mdf rear shelf help****** oppinions

[dazleeds]

ok im wanting some decent sized rear shelf speakers

my plans are a pair of 8 inch componants in the middle of shelf and a pair of 6x9s on the ends of shelf if that makes sense? lol

anyway previous owner saw fit to hack up the metal under my shelf so my plan is to go further with this but a lot tidier than he did see pics




in the next pic the green section is what i want to remove and replace with a nice thick slab of mdf

yes i know art isnt my strong point but you get the idea


so my question is when i remove the section of shelf am i likely to have an impact on the structural strength bt removing it?
bear in mind the section im gonna remove is only tagged into place and isnt majorly welded in at all so im assuming this wont make a lot of difference? am i right? if it is going to have a bad effect then im happy to have some strengthening bars welded in below the shelf to reinforce everything if neccasary

oppinions please, has anyone done similar in the quest for decent sounds??

pps yes i know i should the shelf alone and do some gardening but it aint my thing so can wait

[dazleeds]

ps again

i would have preffered to make a full mdf rear shelf and bin the original altogether
but dnt fancy trying to refit the blind to mdf and still keep it looking neat

oh and yes i realise making holes for the 8s will interfere with the spring bars that hold the bootlid up and this will be addressed when i get to it

any solutions to that are also welcome

[tailoutcharlie]

from what i understand the main structural part is the seat back in a saloon and you can hack away the shelf to your hearts content. like the previous owner seems to have done.

however ive been wrong before

[riklusby]

To be honest m8, i would try and leave as much as poss original, if you get your MDF shelf cut to size and lay in position in the car, then position your speakers, at the angle you want them, draw in and cut out where the magnets need to go through your MDF,
Cut yourself some MDF rings that the speakers will fit and screw into, smoothe the outside rim of the rings as this will make the finish easier, mount your speakers into them and position again in car using blocks to get them angled right, when happy glue and screw into place.
After it sets take the whole lot back out, throw a sheet of fibreglass over it, stapling it to the underside of the MDF shelf, mix and paint on the fibreglass resin, wait a while(an hour in summer is plenty i find), repeat this with another layer of fibreglass but no need to staple the second layer.cut the fibreglass away inside the speaker rims and pre drill the speaker fixing holes.
Fill if required using fibreglass bridgeing compound, smooth it all off after drying,cover with desired material using something like Evostick contact adhesive stick it back in the car put your speakers in and bobs ur uncle !!

[kingcruizer]

To be honest m8, i would try and leave as much as poss original, if you get your MDF shelf cut to size and lay in position in the car, then position your speakers, at the angle you want them, draw in and cut out where the magnets need to go through your MDF,
Cut yourself some MDF rings that the speakers will fit and screw into, smoothe the outside rim of the rings as this will make the finish easier, mount your speakers into them and position again in car using blocks to get them angled right, when happy glue and screw into place.
After it sets take the whole lot back out, throw a sheet of fibreglass over it, stapling it to the underside of the MDF shelf, mix and paint on the fibreglass resin, wait a while(an hour in summer is plenty i find), repeat this with another layer of fibreglass but no need to staple the second layer.cut the fibreglass away inside the speaker rims and pre drill the speaker fixing holes.
Fill if required using fibreglass bridgeing compound, smooth it all off after drying,cover with desired material using something like Evostick contact adhesive stick it back in the car put your speakers in and bobs ur uncle !!

what he said but if you use your excisting shelf you can keep your blind and no need to smooth off the glass fibre to much if your triming it. just glue a 3mm piece of foam over first then glue your fabric to that. it looks better and hides the small imperfections. hlh

[B7]

Who the f*** was the last owner?! Edward Scissorhands!! Jesus what a mess.

Personally I'd go for a custom MDF shelf from Auto Acoustics. http://www.auto-acoustics.co.uk/index.a ... ductid=125

I've fitted these to e30's, e34's, Saphires, golfs, granadas and more and believe me, they may be dear but they make a really easy job of it.

[dazleeds]

im thinking now to clean up the holes in the metalwork
then have the mdf on top otf the existing shelf behind the blind butted up to rear of seat then recloth the entire shelf

seems the easiest option plus will lift the speakers a little higher and mean losing less metal

B7 nice find but id still have to lose metal and at £99+vat id rather chop some mdf meself
total cost under 30quid when done guarenteed

[riklusby]

Good point Kingcruiser, didnt think of that !
Hey dazleeds, if you get stuck in about it the shelf will take you a day and youll only need to tidy the existing holes up, fibreglass really is a breeze to work with apart from being a little on the messy side (i did mine on the veranda and was busy with a chisel for some time after it was finished ,with the missus breathing down my neck)
Fibreglass doesnt cost much as long as you dont get it from Halfrauds and itll look the danglies when its done

[dazleeds]

good point with the fibreglassing but dnt think i need to go that far as im going pure stealth so shelf with be relothed when done for a nice subtle look

top of shelf should be pretty much flush all accross it then will get some accoustic cloth
and try make it look tidy

if it does come to fibreglassing tho im lucky there my stepdads and fibrous plasterer and mould maker

once got a gold medal for being the best in the uk for moulds has done all sorts from kitcar bodys to coving to fireplaces also several yrs at pinewood studios and now works restoring castles so fibre glassing is not a problem

[placey]

daz

i did shelf cutting and everything else on mine so here's some thoughts:

shelf strength comes from the 2 bars that run across the shelf from rear window to seat back and the previous owner hasn't hacked away at them so the rest of the metal can go without worry. cut and sleep easy.

8 inch and 6x9s - why? i'd strongly suggest a sub in the middle (a bit more cutting) and some components on either side - either 5 1/4s or 6 1/2s. much better sound. worth buying/waiting for, you will never regret it. it's not worth doing this twice.

torsion bars will require removal - a pair of bonnet gas struts from an e34 and a folded up bracket bolted to the rear seat back can be attached to the boot hinges as a superior to factory replacement. easy and cheap as chips.

well worth dynamatting the shelf once cutting is finished and before fitting anything else! £15 well spent.

a decent 18mm piece of mdf bolted up to the underside of your shelf with roof bolts (low profile heads - handy!) will provide a sturdy and effective baffle. some more bits templated and cut and fitted to the topside in the dips will give a good smooth basis and allow your drivers and tweets to sit on top of the mdf baffle but flush with the hight points of your shelf - perfect.

your original shelf trim complete with blind can be cut to match the driver holes you end up with and then re-covered with acoustic carpet before final fitting - completely hiding everything and looking entirely factory while leaving your blind intact and still operational. well worth gluing a couple of layers of stretched cuttings from some of missus tights over the holes first before trimming as this prevents sagging.

hth - paul

[miniblob]

8 inch and 6x9s - why? i'd strongly suggest a sub in the middle (a bit more cutting) and some components on either side - either 5 1/4s or 6 1/2s. much better sound. worth buying/waiting for, you will never regret it. it's not worth doing this twice.

Gotta agree!!! 6x9's will interfere with the components and not help the sound quality at all imho.

I would deffo go with a sub in the middle and prob box it under the shelf (otherwise the air that moves will interfere with the components, unless you're boxing those in?).
That's if you have to have rear speakers!!

Personally i'd chuck a sub or two (or three or whatever!!) in the back and then put in some decent components up front!!
The soundstage is meant to be coming from in front of you, not behind!! Bass is pretty much non-directional, hence why subs can just be chucked in the boot (mostly!)

What sort of sound / system are you trying to achieve - max volume, or bass, or sound quality???

[dazleeds]

some good points there lads

im after a mix of clear bass and good quality sound

im a big drum n bass head so will want big bass but not to the point of total distortion and instant headaches lol
bit old for that now

have been doing a lot of rethinking about this shelf
and im either gonna put a pair of 8" coaxs prob infinity or just a pair of 6.5" comps instead of the original plan

ill still have to mdf the full shelf to hide the previous bodges etc

heres a list of stuff thats deffo going in the car
in boot
2 x MTX Thunder 4320 Amplifiers
1 x Phoenix Gold Line Driver PLD1
1 x Phoenix Gold EQ215ix Graphic Equaliser

1 x ALPINE V-POWER MRP-T130 running front comps
1 pair 5.25 comps in kick panels tweets on rear mirror triangles

1 x jbl 15" sub unported for now till i build better box

kenwood psw9524 head unit and remote


i also have a pr of 12" subs lying around that could go in if i need more bass


the 8s on rear shelf came from an old setup i had
i had 4 of em on the shelf with a decent amp and no sub and the sound and bass was amazing for such a small setup but im realising that butchery would be needed and going off this idea now.

im thinking to have the shelf baffle board on top of the original shelf then bolted thru the metal under shelf if that makes sense?
this is partly to lift everything higher and also to hide the nasty 6x9 holes that have been cut in both the metal and the top shelf
plus i think having the baffle on top will mean i dnt have to remove the boot torsion bars too



oppinions please and any advice more than welcome


Placey you got any pics to inspire me??

ps any solutions for getting the kick panel speakers to sound better??