FrankCashio
Jul24-09, 08:51 AM
I have no one to go over my math and I just wanted someone to go over this. Does this look right to you guys? Just for those who don't know a ribbon speaker is just basically a really thin piece of aluminum foil suspended in a magnetic field. Audio signal is sent through it and lorenz's force makes it move to produce audio.
Bl - The product of magnet field strength and the length in meters of ribbon suspended in the magmatic field
Re - DC resistance of the voice coil, measured in ohms.
Mms - Mass of the diaphragm, including acoustic load, in kilograms.
Sd - Projected area of the driver diaphragm, in square meters.
η0 - The reference or "power available" efficiency of the driver, in
percent
η0 =(5.445×10-4 m²·s/kg * (Bl²*Sd²/Mms²*Re ))*100%
dB(1 watt) = 112.02 + 10*log(η0)
SPL at 1 meter for an input of 2.83 volts is then:
dB(2.83 V) = dB(1 watt) + 10*log(8/Re) = 112.02 + 10*log(η0) + 10*log(8/Re)
Bl - The product of magnet field strength and the length in meters of ribbon suspended in the magmatic field
Re - DC resistance of the voice coil, measured in ohms.
Mms - Mass of the diaphragm, including acoustic load, in kilograms.
Sd - Projected area of the driver diaphragm, in square meters.
η0 - The reference or "power available" efficiency of the driver, in
percent
η0 =(5.445×10-4 m²·s/kg * (Bl²*Sd²/Mms²*Re ))*100%
dB(1 watt) = 112.02 + 10*log(η0)
SPL at 1 meter for an input of 2.83 volts is then:
dB(2.83 V) = dB(1 watt) + 10*log(8/Re) = 112.02 + 10*log(η0) + 10*log(8/Re)