Hi All
Does a Tapped Horn Affect the nominal impedance of the speaker like a Sealed chamber front loaded Horn does? if so, what is the best way to calculate the nominal impedance of a Tapped Horn sub to determine the best power amp(s) to use.
Thanks for any help.
Hal
Does a Tapped Horn Affect the nominal impedance of the speaker like a Sealed chamber front loaded Horn does? if so, what is the best way to calculate the nominal impedance of a Tapped Horn sub to determine the best power amp(s) to use.
Thanks for any help.
Hal
Model it in HR or Akabak, and you can look at the impedance vs frequency graph, and note the impedance in the frequency range you plan to use it.
Hal,
TH, FLH and BR all have impedance peaks above and below the nominal rating of the driver used.
Most designs actually have an impedance minima close to the DC resistance of the driver used, even though the "average impedance" could be above the speaker's nominal rating.
If an amp choice looks suspect for the DCR of the drivers used, pass, especially if the amp uses a lot of current limiting.
There are some two ohm rated amps that actually put out less power at 2 ohms than 4, the current limiting can make them "cough" when certain musical notes (or drum hits) correspond to the impedance minima.
Art
Thanks Art and Oscars
Art: Glad to see you're still going strong. I'm old enough to remember the Southern Thunder days 🙂
Art: Glad to see you're still going strong. I'm old enough to remember the Southern Thunder days 🙂
Old is just a state of mind 😉.
Every once in a while I hear from people that are still using Welter Systems cabinets built during the Southern Thunder Sound era from 1979 to 1992.
Other than bass drivers capable of double or triple the excursion than the drivers used back then, not much has changed in the sub world, with the exception of readily available free programs like Hornresp, allowing one to get a design pretty darn close to right before actually making sawdust.
Hornresp also allows comparisons of different designs, it is interesting that the single 18" BC18SW115-4 (15mm Xmax) Keystone tapped horn design I currently use can put out slightly more SPL (130+ dB) and go a bit lower than the quad 15" EVX-150 (6.4 mm Xmax) loaded L-4 we were using back then.
Weighs a lot less, and is smaller too.
That said, loaded with modern drivers, and enough power, the L-4 design would have a lot more output per cubic foot than the Keystone.
But I couldn't fit a pair of L-4s in my 5x8 trailer with the rest of the sound system, and I couldn't lift them by myself at my age 😀.
Art
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another thing to consider as well as the Impedance Curve of a Driver presented to an Amplifier is the Power Factor. Adverse Power Factors are more likely to cause early protection onset as the VI characteristics exceed the design load line of the Amplifier. Some investigation of this which I've done here: Power Factors for 'Speakers - Speakerplans.com Forums - Page 1 Unfortunately it seems that none of the design software packages really address this Mik
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