2" 223Hz tractrix horns

[jwc]

very nice work

jc

[awsjr]

Very nice! What do you think of the Fostex tweeter. That is on my list of tweeters to try.

the fostex tweeters are very nice horn tweeter...I had used both JBL 2404 and 2405 prior and while

those are very good too, I like the fostex...

thanks -Al

[Invidiosulus]

Erik Forker has a column in his spreadsheet that has 'stretch' values for the sides, since those are curved, but I think still along the centerline. If those could be calculated, you should be able to adjust/calculate for the angle of the top and bottom as well, so you could draw out the curves with the wood flat on your table.

Just to clarify,

Erik's spreadsheet calculates a horn that is rotated 90 degrees from what we would consider standard.

Thus his sides are our top and bottoms. as shown here http://volvotreter.de/pics/08010006.jpg

The column of numbers you should use if you are going to make a jig/pattern to cut your top and bottom pieces would be column C the "Sidewall (Stretched) [mm]"and the Height[mm](our width) measurements as your X and Y coordinates for the curve.

If you use the numbers from the "height"(our width) column and the Distance from mouth [mm]/distance from throat columns your curve will be too short once rotated to form the top and bottom.

If you were cutting the curved sides out of a solid block of wood on a bandsaw you would want to use the "height"(our width) column along with the Distance from throat[mm] Column.

This of course may only apply if you are using Erik's spreadsheet, I have no idea about other programs or utilities used.

-Josh

Edited because I'm a tard.

Apparently I was really out of it yesterday and got myself confused.

However, should be all good now.

[capo72]

What is that in your avatar that you are replacing, Oris w/ a full range? How does this compare? I have built these 2" tractrix @225 Hz and I like them, but now I want big round horns. BTW nice job!

Jeremy

[awsjr]

What is that in your avatar that you are replacing, Oris w/ a full range? How does this compare? I have built these 2" tractrix @225 Hz and I like them, but now I want big round horns. BTW nice job!

Jeremy

hi Jeremy...I remember your build...in fact after seeing yours thats when my project started...so thanks.....

yes Oris 200Hz horns with AER MD-3 drivers....I wouldn't say "replacing" yet.... although I am amazed by the sound from wood horn....

I will have to listen some more and set up the Oris again....if I had never heard the Oris and AER the wood horns would suit me just fine....

also if you were to compare my cost of materials for the wood horns (~$100) plus Altec 292 drivers (~$250) and the Oris/AER ($$$$.00)...well....

thanks -Al

[capo72]

Al,

Well, if you ever decide to sell the Oris /AER combo, let me know. It may be out of my range, but i'd like to at least know about it if you ever sell.

You did a wonderful job of prettying up your wood horns. Mine are in a box so you only see down into the throat, so no pretty for me. Thanx for sharing your project.

I think we need to get a compilation thread of all these DIY tractrix projects and sticky it.

Jeremy

[Invidiosulus]

Al,

Those are really nice looking [Y]

-Josh

[Dresden]

I'm always thinking about the proportion of sound coming from a driver on a mid horn and the horn itself, and I'm thinking that I'd like to continue working on building horn/driver combos that cut back the size of the horn and put more emphasis on the driver. Another way to put this is a bigger driver to horn ratio. This is one of the things I like about the 2" driver/tractrix horn idea for my Khorns. Taking the driver to horn ratio a step further means building a horn that is shallower and smaller but still keeps the 2' driver, much like the Martinelli horns that Mike K is using with his Jubilee bass bins. Going even farther means moving up to cone drivers for the horn, which probably means a big jump from 2" compression driver to 6" or 8" cone driver. Wouldn't it be interesting to cross the compression/cone technologies into a 3" or 4" midrange driver?

Greg

I've mentioned using a cone for the mid driver before (or upper bass). I've got four 5" Galaxy Audio speakers sitting here to test out, but I'm not sure if they are efficient enough.

Power handling: 100 watts RMS/140 watts max
* Voice coil diameter: 1"
* Impedance: 8 ohms
* Frequency response: 200-18,000 Hz
* Magnet weight: 40 oz.
* Fs: 140 Hz
* SPL: 92 dB 1W/1m
* Vas: .24 cu. ft.
* Qms: 1.34
* Qes: .38
* Qts: .30
* Net weight: 3 lbs.
* Dimensions:
A: 4-3/4",
B: must be rear or flush mounted,
C: 2-3/8",
D: 4",
E: 1-1/8"

I was thinking of 250Hz up, or even 300Hz. These things aren't expensive at all. ($37 at PE) They also make a slightly more efficient model with neodymium magnets for $49.

I'm quite certain Avatgarde Acoustics uses cone drivers for their mid horns. Their systems are quite expensive...irregardless of the fact that, personally, the drivers appear to be of inferior quality (when compared to numerous cone drivers I would attempt to use for such an approach).

[Marvel]

I'm quite certain Avatgarde Acoustics uses cone drivers for their mid horns. Their systems are quite expensive...irregardless of the fact that, personally, the drivers appear to be of inferior quality (when compared to numerous cone drivers I would attempt to use for such an approach).

Welcome to the Klipsch forums.

Quite some time ago I was looking at a 6.5 inch B&C with a phase plug. The link below is from forum member Dave Harris, who has made one using this very speaker, and it is looking nice... Huge but nice.

Bruce

http://forums.klipsch.com/forums/t/130479.aspx

[Al Klappenberger]

I started a 2 inch Tractrix horn, this is just a prototype for testing.

I have started a 2-inch Trachorn too. Bill Martinelli is working on a prototype for testing now too! It will be a 400 Hz horn directly interchangeable with my 1 inch Trachorn in the same frame.

An odd coincidence, isn't it? I also thought this forum wasn't for sales solicitation of products. I guess I was wrong! It's also odd that I am the only one who catches any flack about it!

Al K.

[Al Klappenberger]

That beast looks awesome. Can't wait for the sound results.

Is it possible for a horn to ever be... TOO big?

Yes, It can!

It happens when the mid-range horn and driver's frequency response extends so low that both the woofer and squawker are making the same sound at the same time withOUT time alignment. Then, a 1st order network will do NOTHING to provide a crossover since the horns do the crossing-over acoustically. If they overlap there IS NO CROSSOVER, just interference between drivers! Note what PWK did: Woofer goes up to 400 Hz and the K400 squawker goes down slightly below 400 to work with the A and AA networks 1st order filters. This is how a 2nd order network for the woofer to squawker cross combines it with a shoar slope cross from squawker to tweeter. Reference the Klipsch AK-3 network. It has a 2nd order woofer filter and an "elliptic" (pole placed) tweeter filter. The fact that it's not done completely is not relevant to the point.

I might point out also, that the solution with wide overlaping ranges is a crossover network that will have sharp slopes so as to direct each sound only to the driver best suited to reproduce it. To take advantage of the big mid-range horn the crossover must be at the low extreme of its range. It will be large and expensive. Now, who do you know capable of designing one of these? You could also cross it higher, at 400 Hz and waste the entire low frequency capability of the big mid-range? What if you have a Belle or LaScala with a woofer that can go as high as 600 Hz or more. Where do you cross that over?

KLIPSCH: Start putting a modern horn in your heritage speakers, like you do with all your other speakers and put an end to this sillyness!

Al K.

[Al Klappenberger]

I forgot one other factor. In case you haven't noticed, tweeter horns are a lot smaller than mid-range horns. Make a mid-range horn big enough and you won't have descent dispersion of the upper mid-range. If a horn can't be too big, why not run the Khorn woofer all the way to 20 KHz? A mid-range horn should be just the right size. Not too big and not too small. For the Khorn ,the correct size is 400 Hz with some safety factor. No lower. For the Belle and LaScala, 400 - 500 Hz is the right size. That is SMALLER, like the K500 in the Belle. NOT larger. Yeah, then there's coaxial drivers. The high section of those usually have their own internal high frequency dispersion devices and do not depend on the big mid-range horn.

Al K.

[Guest David H]

An odd coincidence, isn't it? I also thought this forum wasn't for sales solicitation of products. I guess I was wrong! It's also odd that I am the only one who catches any flack about it!

Al, you are correct. It has been made clear to me and other builders the it is not ok to solicit products on the forum. Amy Unger made that clear recently, maybe you missed the thread. This thread you commented on is over a year old and I suggest you go back and read the rest of the DIY article. Not only did I outline the build process, I also shared all of the horn info with others so they could build them for themselves as well. This horn was a one off project for JC, as is the BAT Horn.

I have started a 2-inch Trachorn too. Bill Martinelli is working on a prototype for testing now too!

I think you will be pleased with the results, I built a pair of 2 inch direct replacements for your Trachorn some time ago, and must say they sound very good.

Dave.

[Al Klappenberger]

Dave,

I think you see my position here. I try my best to stay clear of doing "sales" here. The problem is that when you point out a deficiency, it usually overlaps with stuff you are doing for that very deficiency. When you are actually SELLING these fixes, just pointing out the deficiency gets you pegged as abusing the forum. If you DON'T point it out when somebody asks, then you get bitched at because you didn't help! You can't win!

In the case of the 2-inch horn, I never wanted to get involved with a 2 inch, but that seems to be what everybody wants. I have no choice but get in and compete. The time when I could stay clear of it is over! I always believed a 2-inch horn was for movie theaters. Bill Martinell, who has been building high-end wood horns for years, says a 2-inch has an "airy" sound compared to a 1-inch of the same quality, I have to bow to his expertise.

In any case, what the market wants is what vendor must provide or go belly-up! The big fallacy is the old myth that bigger is always better. More is not always better!

AL K.

[ClaudeJ1]

I forgot one other factor. In case you haven't noticed, tweeter horns are a lot smaller than mid-range horns. Make a mid-range horn big enough and you won't have descent dispersion of the upper mid-range. If a horn can't be too big, why not run the Khorn woofer all the way to 20 KHz? A mid-range horn should be just the right size. Not too big and not too small. For the Khorn ,the correct size is 400 Hz with some safety factor. No lower. For the Belle and LaScala, 400 - 500 Hz is the right size. That is SMALLER, like the K500 in the Belle. NOT larger. Yeah, then there's coaxial drivers. The high section of those usually have their own internal high frequency dispersion devices and do not depend on the big mid-range horn.

Al K.

I remember being at PWK's house in Aug. of 1985. He had a Belle in the middle of his setup (all Walnut Oiled). I had the same mono center setup as he did, except that my Khorns (purchased when I was a poor 23 year old) were raw birch, which, of course, I used a LaScala in the middle as opposed to a Belle like he did.

So I asked him about the difference in the Midrange horns. He said, and I remember DISTINCTLY, that when he designed the K-500 for the Belle he concluded, after many measurements, "which led me to the conclusion K-400 was actually much longer than it needed to be."

So, based on that and personal experience since then, I agree with your comments.

Also, there are so many 20-30 year old large format drivers availble on the used market today at a low price that the DIY folks are buying them. Drivers that cost $600 and up are going for about $150 or less. I recently sold a pair of EV DH-1A's for $200 to another forum member.

Basically, the pro market has changed to flying arrays, and no one wants to hoist drivers that have "mud magnets" that weigh an extra 40-50 lbs per cabinet. Since NeoDymium is now the material of choice for lighter drivers, it make for some high perfromance drivers available on the used market to use at home, even though a 2" throat is overkill for the home speaker, one does enjoy amazing clarity, efficiency, and ridiculously low distortion in the process. Especially those of use who still want to do a 3-way system with a supertweeter at 6 Khz. or so,which is where the driver/horns naturall roll off in a CD horn design. I don't know much about network design, but by using single caps with driver mass rolloffs and horn cutoffs, I'm getting some very dynamic natural sound. I have yet to try 48 db/otave slopes from my Behringer. Once I do, I may commision you to do a custom ESN, since so many of my audio buddies here rave about them, but it will have to wait until I have the cash to attempt such a thing.

Witness the 2-way, custom EQ's Jubilee, which would fall short the perfromance goal if we adapted a 1" driver to the K-402 horn.

[DrWho]

Is it possible for a horn to ever be... TOO big?

Yes, It can!

Only when implemented by an incompetent designer.

Frequency response is not the only parameter that affects audible perception.

[Al Klappenberger]

Another "expert" heard from!

Al K.

[Deang]

"Is it possible for a horn to ever be... TOO big?"

"It happens when the mid-range horn and driver's frequency response extends so low that both the woofer and squawker are making the same sound at the same time withOUT time alignment."

You disagree with Al's response? I don't, and I don't think Roy would either. The big horn/driver combinations allow for a lower crossover point which most are taking advantage of -- and this requires steeper slopes.

[Deang]

Now Al, you've been around long enough that you should be able to recognize baiting when you see it!!

[Pete H]

"Is it possible for a horn to ever be... TOO big?"

"It happens when the mid-range horn and driver's frequency response extends so low that both the woofer and squawker are making the same sound at the same time withOUT time alignment."

You disagree with Al's response? I don't, and I don't think Roy would either. The big horn/driver combinations allow for a lower crossover point which most are taking advantage of -- and this requires steeper slopes.

I would like to ask a specific question, regarding these comments, to Al and Dean and anyone else that wants to chime in. I'm taking a set of Cornwall 2's that are in need of cosmetic attention anyway, and going to beef up the cabinets and create a Cornscala. So what's the right size mid horn to build for this type of project? In my very unexperienced mind, and this is the only way that I can describe what I'm trying to accomplish with this project, I want the 3 individual drivers to produce the most accurate sound they are capable of, within their range, with as little distortion as possible. I'm going to use the same woofer and tweeter (K34 E and K 79 K1) so my choices are limited to the mid horn. I'm not worried about fitting everything into the original cabinet if the best mid horn choice needs to be mounted on a new, or additional motor board. Again, I will qualify my lack of experience by saying that in my mind, it doesn't make sense to have 2 drivers producing the same sound over a large frequency range, if that makes any sense. Don't hammer me too hard on my lack of technical knowledge. [:$]