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yggdrasil
04-11-2005, 12:26 PM
From other posts on this forum I have gotten the idea that it is possible to improve on the H91.

So I have found some info on the smith-horns, and with help from Widget I tried to resize them to 1200Hz.

I have also made a prototype from MDF, thinking that I would have to do this many times.

Here are the construction drawings used.

yggdrasil
04-11-2005, 12:28 PM
Some pictures of horns and adaptors.

yggdrasil
04-11-2005, 12:29 PM
Have not been able to try them much. Family you know...


First impression is H91 - goodbye.:D

It will be a hell of a job to redo the baffle...

Ian Mackenzie
04-11-2005, 01:50 PM
Nice work.

Very tempting, how did you craft the curves..with a router?

About the baffles..been there done that...LOL....messy and it tends to be one way trip. I have to say the 2397s were fun but tended to take over at times according to my neighbours. Used correctly however they are most transparent, open and non sounding horn.

Don't panic, I am not going to hack into the 4345's (yet) next on the list is is quad amping and 275nd drivers.

I think an array of 2397 style horns would be very interesting, say 250-800, 800-4000, 4000-daylight.

Ian

Mr. Widget
04-11-2005, 02:31 PM
Very nice work!:thmbsup: I guess if you like them as much as hoped you may want to try a crack at them in a nicer wood. I may have to bang out a set and get some measurements of them....:hmm:

Widget

Robh3606
04-11-2005, 03:34 PM
Those look nice!!!

Rob:)

yggdrasil
04-11-2005, 04:46 PM
I crafted the curves in two steps, and there might be some problems with my english now, but I'll try.


Step one I used a cutter to give the edge a 90 degrees curve with the base lowered 4-5 mm.

Step two I used an angle grinder with a 40 sand paper on to smoothen the transition. Next time this step will be done with a band grinder because I have never ever seen so much dust. I was totally white afterwards.

I have had a few minutes listening to them today, and I can say for sure that this is a huge improvement.:D

Will have to make a pair that is more representable. The rest of the speaker is in pine veneer, so maybe pine is a good solution. Will have to think about it for a while, at least a day or two.

aust-ted
04-12-2005, 12:25 AM
I have communicated this to Johnny privately but as I am no expert on Smith horns so thought it worthwhile to canvass publicly. While the horns themselves look great, I am not sure the throats are optimal. The adaptor board has a 1" circular hole which I would guess to be about 1/3" thick. It is then mated with the a sort of rectangular hole which Johhny has somewhat modified to fit with the 1" hole. Would it be an improvement to also shape the hole in the adaptor board so it has no discontinuities with the horn throat?

This arrangement is quite different from the JBL 2328 adaptor. Not sure what type of adaptor Westlake use on their horns. And Widget posted details of an alternative adaptor, he designed, some time ago.

I understand the throat design is very important especially for HF response. Can anyone, perhaps Widget, advise on this aspect of the design.

Regards
Ted

PS Johnny, might also be helpful to paint the inside of the throat and adaptor board with a hard varnish or epoxy and sand to get a smooth finish.

Mr. Widget
04-12-2005, 12:40 AM
I understand the throat design is very important especially for HF response. Can anyone, perhaps Widget, advise on this aspect of the design.


PS Johnny, might also be helpful to paint the inside of the throat and adaptor board with a hard varnish or epoxy and sand to get a smooth finish.

Two good points!

I was surprised the modification to the horn was necessary. I thought it was going to be made 2.54cm tall and not need to be eased. I think this could work well none the less. I do agree that I would try to minimize the mounting plate thickness by using an aluminum plate, but this configuration could work very well as is. Based on my experience, I would expect it to work better at the upper frequencies than one with a 2328, but loose some of the lower frequency performance. As long as there are no discontinuities the HF performance should be fine.

Widget

yggdrasil
04-12-2005, 02:25 AM
I have enlarged the throat area and transtion in this drawing. As you will see when laying the driver throat on top of the horn throat there is actually a very small transition needed. It may be significant with regards to high frequencies, I just don't know. What I do know is that when all these parts were finished the needed transition was very small.


The mounting plate / adaptor is 14 mm thick.

Think maybe I will make new and thinner mounting plate / adaptor later, but for now, living in a metric country, I was unable to acquire 1/4" flush screws!

Actually I made one mounting plate / adaptor on sunday, very eager to get the first listening experience. This was kind of disaster with a rough, uneven inside. After acquiring new tools yesterday I was able to make a better mounting plate / adaptor. The first version gave a hint as of what these horns can do. The second version was a major improvement to the higher frequencies.

Will do testing shortly, but - I still have phenolics. I have one d16r2425 that I can put in for the test.

Steve Gonzales
04-12-2005, 02:40 AM
Well done Johnny!. I want to tackle this project too. Thanks for posting your results.

jandregg
04-12-2005, 06:17 AM
Very nice. I have been thinking about a similar project, although far into the future. Please post your progress. And thank you for sharing.


John

yggdrasil
04-14-2005, 05:21 PM
BEAUTIFUL!!!!:D :D :D

Have been listening a little now and then. I can't find words to describe these beauties.

Won't have time to do measuring until sunday. My wife is 40 and having a major celebration on saturday. Any more speaker work now and I'm dead...:banghead: Have you ever got the feeling - my wife don't understand me?

yggdrasil
04-18-2005, 06:12 PM
Today I finally got the time to do some testing.


Testing equipment is far from adequate. Will have to get a decent mic and software. Probably also better hardware for signal generation.

Here's the results with phenolic diaphragm.

yggdrasil
04-18-2005, 06:14 PM
And here's the result with the titanium diaphragm (d15r2425).

yggdrasil
04-18-2005, 06:25 PM
I run this test on my laptop with a demo-version of WINAIRDD.

The titanium dia's are rolling off earlier than the phenolics?

The results were checked on a Klark Teknik real time analyzer with a test microphone, showing the same results, but actually they were readable.

Phenolics -3 to 0 db from 800 to 8000.
Titaniums -4 to +3 db from 800 to 8000. (-5db from 400...).

Tried the signal generator on another software, but with that software the resulting curve was only flat from 1.6K to 4K measuring on the Klark Teknik. Did not have the cables etc. to use the Klark Teknik as a signal source.

Mr. Widget
04-18-2005, 11:25 PM
Did you ever get a calibrated mic? I would bet it is the mic and not the horn that is HF limited and perhaps even affecting the frequency response curve as there really should be a radically different curve between these two above 8KHz.

Widget

Ian Mackenzie
04-19-2005, 12:23 AM
Johnny,

I use this program...but user beware.

Did you make a calibration curve with the cables and everthing in the loop ie from the souncard out to the amp and then back to the input of the card?

Second, I always Gate the time response to get rid of the room effects and measure at 1 metre, any closer and you get proximity effects off the mouth of the wave guide and will lead to false readings, and use 44.1 khz sample rate and 2048 or 4096 sample length...your response about 10Khz is chopped.


Below is an example

Hope this helps.

Talk some more on the weekend.

Ian

T

yggdrasil
04-19-2005, 03:25 AM
No calibrated mic in the computer setup.

I saw a Behringer mic at parts express, think maybe its time to order this one, and upgrade to the full version winairr.

In the mean time I can just have fun playing :D

spkrman57
04-19-2005, 06:48 AM
Is someone going to document the plans and add them to the technical library on this site?
Ron

yggdrasil
04-19-2005, 12:15 PM
I tried measuring on a 2441 on 2380 (in store for a future project..).

This unit cut of earlier in both ends than the LE85 on the smith horn.

Conclusion: serious amount of erroneus information in test setup. Will be back with more info when this is sorted out.

Ian Mackenzie
04-19-2005, 12:32 PM
I use a Panasonic capsule mounted in the end of 1/4 inch diameter tube and a small battery powered pre amp...the sound card preamps will be too noisy with the pc internals . The Beringher mic is a good buy.

The above curve is the 2307 without the lense using the 2425 dias incl th crossover function of 3145 network.

Ian

Ian Mackenzie
04-19-2005, 12:37 PM
I tried measuring on a 2441 on 2380 (in store for a future project..).

This unit cut of earlier in both ends than the LE85 on the smith horn.

Conclusion: serious amount of erroneus information in test setup. Will be back with more info when this is sorted out.

Why not invite The Widget for a visit and holiday and bring Clio to help measure your horns.

But lock up your woman! Trust me. Muhhahahaahahahahahahaha.

Macka

yggdrasil
04-19-2005, 04:15 PM
Widget are you ready for some serious fishing. In this picture, the kids got 16 pounds of cod in one throw...... DAD!!!! FISH!!!!


The fishing season / summer is coming fast now. Midnight sun - YOU WON'T BELIEVE IT. Have to be experienced.

John
04-19-2005, 09:56 PM
This is what Westlake uses to mount a 1" driver to there small wood horn in the SM-1 studio moniter. The hole is a straight 1" bore. The aluminum plate is 1/2" thick.

John
04-19-2005, 10:04 PM
Here is some more.

John W
04-20-2005, 03:51 PM
I have a pair of 1" drivers also, so am following this thread with great interest.http://audioheritage.org/vbulletin/images/smilies/biggrin.gif
While looking through the previous threads regarding these type of horns it seems apparent the 2397 horns sound better with 2" drivers rather than 1". I also ran across an interesting statement from Earl K in this thread:
http://audioheritage.org/vbulletin/showthread.php?t=3303&page=2&pp=15&highlight=2397
that one possible reason is the height between the bells may need to be about .5 of the horn mouth.
Has anyone tried retaining the original 2397 dimensions, but reducing the gap to 5/8 or so? Could this retain the 800hz size, but still give good results?

yggdrasil
04-20-2005, 03:58 PM
Reducing the gap, keeping all other dimensions, will increase the crossover frequency. At least according to Smith's formulas.

yggdrasil
04-21-2005, 07:56 AM
Smith calculations.

Michael Smith
04-21-2005, 05:06 PM
Well done I'm in.
Will be starting my prototypes next week and I will post pics of my progress,wooden horns have always had a sensual simpatico for me, getting alittle wood just thinking about it.

Michael

grumpy
04-22-2005, 10:32 AM
Careful with that belt-sander, Eugene :D

(er, Michael)

Michael Smith
04-22-2005, 04:44 PM
Point taken.
Also thanks for the Westlake alum bracket posting John,Ifelt like a blonde with my ruler on the monitor

Michael

John W
05-01-2005, 07:30 PM
Finished my first go at the 1200hz horns in mdf.

Here are a couple shots from the construction.

I started with a full size pattern of the horn in 1/4 hardboard, carefully getting the arc to plan, but leaving a little more than the 135 degrees so I could screw it down during forming.

Using a pattern bit on the router I made the initial arcs.



Next I made a 90 jig for cutting a precise contour to the horn. Mounting the jig a little forward of the center-line of the blade on the table saw, I carefully made 4 passes in a slow arc to follow the profile of the plan. The horn pivots down into the blade from the center of the circle.

Feathered in the curves with a hand plane.



I also used a router jig to shape the vanes. Basically the same method. There are two holes on the top positioned by a couple nails to center the vane and help hold in place.



I cut the back off a little further than on the plan so I could make a clean transition to the compression driver.

John W
05-01-2005, 07:30 PM
They sound great. I hooked them up to the midrange on my L222 Disco’s. A little out of balance for now, but for vocals very natural and engaging.



Next step is a walnut version. My plan is to incorporate them into their own three-way.

4313B
05-01-2005, 07:50 PM
Fantastic! :yes:

John
05-01-2005, 09:21 PM
Those look "SLICK":applaud:

yggdrasil
05-02-2005, 12:55 AM
Excellent:applaud:

Zilch
05-02-2005, 02:26 AM
Gorgeous!

[*Drool*] :p

Earl K
05-02-2005, 04:35 AM
Oh My - Those are Nice !

You Guys are Masters of the DIY Kingdom.

:cheers:

jandregg
05-02-2005, 06:05 AM
Very nice. Please make mine in walnut.


John

Woody Banks
05-02-2005, 09:09 AM
Nice job John! I like the jig for the vanes. That just happened to be my next project. Very timely. Keep up the good work!

Woody

spkrman57
05-02-2005, 09:14 AM
I'm envious as I have little to no woodworking skills at all.

Ron

:applaud:

Mr. Widget
05-02-2005, 10:19 AM
Looks very nice! What did you use to seal the MDF?

Is your horn based on Johnny's drawing or is it different? I notice the mounting/throat adapter is different.

Widget

John W
05-02-2005, 02:01 PM
I sealed the mdf with a couple coats of automotive primer, then sanded smooth and finished off with Krylon black semi-gloss.

I did deviate from the plan around the throat. I cut it back about 1/2in, and shaped a smooth transition from the 1in driver to the horn out of a 3/4 piece of mdf. This piece screws into the horn and has a couple of square nuts captured on the back side. There is a 7/16 piece of oak that bolts onto the driver and then from the otherside onto the horn.

On the vanes, I built the pattern and drilled two holes in the top along the center line the, same diameter as a couple 8p nails. I tapped the nails through the holes on the blank I was shaping, then drilled into the marks that were registered. This way they could be flipped end to end and still line up correctly.

bbrown
05-06-2005, 09:42 AM
Very nice John. I was going to use the two pin registration (nail) method for the vanes as well, but make a pivot or arm to mount on a bandsaw. The 8 inch vane has a beautiful 24 inch radius on it. Swing through the bandsaw, flip the piece over and swing through again. Then it's done, except for final sanding and finishing for each vane.

Bruce

John W
05-06-2005, 10:05 AM
That is a great idea. This was the most tedious aspect of the project. Make sure you clamp them down good, especially on the second side. Being so thin they tend to shift off perpendicular.
Is the radius you mentioned for the 1200hz, or the full size 2397? I think the 1200hz vanes are 6.15 inches rather than 8.

Mr. Widget
05-06-2005, 10:22 AM
The 8 inch vane has a beautiful 24 inch radius on it.

That is so funny... I never thought to check. I just checked my original CAD It is indeed a perfect radius. 24" will give you an error of about .09" at the tips. You should use a 25.25" radius.

Since I plotted these from cross referencing several sources and machined them with my CNC router, I never bothered to check. Thanks for pointing that out.

These numbers are for the full sized 2397.

Widget

bbrown
05-06-2005, 11:21 AM
Thanks Widget. The 24 inch seemed to line up on he drawing pretty well, but there was obviously some play with the pixels. I'll just change my notes that it should be 25.25 inches.

It will be during the summer before I get to any of this, but I've been gathering notes long enough.

Bruce

Woody Banks
05-06-2005, 12:34 PM
Widget
I discovered the same thing by accident with the radius while I was constructing the vane gig. The first pair was without a gig came out alright but not perfect. I used Jotoba because it was what I had in the shop. I will start the full size pair this next week using 6/4 Jotaba. Thanks for all the input.
Woody

Michael Smith
05-20-2005, 02:35 AM
Here are some pics of my prototype Johnny inspired Smith horns.
I have used 32mm MDF top and bottom plates with both sides of the vanes rebated to ensure a nice snug fit (probably alittle anile ) but what the F.
It goes together like a dream.
I will finish these then give them a test drive and report.
My intention is to fashion them out of sequoia and french polish them (any problems with my timber choice? ) if so feedback would be appreciated.
Regards to all
Michael

yggdrasil
05-20-2005, 03:45 AM
Hi again. Just back from 2 weeks of defrosting in Crete, Greece.


Woody, great looking. Beautiful work.:applaud:

Michael, great work. Nice work with the router. :applaud:

I must admit getting more than a bit envious at your abilities and tools.

Bruce / Widget: I have done some calculations on the 6.15" vane "radius". Using the CAD-drawing and measuring radius would be 48.6cm / 19.13". I tried using the worksheet, and calculate the ratio, giving 49.3cm / 19.41".

Rjig = 3.156 * vaneLength

Widget - are there any differences between JBL and Westlake vanes?

I would think that the formula for Rjig would be sufficiently accurate for practical purposes.

Mr. Widget
05-20-2005, 10:07 AM
Widget - are there any differences between JBL and Westlake vanes?


Nope.

This is how I mount the ribs. I too have rounded corners in the rabbets, but then I notch the ribs. This way they are still sharp. I don't have a photo of just a rib, so this is a CAD drawing of one.

Widget

bbrown
05-20-2005, 07:13 PM
Michael,
Do your top and bottom plates just have a rounded front edge, instead of tapering a bit like Widget's drawings? Sure would be easier to make.

Bruce

Michael Smith
05-20-2005, 10:55 PM
Bruce I did it that way because I thought that 32mm would look crappy,How thick is your base you pictured Mr Widget?
As this is the prototype I could and probably would change it if I can get my hands on a bigger chunk of timber.

Michael

Mr. Widget
05-21-2005, 01:49 AM
How thick is your base you pictured Mr Widget?


I started off with 8/4" rough lumber. I planed it down to 1.75" for the Westlake clones and 1.625" for the JBL 2397 clones... in the case of the 2397s I picked that thickness as it looked the nicest to me.

Widget

Ken Pachkowsky
05-21-2005, 07:46 AM
Title says it all.

:applaud: :applaud:

aust-ted
05-22-2005, 04:28 AM
Title says it all.

:applaud: :applaud:

Great work

Regards
Ted

John
05-22-2005, 09:00 AM
One thing to keep in mind is that on both the JBL and Westlake horns the dividing vanes are razer sharp at both ends???

MatthiasA
05-26-2005, 09:38 AM
i made a bigger CAD-drawing than the one on the first Side
if anybody want it its a DXF - file
greetings Matthias

MatthiasA
05-27-2005, 04:45 PM
today i made the Horn :-)
very good sound with a 2425H driver!

greetings Matthias

yggdrasil
05-28-2005, 02:41 PM
Mathias, there is also half a vane on each side, right next to the side panels.

What material did you use?

Nice work as always.

MatthiasA
05-29-2005, 09:47 AM
oh its only a package tape ;) :p :o:

the Horn on this picture isnt finished!

now its finished
i fixed the sides and removed the tape! :)

yggdrasil
08-21-2005, 03:48 PM
Finally got everything set up. Did a test a couple of days ago, to familiarize with the equipment.

The equipment:
- Laptop computer
- Behringer measurement microphone
- WinAirr

I am a little disappointed with the measurement. The equipment does not seem to be able to give exact measurements. I am installing a new computer, and I will try the test later with the new computer to see if it will be more accurate.

I will attach 3 graphs. All are done on the same equipment, with the same procedure.

1) Run 100 tests without signal, captured and subtract.
2) Run 100 tests average, white noise, 20 miliseconds, sample rate 48KHz

Pic 1 is Smith horn with LE85 equipped with D16R2425
Pic 2 for comparison is 2441 on a flat front biradial 238x
Pic 3 also for comparison is 2402

It seems they are good to 8Khz, maybe usable to ~13Khz.

Ian Mackenzie
08-21-2005, 04:26 PM
Try theses settings.

Pulse excitation mode, frequency, average 100, sample rae 44khertz, sample length 2048.

Do not rely on the sound card mic preamp, use an external preamp and use a low diffraction mic. The diffraction will otherwisw give incorrect result.

I use the same Panasonic capsule as the Mitey mic on a 2 ft think alminium tube.

All the same the response is limited, my 800 Smith horns were also limited above 10K. I wonder if the throat may need some modifications. Any abrupt changes there will effect the final result.

Ian

yggdrasil
08-21-2005, 04:32 PM
Hi Ian.

I have several points on my list to look into.

1) The vanes are not 100%
2) The finish is just plain particle board
3) as you say the throat.

Anyway now there is a measurement to work from.

I don't have a mic preamp now, but I don't have a line input on my laptop either. Will try again shortly with the new laptop, which is a HP. The old one is a brandless.

Ian Mackenzie
08-21-2005, 04:36 PM
Okay,


Please keep us informed...and how does it sound?

Ian

Mr. Widget
08-21-2005, 05:02 PM
All the same the response is limited, my 800 Smith horns were also limited above 10K.

Here is a plot of the stock 2387 (800Hz) Smith horn with 2441 and TAD 4001 drivers... they aren't dropping off up top like yours seems to be.

Widget

Ian Mackenzie
08-21-2005, 05:37 PM
Oh come on, do you call 10 db down above 10 k or so extended?:D

You of all people should know better....Tad = miss information..:applaud:= :offtopic:

My old graphs are some where on ice, however its obvious the diffraction loading gives up above 10 k due to the 2 inch gap.

Are you sure they are not the eq'd westlake horns??

Ian

Mr. Widget
08-21-2005, 05:51 PM
I have no idea what you are trying to say.

I posted that plot simply to show how the "full sized" 2397 compares to Johnny's recent post.

As for the TAD vs. JBL thing... here is JBL's own published take on a comparison.

Widget

yggdrasil
08-21-2005, 09:05 PM
Please keep us informed...and how does it sound?

To me they sound beautiful. :D

I threw out the H91's at once (Hong Kong).

I can't seem to get enough. I had been turning the L-Pads with just my ears to help me for some time. Measuring showed them at least 6dB up compared to the all the others...

Eventually I will get around to making a pair in birch or some other kind of wood I have lying, just waiting for a project.

Mr. Widget
08-21-2005, 10:49 PM
To me they sound beautiful. :D

I threw out the H91's at once (Hong Kong).

That's great! I know the feeling.:applaud:
Are they being augmented by the 2405s or are they fine on HF extension?

Widget

Ian Mackenzie
08-22-2005, 12:18 AM
What I am driving at is will a diffraction/Smith horn go flat above 10K by design?

The Westakes Ken has have a one inch driver on what appears a mini Smith Horn ...the details I am not very clear on, but it would seem to go up above 10 khertz altough i have not seen the response graphs.

Anyone have data on this?

Ian

yggdrasil
08-22-2005, 03:22 AM
That's great! I know the feeling.:applaud:
Are they being augmented by the 2405s or are they fine on HF extension?

Widget
The 077's come in at 7K. The HF extension in my setup is not an issue.

Will make a new pair where I address the finish, vanes and throat issues. Then we will see if it is possible to use them over a wider range.

Would like to be able to set the crossover frequency to 10K to see if the integration will be different.

yggdrasil
08-22-2005, 03:29 AM
What I am driving at is will a diffraction/Smith horn go flat above 10K by design?

The Westakes Ken has have a one inch driver on what appears a mini Smith Horn ...the details I am not very clear on, but it would seem to go up above 10 khertz altough i have not seen the response graphs.

Anyone have data on this?

Ian
The small Westlake's do not have the vanes.

It would be very easy to make a pair.

Will need measurements (height, width) and preferrably some pictures of the throat / transition.

I have been playing with the thought of making a tiny Smith horn and copy JBL's compression chamber from the 2403/2404. Then mount the whole thing on a ring radiator with a 2405 dia.

Would be very nice- :yes:

Ian Mackenzie
08-22-2005, 05:10 AM
Perhaps we an ask Ken to take a close macro shot of his smaller Westlake horn.

Ian

Earl K
08-22-2005, 06:46 AM
Hi Ian

Perhaps we an ask Ken to take a close macro shot of his smaller Westlake horn.

- Ken has already posted that pic here (http://audioheritage.org/vbulletin/showpost.php?p=33161&postcount=19)

- Dimensions are ; a 3/4" high slot by 13" wide . ( I'm assuming a standard 140° horizontal coverage pattern, as in the 2397 ) .

:)

Ian Mackenzie
08-22-2005, 07:12 AM
They are rather yummy aren't they. I think that system crossover point is 250hz 1000hz, then 4500 as I recall

Time for some negative engineering...they would appear easier to make without the vanes sez I. Actually I think I can see what Westlake are doing, each driver is about 2 octaves, narrowing the horn bandwidth eases up the horn specs and reduces distortion, and I would not be surprised if they were 6 db slopes or 18 db as an allpass system.

Ian

yggdrasil
08-22-2005, 03:10 PM
Just closed the baffle. They are no beauties, but the sound.....

yggdrasil
10-27-2005, 03:57 AM
Almost finihed a pair in birch. Have tried to be more accurate in all aspects to see if there are more HF in these babies.

I have serious trouble with my measuring computer, so the graphs are very rough. Will have to look into this later on.

Driver is 2425J.

Will finish the second horn later today, and start laquering.

Mr. Widget
10-27-2005, 11:27 AM
That wood looks wild! I bet it'll be beautiful with finish on it.

Have you compared both drivers to see if there are significant differences between the two? Do you have other 1" drivers you could try?


Widget

yggdrasil
10-27-2005, 12:08 PM
Found a setting on the computer that seems to be reset every time I start Winairr - Microphone boost.:banghead:


Looking at this graph - the HF extension is quite good.

The wood is what we call (free translation) sour birch. That is birch stored as log for some time, keeping it moist for a very long time. So it has started to rot.

I have an LE85 I will try after the horns have been finished

Ian Mackenzie
10-27-2005, 12:57 PM
Johnny,

Per my email: The mic response will be noisy and also maybe not flat.

Have you made a calibration file by looping the output of your preamp/line output back to the mic input?

Take a measurement of the loop incl all cables from the preamp/line out back to mic input and store the file as wincal.

Then retrieve the file and subtract from the signal with the menu option during the horn measurement, you will see the subtraction as a grey curve and signal curve will move upward but be adjusted.

Ian

yggdrasil
11-03-2005, 04:33 PM
Thank you Ian.


The measuring finally looks ok.

I had 5 coats of lacquer on these babies.

Third picture gives a closeup of the mounting plate. Now its getting there.

yggdrasil
11-03-2005, 04:39 PM
Measuring LE85 with D16R2425, on horn 1 direct up front, 30 degrees off center and 60 degrees off center.

Fourth measuring is 2425 with original dia on the same horn and mounting plate.

yggdrasil
11-03-2005, 04:41 PM
Here's the same measurement on the other horn.


1) On axis, 2) 30 degrees off axis, 3) 60 degrees off axis.

yggdrasil
11-03-2005, 04:44 PM
I have played a couple of CD's on them. The better HF extension is very evident. They play just wonderfully.


Looking forward to more listening.

Ian Mackenzie
11-03-2005, 05:33 PM
I have played a couple of CD's on them. The better HF extension is very evident. They play just wonderfully.


Looking forward to more listening.

Wow,

I might start making a pair this weekend ...I will review your plans

regards

Ian

Mr. Widget
11-03-2005, 05:39 PM
Very Cool!

Have you done any subjective comparisons between the 2425 and LE85 drivers?

If I had any 1" drivers looking for horns, Id give this some serious consideration.

Widget

bbrown
11-08-2005, 11:42 AM
Johnny,
I'm curious, but is there no flare at all on your mounting plate? Does that just connect straight to the wider opening on the back of the horn? In other words, it looks like you have the driver throat diameter on your mounting plate not flare any into the wider opening on the back of the horn, so there is no transition at all.

Bruce

John
11-08-2005, 01:12 PM
Hi Bruce Westlake audio currently uses a straight bore on the mounting plate used between horns and drivers on their systems. They might know something about this:hmm:

yggdrasil
11-08-2005, 02:15 PM
It is almost straight. Just a 3-4 mm flare. I made it on free hand, just to smoothen the transition into the horn. You might be able to see it if you look closely at the picture.

bbrown
11-08-2005, 03:01 PM
A straight bore would certainly make them a lot easier to make. And to think that all this time I've been trying to figure out how to make Widget's throat adapter.

Bruce

Mr. Widget
11-08-2005, 03:14 PM
And to think that all this time I've been trying to figure out how to make Widget's throat adapter.The throat adapter seems to have the greatest effect at the lower end of the horn's band. I guess since Westlake crosses their 26" wide 2" horn over at the relatively high 1200Hz frequency, it doesn't matter.

As far as Johnny's small 1200Hz horn, I have yet to play with these, so I'd suggest we follow his lead.:)

It does look promising.


Widget

yggdrasil
11-08-2005, 03:45 PM
I have been playing a few hours on them now. Sorry to admit that the electronics is rather poor. Since my wife occupies my good amps and cd-player on the Sovereign's I have a very low cost DVD/CD player with a variable output directly connected to a Crown 460 CSL.


When the program material gets complicated the CD-player just says thank you and good night.... Have started looking around for a usable CD-player. I haven't been paying any attention to this market for years, so there is a job to do.

If, on the other hand, the program material contains less information....

The horns play very well. I have not yet grown accustomed to the improved HF extension.

I have a 2-seat couch, with the sweet spot in the middle. For the first time it is possible to sit anywhere in the couch.

I have a second 2425 on the way. Snail mail from US, 4-6 weeks++, should be here in a couple of weeks. Will do a subjective comparison with LE85 later.

DR Carlson
01-20-2006, 10:48 AM
I've been going over the varous posts concerning the Smith horn, and I'm interested in building some. The problem I am coming up against, is getting enough info to design then build one properly.
I have down loaded the 1951 artcle from Audio Engeering written by Bob Smith, but it is not the best copy, on page 17 figure 5 there seems to be a triangler plug right at the mouth of the horn spaced 5/16" in front of the back plate. Can anyone enlighten me.
Also is it possible for anyone who has design/construction info on these, Perhaps other magazine articules etc to be able and send them to me. I can take most formates including DWG DXF, JPG etc.

Thanks Dave C.

yggdrasil
01-21-2006, 10:04 AM
I tried redrawing the original Bob Smith drawing using his calculations, drawing and a CAD-program. There were some errors in my calculations. I got quite close but...


However - the triangular drawing in the horn throat shows the origo (circle centre) and the angles of the 5 vanes / islands.

Anyway the drawings presented in this thread are built on JBL's work on the 2397 horn. I have not tried to make any horn following Bob Smith's design 100%.