Tapped Horn for the Lazy and Impatient

[Jwsewell]

I have a woofer tester on my wish list.

 

[WaVeInFoRm]

Any one know how to digup an ole ole post by 'naudio' concerning a 25hz eminence definimax 12 tapped horn.. Im clueless of how to find it, n search won't work on my mobile..
..i remember i was in some stage of the collaborative th project and some mike fellow was building a simuler 30hz one.
I extended mine, as felt better for purrpuss desired.

 

[Jwsewell]

http://www.diyaudio.com/forums/subwoofers/97674-collaborative-tapped-horn-project-171.html

Post #1707?

Try this on google when searching...
Naudio 25 Hz Definimax TH site:diyaudio.com

 

[Jwsewell]

Here is the input information and frequency response plot for the model above. (POST #91)

Notice the 15dB dip at 90 Hz for 23(Dakota), my Ranger is smaller, I suspect I have this same suckout near 100Hz



Would it be foolish to try and "fill that dip"??

 

[Patrick Bateman]

Stuffing the TH could deal with the out of band peaks.

Unfortunately it can also reduce the TH's overall output.

If you're using the Alpine 8" Type R drivers, I've be tempted to go with a simple offset TL instead. Easier to build, less likely to have overly horrible out of band peaks.

Good advice here.

Tom Danley used helmholtz 'traps' in the very first tapped horn, but never used them again. I can only speculate, but I'd bet that he figured out that it's easier to tweak the geometry of the horn.

IE, you CAN smooth the output with fiberglass damping and resonant traps, but that also reduces your output. And with some careful juggling, you don't need them.

 

[Patrick Bateman]

Stuffing the TH could deal with the out of band peaks.

Unfortunately it can also reduce the TH's overall output.

If you're using the Alpine 8" Type R drivers, I've be tempted to go with a simple offset TL instead. Easier to build, less likely to have overly horrible out of band peaks.

I'm leaning this way too, for my current project.

But since jsewell is doing a tapped horn, keep in mind that the massive gain you get from putting the sub in a car can substantially flatten out the in-car response.

Here's a couple graphs of a horn sub in a car* and a tapped horn in a car.**

Car Audio | DiyMobileAudio.com | Car Stereo Forum - View Single Post - Small Tapped Horn For a Car

* the horn sub is a 'clone' I made of the autotuba based on pics online
** the tapped horn sub is a 'clone' I made of the TH-Mini based on the spec sheet

BTW you're part of that conversation too

 

[Jwsewell]

I'm really thinking of building both the tapped horn and the Autotuba, (two 8's 32" wide)

Tapped horn first since it fits my existing blow though.

 

[snappyturtle]

I'm really thinking of building both the tapped horn and the Autotuba, (two 8's 32" wide)

Tapped horn first since it fits my existing blow though.

the amount of bracing required to take that box (autotuba) to 32" wide is silly, and w/o cut sheeting it, likely an unnecessary pain in the *** to mill. better off building two separate boxes and coupling the mouths.

 

[Jwsewell]

the amount of bracing required to take that box (autotuba) to 32" wide is silly, and w/o cut sheeting it, likely an unnecessary pain in the *** to mill. better off building two separate boxes and coupling the mouths.

Thank you very much for that tip.
I had not worked out the bracing yet but was aware it needed to be done.