This is a Simpline, so it's simple to construct. Start by cutting the 6 boards and the 4 boardlets.
Assembly starts by attaching the top board to the front board. Elmer's yellow Carpenter's Glue is a fine glue for assembly. You can use 2" finishing nails spaced about 6" apart to hold the boards while the glue is drying. They can be countersunk about 1/16" when the enclosure is completed. The actual structural strength is created by the glue (and the above mentioned damping and stiffening compound, which will literally cast the entire enclosure, except for the back board, which must be added after the stuffing, into a single piece.)
Next add the long side. Then the bottom panel, followed by the short side panel (which creates the port). Note that to create a mirror imaged pair of enclosures for stereo, the long and short side panels should be reversed on one enclosure. The front to back cross brace may be added at this time. There is no magic location for this. (At least that I know of.) But be sure to mark its location on the inside of the back panel so that area will remain free of the damping compound, if used.
After you get this far, add another coat of glue all around, eat, watch MTV, sleep and get back on the job (unless it's Monday morning, then go to your other job.)
This is the time I like to make the cutouts for the speakers. If you use a cup (I mean for the input terminals.) make a cutout for it near the bottom of the long side, opposite the port.
A couple of years ago I was looking for some kind of goopy stuff to pour onto the boards and joints of an enclosure to improve its integrity. I didn't want to spend a bundle like on that expensive NASA stuff. With ~ at you're paying for heat resistance in the red glowing Kelvin range. It might be good for hot music, but hell on cool jazz. No, all we need is something that has a little mass, held together by something stiff and dead. (It's getting to sound like Funeral Day at the St.James Infirmary!)
I recalled using agricultural gypsum to loosen up the salt bound soil in my back yard in the 1950's. My house was on filled-in bay land. The stuff (The gypsum, not the bay land.) came in 100 lb bags for about 5 dollars in those days. Nurseries still sell it. I didn't need that much of it. I got a 10 lb paper sack of it for just under 5 dollars. I got a gallon of white glue on sale for 10 dollars. It's usually about 15 dollars.
In areas, such as middle America, where the oceans don't fill the topsoil with salt, gypsum might be a bit harder to find. I would imagine that agricultural lime might do as well. Just make sure you get slaked lime and not the active quicklime. I'm sure quicklime is not a product sold in nurseries. You could also use chalk, powered marble, pumice and maybe even dry powdered dirt. I call this mixture Goopy-Stuf.
You mix the stuff up by pouring the powdered gypsum into the liquid glue. Your wife or mother can show you. It's just like mixing hotcake batter, only you mix it a bit thicker. A mixture that settles out into a pool about 1/8" thick is just right for our purpose here. That manages to dry out to a manageable degree in a day or a day and a half or so in my Northern California climate. It works best at 70 degrees F or higher. Below 60 degrees it may not completely dry. I imagine this could be corrected by removing the enclosure to a warmer place for a rest cure. (For starters try using equal volumes of glue and gypsum.) Cover your bench with newspapers (just in case). Set the enclosure on its front. Make sure it's flat. Use a level if you have one. (I confess I didn't use one. Now you know this article isn't on the level.)
I was working in the kitchen and I used a Dixie cup (several fillings) to mix in, but perhaps a cottage cheese type container would be more convenient and it might have a lid to save the surplus until the following day. ~ tongue depressor worked well for stirring and a small putty knife was good for leveling and getting into the corners. It would probably stir as well. (A small plastic knife I obtained at a Hamburger Joint worked well for all functions, including the bun cutting.) Push the material into the edges and corners say to a height of 1/4" or so and let it run down and seek its own level. This allows coved corners to be formed. When you come back to the adjacent panel (the next day or so) go back to the same edge or corner and backfill again.
Cast the glued end of the cross brace into the mass in the same manner. You might as well do the inside face of the back panel at the same time so it can be drying out. Mark off a margin of at least 1" in from all edges. Carefully measure and mark the area where the cross brace will contact the front panel. It would be prudent to mark a line about 1/2" beyond the perimeter of the cross brace marking, to insure that the goop stays in its place. Adding a bit more gypsum to the mass at the places where borders are important might allow more control. This would include areas on the top, bottom and side panels near the back edges. Remember to use the level each time you rotate the enclosure. (Do what I say, not what I didn't do.)
When all of the panels have been covered and the goop has dried to the point where the enclosure can be moved about, the input terminals can be mounted. I strongly recommend using an external crossover. It's easy to get to in case I (or somebody) comes up with future changes and it keeps the crossover elements away from magnetic fields and pressure fluctuations. I used a plastic cup designed for bi-amping, from Parts Express. (#260-304). It looked pretty flimsy when I received it, so I buttered some of my favorite material (Bondex Ready Mixed Concrete and Mortar Patch #31084, from Wal-Mart. It comes in quarts. It's in the Paint Department.) about 1/4" thick in places where it won't get in the way. I also used this material to cover the magnets on the tweeters and on the magnets and the outsides of the "woofer's" baskets. Be sure to keep it away from the mounting surfaces and the connecting terminals and don't put it on so thick that it will block the spaces between the basket legs and thus stifle the breathing of the speakers.
With the cup in place (you should be ready for anything) you can cut the speaker wires and solder them to the terminals. Make them long enough to protrude about a foot beyond the speaker cutout holes. Mark them woofer and tweeter and + and -. Please note that the tweeters are wired in series. This is of the greatest importance as it is necessary to maintain a safe impedance load to your amplifiers and to maintain the proper spectral balance of the system. Loop a couple of feet of wire through the tweeter holes with the ends poking out. One end will connect to the - terminal of the first tweeter. The other end will connect to the + terminal of the second tweeter. The stuffing which you will now be putting in will temporarily hold the wire in place. Note: these speakers were designed and voiced using 16 ga zip cord wire (from Radio Shack). The use of exotic wires will possibly (probably) upset the spectral balance of the Wallflowers. I urge you to keep the Simplines simple in this respect. 13 years of intermittent development have gone into the Simpline series so they could be simple for you. Sometimes it's very hard work to maintain simplicity.
Now it's time to install the stuffing. I used 14 oz of "Poly-Fil" pillow stuffing from Wal-Mart. I don't like Wal-Mart's principle, but as a writer, writing to thousands of readers, I find it comforting that they can often merely reach out into their local community and grab the same thing off the shelf that I, myself, used. I have used many other brands over the years and they all worked well. Just use the fluffy pillow stuffing type and not the bonded material made to fill blankets and comforters.
"Poly-Fil'' comes in 20 oz bags. the easiest thing to do is to measure out 6 oz and then use the rest of the bag for stuffing. An inexpensive postal scale from a drug store could be used. A piece of cardboard, such as that found on the back of a note pad, could be taped to the top plate of the scale. Be sure to re-zero the scale after attaching the cardboard.. It would be easier to measure a few smaller batches rather than to pile all of the "Poly-Fil'' on the scale at once.
One thing about "Poly-Fil''. There is a surprise in every bag. There is a length of wooden dowel in each bag. It is used to poke the stuffing into the arms and legs of stuffed dolls. I'm sure you'll wish to remove it.
There is no magic way to stuff the Wallflower, just take the stuffing from the bag and pull it out a bit. If there are any hard knots that are difficult to pull out, just make sure they are in the 6 oz pile you will discard. I have never found any hard knots in "Poly-Fil". With the enclosure on its front merely place the material in as evenly as you can. Lift the wires as you go and place at least an inch or so of the stuffing beneath them and between them and the sides of the enclosure. In the same way make sure they will be isolated from the back panel when it is installed.
I have a gut instinct that when sound waves go through the stuffing and emerge out the other end, they have averaged their way through denser and less dense areas. Mother Nature is on our side. In constructing over 35 hybrid transmission lines I have seldom felt the need to make adjustments to the evenness of the stuffing.
Before installing the final panel make sure that once again you have newspapers under the enclosure. Then push the stuffing down and back from the edges which are to be glued. I'm sure over time the stuffing will eventually spring back into place. If not it never seems to matter.
Start the nails into the edges of the outside face of the panel and maybe one into the center of where the cross brace will be. If the nail points come through too far, hammer them back so they are flush. Now lay a massive bead of glue, about 1/4" wide all around the exposed upper edges of the enclosure panels and the cross brace. Make a final check to see that the panel is oriented correctly so that the cross brace will line up with its corresponding area on the underside of the panel. Bring the panel down into place on the enclosure. Line up one corner and tack it in place with a couple of strikes of the hammer. Be very careful because the panel will try to slip around because of the wet glue's lack of friction.
Then go to the diagonally opposite corner and line it up and whack the nail. Do the same for the remaining corners. Then starting with the middle nails, drive them home. Moving from the center to the ends of the enclosure, nail by nail, side by side alternately and from end to end in the same fashion, drive the remainder of the nails home. Now you can wipe up the gluey gooey mess that is running down the panels. Then countersink the nails. Then go to a movie. You've earned it. And off to bed.
Next day go around the joint you worked on yesterday and fill in any voids you find. Then fill in the holes created by the countersunk nails. At this point you may consider your options for making your Wallflowers respectable speakers. If you are merely going to paint the Wallflowers you might wish to add the 3 Gravity Loaded Stabilizing Wall Coupler cleats so everything can be painted together. If you are going to veneer, or add Formica, etc.,it might be better to add the cleats later. With the cleats in mace the Wallflowers may be trained to stand upright for staining by the simple insertion of a small piece of 3/4" stock underneath the rear edge to match the height of the cleats.
When the enclosures are to your taste, mount the speakers using #6 x 3/4" pan head sheet metal screws. (~" for the tweeters.) Pre-drill the holes with a l/16" drill bit. Make sure you reach into the speaker holes and press down the stuffing so the drill won't twist its way into the stuffing and jam the drill into the hole. Wire up the speakers making sure the correct wires go to the speakers and that the tweeters are in series hookup.
[ Back to Projects | Contents | The Wallflower | Assembly | Parts | Epilog | Appendix ]