The Smallest Tapped Horn

[Patrick Bateman]

Here's the predicted impedance, along with the measured impedance, of the sub from this thread. If you've built a tapped horn and you don't see multiple dips in the impedance plot, you're doing it wrong

The dip at 50 hertz corresponds with the tuning, and excursion will be very low. Below that, it's going to unload, so watch out for overexcursion

[Brian Steele]

Originally Posted by Patrick Bateman

The pic above shows the predicted response of the subwoofer I've documented in this thread.

Why are you modelling in 4PI space?

[Patrick Bateman]

Originally Posted by Brian Steele

Why are you modelling in 4PI space?

I've switched to 2pi, makes it easier to work with Akabak.

Also, I've updated the plans, because the P-Audio woofer is no longer made. The new plans are the same as the old plans, except they use a woofer that's readily available from Parts Express, costs about half as much, and weighs less. How's that for progress?

Audio Psychosis • View topic - One Hundred Dollar SQL Sub

[Brian Steele]

Originally Posted by Patrick Bateman

I've switched to 2pi, makes it easier to work with Akabak.

Also, I've updated the plans, because the P-Audio woofer is no longer made. The new plans are the same as the old plans, except they use a woofer that's readily available from Parts Express, costs about half as much, and weighs less. How's that for progress?

Audio Psychosis • View topic - One Hundred Dollar SQL Sub

That's a bass guitar driver you're suggesting as a replacement - are you sure it's up to the task of doing low frequencies with low distortion?

How about this one? B&C 10CL51 10" Neodymium Woofer | Parts-Express.com

[Patrick Bateman]

Originally Posted by Brian Steele

That's a bass guitar driver you're suggesting as a replacement - are you sure it's up to the task of doing low frequencies with low distortion?

How about this one? B&C 10CL51 10" Neodymium Woofer | Parts-Express.com

That's a better choice I think. I opted for the Eminence because it's widely available, and Bill Fitzmaurice tends to choose good drivers for horns. (He uses that driver in some of his designs.)

The stamped frame 12" woofer from B&C looks good too. Not much more money, and offers a lot more displacement.

Also, I found a mistake in my folding scheme. I don't think it will affect the response much, but it *will* make it easier to build if you fold it differently. Details here:

Audio Psychosis • View topic - One Hundred Dollar SQL Sub

[Brian Steele]

Originally Posted by Patrick Bateman

Also, I found a mistake in my folding scheme. I don't think it will affect the response much, but it *will* make it easier to build if you fold it differently.

The fold works (see the THAM15 thread) but, as I found out, you need to be pretty anal about the bracing in the first part of the fold, to avoid measurable and audible distortion due to panel flex (particularly as one of those flexing panels is in contact with the ground).

My "Dogfood Duct" mod can be used to deal with the sharp dip that sometimes appears 'round 150~200 Hz, effectively extending the effective bandwidth of the horn. The mod lowers of the 'Q' of the horn's rolloff at the lower end a little, but this might actually be a good thing, depending on the intended use. It's similar to the "mass-loading" that Taterworks brought up in that thread (which to me sounds like the alignment is just being converted into a big 6th order series-tuned BP box), except that the panel is located within the horn itself, rather than at the mouth, and there's little or no drop in efficiency, and more important, the size of the horn doesn't change .

[viki_v2]

Originally Posted by brsanko

Well here's some pis of a very small tapped horn I designed and had built from a 5" driver from a JVC HTIB system. I will post the design I came up with for the TB 6.5 as soon as I draw it up again. I sell my computers and I have lost a few HDDs lately so I will have to model it again. As soon as I have the $50 for one of those drivers I will build it up for sure.

Hello brasko,
I yhink I have a similar Jvc 5" Sub. can you share plan for tapped horn you made for this Sub

Regards
Viki

[hm]

Hello i get a measurement feedback for my SUB FANFARE double TH,
eliminates the lowest bass reso impedanz, no peaks over 100 Hz, for using up to
250 Hz.
measurement in a very large room, my own passiv in 22 qm,
take a look:
fanfareFB
fanfaremess