diy 20 Hz tapped horn plans

[slisgrinder]

Any good diy 20 Hz tapped horn plans that are relatively easy to build like William Cowan's 18 Hz tapped horn?

 

[FlipC]

Didnt you just answer your own question?

There are quite a few if your looking for low SPL. IE non PA usage.
What SPL do you want to hit?

 

[slisgrinder]

yeah, william didn't post plans for the 18 Hz, only the 30 Hz... my SPL requirements are ~125+... I am going to build atleast 2 THs ( one in the front and one in the back)... possible?

 

[GM]

There's a number of drivers that either singly or in multiples will cover your BW/SPL goals, so what's driver and space 'budget'?

GM

 

[jbell]

You'll exceed xmax above 30volts, but this gets you very close (within a db) of 125 in an under 300liter cabinet, in a corner from the lowly 55-2421.

 

[slisgrinder]

Thanks for the horn resp parameters but I am a complete n00b at horn resp and when I select tapped horn from the driver arrangement selection I don't get the same screen as you do...i have attached an image...if anybody else has plans please feel free to share...

 

[slisgrinder]

wait, I got the parameters correct and everything is correct, but the parameter "TH" which is in red only shows a value of 1...what am I doing wrong?

 

[slisgrinder]

In the attached image, the TH parameter only shows a value of 1...please bare with me since I have never used horn resp before...

 

[FlipC]

Under Tools drop down.
Select Driver arrangement. Input 2 in parallel. Less you want to wire the cab in series. Then put the 2 there.

Post up the amount of space you want these
cabinets to take up and someone will whip you up something. I am sure.

 

[slisgrinder]

Thankx...If I wanted to design my own tapped horn, what do I need to take into consideration? I was reading up on Tom Danley's white paper on tapped horns and found that the length of the horn needs to be a quarter wavelength of the low cut off frequency (so if I wanted to a 20Hz horn, then the length would have to be 169.5 inches) so what about the mouth and the throat of the horn? how do you calculate that in reference to the length of the horn?

 

[Don Snyder]

Chris8sirhC and Layertone have built copies of my Lab12, 20Hz horn. Check them out.

 

[FlipC]

Ok
Do you realize HOW big that is?
Also - since this is for HT and not PA. You get to cheat a bit. IE If it can/will go along 2 planes (wall and floor) model in 1 Pi. If you can stick the sub into a corner model in .5

Start with a driver.
Look for one that has an Fs about 30-35 Hz. Input it's parameters into HR and then go to Tools-Tapped Horn Wizard (Ctrl+H). Bottom left drop down choose response. Start playing with the sliders after that. This will be the easiest way for you to design one yourself. Countless hours later and wolla.

At the end
HR will give you the data you need. You then figure a folding scheme for said data.

 

[lawbadman]

Don, do you have a link to the Lab12 project/plans?

 

[Don Snyder]

http://www.diyaudio.com/forums/showthread.php?t=143714&highlight=layertone

 

[Chris8sirhC]

The one I and one other person have built covers down to 20 hz and two of them will definitely meet your spl requirements at 20hz. It will do much more than that at higher frequencies. Its on the main collaborative tapped horn thread. It uses the very high quality, yet low price, eminence lab12 driver.

 

[slisgrinder]

Kewl, Thanks...and LAWLS on the insanely braced Lab12...

 

[slisgrinder]

When I am looking for a driver, I am supposed to look for on that has an Fs of 30 - 35 Hz. Is that necessary for all tapped horns or is that just for my case?

Chris, were you referring to this.

 

[slisgrinder]

So how am I doing? I am trying to aim for flat response right? so Is this what its supposed to look like? Its based on the Lab 12 Driver...

 

[slisgrinder]

or atleast am I on the right track?

 

[MaVo]

or atleast am I on the right track?

TBH I dont think you are, looking at the posted graph. Check the collaborative tapped horn thread for all the info you need and alot of good simulations, plans, etc.