All reviews are from people who have redeemed deals with this merchant.
Reviewed September 21, 2015
What You'll Get
Choose from Four Options
- $25 for single-day admission for two ($50 value)
- $50 for single-day admission for four ($100 value)
- $75 for single-day admission for six ($150 value)
- $99 for single-day admission for eight ($200 value)
Visitors gather on Saturday, September 19 and Sunday, September 20 for the Highlands Festival at Waterloo, featuring live music and a fair-trade market, along with a craft-beer garden and local food.
Loudspeakers: Magnetic Music
The venue’s sound system will add pep and power to the event. Learn how speakers let everyone feel the music or the wedding toast with Groupon’s look at a loudspeaker’s guts.
Whether they’re as tiny as earbuds or as huge as the loudspeakers once found at the Roman Coliseum, speakers work according to the same basic principles. All sound travels through the air in the same way that waves travel through the ocean, so speakers need to convert the electrical signals they receive into motion and thus sound. The mechanisms responsible for this translation are called drivers, which have three parts: a permanent magnet, an electromagnetic coil, and a cone. When the coil receives an electric current, it reverses polarity and is pulled toward the permanent magnet or pushed away from it. The cone moves accordingly, compressing the air inside the box and pumping amplified sound waves into the surrounding air. The frequency of the vibrations controls the pitch of the sound, and the amplitude controls the volume of the sound.
Top-quality speakers typically have multiple drivers dedicated to high, middle, and low frequencies in order to reproduce the full spectrum of audible sound. Woofers are the largest in order to move the volume of air necessary to make lower frequencies. Tweeters are the smallest, responsible for higher frequencies since they can vibrate fastest, and midrange drivers handle the frequencies in between. In most cases the boxes that house these are sealed—otherwise, the motion of the cones would produce sound waves in both directions—though it is possible to use vents to “tune” the box itself and produce additional resonance.
The Fine Print
Promotional value expires Sep 20, 2015. Amount paid never expires. Limit 1 per person, may buy 1 additional as gift. Limit 1 per visit. Valid only for option purchased. Online registration required. Takes place rain or shine. Merchant is solely responsible to purchasers for the care and quality of the advertised goods and services.