Another tapped "horn" ?

[zobsky]

Originally posted by GM
Hmm, guess I misunderstood the Q.......... click the EDIT button and now the Tapped Horn Wizard is highlighted. See HELP pg. 9.

Thanks, I fixed it . You MUST specify 3 sections for the tapped horn option to activate. Additionally, while fiddling with parameters, Hornresp accidently datafilled my Vrc to a non - zero value thus disabling the tapped horn option.

Hope this bit of info helps others.

[jamikl]

I looked at this one when you mentioned it several weeks ago. I wonder how it would perform with the Karlson slot instead of the port.
jamikl

[moray james]

make a cabinet with the last two feet of panel above the open mouth area exchangable so you could play with tapers or if you choose just leave it solid. Dave (planet 10) is playing with tapers on a BIB in the IBIBK thread below. iBIBk developement thread.

[phase_accurate]

As feared it seems only usable at the two frequency extremes. Inbetween there is a 10 dB dip according to Hornresponse.

Regards

Charles

[moray james]

perhaps you could check with David McBean to see if Hornresponse will actuall simulate such a horn properly.

[Tom Danley]

Hi Phase accurate

The configuration you posted would be a Tapped Horn, if it were tapered.
It could have flat response if it were “large enough” and you got all the acoustic and driver parameters right.
I found the “Tapped horn” while exploring the reflected signal within the full range coaxial horns I design for work and thought how can I use that.
The Tapped horn works because the acoustic impedances all (when everything is right) all compensate each other, the dip between the first and second peak on a normal “too small horn” is gone.
Those peaks in a conventional horn reflect the changing load presenter to the cone, they correspond to peaks and dips in the electrical impedance and that governs how much power is delivered vs frequency.
Where the dip would normally be, now both side of the cone radiate fully additively within the horn and that load is present in the impedance as an increase in delivered power.
I don’t know if the link works at work (a new web site sigh, I liked the old one) but there is more of an explanation in the White paper (which also has a “phase accurate” horn too)

Anyway, when everything is right, compared to a conventional horn, for the same size, one can make either a smoother response horn or one with the same sensitivity but lower cutoff, or a combination of both, when the horn is “too small”.
Personally, I think the prior art devices, like the Klayman, Jensen transflex aren’t in use not because of a secret plot to deprive people of bass, but because they all have uncontrolled resonances which sound icky.
Don’t forget, an advantage of a horn is that it has different acoustic impedance at each end, the Tapped horn has a third node which is also variable.
Connected to these is the driver at two of those and radiation resistances driven by the variables set by driver parameters.
What your doing in a sense producing a source which conjugates the load, if that is “near perfect”, you get a nice response and significant sensitivity increase over the driver as a direct radiator and similar increase in maximum output. This can be as much as 10dB or more.
Once the horn is properly large acoustically speaking, the Tapped horn has no advantage however.
Best,

Tom Danley
Danleysoundlabs.com

[phase_accurate]

Hi Tom

I do in no ways doubt that a tapped horn as such works well (you are the master of bass reproduction after all). But the places where I intended to tap the horn seem not to be the best suited ones I have found out after a while.

As a chartered EE I know that in RF one can do transformations and compensations with many kinds of stubs and the like. I was always convinced that this must be feasible with horns also. I am not knowledgeable enough that I had come up with such a thing by myself however.

I am aware of your unity horn design and it's transient properties and I appreciate your attempts for improved transient reproduction in live-sound.
This design would be tempting for a home system as well - its SAF is rather low unfortunately !

Regards

Charles