HIFI Subwoofer for Cinema and Music

Welcome to my second instructable.

In this instructable I'm going to show you how I built my subwoofer. I want you to use this instructable to come up with your own ideas, for brainsurfing or to use this as a guide. Mostly I would like you to be innovative and creative when you're building your own!

I hope you'll enjoy my instructable!

List of needed parts and materials with link/description of where I bough them:

• Speaker unit (MGR FAT-104, 10" unit in my project), (bought from ljudia.se)
• Reflex port (3" port), (from ljudia.se)
• Amplifier (or crossover for a passive subwoofer), I bought a used Zachry dsw-150 for about 65 USD.
• Vinyl Wallpaper, (bought from bauhaus: http://www.bauhaus.se/designfolie-sjalvhaftande-faner-svart-tra-45x200cm.html)
• Rubber feet
• 19 mm MDF-board (bauhaus)
• Glass wool or other damping material (bauhaus)
• Screws
• Sandpaper, sanding machine
• Wood glue

Then you'll also need some tools but instead of listing them I think it is better for you to see what I'm doing so that you might find another way of doing it if you don't have the same tools.

To get a speaker unit for my project I searched for speaker units that included plans for good box measurements. Ljudia.se, a swedish online shop have lots of speaker units and some of them had plans, so I bought one of them that had a nice frequency range and also a good box. I don't have a lot of knowledge about speaker properties. But I did my best to read on forums etc. to find a pretty good speaker unit and a pretty good box.

What I looked at most was the frequency response curve, Fb and F3 values because I wanted a pretty deep bass.

The inner volume according to the plans was 60,64 L and the box inner measurements were 550x350x315mm. So I decided to make the MDF pieces in these sizes (not exactly as the plans):

Front: 588x388mm

Sides: 588x334mm

Top and bottom: 350x334mm

Back: 550x350mm

When the pieces where in the right sizes I made holes for the speaker unit and the port on the front board and a hole on the backside for the amplifier.

I used a sticksaw for all of the MDF pieces and sanded the edges straight.

All the pieces were glued and screwed together. I bored a 2mm hole before screwing the screws in to avoid cracks.

When the box was assembled I sanded the whole box to remove edges etc. Then I used a hand milling machine to round the upper side edges so that the vinyl wallpaper could go all the way around without making extra edges on it.

To cover up the screws I made some own putty out of mdf powder that was in the sanding machine's powder collector bag that I mixed with wood glue. It worked pretty well but I recommend using some "real" putty instead of this. It became really hard when it dried and was really hard to sand without sanding down the mdf around it.

Now it's time to damp the box with glass wool. This will make the speaker think that the box is bigger than it is as will result in a better sound.

I just squirted some wood glue on the walls of the box before applying the glass wool. Then I also put a few screws with a plastic washer to decrease noise and to secure it better.

I used a damp cloth to clean up all the sides of the box from the sanding.

Finally the inside of the speaker was finished and I could to some sound tests and I was really happy with the result!

Now it's time to apply the vinyl wallpaper. I chose a black wooden look which I thought would look really nice.

I made sure that the surface was clean and the I applied the outer edge of the vinyl and slowly applied the rest of it to make sure that it was straight without bubbles etc. Then I used a sharp knife to cut away the leftovers. I did this to all of the sides and added four rubber feet to avoid scratches to the vinyl and to also reduce noise from vibrations.

Now just put on all the electronics and you're done! Finally!!

Done! Finally done with the subwoofer!

I am really happy with the result. It seems to work really good down to about 25 Hz then it starts to sound weird, but 25Hz is really good. The sound depth in movies is much better and it sometimes feels like my apartment is shaking!

The subwoofer makes music much better aswell. I'm using it with Canton 490 and canton 416 and it works like a charm. The total cost was about 230 dollars I do not think that I would have gotten a speaker as good as this one if I would've bought one. Those subwoofers that you buy in a store usually are so slim/small that the frequecy span is very narrow compared to a home build one.

I hope that my instructable has inspired you to build your own subwoofer and hopefully you'll find out many different innovative solutions.

Thank you for reading my instructable! I hope to see you again!