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Discussion Starter #1
The fronts are easy , just mdf rings so ill get to them later ...
I'll be using off cuts from the box build , and the majority of the job is sound deadening that won't arrive until weekend so I'm doing it backwards ...
I ALLWAYS do front first .. even with known components and how they perform as a system , cabin gain/transfer function and box placement can vary massively from one car to another .
The car I am fitting doesn't have a lot of space and I'm doing a stealth(ish) install , so sub placement is a BIG problem .
I'm limited to a REAL small sealed enclosure so sub choice s severely limited . In fact it's a choice of two . My math is just a rough estimate until the box s finished , and even then I may ave to scrap it !!!
I'm getting a head start on it as it may not work out and I'll have wasted a lot of time on plan A

Anyway , here is what we start with once the rear panel s removed




First job is to remove everything , take some measurements , do some math , and do a lot of drinking smoking and head scratching .




Next job is to cut a cardboard template and double check the math .
I'm aiming for .30 square foot .... Pushing it !!!



Double check with a trial fit before tracing the template onto mdf .

 

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Discussion Starter #2
Next up is the back of the box .
Space is very limited and I have to use every little bit I can get , so it's going to be a funky shape (doesn't really matter with bass) and there are all kinds of angles you don't normally get on a sub enclosure .
Fibreglass would be the easier bet , but I like a solid box plus I will be doing a **** load of fibreglass on the next install in my 964 so I'm hoping an mdf box will work out ...

Here is the back panel cut measured and math worked out .




And here is the cardboard template I made earlier temporarily screwed into place .



Next up is working the angles so I can use every bit of space available .
Not only is it a funny shape , but I ave to allow enough depth for the sub to fit in .
This means scraping every last bit , so the rear will not be parallel to the front .
A tip to work this accurately and easily is to se bolts fastened to the rear panel with a nut and washers , to act as adjustable spacers on the front panel with a nut and washer either side of it .

Here is the rear panel with bolts/spacers attached



Heres the front panel sitting in place .
next job is to carefully tighten the nuts so the rear is pushed back into the cavity as far as it will go .
the heads of the bolts sticking out of the rear panel are my guide ... once theyre removed there will be a gao between the rear of the box and the inside of the quarter panel .





And here is the front panel attached to it , and bolted down .



Tomorrow I will update once the mdf sides are cut and glued/screwed in place .
Hopefully the pics will show the angles I'm working with .
 

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Nice work! Maybe I missed it, but is this a speaker enclosure or a sub enclosure? You mention sub, but wasn't sure if you are placing it here or not.
 

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Discussion Starter #5
Slow progress tonight , but I eventually got the initial part of the box made and glued !!

I had to make some small notches in some of the sides so a lip on the factory sheet metal will sit in a groove and help bold the box in place . The lip is the piece I temporarily put 3 tek screws in to hold the top of the front plate in the previous photo of the trial fit after I'd transferred the cardboard template to mdf ...



Then all the sides where screwed in and after a couple of trial fits and some small notches to clear sheet metal it finally went into place .



All that was left to do tonight was drill a few more holes then glue and screw .
It may seem trivial but this was a major milestone .....
The hard work is done , and soon I will find out of its all been in vain and I have to start all over again making the rear section in fibreglass !!
















 

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Discussion Starter #6 (Edited)
Oh , and the big brown cardboard box that its sat on for the photos is the sound deadening that arrived today !! :)

This should keep Debbie ( DJJ BUG ) whose beetle it is , busy for the next couple of nights while I'm doing more woodwork ...

 

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Discussion Starter #8
Haha , Sonic electronix in Valencia ca . Via eBay $70 a pack free shipping :D

Im not sure about that . i think Most people are more than happy with a box in the trunk ....
Along with the stealthbox that goes under the spare and the regular size subwoofer boxes JL audio have some affordable , neat ready-made boxes that could easily find space in a beetle trunk and are small enough to move out if you need extra space or to get to the spare ...

Car Audio - Subwoofer Systems - MircoSub?
 

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Discussion Starter #9
Tonight's progress has been that slow it feels like I'm going in reverse :(

I forgot to charge the batteries so I have no pilot drill and no screw driver .
The screwdriver I can do without but there's no way I'm attempting to screw mdf without a pilot hole !!!

This is as far as I got upto now (7pm)
I'll try to do more as I don't want to spend my weekend off working on this ....

I used my old cardboard template to get rough measurements of the outside edge , and the inner section that I removed from the last "top" piece to make he next "top" piece .
(I'm not sure what I should be calling them , but all these "top" pieces will build up the front of the enclosure as far as I can )



And this is what I ended up with ...



You may notice some of the sides are slightly bigger , as I want to extend it as far as I can to get n good metal to make solid yet isolated mountings .

Also note the inner cut-out is getting larger ....
I will round off the inner edges to get a little more space in there !!
I need every little bit I can get in this small space .



And here is JOB STOPPED due to lack of drill :rolleyes:

I'm not being as carefull with the woodwork aspect as I normally am , as I am working in adverse conditions and its being coated in fibreglass if it works ....
If it doesn't its being trashed anyway ..

Here it is clamped up and I'm hoping to get it screwed together later for yet another trial fit

 

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Discussion Starter #10
So I'm done for the night ...

Debbie wants to apply some sound deadening tomorrow and I only have the one rear panel off , not leaving her much to do .
So I grabbed the battery off the charger to drill the rivets on the opposite rear side so she could deaden that panel as well .

That is when I broke my last pilot drill bit :rolleyes:

I can do no More on the subwoofer enclosure tonight , but at least both rear quarter panels can get sound deadened now the rear speakers and styrofoam is removed .
 

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Discussion Starter #11
I had to work Saturday , so debbie had time to give everything a couple of layers of sound deadening .
She also treated the other side where the amps will be , to seal the cabin and cut down on road noise a little .
We used is stinger roadkill . the equivalent of dynamat extreme .
good stuff if you can get a good deal on it like i did . (Around 1/3 of the price)

Note the blood from my thumb .... ******* beetles !!!!







then i had a rush today to get the rear section finished and sealed then I could measure it with sand ....
Got my exact cubic foot figures ...... SMALL !!!
I will call the sub manufacturer tomorrow to discuss my 2 or 3 options .



I screwed and glued the piece i had clamped the other day on , then looked to waterproofing ...




I coated the mdf with with 3m resin diluted with acetone to make painting it on easier .
I left one side so I could monitor how far into the mdf it was soaking in .
This side too will be coated .
Mdf turns to **** if it gets moisture in it , so needs to be fully coated and waterproofed .
This also means removing any "surface" screws to coat the hole and screw before re- fastening (unless you are going to coat the whole thing with fibreglass/paint etc. )



Next I got out the fibreglass to fill the joints and mould the curves etc .





Then rough sanding ...











The next step is determined by what you want the end result to be .
Either refinish to take bodywork paint , or carpet , or like I did ....
Just a quick skim with 3m body-filler as it will have a rough textured rubberized paint , then sound deadening .



One last trial fit and measure before final sealing ...





Then I poured in some resin with just a tiny amount of acetone to buy me some time .
A quick swirl around to make sure the sides are coated , then left to self-level .





All that was left today was to give it a quick sanding , final radius on some angles , then mask and paint with 3m rubberized paint





Debbie will be soundproofing the box tomorrow after the paint has been left overnight to cure .
If we hadnt run out of light I would of just stuck it onto tacky paint as I won't harm adhesion ..




I thought I'd also show you may latest mod to the porsche .
I lost the rear seats when I fitted the cage , so I got me a new "stick family" decal .....

 

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Discussion Starter #14
I got the rear of the box sealed and filled with sand and I got 0.2 cubic feet .

Although this is very small it would work with a 6x9 sub or a round sub at 6.5/6.7/6.8 .

The 8" sub I was originally looking at is not optimal for a box that size , and the other 8" sub that they designed for an enclosure that small is too deep to fit behind a beetle rear panel .

So after going backwards and forwards with the speaker manufacturer all day yesterday I decided to go with the original plan of a small trunk enclosure .
This decision was helped by securing one of their top of the range 12" subs for WAY less than 1/2 RRP :D

So now , as originally designed , the amps will be housed seperately behind these rear panels (saving me headaches with space and forced air cooling ) and I can use the abandoned box to measure for amp racks .
 

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Lots of work to just toss, but you could still put regular speaker in there.

Following along on the new box though.
 

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Discussion Starter #17
I like to relax in my spare time by working on cars , and it was always just a rough-made experiment , so it's really no biggie .
I wasted maybe 10 bucks on the mdf , but I needed some anyway to make the front speaker adapters ...

I can use the old enclosure to help with measurements for the amp racks .
If its still intact after that and somebody on here can use it , they can have it
 

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Discussion Starter #18 (Edited)
Version 2 started today :)
A fine way to spend a Memorial Day off work ...

Much easier to work in a big space trying to make the enclosure as small as you need , than working in a small space trying to make the enclosure as big as you need !!!!

I'm working with a cdt 12" sq sub .
One of the finest on the market that will work in a real small enclosure .
A half of a cubic foot is my aim , plus 0.12 to account for the basket and magnet etc taking up space in the box .

The sub is more or less flat throughout its range in this size box , but IF it comes out bigger once sand-measured after assembly , it is easy to make a box smaller (bracing , sound deadening , 1/4" mdf "walls" added to the inside all make the enclosure better )
If it comes out too small about all you can do is add polyfill .
I'm erring on the side of caution with this build as I have plenty of space to make it slightly bigger .

This sub really is deep ... Over 6" mounting depth , but has a real big vmax to suit :D
That , and making the enclosure blend in are the biggest headaches on this install .


First I made a template out of some scrap 3/4" mdf to mount the speaker so I could see where I was upto with space and angles etc. to get a vision of how it may look when finished .







Then I used the rest of the off cut to simulate the "floor" of the enclosure in the car and sat the speaker template on it ....









You can't see , but I have the speaker magnet rested on a t-bar driver at the bottom , and a sharpie at the back .
This is so I could get it in position with plenty of space whilst I looked behind it , and took measurements etc .

My calculations with the box ending where the speaker template sides are gives me 0.194 cubic feet .
Not enough , but if I extend the width of the front to 18" I get 0.275 , which is good .

These figures are not exact as I am building a funky shaped enclosure yet again , but I have plenty of space (I can go upto 27" wide) and I will measure with sand to get an exact position of where the final wall needs to be to hit my figures before cutting and fixing it .
Any excess space will be used to make a shelf to store items such as a cleaning cloth and umbrella that she keeps in the trunk .

Another part of the design is that it needs to be removed easily to get to the spare wheel under the carpet .
I will use neutrik speakon connectors to quickly unplug it , as I have spare music stuff I can use .

Also , The amp supplying the sub is a jl hd750 monoblock .
Chosen for its ability , small size as it needs to go behind a rear panel , and the fact jl sell a ready-made remote for this amp that effectively turns it off when on minimum .

Next job is to go buy some new mdf so I can start in earnest ....




.
 
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