S.P.Q.R. EZ10 for the AN Cast 10

I know, I know, I keep starting new threads. I am evil. :devilr: Devilishly so! hehe Ok, gotta nother new one. Will be a first I believe. Super easy to build horns for the Audio Nirvana Cast 10. Just threw some base plans together this afternoon. They look like they will perform very well. Sims look great. Very flat response. F3 of around 45-47 Hz. With room gain I am positive of 40 Hz. After all, it is a 40 Hz horn. Corner support will help but won't be remotely crucial. These things will go low anyway. I should have the plans up soon. Here are the teasers and a sim graph.

Tom

(EDIT)

Part 1
Ok, I thought I would add some information about why I designed these. I know many are not super advanced woodworkers or do not have the patience for more complex builds. Dave's Frugal line (designed with simplicity in mind) was sitting in my head as I looked at the Model III and thought, "well, that won't be easy if people don't know what they are doing". So, I decided to begin my EZ line of designs. This thing should be almost so easy it will build itself. Ok, maybe not but it isn't much in the way of parts or skill to assemble.

Part 2
I wanted a small enclosure for this monster of a driver. The an cast 10 is big and will go really low. One problem with really low and a big driver. REALLY FREAKIN BIG CABINET. I made a compromise and decided against a 35 Hz cabinet. So, the cabinet has, more or less a 40 Hz flare rate in a 1/32 scale horn. As it is a compromise design, it will roll t/l action in to compensate the bass down to an f3 of around 45 Hz. All of that being said, I wanted the enclosure small and it is small. I heard talk of an 85 inch BIB for this driver that won't go all that much lower than this horn, so this seemed to me a better solution. Not to mention the immediacy and energy of a horn in the bargain!

Compromise, compromise, compromise. What can you do? I hope everyone enjoys this one as I am really excited about it. I may have to build this next after the model II, instead of the model III.

Tom
 

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Scottmoose said:
Cool. What you have there is basically a variation on the Jensen Imperial cabinet. No bad thing.


???? Where can I find this? See Scott, this is what we are talking about when we thank you for your information. You have knowledge of the history that I do not. If you have access to a plan I would be interested to see it. Man, now I feel like I am reinventing the wheel. Ah well, such is life.

Tom
 
HA! I just found it. Nice. The only real difference is that mine is not a bass only horn. Oh, and mine is not upside down or right side up depending on your point of view. For anyone interested in what Scott is talking about, here is a link. http://www.geocities.com/loudspeakerguru/Jensen_Imperial.doc

Good, stuff, thanks for the complement Scott. Kinda funny how things are discovered again and again.

Tom


(EDIT)

I was just reading about the Jensen and it mentions that people using full range coaxial or triaxial drivers should flip the horn so the driver is on top. Hehe, my design is very similar. Thanks Scott!

TOm
 
I have been squeaking the design this morning to get better simmed FR plots. Here is a shot of the insides now and an in room FR plot. The FR plot is based on the front baffle being 20 inches from the rear wall which means the enclosure is 2 inches from the rear wall. You can see in this plot that we are hitting 50 Hz dead on and the F3 is absolutely 45 Hz. Good building guys!

Oh, and in response to the question about the imperial, though it is off topic, I don't believe it will work properly. The Imperial is designed with a 15 inch woofer or full range (coaxial in the case of past 15s) in mind. Your expansion won't be correct and though you might get something out of it, it will definitely not work as intended.

I just love the fact that it is only 11 pieces of wood. hehe. :D


Tom
 

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Harderror said:
Oh, and in response to the question about the imperial, though it is off topic, I don't believe it will work properly. The Imperial is designed with a 15 inch woofer or full range (coaxial in the case of past 15s) in mind. Your expansion won't be correct and though you might get something out of it, it will definitely not work as intended.

Why would the expansion not be correct? A horn taken as a horn is independant of the driver; the latter's cross sectional area is basically neither here nor there. So, the expansion of a horn itself would remain correct irrespective of the driver. I could drop an FE83E into a Tannoy Westminster, and that won't mean the expansion isn't correct. Whether the horn as an overall design would be optimal for a particular the driver or not is a separate issue of course.

FWIW, this roughly what you could expect from the AN Super12CF model in the full-sized, 96in tall Imperial. It's not ideal for the driver: the air cavity volume could do with being greater, but you should be able to damp out a lot of the midrange leakage.
 

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RE: The imperial with AN 12"

Oh, I was just having dirty little thoughts of the Imp. with the AN 12" and a pro 18" :devilr: To read Steve D's write up of them, you'd think anything would work in that guy. I have a soft spot for really big speakers(but no space to put them :( )

Back on topic, Tom you have to stop putting these great cabs out where I can see them. :) I've already have to much on my too do list.

I do wonder how far does this approach scale down? Could a simplified model II be done? I've seen someone scale down the imperial for two 6.5" Fostexs.

Uh-Oh, used up my smiley quota on this one.
 
Scottmoose said:

FWIW, this roughly what you could expect from the AN Super12CF model in the full-sized, 96in tall Imperial.

FWIW, you never ever, ever want to have a major in-room dip in the ~60-120 Hz BW where the heart and soul of bass reproduction lies and ideally out to ~300 Hz where the highest amplitude transients reside, though often folks under-size their amp so much that it can't reproduce the latter without clipping, so in this case a modest dip centered around 300 Hz is beneficial.

GM
 
No disagreement from me Greg. I just plugged it into MathCAD out of interest. Not ideal; having said that, I've seen worse too -have you seen the response of Fostex's 206 box? Not pretty.

FWIW, this is what I'm getting from a simple J-bin with the An S12 -big, but not of Imperial proportions (5ft tall, 20in wide x 18in deep). I'm not sure it'd be worth going much further with a big FR driver -probably better expending the effort on a dedicated woofer system handing over to something around 100Hz or so.
 

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