tapped horn design

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   the way I have used hornresp is to model as an exponential horn. I use two sections - one which will be the section behind the driver tap and the second the rest of the horn in front of it. the first section should be approx 1/4 the total length but IMO there is a lot of leeway in this. I try to keep the flare contstant of the two sections roughly equal. I think when william said 2:1 compression ration he meant the ratio of Sd to the end of the horn NOT the cross section where the tap is. I assumed that the lowest bass response (which is what we are after with a tapped horn) would be obtained by tapping the driver into the horn where the cross section is the same as Sd so I make the throat of the second section in the model equal to Sd. If you want to use a much smaller horn then instead of increasing the compression ratio find a driver with a smaller Sd but same motor. Sd:mouth ratio should be about 1:3. I modelled in half space and aimed for 6dB-9dB of dip. start by deciding on a low cut off (which will roughly determine the total length) and a cabinet volume; choose an Sd and then play around with the mouth size (which is going to roughly determine the amount of gain and flare constant) and tap position and see if you can get it to work. then try and work out how to fold it! I actually started off by sketching different ways of folding them before I modelled anything. I think I have guessed the folding in three of the danley boxes and one by outline and have come up with a good one of my own. there are dozens of ways to do it but I think ones that have fewer bends near the mouth and avoid an access panel and let you see the cone excursion whilst in use are the most elegant. hope that all makes sense.

Phil