Evolution of the Tapped Horn

[GM]

Originally Posted by bentoronto

1. Strange, why are there often 3 impedance peaks measured? What are the driver impedance (cone motion) peaks towards the bottom, how do these relate to wave/length/phase, and how to these relate to sound output?

2. How do you account for the high sound output (comparable the the enclosure-reinforcing levels you talk about) but found far north of them from say, 120 to 200 Hz?

Many thanks for your help... I am sure others appreciate it too.

You're welcome!

There's actually four or more depending on its tuning, i.e. tuned to Fs (simplest) down to a 1/2 WL below Fs. Remember, these are basically 6th (or in a few cases, 8th and 10th) order alignments, so in its simplest form, #1, #2 impedance peaks bracket the pipe/horn's fundamental resonance (Fo) with #2, #3 bracketing its tuning frequency (Fc) and #3, #4 its HF corner tuning. There can be a phase inversion between each one or linear through them all if there's enough acoustic loading. Sound output is the summed responses of the two systems same as any driver/box loading.

The horn's gain BW begins where it's acoustically a 1/2 WL long, hence the two stage response of many of the alignments since they are too short/small.

GM