Rear Parcel Shelf

[MirKz]

Hey all,

ive decided im probably gonna try my hand at making my own rear parcel shelf.

i dont particularly feel like paying around 200 bucks for a custom one to be made by audiocom here in rockingham !

what would be your opinions on what to use etc?

anything i need to keep in mind etc?

im thinkin of using about a half inch thick MDF for the shelf, buy some carpet stuff etc to put that over it. I figure i can just use a jigsaw to cut it out mostly etc? specially the speaker holes etc.

i am making it thicker than what it is now, because i want more bass without having to try very hard

i also want to stop vibration coming from the shelf aswell...

is there something i should lay underneath the parcel shelf? some sort of sound deadening foam ? or some cotton sorta stuff that u find in computer subs etc?

cheers for any advice, help or tips on the matter...

i plan to get this underway over the next couple of weeks. (probs next week)

[fane]

mirkz, are you planning on putting a sub in the parcel shelf?

if you put any speakers in the shelf put a sealed box underneath the box so that each speaker sits in a box and it will sound better.

[MirKz]

thats a lot of effort but aint it... i was only really intending on messin with the shelf itself, not start a lil woodwork thing and make boxes aswell

i plan on gettin a sub later, but that will sit in the boot.. but apparently if i get a thicker wood etc it will sound more bassy than it is currently... which is what i want.

[fane]

if you put 6x9s in boxes, powered by an amp on the parcel shelf you wont need a sub, thats how much it improves the sound...

it will always sound empty if you are using the whole boot as the backdrop of your speakers, its worth the effort of the boxes.

[MirKz]

nar im only having my 6inch speakers in there... not getting 6x9's

eventually what i want is 6 inch rear (which i have got)

6 inch front splits. (dont have yet)

amp/s and sub/s .

[ix9]

*points at stupid*

I'm with fane, putting boxes behind 6x9's make them pump compared to an open-air mount!

I wanna get some 12-15mm MDF and replace my parcel shelf one day.... one day... If you manage to do it Mirkz that'll give me a template!

P.S. I _may_ be able to get my hands on some sound deadening insulation (almost like pink batts, only it's blue) for ya

[MirKz]

yeah, im not gonna put boxes under them tho... theyre only 6 so its not like i want HUGE bass from them... but yeah... the new shelf when finished should be more than enough.

itd be great if u could get some of that stuff... as long as its good stuff and works well... and stops a bit of vibration im all for it!

im using my current rear shelf as the template for the new one so yeah

gotta cut all the vent holes in it that the current one has and speaker holes etc.

i shouldnt need to bolt down the shelf should i?

or when i install the speakers on it... do i bolt the speakers down, onto the shelf and then have it go through the frame of the car aswell ??

[NuGGeT]

i dont understand why u need a new shelf for 6's? mine bolted right in?

[fane]

so did mine...the you wont get any advantage out of using thicker wood on the parcel shelf unless you fit boxs to the speakers....

that would be you only way of increasing sound quality/bass from the parcel shelf...

[MirKz]

my current shelf is a lil gay an thin.... i want it thicker... and i want new carpet cus the current stuff looks a lil ratty in my opinion.

[loz]

all you have to do is buy yourself some about mdf how ever thick you want it just dont go over the top take out your old parcel shelf trace around the outside of it and were you want to put the speakers then firre up the jigsaw cut the out side first then drill some holes near the line you traced for your speaker holes make sure the holes are bigger than the jigsaw blade cut them out.

then go to hardware and buy some spray on adhesive got audio store buy some sub box carpet what ever colour you fancy usally only grey or black.

spray the board with the glue put carpet over and spray some glue on the under side of the shelf so you can fold some of the excess over and stick it to the bottom...

then make cross shaped cuts in the speaker holes in the carpet and fold it through to the other side and glue that down as well...

[zanda]

Mirkz, everyone is entitled to his/her opinion, but some of the answers in this thread could be best described as contrary to popular speaker design.

firstly, 6x9s are not supposed to be bass drivers, they provide midbass fill. granted, if you mostly listen to rock music - 6x9s own. the debate about whether 6x9s are actually worth having depends on your music tastes and is probably a discussion in itself, but suffice to say that 6x9s are actually designed to work on an infinite baffle (parcel shelf). boxing them in a smaller box (than the boot) will certainly make them sound more punchy, but will actually reduce their response at lower frequencies.

having made a parcel shelf, I can provide the following insights:

1.) get very thick MDF if you plan to use a sub later on. because of the design of the r33 factory shelf, you will find it difficult to stop vibration using the 2 child restraint bolts alone - particularly if the mdf you have flexes under load. I used 15mm mdf, and although granted I have a 15" sub, I still have had to jam the corners (you'll understand when you pull the shelf off) with foam and cladding to stop the cantilevers wobbling. a thin layer of foam from clark rubber is a good idea if you want to isolate vibrations from the chassis too - and can be had pretty cheap..

2. ) using thick MDF will be very useful if you want to use a deep 6 or a 6x9, since the holes in the parcel shelf are actually quite small - comensurate with the piss poor paper cones from factory. the alternative is to use a spacer, which you can also cut from MDF. I ended up doing both, because I needed to fit more than 1 speaker..

3. ) using thick mdf will mean that you will need to bevel the edge of the cut using an incline on the jigsaw (not vertical blade), otherwise you wont get the bastard to line up. this means that the best way to cut is probably to trace around the factory shelf - onto the bottom of what will be your custom shelf. this will ensure that the cut closest to the line will reflect the space avalable around the window. a leccy sander or some patience is also useful.

4.) give yourself a weekend. once you start pulling out seats and stuff, the whole thing is a bit of a pain in the arse and you'll struggle to do the job properly in 1 day.

5. ) carpet and spray adhesive can be gotten from jaycar and/or altronics relatively cheaply. I covered the spacers and shelf in one piece, as proper speaker carpet is hell stretchy and easy to work with - providing you're patient, though try not to over-handle the top of the carpet if you get glue on your hands, and try not to over-glue, or you'll find it hard to get a consistent texture.

6.) depending on how cashed up you are - you might want to do tinting on the back of the car whilst the shelf and the seats are out. this will make tinting easier and extend the life of the drivers considerably.

7.) finally, you've got to be a little bit realistic about what can be acheived with individual speakers and amps, given your budget and your end target. just like modding for performance, set yourself a goal. this will be important since it will define what you want to acheive out of the back shelf. also think about what music you're trying to make. for example, I listen to a lot of percussive music with lowww bass and have tried to think about what that means given speaker combinations and driver position in the car.

conventional ICE designs usually work on the premise that the rear parcel shelf should provide fill. this is largely because it is much easier to acheive good midbass and listenining quality by spending extra money on sound deadening the front doors and using quality drivers/splits in the front (and "less quality" ones in the back). it also makes it easier to avoid muddying the sound provided between back and front due to destructive interference.

if you want to use a sub in the future - this is probably the way to go. whilst there are always exceptions to any generalisation, base and sub-bass takes a lot of power, and generally a lot of cone surface area to generate, and therefore the best way to make bass will be to add an amp and sub. (jaycar make very cheap and very good amps. I understand their subs arent too bad either.) you'll struggle to get actual bass out of a factory deck.

sorry for the monolgue. got a bit carried away, but have generally found that there's not a lot of knowledge about stezzas on this site - and most of what there is is wrong.

[MirKz]

cheers alex, i really appreciate the information. Youve given me a good indepth answer, i really appreciate it.

thanks again!