KC-Dub

Ok guys... I installed an Alpine PLV-7 powered sub last night and I've got a pretty big problem I'm hoping ya'll can help with.

I've got everything hooked up and the sub works fine (signal coming from the unplugged stock sub). It's super loud in the trunk, to the point that I'm going to have to do some serious dynamatting back there.

But the problem comes when I move to the driver's seat... barely any of the bass is making it up front. Even when I open the rear-seat pass through, it's not that loud in the cab. Especially for how much bass there is in the trunk. I can feel the car's floor vibrating even, but the bass is noticeably absent.

So, what do I do to get that bass into the cab? Would taking out the stock sub to make an air passage-way help? Any ideas guys?!

Thanks!

rodneyc77

iTrader: (1)

What I did was remove the stock sub and cut a pass through hole (right under where the stock sub was) in the trunk linning. I did it with an exacto knife... should help a bit...

KC-Dub

Thanks for the idea Rodney... I think that may be my next move.

A little bit of an update too. I figured out that if the trunk is open, even just cracked open, that the bass in the cab gets much, much louder and clearer, more like what I would expect from this size of a sub. The increase in volume with the open trunk is consistent whether or not the back seat pass-through is open.

So this leads me to think that the problem lies in the trunk itself being sealed too tightly for the bass to develop, not on a blockage between the cab and trunk.

Any ideas on how to solve this? I've thought of fabricating a port of some kind in the trunk to the outside, but I'm really hoping there's a better way.

Desert_TL

Acoustics in a car are pretty complicated. Chances are that your head, when in the drivers seat, just so happens to be in an area where sound waves destructively interfere with each other. Relocating the subwoofer to another part of the trunk will probably fix the problem.

sunnyflava99

The audio shop I used replaced the stock sub with a JL W6V2 and built a box around it. Sounds real good!!!

May have them use some more foam because I can hear some rattling when I raise the volume.

Good luck with fixing your sub issues

KC-Dub

So... sending the Alpine back to Crutchfield and trying a different setup.

The new system will be installed this Saturday and consists of:
- 1 Kicker SoloBaric 12L7 Sub
- Kicker 750.1 amp running at 2 Ohms
- 4 Farad capacitor
- Custom box and beauty board by Earmark in Plano, TX

Pictures and all to come...

italian_spak

i had 2 12L7 subs with a 1400wrms amp running in my old accord and man, this setup will make your car advance by itself

KC-Dub

I'm a big fan of the L7's as well. My last vehicle was a Dodge Ram regular cab. I had custom ported boxes built and installed behind the seats. The shop was able to squeeze out 1.75 ft^3 per side, which is huge for a regular cab truck. See the pics on Crutchfield... this was before a lot more clean-up on the outside of the truck including rims and such, but you'll be able to get the idea.

http://www.crutchfieldadvisor.com/cu...arren_ram.html

The truck had 2 10L7's and 1200W of Audiobahn power @ 1 Ohm (still didn't get hot, that amp was dang stable). And it hit... hard. The thing that amazed me though is just how clean the subs sounded. Even with the ports firing up right behing my head, there was no port noise and very little distortion even under competition stress (139dB was my best).

So I'm hoping Kicker won't let me down this time. I figure 1 12 will be enough to provide fill bass for the rock / blues / jazz that I listen to most of the time and still allow me to enjoy some hard hitting bass when I get in the rap mood.

KC-Dub

I'm a big fan of the L7's as well. My last vehicle was a Dodge Ram regular cab. I had custom ported boxes built and installed behind the seats. The shop was able to squeeze out 1.75 ft^3 per side, which is huge for a regular cab truck. See the pics on Crutchfield... this was before a lot more clean-up on the outside of the truck including rims and such, but you'll be able to get the idea.

http://www.crutchfieldadvisor.com/cu...arren_ram.html

The truck had 2 10L7's and 1200W of Audiobahn power @ 1 Ohm (still didn't get hot, that amp was dang stable). And it hit... hard. The thing that amazed me though is just how clean the subs sounded. Even with the ports firing up right behind my head, there was no port noise and very little distortion even under competition stress (139dB was my best).

So I'm hoping Kicker won't let me down this time. I figure 1 12 will be enough to provide fill bass for the rock / blues / jazz that I listen to most of the time and still allow me to enjoy some hard hitting bass when I get in the rap mood.

KC-Dub

Sorry about the double post... dang VPN connection died and I had to refresh.

italian_spak

kicker always worked for me , i was thinking of installing 1 12L7 in my Tl this summer, but i dont know if im gonna sell it

b827

I recently just but to L5 10s and when the trunk is open it the bass is crazy, but the same thing, when the trunk is closed even with the pass through door open its just not as loud in the car.
I already dynamatted the trunk (specifically where the lic. plate is) and the lic. plate assembly still rattles a bit so i may have to go over it again... Somthing else to think about is dynamatting the rear deck, because mine rattles alot even with the stock sub removed.

KC-Dub

Can you provide more specifics on where you put your subs and what type of box you're using? Ported? Sealed? How big is the box?

Anyone else having this problem? For you guys that have systems and they sound good, does opening the trunk lid make any difference in the sound of your bass? I think it'd be helpful if we could isolate what causes this problem. Is it sub location, box type, stock-sub removed? Please chime in.

ashtray00

also.. did u replace your mids? Do you have a specific line run to the front with an aux bass control mounted to control the sub base in the back?

Some pics would be amazing too of how u took the stock wires connected to the sub and connected it to the other aftermarkets...

bklynpanman

i'm using 1 12inch alpine in a small sealed box and it is loud as hell.. something isn't right with your setup.

sunny201

im using 2 12" audiobahns 1100rms each and its in a sealed box and sounds louuudddd! inside and out. Its just time for me to dynamat the trunk now. Are u using a ported box? maybe thats why its like that.

italian_spak

have any of you guys tried turning the subs toward to front of the car instead of the rear? do you get more sound even with the passtrough opened? The car must be very well isolated thats why the sound has a hard time coming trough

let us know how it sounds in this direction

Kirk3272

iTrader: (1)

If the bass level is rising when you pop the trunk then you will need to seal off the rest of the trunk from the box. For example: My subs face forward (2-12" Fi Q's) so I fabricated a board that goes from top to bottom, side to side, sealing off the box from the rest of the trunk. I saw a picture in this thread of how to properly install a rear facing sub. Simply placing a box in a trunk will not yield good results a majority of the time. If this is all you have then I would face the subs to the rear and push it as far back as it will go. Get some deading material for the license plate.

I do have the OEM sub and rear speakers removed.

As far as the rest of the speakers. I use Seas 7" Nextels in the doors and Scan Speak tweeters at the moment. I am in the process of trying out a pair of Audio Technology 7". (Skaaning) Got one in today. Will get the second in tomorrow.

KC-Dub

Problem solved!!

https://acurazine.com/forums/showthread.php?t=151431

redsly

You did realize that bass can be to low to hear, right?

Anyways, a big problem with bass is that it is just a movement of air. What I mean by problem is that when you have the windows closed in the passenger compartment, the air mass has no where to move to... When you open your windows, it allows the air mass to move out of the vehicle and cause a "louder" (more audible) effect on the frequency that you hear... I forget what the frequency is, but the average human ear is unable to hear under a certain frequency response. You'll notice this when you walk further from your car and it seems like the bass is louder. That is because the sound waves are more dispersed and at a higher frequency for your ears to hear it...

Good choice with the L7 though. That is what I plan on buying soon.

KC-Dub

Wow... I don't even know where to start with that response.

1) Yes, I realize that bass can be too low to hear. The human hearing spectrum is between 20Hz and 20,000Hz. Sound below 20Hz is generally 'felt' more than 'heard'.

2) I also realize that bass is affected by a large number of factors including the air space surrounding the sub, the type of box, port (or lack thereof), and box volume.

3) There's a distinct difference between frequency and amplitude that I think you may be confusing. Sound travels in waves... the distance between the peaks of the waves is the frequency and correlates directly to how 'high' or 'low' a sound seems when it reaches the ear. Amplitude describes how much energy is in the sound and is represented by the height of the sound wave. The higher the amplitude, the louder the sound (hence the name 'amplifier', get it?).

4) The tendency for bass to get louder and softer based on the position of your head in relation to the subwoofer has to do with convergence of the sound waves on a certain point. Bass is highly omni-directional in nature as opposed to higher frequencies which are directional. As such, sound from a sub travels in all directions. Bass appears louder in some places instead of others when the deflecting sound waves converge on a point, ideally the listener's ear.

All that being said I still don't know exactly why the Alpine sounded like crap in the TL while the new L7 setup sounds really good. My guesses are the upward firing port on the Alpine, the 4th order bandpass box and the location of the sub in the front corner of the trunk. Whatever the cause, I'd recommend that TL owners stay away from the PLV-7.

KC-Dub

Try a sealed box... it made all the difference in my car. The stock sub still in place, passthrough closed and it hits.

Jesstzn

Not having the fancy subs etc, in my Passat I had the same issue ... I was using a Bazooka 8" tube and in the other cars it was fine but in the Passat .. nada .. Having the ability to move it I found placing it 5" from the rear corner of the trunk produced the needed bass.

The Passat is like the TL .. very sealed and the whole cabin actually vented out through vents at the lower edge of the trunk opening.

VelfarreClubber

I have the same exact thing going on too. I have a JL 12" w6v2 in a sealed box, if i want louder bass I would open the pass through and windows. What do i need to do to fix that issue? Im looking to get 2 10's later this year, and want bass that I can feel on my stomach.

KC-Dub how did you set up your new box? Is it sealed with no open space for the pass through??

KC-Dub

See my thread here: https://acurazine.com/forums/showthread.php?t=151431 for some pics of the new install. The box is a large sealed (2.0 ft^3 for 1 12" SoloBaric) type and the speaker faces the rear of the car. An interesting note is that the box is spaced back from the seat a bit because of the amp rack mounted in between the seat and box. Again, see the pictures on my other thread to see how it's put in.

I'd recommend emulating my setup if you can... it makes the most of the TL's acoustic properties. The bass is generally louder in the cab than it is in the trunk. To answer your question, the passthrough stays closed all of the time. Even if I open it, it doesn't make a bit of difference in the sound. The sound is also the same with the trunk open or closed. It's a world of difference from the Alpine setup.

You guys keep sharing your experiences with different setups, maybe we can isolate what makes the a sub setup in the TL sound good vs. bad.

dnd2984

iTrader: (6)

NICE. Also that alpine setup is made for SUVs and Hatches....

KC-Dub

Yeah... like I said, I think it'd be great for SUV's and such, but not for our sedans. It was worth a shot though.

Greengecko

Another thing that I found really helps which I've done in my 2004 TL and in a 1995 Legend I had is to fill the frame of the trunk lid itself with expandable foam sealant that you can buy at Home Depot or any number of places. You wouldn't believe how much tighter it makes the bass sound. I just removed the trunk lid lining and filled the all spaces I could find, but I stayed away from the area where the latch and cables are, of course. The TL also has a counterweight installed inside the trunk lid that you can remove while applying foam, then after the foam has cured you just cut enough of the foam to put it back in.