The Forestry Forum

I figure at least one of you out there have built speaker enclosures before. I need to build two speaker boxes for two 8" woofers. I know I can use 3/4 MDF, and I have plenty of that available, but I was wondering if anyone knows if solid wood is better.

I have a variety of hardwoods at hand, mostly native. Would any hardwood be better than the MDF?

The boxes will be 12 3/8" wide x 19 3/4" tall x 7 3/8" deep, inside measurements. (1.06 ft^3)

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most  boxes are made out of what i call particle board (sawdust with glue)

cheap!   thumpin and bumpin,  then it all slowly blows apart.    buddys car , box store box, and even homemade boxes,  with 2 , 1000 watt amps,  12"s and such. stripped and broke drywall screws off.

best idea is use 1/2 particle board,  screws every 2 inches,  then break out the black cloth and fiberglass resin.  precut the cloth and fold it up like a little present.

The ones I made was marine grade 11/16" 11 ply birtch. bg

instrument builders use maple sometimes.

My guess is that if particle board is "acceptable", then anything would work!

I built mine out of 1/2 inch Russian birch.  Solid.

I've gathered that solid wood is a no-no in speaker boxes, particleboard is just "ok", good plywood is better, but MDF is the best, as long as it doesn't get wet. Guess that's what I'll be going with. I will probably spray paint them black. They will be hidden behind the seat, so looks don't matter, just sound.

There will be no "bumping" with these speakers unless it's country or rock n' roll :D I got them for free, brand new 8" Pyle Drivers. They will be a nice addition to the stock speakers in my '85 ram ;)

I'm no expert by any means, but in the past when I thought about making new cabinets for some plder but really good speakers, research told me that MDF was best because of the density. I would thing a very dense hardwood could be used.

Apparently hardwood is a bad choice because the density is not uniform enough, and it changes with the weather. It would cause the speaker to be louder or quieter at different frequencies depending on humidity, etc. MDF works because the frequency range is "flat", meaning the sound level is pretty consistent from low to higher frequencies.

Thanks for your help!

The Russian birch I mentioned is 1/2 inch plywood, some 8 plies I think.  Substantial wood, no holidays.

I'm sure the russian/baltic birch plywood would work fine. The main thing with plywood is to make sure there is no voids I think. But that stuff is $$$ :o so I'll stick with MDF since I already have it. About to go out in the shop and make them in this 98 degree heat :o (guess I better make a bunch of them to sell so I can afford a/c in the shop :D)

I used red oak plywood, and the speakers I used were for a vehicle because I hooked up a car stereo that had a 6 disc changer. Car speakers are different than those for your house, they are for small enclosures. It was nothing to brag about, just hated seeing the stereo sit in a box never to be used. ;) Trouble was the face that comes off the stereo front (anti-theft) is known for the light diode to burn out. I fixed it once while mounted in the truck. The second time was hooked to the home built speakers. So it ended up being boxed after all. It would have also helped to add an amp, but never did. I used an inverter to get AC.

Green Sweet Gum. Makes the music sound like MAGIC!  :)

Have used MDF for years now with no problems. Glued and screwed and still thumping after all these years. Used corner glue blocks on the taller and heavier boxes.

Taking a break for supper, managed to shoot a brad through the meat of my thumb- in one side out the other, missed the bone though. First time doing that particular stunt! Doesn't hurt too bad so I'll be at it again after supper. Gotta love the brilliant things I do sometimes ;)

I used to build speaker boxes for myself and friends when I was in high school. That's actually how I got my humble start in "woodworking". As you figured out, MDF is the best material, by far. If you're using brad nails to assemble it, I hope you plan on going back and reinforcing them with screws! Spax makes some excellent MDF screws that you can buy at most any Home Depot. They sink right in without cracking the edges, and they hold much better than brads.

If you can't find the Spax screws, Lee Valley has them and probably cheaper.

  MDF would be best, with particle board next.  You want the enclosure to be acoutically "dead".
  Solid wood will vibrate and "color" the sound.  Plywood will too, but not as much.
  Make tight dado joints and glue everything except the back.  Dado the back panel too.
  Add fiberglass or some other sound deadening material behind the speakers and in front of the back panel.  Attach the back panel with enough screws to keep it from vibrating.  That depends on how loud you run the speaker.
  The thicker the MDF, the less vibration you will get.

Yes, the brads were only used to help during assembly ;) on the second box I used pocket holes and they've held up so far.

I'd have to look at my speaker box in the back of my Jeep - I know it's a double bandpass with two 12's facing inward at a 45° with a plexiglass front cover.  Not sure what kind of wood it's made of though. 

I've had it for a good 13/14 years now and it's still in perfect condition so I assume it's just particle board instead of MDF?? 

I'd assume it's MDF, not particle board. Although it could be either, MDF would probably last longer.

I've seen a lot more speaker boxes made from particleboard than from MDF, but that doesn't mean it's a superior material. It just means that it's a cheaper way to build a speaker box and the average consumer doesn't know the difference.

If you're really after a great material for a speaker box, solid surface such as Corian glued up is and excellent choice.  Corian is used for many things besides counter tops and has excellent acoustic properties.

I've made several sets of speakers boxes in the 1970s and 1980s.  I have a book on building them that I bought in about 1970. I put 12" full range speakers and tweeters in them.  Whatever wood you use, just make sure it is at least 3/4 inch thick so it doesn't vibrate.  I don't believe it matters what material you use to make the speaker boxes because you should put fiberglass insulation on at least two sides of the inside (top and side) to keep the sound from bouncing around in the box. Then you need to put in tuned ports.  The ports are holes cut into the front board with cardboard tubes that are cut to a certain length depending on the response of you speakers.