Ideas Behind Building Speaker Boxes from Scratch
My brother-in-law is a genius. The reason I'm saying that is because he learns and then makes things all by himself, best of all, what he makes all look like things you can buy off of the shelf. He's not a science person, he's talented in Chinese writing, calligraphy, Chinese seal carving, stuff like that, yet when he has to deal with science and technology, he reads information himself and implements them with common sense, amazingly, he never fails!
Because my sister likes to sing with Karaoke (we simply call it
"K song" in Chinese), that is what got my brother-in-law into building
his own homemade speaker boxes just so she and other family members could sing anytime they wanted, and it would save money too, just to think of it. So he ended up building several customized speaker boxes several years ago for my sister, they turned out to look and sound fantastic. I thought they were bought from a store at first. He even had brand labels attached to them and that indeed fooled me. Today I'd like to try my best to present how he built those custom speaker boxes.
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Building the Speaker Boxes for Singing Karaoke
He happens to have a pair of polypropylene Nanjing dual cone speakers. Although the price isn't high, the quality is very descent, and the voice is so warm, quite ideal for singing Karaoke.
It all begins with a series of tedious calculations. My brother-in-law is sort of computer illiterate, so instead of using a speaker design software, he has to go through his own silly way of calculation. You can ignore his way if you can find a good speaker design software online. A small calculator with arithmetic functions makes the process not too hard for him, fortunately. This speaker's Q value is 0.6, and other parameters determine it is appropriate to be a closed-box chamber, so he designed the box accordingly.
The next step is to saw a board. He uses the regular medium density plywood sheet due to its consistent physical characteristics and ease of processing. There are tools you need during the entire process.
The next step is to saw a board. He uses the regular medium density plywood sheet due to its consistent physical characteristics and ease of processing. There are tools you need throughout the entire process.
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Cutting the Board to Have 90-Degree Bonding Surface
Restricted by the parameters of this speaker, the volume of the box has to be designed as 20 liters which is a bit too large for a 6.5" speaker pot. To avoid increasing the size of the box any further, he only adds an additional 1 liter space to be occupied by the speaker, and eliminates other normally required processes such as rebar and asphalt coating. Now it has to come down to the speaker box strength. Initially he has considered to cut the corners to 45 degrees so the bonded areas will be larger. But considering without rebar, screws can only be tightened on the board, as the result, the strength screws can bear on a 45-degree bonding surface would be a lot less than if it were screwed on a 90-degree bonding surface. So instead of cutting the board 45 degrees, he chose to make it straight 90 degrees.
The board needs to be cut precisely, pay special attention to the corners, make sure they are exactly square everywhere, including the side and ending facets.
45-Degree vs. 90-Degree Cutting
Open the Holes for Cone Speaker Using Wide Blade Circle Cutter
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Proactive Actions for Late Stage Speaker Adjustments
Due to the fact that adjustments are needed in later stage, which require repeated demolition of the speaker box and face board, using just regular hex wood screws may result in damaged screw holes on the panel after all. My brother-in-law chooses to use machine hex screws instead, also glues nuts on the back of the panel so extensive demolishing process can be endured. Either building adhesive or white latex glue can be used for this purpose. A wood strip should be used to support the panels before the glue completely dries out.
Nuts Glued on Back of Panel
Secure Panels with Screws & Construction Adhesive
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The Order of Glueing the Panels
Four side panels should be glued first, then the top panel on the loudspeaker side, inner treatments inside the box are to follow after. This includes minimum of two coating of glue, asphalt coating and adhere sound absorbing materials. Glue the top panel on the subwoofer side after all these are done. That way, since the hole for subwoofer speaker is much larger, doing the rest of the hand works becomes so much easier and convenient. This is very important to know ahead of time, or the inside treatments would become a hassle.
Putty Plastering is the Most Tiring & Dirty Job
Decorate Speaker Cabinets with Black PVC Veneered Sheets
Self-Made Sound Absorbing Material
Initially a kind of stretchable acrylic cotton was picked for sound absorbing. But it turned out this type of material did not seal very well on metal framed speaker cones, so in the end the silicone sealant was chosen.
First, squeeze out a thick layer of sealant into the grooves the same size of the holes for loudspeaker and subwoofer, wait for about 2 hours till the surface solidifies. After that, push the speaker down to pre-determined depth, and then let it stay until the sealant completely dries out. Do it for both speakers. Now you have a perfect matching sound absorbing speaker pad for each of your speaker. The drawback: you need plenty of sealant, but it's not easy to handle the extra amount; also, also this material has a degree of irritations to human body.
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Finished Speaker Box
The Customized Speaker Boxes in the Theater
george dl on November 17, 2013:
The tenor is very difficult to do.
Ramon55 on August 25, 2013:
very nice work, we make speaker box's for car take a look at them.
Sabrina Yuquan Chen (陈玉泉) (author) from Boston, MA, USA on April 24, 2011:
Thanks, Ken, normally we are all a "bit" lazy on building something from scratch :)
KenWu from Malaysia on April 23, 2011:
Superb DIY article! But I'm bit lazy to do all those things :)
Emma from Houston TX on March 11, 2011:
Good hub with attractive pics,thanks for sharing.
Sabrina Yuquan Chen (陈玉泉) (author) from Boston, MA, USA on March 10, 2011:
Thanks, Haunty, for looking into this. I discovered this change last night and did plan to fix my hubs. Hope there won't be too many. Too many things on hands and not enough time.
Haunty from Hungary on March 10, 2011:
Thanks for this useful hub, snakebaby! I counted and it looks like you might have to take away about 36 products or add 1800 words. Sorry. Surely, these changes must be in the best interest of hubbers, so I hope this will improve the efficiency of the hub.
Sabrina Yuquan Chen (陈玉泉) (author) from Boston, MA, USA on November 22, 2010:
Thanks for the suggestion again. I went to search homemade speakers, yeah, I did find sites building them from scratch. And this morning it dawned on me that "speaker box" indeed refers to "??" in Chinese, the word I thought as "speaker" all along! It all makes sense now. Really appreciate your help.
AlanSwenson from Las Vegas, NV on November 20, 2010:
I wouldn't make a homemade speaker, but I would change the title to reflect the actual topic.
Sabrina Yuquan Chen (陈玉泉) (author) from Boston, MA, USA on November 19, 2010:
Now I have to wonder what is considered "homemade speaker"? Who and how many would build the electric part from scratch when you can buy it online inexpensive? So I guess this hub should be good for both homemade speakers and speaker boxes. Any more clarifications? Thanks in advance
Sabrina Yuquan Chen (陈玉泉) (author) from Boston, MA, USA on November 19, 2010:
I thought this was for speakers, then realized it was really for a box/cabinet. I do have a calibrating speaker part, wonder whether adding it to the hub would complete the building speaker part, but on the second thought just now, I assumed building a speaker really means building the electronic part, like building a dual cone speakers, am I right? I may change the title later so it doesn't mislead.
AlanSwenson from Las Vegas, NV on November 19, 2010:
so you are building speaker boxes/cabinets...not speakers.