I want to build the perfect wo for two 10 inch subwoofers.  My plan so far is to build the 24x36 version and adapt it a little. I really like Circlomanen's curved flares, but I have no idea how to lay out an exponential curve.  I was also planning on building the sealed chamber to the correct size of a fourth order bandpass for the subs.  I think these two things will improve the basic WO design, but what other things should I attempt to add?  I want a good all around box, fast accurate and loud.  I believe in the WO after having built three, I just want to specialize it for the subs I have.

I think I might lay out a curve like yours, only keep the straight exit, where the mouth of the original wo is.  I remember you saying the curve is made of a masonite type material right? is it doubled or tripled up?

Okay I think I got a design for a perfect WO using 12s:


Same dimesnions as the ten inch version for starters, except angle the top so that the 12s can fit in the baffle.  This way the 12s have an air impedence the same as the 10s, which should provide for a higher pressure wave. Include the exponetial curve to increase efficiency, I think we have a winner. Plus the horn/transformer has a highjer increase in area.

If someone builds it and it works, subtracting from the heighth will allow for a 10 inch version.

Looked a little closer today and with some extra information the dimensions are nearly square not rectangular.
My eye picked up on a 2 inch differance, so it is only slighty rectangular.
A two inch difference it appears can make an enormous change in sound.
That and possibly the horn ( modified flow ) combined with it makes all the difference. I wanna see someone duplicate the effect several times. I am going to use a partial modified design to see if I can break it down. That will take a little time with my schedule.

j_rock777 if the top of the cab modified like I have it pictured in my head, Would'nt your beer keep falling off it you were'nt paying attention.
Kinda useless don't ya think?

That is one cool design. I would really like to see a picture or diagram of that if you get it going.

heres the best I can do on the paint program at work:



same concept except it keeps the horn the same as the original version except the curved flares...

Quote:


I have a whole lot of them. Mostly too wierd and fucced up, but once in a while I get a good one.

What I am looking for is things that have worked in the past, like Circloman's curved flare.  And then combine them into one ultimate WO.  I really think I may be onto something with the slanted top for higher compression at the horn throat, so I might just build one quick.

[quote author=gexter  link=1121529118/15#19 date=1124363573]Is it not possible if you try to include too many mods that it will depart to far from the design to work well?...............................................

.........................................As far as Ideas "build it and they will come"
Power to the Modders [/quote]


Very possible gexter, but the worst thing that happens when you change more than one thing at a time is that you don't know how much any one thing may have helped or hindered your design. Suppose you have a great idea and a bad idea incorporated at the same time and it improves performance because the great idea was so helpful. But, if you had left out the bad idea the design would have been great. Now compound your error by giving credit for the improvement to the bad idea and your next design includes more of the bad idea.....and you don't know why it doesn't work. Whoops! So, you're right, it doesn't work as well to alter too many things at once.

When I built my first 2 WOs I stayed as close to the design as possible. Then after a few tests I altered the port area mainly because it was either flexing under load or too sharp of a turn and adding harmonics to a pure sine wave. At first I temporarally added a corner filler and got an improvement but I still had some resonance, so I reshaped the port area and doubled it. Then most of the ugliness was gone, but I had a different harmonic become more noticeable. (That's when it feels like your hair is turning gray or falling out in my case.)
After much further goofing around (can't really call it testing this time) I discovered that the 2 sides of the pressure wave were actually out of phase to the point it was audible, usually meaning the horn flares too rapidly in some area. At that point I got out a microphone and some headphones and put the mic inside from the mouth at different positions to try and determine how to fix it. 2 or 4 mics and an o'scope would have helped, but I no longer enjoy such luxuries. After moving a 12" board around the second turn for a while I found the spot that was losing velocity and blocked it up. ......VOILA! No more harmonics in the signal!

I'm not prepared to say that I have improved the design, but I will say my WOs sound much better than before I tweaked them. I will also point out that my next pair will be built as close as possible to the original design, but I have a few tricks up my sleeve in case I need them.

"If you build it they (ideas and friends) will come" It's getting them to GO that's the trick.

Dirtdawg  "If you build it they (ideas and friends) will come" It's getting them to GO that's the trick.

So true

It's a kind of one way thought Johannes and no concrete reason.

I feel that the sealed volume has to be at least big enough or maybe a little bigger, in order to get maximum output from the driver. I also think that sealed volume specs are the absolute minimum. ( this refers to a sub )
So a little smaller= bad a little bigger = not as bad.
When I have too little volume it makes a big differance in low end. I feel that I can manage the volume that may be too big in a full range or sub with the XO method. Plus with a basic box I have been able to shave it.
I can stuff a whole lot of dacron in the chamber in mine and it sounds better just less output.
But I have no specific reason and have not done enough testing to be absolutley sure.

Dirtdwag wrote:
"After much further goofing around (can't really call it testing this time) I discovered that the 2 sides of the pressure wave were actually out of phase to the point it was audible,"

I was not going to worry about a Cm or two while I construct my moddified horn. But now I am going to make sure it is as close as I can get it.
I am using the basic box that I built and adding a smooth horn in the very start of the horn and narrowing it. the spaces left between the new narrower horn and the old will be filled with expanding foam to resist flexing. I think this is better than nothing at all but an empty space.

Hair falling out Dirtdawg? you still have some? you have knowledge and hair? I am jealous

Honestly I am learning the science from you guys more each day  and learn why things may or may not work. I have learned so much over the last couple months I am at the point I can really make really big problems for myself.  :-*

I like everything except #3.  Wouldn't the waves then rebound somewhat after hitting the wall on the other side, instead of being guided down its length.

first, whos John? hehe I am Jerick....

Next, it isn't that big of a change but you get a lip of expansion right at that point, I would rather sacrifice the decrease in expansion rate at that point and not have a point jutting into the wave path.

Perhaps incresing the height of the second triangle you added next to the bottom original triangle would alter the angles enough to keep the same rate of expansion around that turn?

The main question I have is wether or not it is better to have many small angled bends or one smooth curve like Circloman's WO?  I believe the curve would be better, but that is based on the designs of high frequency horns and the like.  Nobody really has designed a well raved about folded horn such as Steve's.  

I still think that for a 12 inch version, tilting the top so that the corner where the waves are inititally compressed is the same area as a ten inch version would prove to be a significant increase in output.  I may try using the wasted 10 inch version I have sitting in my garage and tilting it down to fit some 6 inchers....

Quote:

This makes a whole lot of sense to me.
My small WO did sound very clean and had very little higher harmonics, but my large WO that is very much like the original WO but with a little longer horn extending all the way out to the sides has a lot of higher harmonics and distortion.

I beginning to think that those curved parts are a lot  more important than I realised from the beginning.

My freind built a scaled down WO with two 6,5 inch drivers and even if it could play realy loud, it dident sound as good as my small one.

Its time for some serious thinking about how to build one with perfectly rounded and smoothe expansion of the horn. No sharp bends at all. The port should be fireing straight down into a slowly turning bend. It should not start with a 90 degree sharp bend.

One more thing I strongly belive in, is making the mouth as large as possible. Efficiency and dynamics are all about radiating surface. A WO with four 10 inch woofers and 24 inch internal height wil probably have something like 9 db higher efficiency than a normal WO, mostly due to a larger radiating surface and higher acoustic radiating impedance, loading the drivers a lot better thereby lowering the travel and the distortion for any given spl. And increasing the powerhandling a lot.

Quote:


Thanks Dirtdawg!!!  Thats clear to me now. Very intresting and usefull.
Now I have to redesigne my WO once again..........

Happy Johannes with a lot of new tricks up his sleeve!

What about a straight WO. If one only wants to use it at home it doesnt have to be 36 x 36 x 13,5 inches, since it doesnt have to fit in a car. It could be straightend out and become 30 x 50 x 13,5 inch where the drivers are at the bottom and the mouth at the oposite side. Sure it will be ineffective use of the internal volume but to me thats less inportand than the SQ.
It would be nice to not have those turns and bends and angles.



??? ??? ??? ??? ??? ???

Quote:


Of course the horn must have an increasing rate of expansion but there doesnt have to be any bends on it.
Straight as in not queer...... not bent I mean.
Just a long gradualy expanding tunnel going from the compression chamber in a straight line towards the mouth.

[quote author=Circlomanen  link=1121529118/30#36 date=1124497627]


Straight as in not queer...... not bent I mean.
. [/quote]

Is that a joke? ???  because I am laughing  :)
And if it is not, Whoops!  :-/how terrible of me

Does not the bends help eliminate the High freq content that may be there?
Of course less than 45 degrees would be nice

Sorry  DirtDawg I must be blind!
All I see is all horn starting at the bottom of the K slot. I think the filter is in the behavour of the driver in relation to the K slot and and its interaction of the front wave out  and into the horn
( the sum of the unique air flow)

If you smoothed everything out in the WO and it was a hard reflective surface you lose the simplicity and some of the flexibility in the design, In the bass version anyway.

You would require damping in the Chamber that loads the horn to take care of some of the nasty sounds before you load it into the hard smooth reflective horn.

just a thought and again just a feeling

Feel free to call me nuts everyone else does!
Thats why my wife runs the people side of our home based business! and I just do my regular job.

PS you guys are cool!!!
Too bad Johannes thread disappeared there was a lot of inventive thought there.
I figure even the worst idea has the possiblility of some merit.
Hows that for poltical double speak!

Quote:

Since the WO is part bandpass box it should not be any hugh problem. The WO already has a quite wide frequency responce, being a BP, and I think the smooth straight version should be a lot more smooth sounding in the highbass and midrange.
Thats my guess.

Quote:

Flexibility??

Johannes

[quote author=Circlomanen  link=1121529118/30#41 date=1124552830]

Hey Dirtdawg, you should  post a warning in advance before you post something like that. Thats definitly tripple X rated.


[/quote]

Hey Circlomanen,

You are warned! Almost every time I stick my head in these Decware forums I get "excited" about something. Lately I've needed several sawdust bathes. Skip the cold shower.

P.S. I wasn't the first to post that titillating image.

This is what I had in mind when speaking of a straight WO.


Quote:

Pics??

"Circlomanen flare"!

Nice! I Think that should make a lot of difference. You might want to narrow down the throat a bit. 20-22 mm worked very good for me. I think the way the cable crosses the throat area can disturbe the airflow and create turbulense.

Seeing forward to some listening impressions.

Johannes.

So Gexter, whatever happened to this build? Did you start another thread about it and I snoozed it?

I wouldnt expect any foldedbasshorn to reproduce anything above 120hz. 100% of posts ive seen say that vocals sound 'funny'

Why not make HALF a WO,without any bends in it,to troubleshoot and fiddle around with it adjusting throat area etc.


Circlomanen :
two links on my site for you.

http://www.geocities.com/xobt/basshorns/basshorns.htm



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http://www.geocities.com/xobt/flow_mod/3hz.htm

???