour of the top of the sub to match the trunk carpet contour. Keep the questions coming. Since that pic I have changed the subwoofer to the Infinity Perfect 12. Wondering where the amp is???? I hid it where the old sub used to be. I am using the hole for venalation for the SIX channel KICKER amp. Kepp the q's coming.
MARCMAN18

marcman18

HERE IS MORE OF MY CUSTOM WORK
MARCMAN18