Focus Trap:
This is a fun project that will help "lock in" the imaging of your system. I use one in my personal system, so it MUST be good! It is also SUPER CHEAP!

WAF tip: Buy her some flowers the night before, hold her, love her...She will not complain about the below project!

Look at the photos below, what we are building is the tall white column that is against the rear wall between the speakers.

You will need: 1. Two 4 foot tall by 12 to 15 inch diameter cardboard concrete former tubes (found at Home Depot, Lowe's or any other hardware store. 2. Attractive fabric to cover the above. 3. Black banding from a fabric store or Wal Mart, the "self stick" kind. 4. Spray on contact glue. 5. 1 by 2's for feet, about 6 inches in length. 6. Paint of your choice to paint the feet. 7. Some wood screws to secure the feet.

Unload the goodies from your car. Lay one of the cardboard tubes on it's side.

Take the wood and cut some feet, about 6 inches or so long. Paint them if desired, When dry, secure three of them to the inside of the cardboard tube, leaving about 3 to 4 inches coming out the bottom. Use drywall or wood screws to fasten them.


Now for the fabric...Cut some fabric in such a way that it can go all around the tube, covering it completely with some overshoot on the ends. See below for how to cover the top. We are leaving the bottom un-covered.

Now for the sticky part! Lay your cloth out and spray the spray contact glue on the cardboard tube. "Roll" the cardboard on the layed out fabric. Make sure it has adhered to the tube and cut off the excess after letting it dry for awhile. If this is too much trouble, you can perhaps tape the fabric on the tube.

Cut a circle of fabric out, enough to fit over the top end of the tube with about a 1 inch of overflow. Use the spray contact glue on the outside top 1/2 inch of the tube. What you do next is lay the circle of fabric over the top and then bend down the edges so that they come into contact with the glue, securing it there.

Take the self sticking band and wrap it around the same area to hide the ugly, making a nice finishing touch. See the black band I used on top of mine in the photo above.

You can also put a band on the bottom.

This completes one four foot tube. You can do the same for the other and then stack them to make an eight foot column. You can make some more for other room diffraction experiments.

To fill or not to fill? You can use batting of any kind to fill your tubes, which will absorb the bass in the room, or leave them empty like I do.

Placement: Stack your columns on the rear wall between your speakers, exactly in line with your head when seated in your listening chair. You can fine tune things, moving it a few inches to the left or right.

How it works: What happens in the usual room? The speaker sound waves come around and bounce off the rear wall behind them and then to your listening chair, causing imaging smear, loss and distortion.

When using the above focus trap, the waves come around and are diffracted to the left and right, away from your listening chair, allowing focus and imaging to be improved. You will notice a larger soundstage, depth and an increase in imaging.

There are many things you can do with these traps...make lots of them and place them around the room. Stuff some for bass traps, etc. How about a bunch of them along the wall behind your listening chair for a diffraction panel?

Fast Tweak:

In the last issue, we talked about damping your components with our metal filled box. What we want to do this month is keep floor vibrations from entering your components.

Remember the Masonite? Take some scrap pieces and cut them big enough to go under your selected components.

Get in your car (take your sweetheart so she can join in the fun too) and go to a toy store or Wal Mart. Buy some bicycle inner tubes, the small ones, like 6 inches or so.

Take them home and blow them up about half way, place one under the Masonite and place the selected component on top of that.

Sit down for a listen! What do you hear? I bet it sounds much better!
Mike Morrow