Simply want to know the fundamental frequency of the FH3 diy horn cabinet, I have done a back of envelope calculation and have come up with a figure of around 50hz, is this about right?
thanks
Stevenmowen
thanks
Stevenmowen
Thank you nandappe for the reply, that confirms my thinking. I am going to build a pair using a couple of Peerless drive units that I have, they have an Fo of 50hz so I don't have to alter the dimensions of the horns - though the drive units are a little larger than the 4 inch ones usually used.
According the impedance plot above, the resonance frequency of the combined speaker and driver is about 55Hz - where the minimum dip is between the two peaks. You can also estimate to first order, based on the path length of the horn and the speed of sound - but this is modified depending on taper of the channel and blockage or “mass loading”.