kornny's project

Hey, I figured I would just post the stuff here.

I'll send up a sim later, the original is really worthless. It's the final sim that counts. Once I get the cab down, I'll run a new sim based on the plans in AkAbak, and modify things a little.

I am close on the fold. Just a small adjustment to get both curves to touch the edge in the right side.

This looks like it may be the way to go, with a slightly taller cab. We'll see...

A9X-308 & Penn,
The form factor is set. ~ 60"h x 45"d x 25"w. It is a 20Hz horn with a horn path of over 18ft.

The goal was maximum output to 20Hz 1/2 space at that form factor, with a little wiggle room. These will not be moved around, so portability is out. With the 4pack planned, 145-148dB should be achievable at 20Hz in 2pi.

The side goal was to outdo the previous folded horn design I folded for him. Pretty much the same goals there, only the driver was different, and it was only run to 30Hz. With the four pack getting a little lower.
http://www.diyaudio.com/forums/subwo...an-work-5.html

Fatawan,
It is using one B&C 21SW152 4ohm 21".

I do not want four 180deg corners if I can help it. With the next fold attempt I can get it down the three. I just need to tweak the horn path width some. If I could flip the H & D dimensions I could make the middle fold work no problem. It would be the best option, as the driver is in a compromised position as is.

Looks like it will end up this way. Only two hard 180s, and still up close to the front.

Anytime you put a bend in a horn you will alter the response. The key is to account for it.

It's going to be close, but it should pan out. I can account for the path length, but the acoustic resistance through the bends is a little tricky.

Ok, here is a demo of some things I am thinking about putting into the advanced AkAbak modeling series.

First of here is a simple TH model. I say simple in that it is what Hornresp or AkAbak will give you the normal way people are modeling them. This model contains ~40 sections, so it is pretty thorough. As you will see it still leaves a lot to be desired.

Ok, first up is the "normal" model at 28.3v.

Here is the Impedance

Finally, the Xmax Graph with both drivers.


Pretty normal stuff, right?
Now will will add in the additional acoustic resistance the bends can add at these higher SPL levels.
Here is the same horn will the bends close to the start of the same horn at the same voltage in.
FR

Imp

Xmax


Notice the xmax drop, and think about what this means.

Here are the FR graphs with the bends more in the middle, and then at the end with the tap.

Yes, it can explain it. There is also more there too.


This isn't a switch. This is another set of four subs. The Ciare OD horns should be nearing the building phase in just a bit.


I'm not sure which FR your are referring too. The stuff in the link all pertains to the Ciare OD horn. The FR graphs I have posted here are from another "real" TH.


Nope, this is not for a HT. Kornny has been very adamant about extension, so that is what he is getting. Four 40Hz horns of this size could have been playing in the 150s, but that was not wanted or needed.

As far as extension vs. sensitivity I do not follow. What do you think the sensitivity on these are individually? The TH is still up in the air, but the Ciare is in the triple digits.

To big for what?

You went with 6!

Pics!