Speaker Build

I have always loved building speakers and having a large collection of raw speaker drivers.

One special lot of 16 drivers were some Bose speakers I picked up while working for Muzak in 2000, thinking I would build me a pair of BOSE knock offs!

Now that was in 2000 and I have I moved three times to three different states taking the box of these speakers in each move, thinking one day I would build a pair of speakers.... and with the weekends with no where to go because everything was closed, I decided to get to building! I had 16 of the Bose replacement speakers (1.6 Ohm), some extra time and some nice MDF 3/4 inch board, I would set out to build a pair of Bose 402 style speakers. Now the originals are plastic cased or wood case, I figure I could do a pretty good job with MDF. It was a challenging build but I am glad I did the pair at the same time. Usually I would build one cabinet and see how it sounds before cutting up more wood to make the next cabinet. The complexity was in the 30 degree 70 degree wedge for each driver. also trying to figure out port spacing, my ports on either end were bigger and allowed more air movement than I wanted… I ended up poly filling the entire internal cabinet. I sketched out the details on a sheet of paper before I set up in my garage to cut the wood.

Wood glue

MDF sheet

Strip of 3/4 inch square pine wood

8 speakers; Bose, 1.6 OHM drivers

Table saw

jig saw

band saw

screws

screwdrivers

speaker wire

speaker wire stripper

solder and solder iron

Paint, optional

poly fill

staple gun

staples

speaker grill fabric

speaker grill pegs/sockets

time and patience

Persistence!

per·sist·ence
noun

firm or obstinate continuance in a course of action in spite of difficulty or opposition.

I used a half sheet of 3/4" MDF and to cut it all I used a table saw, for the smaller delicate cuts or speaker hole cut outs I used a jig saw and a band saw for all of the angle cuts for the wedge design.

Wood glue was used to put it all together, a router was used to round the edges after the build.

I used a solder iron to attach all the speaker wire to the connections.

I used a hand drill to drill the required holes for the 1/4" speaker jack and the fuse hole.

I needed a bunch of clamps to hold everything together as the glue dried.

A router to round the edges.

After the speakers cabinets were put together I painted them white some extra white paint I had after painting a room.

I also used two 22uF 100V capacitor was the low end filter and a 3amp fuse was also put in to protect the speaker like the original. 1.6 Ohms per driver gave an over all speaker impedance of approximately 6.4 Ohms.

With out clamps and weights to hold the wood together as the glue dries it is impossible to get a good clean fit and seal on each piece... you can see a small space in the photo with the magazines as weights, i ended up having to clamp everything.

During the build it is critical to check as you go, look for errors, or areas that might not allow the speakers to be put into the design of your speaker.

Each stage of drying of the glue, you will need to check that the next part will fit.

It is never fun to finish a speaker build and to start listening to your music only to hear a whistle or an area where the air comes out of a small tiny hole giving a weird air vent sound.

So in the step of this build I used caulk and placed a bead on all joints of the speakers.

It was good to get at least one speaker fully populated with the drivers to listen to them before finishing up with paint and completing both speakers.

The white paint is really just my use of what I had... could be cool to paint a few different colors, 'Mod Podge' tissue for the look of antiquing the outside speaker cabinets, or even add a nice veneer to make them look like a high end custom speaker.

I plan on using my speakers for public, private gatherings inside and outside events and in the sun the white will help them stay cooler.

Using some scrap wood and cutting it into 3/4 inch square strips, I hand cut each section to fit the length of the speaker and then scrap wood to make the width, gluing and clamping these frames was the best way to make the frame for my design. Check before gluing that all the pieces fit the speaker!

There is a speacial fabric used for the grill... acoustic transparent fabric was used and I just used a staple gun to go around the frame and secure the fabric.

I used plastic grill holders which have little pegs that go into a socket to secure the frame to the speaker.

I set them up to listen to my new creation...

So the speaker testing was done on a Bose amplifier receiver with the setting for the EQ at the 901 Level and the speakers did the sound right, flat with a hint of bass, but will be set up in the garage with a proper Bose EQ and an amplifier what will allow the 100 watts recommended amplification to see if they will shine.
Now since the frequency range is 90Hz to 20K Hz it is paramount to have a sub woofer to back up the low end… I plan on making a 12 inch woofer in a small cabinet what will allow bi-amplification and a good full range sound if I did use these in a small gig, for a backyard party or at a bar to do some DJ’ing.

It is amazing to hear the difference of a phased array speaker compared to a front firing speaker. The fuller sound with a "LIVE SOUND" feel can be heard and I think it was worth the wait and the complexity of the cabinet build.

Not the best sound due to the Recording device, but if you could be here in the kitchen, they sound great!