Loudspeakers

Exertion Instruments use common loudspeakers.  For best results, choose speakers with:

• Higher power rating in Watts (e.g. 5W-100W)
• Heavier magnets, as they are more efficient than smaller speakers.  (e.g. at least 5-15 oz.)
• Wider cone, so that smaller, more efficient excursions move a larger amount of air.  (e.g. at least 4-6 inches)
• Lower internal resistance in Ohms, so that more power is dissipated in the speaker, rather than in the amplifier's transistors.  (e.g. 4 Ohms - 8 Ohms)
• Softer surround, so that their resonant band is narrower and thus more efficient. 

Good places to buy speakers at surplus prices: 

• http://www.parts-express.com/speakers.cfm
• http://www.sciplus.com/category.cfm/subsection/17/category/158Resonances
• http://www.smcelectronics.com/earph.htm
• http://www.surplustraders.net/a/0109.shtml

Speaker Physics Links

• Speaker efficiency-related Links:  http://delicious.com/enzo308/speaker+efficiency

  Resonances