Archive | Technically Speaking

Beam sound

A transducer can be made to project a narrow beam of ultrasound that is powerful enough, (100 to 110 dBSPL) to change the speed of sound in the air that it passes through. The ultrasound is modulated– it consists of an audible signal mixed with an ultrasonic frequency. The air within the beam behaves in […]


How a Speaker works detailed

The key working components of a loudspeaker are shown in the diagram below. When an electrical current passes through a wire coil (the voice coil) in a magnetic field, it produces a force which varies with the current applied. The cone, connected to the voice coil, moves in and out, creating waves of high and […]


Speaker Repair “No No”: What Not To Do

When you recone a speaker you must set the spider and cone level. In our speaker reconing instructions, we advise that you gently turn the spider once it is in place to insure it returns to level.Someone obviously missed the memo while reconing this Electro-Voice EVX180. As you can see the spider is not level. Sunken spider […]


Polk SL1000, SL2000 Tweeter vs SL2500

The original Polk SL1000 tweeter had an aluminum faceplate. That tweeter is no longer available. Instead Polk offers a black faceplate tweeter. They used the faceplate from the SL2500 and the dome from the SL2000 to make a replacement tweeter that is suggested for both the SL1000 and SL2000 models.  The new faceplate does not […]