Bass horn ideas again. A possible build. Need criticism.

[jwc 876]

Spk-f. No harm done. Again. Appreciate ALL the input. Didn't consider it a hijack.

Ok

Put my idea aside a minute:

Reread BFD thread (which died by the way!)

Dana, you mentioned how he did the throat. I actually can't find exactly how he did the throat. The paper has the throat at 45 sq in. Did he do that? Also what slot cutout did he use. The most simple slot seems to be the 5" x 9". I assume with a "splitter" of the horn with the initial chamber depth being 2.5 inches deep, that would keep in line of keeping a 45 sq in throat right?

Now reading the AES again gives the area of the horn at point "B" being 94.55 sq in. The height of the horn in the paper is 37.95 inches. knowing these Kinda things I can figure out:

1) The flare coming from the throat

2) width of the horn at area B,C and D.

The paper does leave out a lot of stuff and there will have to be assumptions like exactly what size of splitter? How to Flare the port or rubber throat it.

Speaking of porting, look at these images and make comments. Should I really try and port the thing? I mean...how will know how long the active port need to be? Drone? Which to use?

You are right....can be built. Few unknowns.

jc

[jwc 876]

Are you in approval of this?

[jwc 876]

The slot on that one is more narrow and shorter and the overal height is slightly shorter.

[Guest " "]

jwcullison

I just unloaded my truck of some birch plywood, bought some new blades, and cleared out space im my garage. Do I approve, have to say yes, will be building a set soon.

These things are just so big. Might scale them down and go with smaller drivers. Still thinking about the final foot print.

[jwc 876]

ooooooo

Might be a paralleled project.

jc

[D-MAN 2]

3x10" drivers would be cool. But remember that you can't scale the mouth size down and still get the lows out of it.

DM

[Guest " "]

D-MAN

That's right.

But since the Jubilee is not a deep kicker, was thinking about a reduced footprint relative to the crossover points my active sub offers. Meaning it may not be a big deal to loose a half an octave as long as my sub's xover can be adjusted accordingly.

Seems like there may be an expectation of more robust mid-bass by using smaller drivers as well.

Also going to guess that my speaker building water stick could find a slightly larger horn throat area size that when coupled with a higher excursion woofer, may be able to mitigate the effects of using a reduced foot print enclosure.

[D-MAN 2]

Sounds like you have a good handle on it!

[bodcaw boy 2]

wow guys!! i must say that i am impressed. not only do you guys talk bass horns, you build them and that is not an easy undertaking. if i may, if it's okay, a couple of comments/observations:

folded horn vs straight ones, if done right, should only differ in the high end extension. by the very nature of the geometric shape of folded/bent horns, they have path length differences and that is the only thing, all other things being equal, that will roll off the top end.

fast flare rates at the throat (or rubber throats) are only necessary when the expected velocity of the air thru the throat will be such that distortion will not be negligible and there is no way to continue expanding at the intended lower freq flare rate. the bigger the throat, the less likely the air will be compressed to the point of going nonlinear. Paul explained it to me this way: a 2" throat of an 500 hz horn will achieve higher spls with than a 1" throat given a certain distortion level. now you want smaller throat areas because the spl goes up but not so small that you give up bandwidth. imagine a high wire act; keep it balanced......

the drone thing; hitting a man where his heart is at!!!!

as long as the area is expanding you should be in good shape. you can have two opposite sides be parallel as long as the other two are not. what is important is how the bubble is disturbed or contorted.

and as someone has already said, horns layouts/geometries do not scale; tried it a couple of times. hey what can i say, i was in a hurry. the fish went getting any younger.

roy

[Guest " "]

bodcaw boy

intresting comments.

Message recieved.

Thanks.

[jwc 876]

"the drone thing; hitting a man where his heart is at!!!!"

Roy. I guess that by that statement that the idea of putting the drone in your Jubilee is still something your heart desires.

I appreciate you looking through this thread. As you can see from the "top view" that someone put together for a "Jubilee Clone", there probably isn't enough room for 2 12" drivers and a 12" drone. The rendition above has the Jubilee slightly shorter than your AES paper.

jc

[Guest " "]

jwcullison

Thats the message I got.

I am going with this on my version, but I'm thinking it's going to need an independent exit path/channel arrangement to avoid any wave cancellation issues. As a result, there will need to be at least two seperators the lenth of the pathway.

Another drone placement consideration might be the top facing up and having the exit path travel down the back of the cab, and wrap around the bottom exiting to the front. The horn lenth for the drone would be about 5 feet. Having the drone exit mouth on the floor makes "bass" sense to me, and would clearly isolate the chances of any wave cancellation in the horn pathways.

[jwc 876]

That drone idea sounds complicated.....you kinda lost me on that one.

[D-MAN 2]

BigD's Jube throat layout.

[D-MAN 2]

If it were me, I'd go with the normal Klipsch style of throat channels... ONLY because there are less parts to cut.

DM

[bodcaw boy 2]

okay speakerfritter and jc,

any progress? what's the holdup? i expect to see a report in the morning on where you are at or why you haven't gotten anything done? .....whoa! thought you guys were doing research for klipsch.

seriously, let me know about the progress you guys are making, fellow lowoctaveacoustictransformerlovers.

roy

[jwc 876]

O Roy. I love that challenge. I built 4 types of speakers last year of my own design (non bass horn). I had one pair at Hope and I'm sorry you didn't get to hear em. You can see pictures of them by clicking on "photos" and look at the Pilgrimage pictures.

You know, I can't decide. I've come up with some of my own stuff and get boggled by other options of some "Knowns" that are out there. You see, the way I started this thread, was in a design I know I could build because I knew it from the ground up. Who knows what the results would sound like? But it would be fun.

Then on the other hand, I get some expert opinions with pros and cons...which is very good. Then my head just fills up.....then I can't decide. Cause once you start building...you've just bought yourself a lot of personal time to complete it. In the end...it could suck.

Now interesting. The plans for Jubilee "like" are out there. I fact, the one above with the "top view" makes good sense and enough info is there to build. But I spot out some differences than the AES paper. Starting with the height. The areas at point ABCD are the same though. And I think the throat is...not sure.

Also...and more difficult...Is to incorporate a port/drone in it. Waaaaay out of my league.

The one driver bass horn is easier for a rookie like me to understand mostly from start to finish. Will have to ponder some more. Not sure the non-ported dual 12 driver bass horn will thump me anything like your creation.

But it is one or the other. Either start cuttin and experimenting or I dial 1-800-buyme-jubilee.[]

jc

[Guest " "]

okay speakerfritter and jc,

any progress?  what's the holdup?  i expect to see a report in the morning on where you are at or why you haven't gotten anything done? .....whoa!  thought you guys were doing research for klipsch. 

seriously, let me know about the progress you guys are making, fellow lowoctaveacoustictransformerlovers. 

roy

I have been on the road all day today. Just go back. Let me do a little catchup before i start looking at the home work.

[Guest " "]

jwcullison

After my eyes stop spinning from driving all day I draw something out.

[D-MAN 2]

Roy, another ported-throat patent!

DM