Spingjp

Hello, just wondering if anyone has installed a sub in the rear parcel shelf in the g37 sedan. i have a 2011 g sedan but i have the non bose so im curious to see if any one has attempted to cut the deck lid and install a sub up there.

Rickblkg

I wish i never got bose :/

hinomura

iTrader: (4)

I don't know if it's been done here and shared on the forums but my friend did it on his old Honda Accord. You'd have to run the wires and install it (and the amp and probably a line-in convertor) as if it was a stand-alone subwoofer but I would imagine it would work. You would just have to worry about finding a sub that works in free air and also excess vibration. The rear deck was probably not fabricated to hold a sub so there is probably not enough sound dampening insulation and you might get a lot of buzz and rattle.

Dj1ofDet

iTrader: (5)

Me too! I could have put together a much better sounding system myself.

Spingjp

well i can always dynamat the lid, or my other option was to put a 8" or 10" polk mm or db there both 4 inch depth so hopefully i can squeeze them in the door.. any idea of exact depth we have in our sedan doors?

lkoh

Hi Spingjp,
It can be done. I have DIY'd my Skyline 250GT (G25?) with this very same setup.

Some pictures attached
1) The rear parcel shelf itself is flimsy (you probably know that already). I mounted the sub on the metal deck *below* the rear parcel shelf. For aesthetic purposes you might want to cut a hole in your parcel shelf (My non-bose has no subwoofer deck part 1.jpg)

2) There is a hole in the metal deck. You can see it when you take the trim out of your trunk. You will need to make a bracket for 8". ( 8 inch Polk sub with bracket ) I do not know if you can mount a 10" without a bracket.

3) Depth isn't a real issue. My 8" polk was 4 1/2" deep and there was room to spare.

4a) Hinomura is right, there isn't enough sound dampening insulation. I did get "more buzz and rattle" with that setup vs a trunk mounted sub. You will have to get creative with sound deadening. ( final sub in rear parcel shelf setup.jpg ). You can see how I put foam between the 3rd brake light and rear glass. Eventually I added a strip of rubber along the perimeter of the rear glass to insulate it from the rear deck.

5) I don't think the polks are setup for free air / infinite baffle. If you haven't bought your subs yet, you might want to consider those specifically for a free air setup. My polk db840 hasn't blown up yet though *shrug*

Hope this helps. Let me know if you are interested in the dimensions, I will try to dig those out.

Spingjp

Ikoh thats a nice install write up, i kno the polk are not ment for free air but how does your sub sound? does it sound just as typical sub in a box in the trunk or no? and do you regret doing it?

bocaytomas

Springjp brings up a good point, Subwoofer are meant to be ENCLOSED! and no the trunk is not an enclosure. There are however "Free Air" Subs, that do not need an enclosure to function correctly, I had tried this with my Sub and the sound quality was regrettable. I have since made an enclosure for it.

lkoh

Hi Spingjp,

1a) The free air setup is decent after some sound deadening. I was running a "spare tyre sub" type enclosure prior to my current free air which sounded (slightly) better from my drivers seat. Maybe due to my use of an inappropriate sub, maybe not.

1b) Either setup is going to sound superior to having no sub. The sedan's factory 7 speaker option is fundamentally a free air setup; if your objective is to improve the existing non-bose target, you can do no wrong with any setup.

2) I weighed the pros and cons against my own needs. I don't regret the setup. Below are some of my considerations.

For me, trunk space > cost > sound quality > rear passengers. Depending on your priorities, you may choose a different setup.

- I freed up space in my boot. This is my number one consideration.
- If you already have a jigsaw or router, it gives you the least cost solution to adding a sub.
- We already know enclosed sounds better. For me (non audiophile), it was only slightly so.
- The key disadvantage I found (for me) was that the bass was now affecting passengers in the rear, whereas the enclosure type setup was more "non-directional" and hit everybody equally. If you carry rear passengers regularly, something to consider. Yes I know subwoofers are supposed to be non-directional *shrug* Again, could be due to use of the wrong sub.
- the sub weight is now higher up, I am sure a few pounds won't hurt but subconsciously you may feel that handling is affected.

Hope this helps. I did not want to turn this into a "free air" vs "enclosed" argument. (the net has plenty of those). I can say the choice of setup is more a matter of weighing the pros and cons.

lkoh

Hi Spingjp,
I mis-read your earlier note (quoted below) on the depth.
I don't think you can put a real 8" / 10" sub in the doors. I think you'd be the first. Many have successfully put component / mid range speakers though

My earlier statement was that you can put any depth on the rear deck, it's only limited by your boot trim (can be cut)

bocaytomas

Yes, you cant put a REAL 8 or 10 sub in the doors, a 6x9 would be the reccomended, does yours have tweeters or not? Because those impact sound quality heavily

Spingjp

i noticed on your picture of the view of under the declid, did how much cutting did you have to in the deck lid? cause you can see the outline of where the bose sub is suppose to go..

do you know of any good free air subs?

im a big fan of polk and really like there stuff so thats why im debating on a free air or just go with a polk and build maybe a small enclosure under the sub..

yeh i need as much space as i can get and dont want to put a sub in my trunk where its noticable, i want to make it look oem,

where did you put you amp?

lkoh

Hi Spingjp,

1) how much cutting did you have to in the deck lid?
No cutting of the metal deck lid. There is an exisiting hole (covered by some felt). I removed the felt and threw it away. The 8" sub is smaller than the hole. see the attached picture, viewed from inside the trunk.
( 1a) sub hole explained viewed from inside trunk.JPG )
( 1b) sub hole view from inside car.JPG )
The only cutting I did was a 6" hole in the felt parcel shelf, just large enough to accomodate the speaker grille.

2) do you know of any good free air subs?
Can't help you there sorry. Crutchfield is a good start, so is the audio/video section of this forum

3) where did you put you amp?
I mounted it on the metal deck next to the sub. There are existing (>6mm) holes you can utilize. (there is plenty of debate in the net whether amp can be mounted upside down or not) ( amp and sub setup.JPG )

Alternatively, you can try to hide it on the passenger side, between the rear left fender and the trunk trim. ( option2-setup amp on left trunk under the trim.JPG ). It will depend on your amp size, fabrication skills, patience.

You can probably come up with better placement ideas than mine once you start removing the trim and explore the car. My setup is less than perfect as I was using whatever materials I had onhand (no mdf, just ordinary wood lol). I assume you are going to diy your setup and I'll be interested to see what you come up with.

Spingjp

yeh i will hopefully be attempting this soon, im going to start from the doors and work my way back.. what solution did you go with for the door speakers in your car?

does any one know the part # to the oem bose grill cover for the sub that goes on the decklid? im thinking if i put a sub ill use the oem sub grill that comes with the bose to make it look clean..

one thing thats stopping me from doing any mods right now is the winter weather here in ohio..

lkoh

Hi Spingjp,

I used a pair of MB Quart FSB216 6.5" components. Decent sound, no complaints. Mind you, I was coming from stock non-bose. I set them up in front and removed the rear door speakers altogether (weight reduction yayy)

Let me know if you need any specifics. Though there are plenty of tutorials out there that can explain how to setup our sedans better than I can.

Can't help there sorry. Time to post in the audio/visual section?


One more thing: I believe your 2011 g25 sedan interior is slightly changed from my 2009. (my rear ski-pass looks different, etc). It would be a good idea if you took your door apart and had a looksee before buying.
I put a few pictures in my album of how I setup my doors; you can use that to compare notes if it helps.