Previously this cabinet had a single 5-6" speaker. Somehow I needed to interface the speaker to a PC where I'll be running MAME. The easiest solution was to trash the 5-6" speaker entirely and put a pair of amplified PC speakers in the cabinet. This is how I did it.
First I disassembled the speaker panel so I could cut some new holes in the plywood. As you can see in the photo below, my speaker panel looks pretty rough to start with.
The plywood panel was covered with a plastic mesh which had a few small breaks in it. The mesh was stapled to the wood and was difficult to remove without breaking. Although I managed to get the plastic off without too much breakage, I'll probably end up covering the panel with fabric instead of plastic. Fabric is much easier to find and I won't have to worry about trying to bend it around the corners of the plywood.
After disassembling the speaker panel, I turned my attention to the speakers. I settled for a cheap set of PC speakers that still have respectable sound quality. These speakers were actually given to me for free.
I opened the speakers to see exactly what I would be working with. Inside was an amplifier, a 3-4" speaker and a small tweeter that was part of the speaker casing. Because the tweeter was held together by the case itself, I decided to leave it out of the cabinet. The tweeter was simply connected in parallel to the main speaker anyway, instead of going through a crossover. If I have a problem with the high frequency noises then I'll go out an buy some cheap tweeters to put on .
After getting a look at the speaker internals, I made a decision to mount them in between the previous speaker hole. This would put a speaker on each side of the cabinet and allow the left and right signals to be distinguished. I measured and marked the center point. From the center point, I measured and marked to each side, 1/2 the width of the speaker. This gave me 2 marks that the speaker would fit exactly between. I also marked 3" from the edge of the speaker panel and set my speaker down on the plywood. I traced around the plywood with a pencil.
The next thing I needed to do was to draw a circle inside of the outlined speaker frame. The circle would be as large as the speaker itself, while allowing a place to screw the speaker frame to the plywood. Luckily I had a glass candle holder that was just the right size. I centered the glass inside of the square drawn on the plywood and traced around it.
Now that I have my outline, I used a scroll saw to cut out the new holes. A scroll saw is easier to use for this than a jig saw. I just happened have a scroll saw anyway. I drilled a small hole for the saw blade, slipped the blade through and cut out my speaker hole.
Once my holes were cut, I just needed to mount the speakers. I placed the speakers over the new holes and pre-drilled for the mounting screws. I used the same screws that held the speakers inside of their old enclosures.
Once the speakers were fastened to the plywood, I unsoldered the speaker cables that were threaded through the old enclosures. This allowed me to slip the cables out and re-solder them back. I was left with 2 speakers and an amplifier mounted to the board. The amplifier will most likely be moved later so it can be more accessible.
After installing the speakers I had to cover the panel back up with some wire or plastic mesh. Both of these proved to be hard to find so I ended up buying some white burlap at Wal Mart. I bought 1 yard for $1.96 and dyed it black. If I were installing this machine in a local 7-11 then I certainly wouldn't settle for cloth. Something like chain and iron bars might be more appropriate for that!
To dye the burlap, I put 1 package of Rit black dye into about 2 gallons of water. I've dyed cloth before so I already knew to only use a stainless steel pot. Otherwise you'll never get the dye out. I boiled the cloth in the dye for about 30 minutes and let it cool off overnight. The next morning I rinsed the fabric clean and threw it into the washing machine.
After a trip through some hot dye and the washing machine, I hung the fabric up to dry. The fabric shrunk considerably which actually ended up being a good thing. This tightened up the weave on the burlap.
After the burlap was dry, I laid it on the floor and stapled it around the speaker panel. The edges were folded under to prevent fraying of the burlap.
To finish up, I put the support braces and marquee/front glass holders back on. Although the fabric is flexible, I think it looks nicer than the plastic did.
Second Chance Arcade