My DIY Backloaded Horn

Over the past 6 months or so, I've been researching and ultimately building a pair of backloaded horns. At the time of this writing, I've only actually finished one of them, but I decided to go ahead and make a post about it.

My Phase Technology Teatro 7.5s sound great, but they're pretty weak on the low-end. I've been supplementing with a shitty powered subwoofer scavenged from a boxed 5.1 surround system, but it just doesn't cut it, unfortunately, so I decided to build some speakers that would cover it a little better.

Since getting my upper-mid horns and hearing their clarity and definition, I wanted to go with another horn for the bass, if possible. I've seen a lot of really crazy, gigantic basshorns on the internet and wanted to avoid the size that would be required to reach below 100 Hz with a compression driver--not to mention the batshit crazy prices that large-scale compression drivers go for on eBay and Audiogon--so I decided to look into backloaded horns.

Ideally, a horn should be as long as the wavelength of the lowest frequency you wish to reproduce, with a mouth of approximately that same diameter, thus bass horns have to be gigantic to reach low frequencies. You can cheat a little, though, by placing the horn against the floor and/or wall of your room, which lets you cut the wavelength requirement by half for each surface, as it uses the walls/floor as if they were a part of the horn. Furthermore, backloaded horns are typically folded horns, which lets them squeeze a lot of length into a relatively small package. Finally, by starting with a large cone driver, your required horn length is reduced further still.

I used this 8" driver for the horns, based on their high sensitivity, though these would also be an excellent alternative. If you don't plan to supplement the horns with a tweeter like I intend to do, you might also consider using a full-range driver, like this one, though it is obviously more expensive. This driver is another good option if you want to play at high volumes, due to its high power handling and *huge* cone excursion.

I came up with my own design for the horn itself, based loosely on some designs I found around online. However, most of the designs I found have the mouth of the horn opening into the wall, which I was afraid would deaden the sound, based on how directive my upper mid horns are. So, I tweaked those designs a bit and ended up with something I could construct out of a single sheet of 4'x8' of wood (MDF [medium-density fiberboard] is the best for speakers, but it's heavy, expensive and rough on your tools; particleboard is a good compromise, IMO, insofar as it is very cheap, but with many of the same characteristics as the more expensive MDF; plywood works, too, but it's ugly).

I used 1/2" particleboard, though TBH, 3/4" would probably have been a better choice, both for rigidity and sound isolation. The sides are 2'x4', the back is 1'x4' and everything else is 1'x2' (i.e., the front, the top/bottom and the interior partitions; the last piece is cut in half and glued together at a right angle). I'm not going to go into much detail about the actual construction, since I'm a shitty carpenter and I'm sure you can find better instructions on box-making online than I could ever provide. Anyway...

Glue the pieces together using wood glue, and don't be afraid to really gob it on. You want it to seep into all of those little nooks and crannies in the wood and form a good seal. You can see the excess squeezing out from under the board in this pic:

To be sure that the junctions are all airtight and won't be leaking air into each adjacent chambers, you can follow behind with silicone caulk or "liquid nails" formulated for wood, which is what I used:

If you look closely, you can also see the right-angle brackets I used to reinforce the box structure.

After all of the interior structure is glued solidly into place, you can glue the other side panel to seal the cabinet shut. I used the liquid nails instead of wood glue to seal it, with a bunch of cinder blocks, books, records, etc. piled on top to get a good connection while the goo dries:

One thing to remember before sealing the cabinet: go ahead and thread some speaker wire through because it'll be much easier now than if you wait. If you do forget (like I did, actually), you can tie the wire around something (I used my dog's Kong toy), drop it into the speaker hole and then flip the whole thing around until it pops out the mouth of the horn. This is harder than it sounds, though, because these horns are gigantic and heavy as shit.

Another bit of advice, do your painting *after* your gluing (unlike me), so you don't have to worry about excess glue spilling over onto your fancy paint job.

Most of the projects I've seen online make a big deal about filling any cavities with sand or kitty litter so they don't turn into resonance chambers, but I don't really notice any problems and I did not do it. Of course, YMMV.

Anyway, here's the finished product:

You can see my small upper mid horn perched on top. You can also see the speaker wire dangling out of the mouth of the horn, since I haven't purchased proper binding posts yet (maybe never...).

As far as the sound, the bass response is considerably more potent than I expected. The driver works as a direct radiator (so better quality drivers will make a noticeable difference in sound quality), while the low frequencies bounce around inside and bellow out of the horn's mouth. The horn produces some of the clearest, most defined bass I've ever encountered, though it is definitely lacking above 1 kHz. That in mind, I intend to pair it with either this tweeter or this one.

One last picture of the finished horn, this time from the side:

The depth is really what makes these guys huge. Special thanks to my wife, who is gracious and long-suffering :-P

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Conclusions and Helpful Links

Continued from Installing the Hardware

That's pretty much it. Just plug it up and give it a shot. If you find that any of your buttons are acting funny, e.g. nothing happens when you press the button until you let go, try swapping the locations of the wires around on the button (i.e., move the wire from the bent post to one of the straight ones and vice versa).

Once again, here's what the final product looks like:


I've presented my own experience here, but there are tons of others' experiences elsewhere online. The Shoryuken.com forums have some really great info on pad hacking and DIY stick-making. You can also find some great things at the arcadecontrols.com forums (HarumaN is an expert and sells pre-hacked pads at reasonable prices) and xbox-scene.com forums (RDC has some great, thorough information about pad hacking, along with some good tutorials on how to salvage pads after a screw-up).

Gamingnow.net sells damn-near anything a stick-builder could want, all at very reasonable prices.

MAMErs can purchase I-PAC interfaces from Ultimarc. Another option that seems to be preferred on the Shoryuken forums is the Cthulhu board, which can be purchased at gamingnow.net.

UPDATE: even better than the Cthulhu is Toodles' new Chimp board, which provides PC/PS3 support and is designed to accept a hacked 360 common ground pad to provide 360 support with automatic switching among protocols. Plus, it's cheaper than bare Cthulhus used to be! You can get it and other stick materials at Lizard Lick.

UPDATE 3/25/11: Even better than the Chimp board, now you can get the Akishop PS360 triple-mod board, which is a no-solder board that supports PS3, Xbox 360 and PC all at once. It costs slightly more (~$45), but it completely removes padhacking from the equation for the first time ever. This and other arcade stick parts intended for fighting game enthusiasts are available at focusattack.com.

If you want to build a standard, semi-low-profile stick similar to what you would buy in a store, I recommend checking out some of the articles on slagcoin.com. The site has TONS of great information about all aspects of stick-making, and their button layout section is unparalleled.

You can learn more about sticks--including the differences between various brands--here. The section about restrictor plates should be considered required reading for any aspiring stick-jockey.

Page 1: Building an Arcade-style Fight Stick
Page 2: Assembling Your Box
Page 3: Pad Hacking
Page 4: Installing the Hardware
Page 5: Conclusions and Helpful Links

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Installing the Hardware

Continued from Pad Hacking

After the Hell that is pad hacking, this part is a breeze and is pretty straigtforward. You just put the buttons into the holes you cut in your panel, then screw down the plastic nut to hold them in place. At this point, I wouldn't bother screwing them down too hard because you might need to rearrange/rotate them later.

Next, attach your microswitches to the buttons. This picture shows a standard cherry microswitch that came with my arcade buttons.

When you go to attach the wires from your hacked pad to your microswitches, the best method is to use .187 sized quick releases (or .110 for japanese-style buttons) rather than soldering the wires directly to the posts, which will make repairing/replacing buttons much easier in the future.

For the joystick, you'll need to drill mounting holes around your large-diameter joystick hole. The Happ stick I chose is a top-mounted stick, but I wanted a smooth surface (i.e., no visible screw/bolt heads) so I countersank the holes a bit and then covered the bolts with wood glue and wood putty before staining/sanding.

This is a pretty permanent solution for better or for worse (no way to reposition the mounting bolts), but I intend to continue using Happ sticks in the future, so it shouldn't be too much of a problem.

After the glue and putty dried, I did a light sanding and proceeded to stain the top and sides.

Once that's all set, you can attach your joystick base by threading the mounting bolts through the appropriate mounting holes and then screwing the nuts onto the bolts. Once you have the base of the joystick bolted into place, follow the instructions that came with your joystick for dropping the stalk into place. The instructions for my Happ were not very clear, so I'll explain my process: first, put the plastic ring--textured side-up--on the stalk, followed by the plastic spacer, then push the stalk through the base until it pokes out the other side next to the microswitches. Next, take the actuator (that funky square piece) and PRESS IT DOWN until you can snap the little clip into place to hold it (the fact that it can be pressed down was not mentioned in my instructions and I erroneously thought the spacer was missized).

After that, you just need to attach your pad to the microswitches via the quick releases. The ground attaches to the side post and the signal attaches to one of the two straight posts on the bottom (one side registers when the button is pressed, the other registers until the button is pressed).


Here is how my first attempt ended up (not so hot):


And here's my second attempt (a little better):

At this point, I added a few extra touches, including hinges for the top to maintain easy access to the wiring and some cabinet handles on the back which also double as cable wraps:


Also, as you may have noticed in some of the previous pics, I attached some staples from a staple gun to the bottom of the box interior. I then used cable ties to stabilize the pads against the staples and keep them from flopping around whenever I move the box.


Page 1: Building an Arcade-style Fight Stick
Page 2: Assembling Your Box
Page 3: Pad Hacking
Page 4: Installing the Hardware
Page 5: Conclusions and Helpful Links

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Pad Hacking

Continued from Assembling Your Box

If you're not going to use the pad hack method and will instead use an I-PAC or similar control chip, you can skip this part, obviously. For this stage of the construction, I recommend you have an exacto knife, some thinnish wire (~22 AWG; I actually used an IDE hard drive ribbon), a soldering kit (soldering iron and lots of solder, helping hands with a magnifier, a good lamp) and a hot glue gun.

First off, you'll need to remove the outer shell of your controller, usually using a small phillips-head screwdriver.

Once you're down to the bare PCB (printed circuit board), you'll see that all of the button contacts are covered in this weird black coating that solder won't stick to, so we gotta scrape that shit off to get to the sweet, sweet copper underneath it (you'll want to scrape off more than is shown in this picture; it's just an example).

I've heard of people using a dremel with a wire brush attachment to do this, but that sounds like a bad idea to me so I stuck with using an exacto with a square-ish blade (lay it almost flat against the board so you shave off the black stuff instead of scratching it off with the point/edge).

However you decide to do it, just make sure you don't damage the copper underneath because that's what we want to solder to.

Once you get a pair of wires soldered to their corresponding pads, I recommend you plug your controller into your PC/console and bridge the wires (i.e., touch the bare ends together to make a circuit) to verify that the correct button registers. If not, you'll have to figure out what went wrong and redo it. If everything works properly, take out your hot glue gun and encase the whole area in glue to make things sturdier and take the stress off of your solder joints.

Here's a picture of my first attempt, after everything was soldered and glued. I used some cable ties (slightly off-frame up above the pad) to clean up the horrible mess of mess of wires I made:

This is my second attempt, which used IDE ribbon instead of thicker wires. Looks much neater, eh?

After that's all finished, I recommend you attach the wires to a terminal strip or something similar so that you may more easily attach/remove buttons or--god forbid--another pad.

Here are some things regarding pad hacking that were not clearly stated in other sources I read online:
I used the official XBox 360 wired pad from Microsoft (unfortunately, the wireless pads are a total hassle and sometimes break inexplicably during the construction process). Unlike the Mad Catz 360 pad, the official pad does not seem to have a "common ground," which makes things a little harder. The pads with a common ground are set up such that the signal pad of each button can be grounded against the ground pad of almost ANY other button on the PCB. This makes for less soldering and fewer wires to connect to your buttons. In the case of the official pad, you'll need to solder wires to both pads of each button. The silver lining is that you don't need to muck around with any "solder plan" or daisychain any grounds.

So-called "trigger hacking" a.k.a. "set[ting] trigger to neutral" is a pain in the ass, serves no purpose that I can see and has the potential to cause serious problems. It involves desoldering the trigger potentiometers and removing the whole trigger mechanism, then soldering a 10k ohm resister to the leads to make the controller think it's always completely extended. Some people make it sound like this is necessary to even use the triggers, so I did it to my pads and ever since then my button readouts have been very strange (hitting a button doesn't map it to, say, joy1 button 1, but rather to joy1 button 1 joy3 button 1; that is, it thinks the controller is actually 2 controllers at once...). Instead of opening this can of worms, it appears that you could just leave the trigger mechanism and potentiometer intact, hot glue everything in place in the open position (to make sure nothing gets wonky while you're playing) and then solder to the points just like you would with a hacked trigger. Sounds much easier to me. The other option is just to ignore the triggers entirely and deal with the slight hassle of remapping the trigger-assigned button(s) every time you plug the stick into a 360.

Finally, it's easier to make these connections IMO if you place a small drop of solder on the copper pads and then attach the wire to that instead of trying to do it all at once, juggling solder, the PCB and the wire. If you should happen to mess something up, don't freak out; you can follow the lead from wherever you screwed up to the little dot (called a "via") where the lead pokes through to the backside of the PCB. Just scratch away some of the green coating there and you should be able to solder to it (RDC of the xbox-scene forums has a great tutorial for this process).

Page 1: Building an Arcade-style Fight Stick
Page 2: Assembling Your Box
Page 3: Pad Hacking
Page 4: Installing the Hardware
Page 5: Conclusions and Helpful Links

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Assembling Your Box

Continued from Building an Arcade-style Fight Stick

As I said, I won't cover much here, but I will go over some of the tools I used in my construction. A router and table saw will make the job much easier, but you can get by with just a drill, some specialized bits and a circular saw.

For the button holes, I used a 1 1/8" spade bit, purchased at the local hardware store for about $5. You can either lay your button layout sheet directly on the wood and drill through it, or you can just mark the centerpoints and save the layout for later use. The only things to remember with using the spade bit are to make sure you go in straight and be patient to avoid it getting bogged down or stuck.

For the joystick hole, I used a 2 1/4" hole saw attachment. Again, take your time lest you end up with a costly waste of wood due to a misplaced hole.

I recommend attaching your pieces using pegs made of dowel rod and wood glue, since that will be much sturdier (and nicer looking) than just a bunch of nails. If you're a master carpenter, go ahead and do a dovetail joint or anything else that will improve the strength of the box, since you'll be beating the hell out of it on a regular basis.

Page 1: Building an Arcade-style Fight Stick
Page 2: Assembling Your Box
Page 3: Pad Hacking
Page 4: Installing the Hardware
Page 5: Conclusions and Helpful Links

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Building an Arcade-style Fight Stick

In anticipation of Capcom's release of Street Fighter 4 on the PC, I decided to build a 2-player arcade console, similar to those available from X-Arcade. There are many options and choices to be made in such a project, as well as dozens of pitfalls, so I thought I'd share my experience to help inform anyone else who wants to give it a shot.

Step 1: Defining Your Goals

This is a pretty intense project, so you'll want to have a good plan from the outset. It can be costly to change your mind halfway through, so make sure you've decided as much as you can before you even get started. Some things you have to decide:

A. Which platform(s) do you want your stick to be compatible with?

Are you strictly a PC/MAME gamer? If so, you will probably want an I-PAC interface, which will make your computer see your stick(s) as a keyboard that is then easily recognized and mapped within your software. This is similar to the approach taken by X-Arcade and other PC-only arcade sticks. These control units are a mainstay of the DIY MAME cabinet crowd.

If, however, you play on a console such as the XBox 360, you might prefer doing a "pad hack" whereby you connect your arcade buttons to the circuit board inside of a console controller. This is what I chose to do because it allows me to use my sticks on my PC *and* on my friends' XBox consoles (thanks to the XBox's use of USB for their controllers). This method is a little more intense than using an I-PAC because you'll need to have a steady hand and some experience with soldering, but it's not terribly tough if you take it slow and exercise some care.

B. Which hardware do you want to use?

When it comes to arcade hardware, one size does not fit all. There is incredible diversity among sticks and buttons that varies by manufacturer, region (Japan vs America) and games that are intended to be played. For example, many competitive Street Fighter players prefer (to put it mildly) Japanese-style sticks (especially Sanwa), while Pac Man pros usually opt for ball-top American-style sticks. Furthermore, Street Fighters usually choose Japanese-style buttons, which are convex and have a shorter throw compared with American-style buttons. I recommend doing your homework and clocking in some time with a few different sticks before you make your choice because it's totally up to individual preference.

I grew up using Happ bat-top sticks and Happ's clicky, concave buttons in the local arcade, so that's what I went with. I purchased them from Tornado Terry on eBay at a really great price.

C. What kind of button layout will you use?

The button layout is almost as personal and important as the hardware selection, so again, you'll want to do your homework and try out a few things before making any major moves. Some prominent stick-makers are using an eight-button layout with four buttons in two rows (as in the Mad Catz Tournament Edition stick), but I often get lost on this configuration and end up accidentally scooting over to the wrong buttons during the more heated moments.

Again, Japanese- and American-style button layouts differ, with Japanese-style layouts having a staggered positioning that mimics the way your fingers naturally fall, while American-style layouts are straight across.

Slagcoin.com has a pretty great collection of sample layouts that you can use or you can modify one of them to create a unique layout that's all your own, which is what I did:

(since I modified it, the measurements may not all be accurate, so you're probably better off printing it out and working directly with the template if you plan to use this one)

I went with a Japanese-style stagger because I find it to be more ergonomic. Additionally, since I emulate a lot of Neo Geo games, I wanted to have four buttons in one of the rows to recreate that feel but not on both rows to avoid confusion. This fourth button in the bottom row also works perfectly as the 'run' button in certain Mortal Kombat games.

D. What materials do you want to construct your stick out of?

This is where you can really put a visible, personal touch on your creation and make something that is instantly identifiable. Arcade sticks are pretty much just boxes that you screw things to, so you can build a box from scratch using high- or low-quality materials, or you can repurpose a box from somewhere else to give your stick a "found materials" kind of look. I won't delve too deeply into this aspect of the construction process since I'm a shitty carpenter and you can definitely find more complete and informative guides to box-building elsewhere online.

I wanted something large, sturdy and attractive enough to leave in my living room, so I opted for a combination of red oak top and two sides paired with high-quality plywood (from the 'project' section of Lowe's, not that splintery shit from the lumber section) for the bottom and other sides. I then stained it with a dark stain and covered it with several coats of shellac, which made it look like an antique piece of furniture.

It didn't turn out perfectly due to my aforementioned shitty carpentry skills, but it passed the wife test so it's good enough for me.

Page 1: Building an Arcade-style Fight Stick
Page 2: Assembling Your Box
Page 3: Pad Hacking
Page 4: Installing the Hardware
Page 5: Conclusions and Helpful Links

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