Because we work on such a vast array of vehicles here we field requests aplenty for tutorials regarding how to undertake various aspects of installations. In response we've written many a tutorial hitherto for various forums, user groups and the like. However with the online world now moving away from these older community formats and onto newer ones like social media platforms we've also had to change our tack; for social media is extremely dynamic and we've found that any tutorial type posts tend to disappear from sight within minutes of them being posted on social media. Therefore we've started migrating the aforesaid tutorials over to this page to prolong their longevity.

Tutorials

Installation tutorials.
• How to install component speakers into your car
• How to install a fuse holder into your car
• How to incorporate a high clearance grille when making your subwoofer enclosure
• How to make rudimentary moulded a-pillars
• How to make a rudimentary fibreglass subwoofer enclosure

How to install component speakers into your car

Over the decades we've written many individual tutorials pertaining to the installation of speakers into cars, hundreds in fact. Rather than attempt to migrate all of these tutorials here we've instead opted to write a more generic one. So without further ado; this is how we install a component speaker set into a car here at Fhrx Studios. This tutorial covers a two-way component set, however if your car has a three-way component set installed from factory then the procedure for the extra smaller midrange is exactly the same as the larger one. Wisdom also dictates that before you start unpacking your new speakers you perform one final measure to double check your maximum mounting depth, not just behind the driver but in front of it too. Lest you find the speaker surround impacting upon the door trim at high volumes, or the magnet fouling upon the window and its associated mechanisms.

Step one - Preparation and protection
The first step of your installation involves simply preparing the door. This means first masking up the door with painters tape. Mask along all edges, mask around any points you're going to be prying against and mask any other places that run the risk of getting marked or scuffed during the installation. Remember to take photos of all screws, plugs and their locations as you set about dismantling the door.

Step two - Stripping and cleaning
After you've removed the door trims put them in a safe place. A safe place is not leaning against the car where the slightest zephyr will see them landing face down on your driveway. With the trims safely stored away you then remove the plastic splash guard and begin cleaning the door proper with wax & grease remover. Clean both the inner and outer skins, removing all debris, dust and sealant.

Step three - Deaden the outer skin
Apply sound deadening to the entire outer skin. We usually start by making two or three larger strips and then use the offcuts to get to all those little nooks and crannies. However make sure you don't block the water drain holes along the bottom of the door. As for how much deadening; the more the better, within reason though. See all mechanical things have a resonant frequency, a frequency at which point they exacerbate and amplify said frequency. By adding additional weight to your door panels you're lowering that frequency to such a point where by it'll be unaffected by the frequencies being reproduced by your midrange. Now we're only talking about sound quality here; if you want to see some more extreme examples of how nasty resonance and oscillations can get, check out this clip of the Tacoma Narrows bridge or this clip of a CH-47 Chinook ground resonance test.

Step four - Install diffusion tiles
It's important to add a large diffusion tile directly behind the midrange speaker. When talking standing waves; the lower the frequency the longer the wavelength. This means that no matter how much money you've spent on your speakers; somewhere within the midbass region there will be a frequency where the sound wave hits the outer skin and reflects back upon itself, effectively cancelling the next cycle. The diffusion tile prevents from occurring. You'll notice it's for this very reason that movie cinemas right through to sound studios have their walls liberally covered with curtains, carpet tiles and other absorptive materials.

Step five - Upgrade the cables
Having sufficiently sized cables constructed from quality materials such as silver or copper is critical for supplying adequate current to your speakers without running the risk of overheating. Do take note of the term adequate current though; for 99% of the time the OEM cables run in modern cars will be of sufficient size and material for carrying the current you require. However if you're looking to run triple digits of watts continuously to each speaker then you're going to need larger gauge cables in place. Run these larger aftermarket cables through the loom tubes into the doors, don't drill any new holes. If you have particularly challenging door loom plugs you may have to remove the door from the car altogether to achieve this.

Step six - Deaden the inner skin
Apply deadening to the inner skin and carefully remove any air bubbles. Make sure you leave plenty of clearance for moving parts such as door handle and lock control rods. Cut out small circular sections where the OEM wiring loom clips attach, do the same for the door trim plugs in order to allow them to get plenty of purchase when you pop the door trims back on. Geometry says you're going to have a split or two in the deadening somewhere; upon these areas you simply place a panel of thin foam. When cutting the speaker hole out ensure you leave a little deadening around the top edge to act as protection against water when it cascades down during heavy rain.

Step seven - Baffling stuff
These days there are many speaker baffle adaptors available to suit a large number of vehicles. However if you cannot find a set to suit your particular ride simply construct new baffles in a similar shape to the factory ones. These must locate through the original holes in order to avoid drilling any new ones thus damaging the door. In doing this you not only keep your insurer happy; you can also return the car completely back to factory if you choose to sell it in the future. Our boutique baffles are usually constructed from timber however we have made plenty from Perspex and even 6061 alloy, dependant on just how robust they're required to be. If made from timber though they should be coated with polyester resin to weatherproof them and then painted black to prevent them being seen through the factory grilles.

Step eight - Install and seal the baffles
Secure the baffles onto the door using the factory holes. If they're threaded holes rather than screw holes ensure you use fasteners with matching threads. For example it's important to remember if you have an American car there's a good chance the thread will be imperial not metric. Once they're secure you seal them onto the deadening with flexible black silicone sealant to prevent potential air leaks during operation.

Step nine - A little unseen housekeeping
If at all possible, use a vehicle specific speaker plug adaptor to avoid cutting the OEM plug off the end of the factory speaker cables. Also make sure that you tie the speaker wires runs down inside the confines of the door to prevent any chance of them being snagged on the window mechanism as it operates throughout its normal range of motion.

Step ten - Solder the terminals
Strip back about 5mm of the speaker cable sheath and tin the end generously. Then deposit a generous dollop of solder onto the speaker terminal. Bring the two together to create a rock solid bond. Generally speaking we recommend against using crimp terminals, because their two best traits are corroding thence creating resistance and falling off at the most inopportune time.

Step eleven - Heat shrink the terminals
Heat shrink the terminals with double wall heat shrink rather than simply wrapping them with plain electrical tape. For the heat shrink will conform to the shape and it cools and solidifies, meaning it cannot fall off after a few months. This heat shrink not only protects the terminals from the elements, it also serves to prevent any potential for arcing at high power. We usually heat shrink the terminals red and black for positive and negative respectively.

Step twelve - Gasket the speakers
Before you install the speakers make sure you install a gasket between them and the baffles. We use dedicated foam strip gasket material here but in reality you can use just about anything so long as it prevents any air escaping as the speaker creates those big compression waves. Remember the laws of physics care little for your speakers' value, ergo running million dollar speakers without gaskets is akin to running a 10000hp top fuel motor without a head gasket.

Step thirteen - Select your fasteners
With everything deadened, diffused, soldered and heat shrunk it's now time to screw the speakers in. Before you do however make sure you get yourself some nylon washers to go between the screw head and the speaker frame. Many speaker frames these days employ magnetically inert materials like plastic or alloy, materials that tend to be intrinsically soft and hence possess little resistance against compression moments; in other words they gouge and scratch very easily. These washers protect the speakers from damage should you ever want to resell them.

Step fourteen - Install the speakers
When installing the speakers go easy on the force. Remember you're only trying to hold them in place and squash that foam gasket sufficiently. Don't go berserk doing them up, and certainly don't use a drill driver. Put your fingers around the screwdriver head to prevent any chance of slippage and tighten them in the same pattern you'd do a head gasket; directly across from one another. Don't just go around in a circular motion because you'll run the risk of warping the speaker frame by the time you arrive at the last fastener.

Step fifteen - Install the bandpass rings
People often quiz us as to what role these thicker front foam rings play. Put simply they change the door configuration from an eighth-order bandpass to a fourth-order bandpass scenario. Putting it another way; they prevent the compression airwave from the front of the diaphragm escaping into the confines of your door trim and becoming trapped and hence redundant. They instead force the air directly out through the grille to you, meaning you not only get all your music with minimal echoic detractors; you also cop all the kinetic force from the midbass too.

Step sixteen - Install trim deadening
Treating the doors acoustically will result in far more kinetic energy. Put succinctly; they'll be kicking like a horse. This will be conducive to the the door trims rattling and vibrating a lot more. To combat this we recommend installing foam on the door trim itself, anywhere it's in close proximity to anything else solid. This will prevent rattles and make the door trim as a whole a lot more solid.

Step seventeen - Install the tweeters
When it comes to tweeters most have a sealed labyrinth / damping chamber on the back. This means they can be installed into the same location as the OEM tweeters without the need for aperiodic membranes, waveguides and the like. If you're lucky they'll lock into the factory tabs, however if not simply make up a cross bracket from a tail strap which then bolts into the factory locations. If this is not possible either because the OEM location resembles a three-dimensional topographical map, you can actually use thick foam padding to hold it in place; for tweeters intrinsically don't vibrate much because of the high frequencies they're outputting. Once the tweeters are in place we cover the entire affair with soft foam to protect it and prevent any possible rattles emanating from around the rear housing and metal portions of the car body behind it.

Step eighteen - One last eyeball
Now before you reinstall the door trims run your eye over everything one last time to double check all the screw and plug holes have been located and that no deadening will be visible around the edges when the trim is back in position. Next plug everything back in and check all the fundamentals are working; things like central locking, door handles and power windows all function correctly and without fouling on anything. Finally check all the ancillary electrical buttons such as the omnidirectional power mirror controllers, seat positioning switches and the like. If that all checks out, you can then pop the trims back on. But don't do them up fully just yet.

Step nineteen - Finish the job and relax
Just before you perform the final tighten of the fasteners and click the screw covers back into place give the stereo a quick test to ensure everything is working. Check each speaker as individually as possible, running the balance from left to right and fader from front to back and so on. If everything is working without fuss then you're good to lock everything down and finish up. You can then sit back, crack open a can of your favourite beverage and enjoy your newfound sound quality and bass.

Step twenty - Conclusion and potential upgrades
So there you go; that's how we install a component set here at Fhrx Studios. If you're a serious sound quality enthusiast though you might find yourself pining for superior staging, imaging, spectral balance and linearity. To achieve this level of aural perfection consider making a set of custom a-pillars like these to install your tweeters and midranges into. Because whilst the factory location is more than adequate in the majority of cases, especially if you're running a processor; you will discover that OEM tweeter locations are not always optimal and that firing directly through OEM grilles can sometimes lend itself to azimuth and dispersion issues.

If you wish to read more about what sound deadening, diffusion panels and sealing does click here. If you wish to learn more about staging and imaging click here and if you'd like to know more about how our ears relate to both of them click here.

How to install a fuse holder into your car

Similar to the component set tutorial above; over the years we've also done many a tutorial pertaining to fuse holders, circuit breakers and their installation. Which designs are best, where to mount them, how to mount them and so forth. Given they're such an important element of your vehicles safety net it's baffling how many installers pay them so little attention, installing them either in the wrong location or very poorly. Therefore read on as we run you through how we install these devices here at Fhrx Studios. Because simply whacking a few self-drilling screws into a wheel arch a few meters away from the battery like this might work initially; it's not healthy for your car or your safety in the long run.

Step one - Find a suitable location
Look for a threaded bolt or hole. An M6 will suffice if need be, but our preference is for something more robust like an M8 or M10. Ensure the location is under half a meter from the battery positive and check clearances with both bonnet and other moving parts, lest the moving elements foul upon either the fuse holder or power cables once installed. Also be mindful of heat, especially with circuit breakers. Don't install your equipment too close to a manifold or extractor.

Step two - Construct your mounting bracket
Though we sometimes depart from the norm, welding up either 4130 mild steel or 304 / 321 stainless brackets; 99% of the time our brackets are made from off the shelf 3mm x 20mm 6061 aluminium strip which you can pick up from your local hardware store. Put a larger hole in the end that's mounting to the car and then you simply bend the bracket to where you'd like your mounting plate to sit. Cut it to length, clean it up and sand it back to give it that brushed alloy finish.

Step three - Construct your mounting plate
Whilst you could just attach your fuse holder directly to the alloy strip, we prefer to make a mounting plate. For aside from looking superior the mounting plate also allows for a fair amount of personalisation, either via a badge insert or by painting the plate the same colour as the vehicle.

Drill two holes for the mounting bolts, preferably directly under where the fuse holder itself will sit so they're hidden. Remember these holes are countersunk and are slightly larger than the through bolts, thus allowing them to freely spin as they screw into the threaded alloy below.

Step four - Drill and tap your bracket
Once you've drilled the holes in your mounting plate, mark them out on the alloy bracket and drill the holes in the alloy. Now remember the holes in the alloy will be tapped, so pick yourself up a drill & tap kit from the hardware; that'll ensure you get the right sized drill for your tap. We recommend something like tapping M4 threads for these holes. Drill them, tap them and then bolt the whole affair together using stainless bolts and nyloc washers. What you do not do is just drill a pair of holes and jam a pair of wood screws in them.

Step five - Drill holes in your mounting plate
Next up drill slightly smaller through holes in the mounting plate, we usually recommend M3.5 or thereabouts. This will allow you to use M3 bolts to secure your fuse holder to the mounting plate. Once again ensure you use washers and nyloc nuts.

Step six - Assemble everything
With all the machining done you now assemble the whole affair. You should have your perspex mounting plate bolted to the alloy bracket with M4 bolts, washers and nyloc nuts. You'll then have your fuse holder bolted to the mounting plate with M3 bolts, washers and nyloc nuts.

Step seven - Install cables
Bolt the fuse holder assembly into the vehicle. You'll then tin or ferrule the end of your cables to avoid possible fraying and to give the fuse holder grub screws something to bite down on. Run all cables with the factory electrical looms, being careful to stay well away from anything heat or liquid related. So don't tie power wires to fuel lines, water liners or even air-con lines. Only tie them with factory electrical looms and then cable tie them about every one-hundred millimetres.

If you want to see many more fuse holders in situ, including all the various designs we've come up with hitherto; then click here. Alternatively if you'd like to see what the entire battery, fuse holder and the whole shebang looks like when it's all done click here.

How to incorporate a high clearance grille when making your subwoofer enclosure

There're many different subwoofer grilles available on the market, some of which we run through here. However one issue with many of them is their thickness. See covering a cheap subwoofer with low excursion is fine, however when you start talking high-end subwoofers you're going to need a better solution, as many have high surrounds with extended ranges of motion. Put simply; these motors can push out well past their frame when being used in anger. This means you'll impact the thinner grille, as best it'll sound terrible and at worst damage the speaker.

Step one - Check the clearance
First things first; measure the surround height and then add 10mm for good measure. You'll see below with out example subwoofer that the cheap Jaycar steel mesh grille was never going to cut it.

Step two - Construct your subwoofer enclosure
First step is to make your enclosure as if you were making a simple surface mount. Construction material is irrelevant, whether it be fibreglass like the left one above or plain timber like the one on the right hand one; the hole you put in this one is the mounting diameter of the subwoofer. For this is the face the subwoofer will bolt too.

Step three - Construct your grille faceplate
This is the top plate that will hold the grille. It's the same dimensions as the enclosure adjacent and will be 12mm thick to hold the grille. The most common grilles we use here are the JL Audio SRGU type grilles as they're extremely deep. We actually cover the entire subwoofer which means we use the next size up. So for an 8" subwoofer we'll use the 10" SGRU-10, for a 10" subwoofer the 12 SGRU-12 and for a 12" subwoofer we'll use the SGRU-13. These grilles are a press fit so the hole size for this plate will be the grille outer diameter plus trim material. So for example if you're using an SGRU-12 it has an outer diameter of 287mm. So we'll cut the hole in this plate at 289mm, which gives 1mm clearance for the carpet when it's trimmed.

Step four - Assemble everything
Glue and screw the enclosure together, including gluing and screwing the grille plate to the enclosure. You then give it a gentle once over with the belt sander to ensure everything is exactly the same shape.

Step five - Trim and load
The next step sees the trimming of the enclosure before you cable and gasket it and load your drivers in.

Step six - Install grilles
Once the subwoofer is installed and happily working away you'll simply press the grill over the whole affair. Because you've left a little clearance to allow for the thickness of the trim material you'll find that whilst the push fit will be tight it's not impossible. Using these grilles you'll have plenty of clearance above the subwoofer surround, even when it's moving considerably.

If you want to see alternative types of grille options please click here. Alternatively if you'd like to see what type of overall subwoofer enclosure designs are available please click here.

How to make rudimentary moulded pillars

We'll start this one with a disclaimer regarding the word rudimentary in the heading. Like anything car audio related you can go to extreme lengths, especially wherein design is concerned. To that end some you can see some of the pillar designs we make here are extremely complex and costly. People often ask if they need to be complex and the answer is most certainly not. Ironically we recommend just making basic pillars like this and instead spending more of the budget on the speakers instead. Even better news is that it's not too hard to actually do. So let's go!

Step one - Create the mounting baffles
When making rudimentary pillars the first step is to make your mounting plate. Assuming you're using fairly small midranges and tweeters you'll make it from 6mm timber. If you're installing large, heavier drivers into the pillar you'll make it out of thicker material; common sense is key here. We use timber instead of Perspex or metal for this particular type of design because the resin will soak a lot further into the material. For some of the more complex designs this baffle will need to machined from a more structurally robust and exacting material.

Step two - Prepare your pillars
Next you grab a second set of factory pillar trims for a wrecker, as these will become the base for the new ones. You then remove any trim and sand the pillar back with course sand paper like forty or sixty grit. This will rough up the surface which provides a superior mechanical grip for the resin. Moreover, you then drill hundreds of little holes all around the perimeter and across the pillar surface where your trim will meet the pillar. These holes allow the resin to drip through which will provide a very strong mechanical grip. This grip is critical because as the pillars expand and contract in the heat and cool of the day and night respectively; the final layer needs to stay exactly where we want it too.

Step three - Grab some Lego
This step is where you position your baffles and glue them to the pillars. The glue we use is Loctite 401 and we actually use Lego blocks to mount them at the right position. If you're not sure where the right position is and you don't want to spend a whole day experimenting with angles, basically if you aim the centre axis at the centre of the opposite head rest you'll be fairly close to the mark. You'll be using time alignment to get the stage and image exact in any case. Just a quick note on why we use Lego a fair bit here; Lego is injection moulded to very exacting tolerances, around one hundredth of a millimetre. Therefore it's terrific for measurements, and because it comes with so many shapes you can set the baffles at any angle you desire. Just take extra time to sit the baffles next to each other to check they're identical in every measurement, angle and position.

Step four - Stretch and wrap
With the baffles in their final position and all glued down you'll then stretch speaker grille cloth over the entire affair. You'll recall these are rudimentary pillars holding lightweight speakers, i.e. 3.5" and smaller; therefore grille cloth is fine for this outer layer. If you're using larger speakers, i.e. 4" or larger; this outer layer will need to be stronger glass fibre mat rather than grille cloth. Even with the grille cloth we're still going to reinforce it with glass mat, but that'll be on the inside at a later step. Take your time and have a few practice goes dry before you start gluing. The grille cloth should attach to the pillar right where your holes are drilled. If not remove the trim and drill more holes. For without this mechanical grip the pod will start lifting from the polypropylene surface the first time the pillar expands in the sunlight. For nothing sticks to polys.

Step five - Resin time
Quick note before the commencement of this step; please always wear a certified respirator, for these fumes and dust are most detrimental to your health. Hopefully by now your pillars are starting to take shape. You now begin the resin process. Grab some polyester resin, MEKP catalyst, 150g chopped strand glass mat and some acetone for cleaning your brushes. Unlike epoxy resin, which must be mixed using a very strict ratio lest it doesn't cure; you can alter the drying time on polyester resin by adding more or less catalyst. So without going too deep into measurements start with something approximately one cup of resin to one teaspoon of catalyst. This will give you a few minutes of time to paint before it the chemical reaction begins the curing process. Paint it on generously and evenly and just keep applying until you use all the resin in the cup. Then allow it to dry for a few hours. Give any burrs or nicks a gentle sand between each layer and do about five layers of resin. Once dry they should now be solid enough to tap quite hard. For a little reinforcement you then apply your chopped strand glass mat on the inside this time to the rear of the skin, painting them carefully through the speaker holes. This fibreglass within with make the shape near on indestructible.

Step six - Sanding and filling
With your skin now resined it should be hard as plastic, because that's effectively what it now is. Now you first sand with 80 grit to get the imperfections out. From there you'll start filling the low bits with filler to get the shape smooth. We use a product called Rage-Gold here, which is like car body filler but a little more flexible. You can also use interior wall plaster too but its not nearly as strong as Rage-Gold. You'll do this filling and sanding processed continually until the pillars are smooth and have taken their final shape.

Step seven - High-fill layer
The pillars should be almost ready to trim now, so from here we apply a final layer of spray high-fill. This adds about half a millimetre but more importantly it makes it all one colour, which is considerably easier to look at in the light to see if there're any fine rises or dips that need attention. Even at this stage don't go too smooth with the sand paper, because the trim will still need that mechanical grip. We usually go down to 200 minimum. If you plan on painting it then you'll need to go a lot finer with the high-fill and sand process, but for this exercise we're assuming trimming.

Step eight - Trim, load and install
Trim your pillars in material matching your car, whether it be leather, vinyl, suede, Alcantara, minotaur fur; whatever takes your fancy. If you're not confident with this step simply have your local auto trimmer do it. Upon their return from the trimmer you can gasket, wire and install your speakers. Then pop the pillars back into your car when you're ready and voila; your aftermarket pillars adventure us complete!

If you want to see alternative types of pillar designs we've built over the years simply click here, for we've built many hundreds hitherto.

How to make a rudimentary fibreglass subwoofer enclosure

As with the tutorial above we'll again start this one with a disclaimer regarding the word rudimentary in the heading. As is the case with most things car audio you can go to extreme lengths, especially wherein design is concerned. To that end click here to view all the various enclosure design types for different budgets. People often ask if they need to be complex with moulded fronts as well as backs and the answer is nay. For this reason we often recommend just making a basic flat front / moulded rear enclosure like this and instead spending more of the budget on the subwoofer or amplifier driving it. It's not rocket science as you'll see below.

Step one - Taping the cavity
First step is to tape up the entire cavity you're going to glass upon. We usually recommend three to five layers of tape and if it's within the confines of the car, i.e. not a spare tire; then place drop sheets all over the car too. You don't want to be dropping resin on the paint work we'll give you the tip.

Step two - Create the foundation plate
First step is to make a foundation plate. So this is the same outside shape as your cavity and is about twenty-five to fifty millimetres wide. This frame will form the foundation that your front face plate will evenutally bolt, to that end be sure to take into account the thickness of your planned front plate; usually 18mm though more serious subwoofers will require thicker. Common sense is key here. Material thickness for this foundation plate is usually 12mm which is enough for the resin to get a solid purchase on. Remember this plate is just the foundation, it's not the front plate that will actually hold the subwoofer. That'll come later.

Step three - Resin time
Quick note before the commencement of this step; please always wear a certified respirator, for these fumes and dust are most detrimental to your health. Your foundation plate should be in place, seated about 18mm beneath where ypu want the front face to sit. You now begin the resin process. Grab some polyester resin, MEKP catalyst, 300g chopped strand glass mat and some acetone for cleaning your brushes. Cut your fibreglass mat into 200mm x 300mm strips and put to one side. Unlike epoxy resin, which must be mixed using a very strict ratio lest it doesn't cure; you can alter the drying time on polyester resin by adding more or less catalyst. So without going too deep into measurements start with something approximately one cup of resin to one teaspoon of catalyst. This will give you a few minutes of time to paint before it the chemical reaction begins the curing process. Starting at the bottom and working with gravity; place the glass matting down and begin painting it generously in resin. Repeat this process piece after piece, coming up the sides and evenutally painting them against the foundation rings inner edge. Then allow it to dry for a few hours. Give any burrs or nicks a gentle sand between each layer and do about five layers of glass; it should be around 5mm in thickness, or solid enough to stand on without it flexing.

Step four - Sanding and trimming
With the backend now done but roughly protruding past the foundation ring you'll now break it out of the mould carefull. Once this is done you then sand the excess glass off to make the enclosure backend finished at the foundation face. Also run the sandpaper around the inside too, to remove any burrs or spikes.

Step five - Construct the front plate
Front plate, top plate, sub plate; call it what you will. This is the plate that will hold the subwoofer. If you don't need a grille then you just make it out of flat ply and get it as close to the final shape as possible. Them tape up the mounting area again and use a little filler like Rage-Gold to fill the excess gaps. Try to make the front plate as close as possible though. If you need a grill on your enclosure see the tutorial above regarding grilles, as this'll necessitae making a similar piece from 12mm to hold the grille.ges with a little Rage-GoldThe pillars should be almost ready to trim now, so from here we apply a final layer of spray high-fill. This adds about half a millimetre but more importantly it makes it all one colour, which is considerably easier to look at in the light to see if there're any fine rises or dips that need attention. Even at this stage don't go too smooth with the sand paper, because the trim will still need that mechanical grip. We usually go down to 200 minimum. If you plan on painting it then you'll need to go a lot finer with the high-fill and sand process, but for this exercise we're assuming trimming.

Step six - Assembly and sealing
With everything marked out you'll screw the front plate to the backend foundation. From ther you then mix up some more resin and paint the inner edge corner from inside the enclosure. So what we're trying to do is get resin where the two faces marry up. If you're particularly dextrous you can actually pour a heap of resin into the enclosure and then tilt and wobble it around to make the resin run around the entire inner join. This will completely seal the front plate to the backend foundation.

Step seven - Deadening
With the whole affair now one piece we turn our attention to the acoustic treatment. Using this specially designed acoustic paint you'll liberally apply three layers, each about a millimetre thick. From there mount it in place and allow it to cure for a few days. It's important the enclosure cures in the spot its going to live, lest it change shape slightly as it hardens if left on a bench.

Step seven - Trim, load and install
Trim your enclosure in material matching your car, whether it be leather, vinyl, suede, Alcantara, minotaur fur; whatever takes your fancy. If you're not confident with this step simply have your local auto trimmer do it. Upon its return you then gasket, wire and install your subwoofer. Secure the enclosure in place, either via bolts before the subwoofer goes in or gravity in the case of a tire or bottom mount. Then enjoy subsonics aplenty without consuming your entire boot.

As aforementioned this is a simple flat time front / fibreglass backend enclosure. If you want to see alternative types of enclosures covering a whole gambit of different budgets please click here, for we've built many hundreds hitherto.