Noise Testing

Hi, Your box is a resonator for lower frequencies. Unfortunate your solenoids are close in the slightly higher range. You can make your box more performant: put the same foam on the outside and cut 6 pieces of sheet lead and surround your construction with it. Do not let them touch each other - connect e.g. with gaffa tape. Put this box on a ridgid surface that resonates @ a different frequency and put the box on soft rubbers. You can do the egg. foam again but that will not be necessary anymore. Now the measurement: Your box is somewhat small, because most of the standard measurements are done @1 meter what will give you a problem in a box of (30,48 cm) cube. I honestly dont know if your dbA meter fits in it as well. If your dbA meter is a high quality make, it will probably also pick up the magnetic field variations through its measuring microphone, unless it is a piezzo type. Make sure to suspend the meter on e.g. some elastic rubber bands to the sides. And also the solenoids. Then at last: you should maybe also do a spectrum analysis, because those solenoids might generated harmonics - with the MECHANICAL components vibrations. In this case- you know at what frequencies your noise is audible. In professional dead rooms - also the floor is suspended on a wire mesh. And distances are a lot more. Also is it better to make not a cube box, but one that is completely irregular, made out of irregular 4 point planes that have no parallel walls. This way reflections are not amplified. Normally they do these measurements about in the middle of the room, with enough distance to the walls in all directions. If you need to use these measurement results, the way you do it is not according regular norms.