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John W
01-22-2007, 02:46 PM
I just finished a pair of smith horns for a pair of 2345 drivers, and did some measuring this weekend.

I started with the design drawn up by yggdrasil in the 1200hz thread. http://audioheritage.org/vbulletin/showthread.php?t=5454, then scaled it up for a 1.5 in driver, which comes out to 900hz. A lot of the design aspects are covered in the original 1200hz thread.
I’ve attached the spreadsheet with the modified numbers. If you have a hard time deciphering the spreadsheet, basically:

the horns are an arc with a 12.75 inch radius
fins are 7.29 inches long and 1.18 inches high
the throat is 1.5 inches diameterThese horns are mahogany and the material is 1in thick.

John W
01-22-2007, 02:47 PM
a couple more shots

John W
01-22-2007, 02:49 PM
Here are a few in-room response plots from the horns. The first is the horn only, no filter, with the mic about 1 meter away pointed directly at the mouth of the horn. You can see the response gently rises to about 15k then drops off.
The second is horn only at a little higher volume level, and the mic about 2 meters away. For some reason this flattens the slight rise.
Finally here is a plot from about 2 meters crossed over to 15” E145 woofers at 800Hz using a Behringer DCX2396 digital crossover flattening out a couple of the peaks, and boosting the VLF response. This is a 2 way setup, the tweeter is not hooked up.

They sound very good. Especially at moderate volumes (mostly because of the room)

4313B
01-22-2007, 02:50 PM
Looking good! :yes:

paragon
01-22-2007, 03:03 PM
Very good work ! Good response. Excellent !!
Love it !

Eckhard

spkrman57
01-22-2007, 03:10 PM
Shows what good thinking will come up with!

Ron

Zilch
01-22-2007, 03:10 PM
Beautiful work, John.

[And nice measurements, too!! :thmbsup: ]

John W
01-22-2007, 03:20 PM
Thanks.
Back to Mr. Timbers notch filter, which I've been trying to figure out.
I can see the CLR filter to flatten out impedence peaks, and some attenuation. What else is it designed to do? Would most of it bennefit a passive crossover?

Zilch
01-22-2007, 03:31 PM
It works with either active or passive highpass.

Recall, for example, how 4430's compensation filter remains in play in the active mode.

The specific compensation is optimized for a particular driver/horn combination, but the design also illustrates a topology which may be applicable to others, with modifications.

Unless you're fluent in filter theory, you'll need to put it into Spice to analyze it; the operation of the elements is interrelated....

grumpy
01-22-2007, 04:04 PM
Nice! I'm glad someone did this.

It will be interesting to see how long these live in your system
(as a measure of how well you like 'em).

-grumpy

yggdrasil
01-23-2007, 07:14 AM
Good looking John.

How do they compare to the 2441/2397 combo you made?

4313B
01-23-2007, 07:30 AM
Thanks.
Back to Mr. Timbers notch filter, which I've been trying to figure out.
I can see the CLR filter to flatten out impedence peaks, and some attenuation. What else is it designed to do? Would most of it bennefit a passive crossover?This compensation filter was designed for use with an active filter. It can be adapted to work with a passive filter. The shots below show the effects of the notch. Note that there is only one notch filter at present. Systems like the K2-S9800 and DD66000 use three. Notch filters could be added to this filter and then evaluated for performance. One at ~ 5.5 kHz perhaps, but only if it sounds like it needs it. These compensation filters are horn/CD specific.

Behringer DCX2396 digital crossover flattening out a couple of the peaks, and boosting the VLF response.Probably the best plan of action for most people.

John W
01-23-2007, 08:10 AM
Good looking John.

How do they compare to the 2441/2397 combo you made?

They are a lot lighter.;)
The combination before was actually using 2440s. I haven't been able to do a side by side comparison, but from what I recall, the 2345s have a lot more detail and I don't need to add on the tweeter to get out to 15kHz.

John W
01-23-2007, 08:12 AM
This compensation filter was designed for use with an active filter. It can be adapted to work with a passive filter. The shots below show the effects of the notch. Note that there is only one notch filter at present. Systems like the K2-S9800 and DD66000 use three. Notch filters could be added to this filter and then evaluated for performance. One at ~ 5.5 kHz perhaps, but only if it sounds like it needs it. These compensation filters are horn/CD specific.

Thanks Giskard, this is very helpful.

Robh3606
01-24-2007, 06:07 AM
Hello John

Those look great!!! How do you like the 2435's??

Rob:)

John W
01-24-2007, 10:08 AM
Hello John

Those look great!!! How do you like the 2435's??

Rob:)

The 2435s are excellent. I just hope I can get the most of them.

glen
01-25-2007, 01:47 PM
Beautiful work as always!:applaud:
glad they've turned out so well.

Joe Alesi
01-25-2007, 04:21 PM
Conratulations John,

They look gorgeous- Starts me thinking about growing it to a 2" throat for a 2440/2441. Any Thoughts guys?

John W
01-25-2007, 04:32 PM
Conratulations John,

They look gorgeous- Starts me thinking about growing it to a 2" throat for a 2440/2441. Any Thoughts guys?
The 2397 design is already available for 2" drivers. This design is a slight shrinking from the already full grown original.

4313B
01-25-2007, 04:42 PM
The 2397 design is already available for 2" drivers. This design is a slight shrinking from the already full grown original.Yes, they were everywhere back then. If it wasn't a Smith it was a Serpentine.

Joe Alesi
01-26-2007, 07:30 AM
Thanks guys--- opps :o: , Back to school. I suppose what I should have said is grow it to a 500 Hz cut off.

4313B
01-26-2007, 07:35 AM
500 Hz is a terrible crossover frequency.

Maron Horonzakz
01-26-2007, 02:55 PM
Giscard...Explain (500hz):blink:

johnaec
01-26-2007, 04:07 PM
Giscard...Explain (500hz):blink:500hz is right in the middle of the range where much vocal articulation takes place, and it's very hard to get a crossover/driver combination that will transition in that region without affecting things in an unbeneficial way, considering phase changes, dispersion differences, etc. between the drivers at crossover frequency.

John

jack_bouska
01-27-2007, 04:45 AM
Here are a few in-room response plots from the horns. The first is the horn only, no filter, with the mic about 1 meter away pointed directly at the mouth of the horn. You can see the response gently rises to about 15k then drops off.
The second is horn only at a little higher volume level, and the mic about 2 meters away. For some reason this flattens the slight rise.

The difference in spectral tilt could be caused by one or more of:
1) nearfield vs. farfield differences, the smith horn mouth is a diffraction slot in the vertical dimension, and you may need to make mesurments (from mouth to mic) at about 5x or 10x the largest dimension of the horn.
2) early reflections from the floor, or the speaker underneath can lead to dips in the response (mostly a sub 1khz issue)
3) the mic position in the room, and the measurment distance from the devices will vary the direct vs. reverberant (diffuse) sound ratio, and can alter the spectral tilt, depending on how live or dead your room is.

Try to make a few (3+) measurments from in and around your seating position, and visually average the various curves to get a better idea of performance. Concentrate on dips, peaks, and trends that are common among the curve families, as these will be associated with the device, rather than the room.

(nice craftsmanship, by the way)

Jack

John W
01-27-2007, 06:27 PM
Thanks Jack,
Nice to hear from you again. I normally do the final adjustments with the mic in the listening position, but was wondering why they changed as you got closer. I figured it was somethin like you described.

EvilFuzz
09-17-2019, 10:03 AM
John W, maybe you can show the plans of this beauty?))

Kirill

richluvsound
09-18-2019, 07:11 AM
The CAD file is http://www.audioheritage.org/vbulletin/showthread.php?23297-H9800-CAD-Data&p=232914#post232914

I have a pair I'm not using anymore if that works better for you .... Not walnut though; resin .

Good luck, Richard

EvilFuzz
09-18-2019, 12:01 PM
Hey, many thanks!
But... "EvilFuzz, you do not have permission to access this page."
I don't know, whats happened((


The CAD file is http://www.audioheritage.org/vbulletin/showthread.php?23297-H9800-CAD-Data&p=232914#post232914

I have a pair I'm not using anymore if that works better for you .... Not walnut though; resin .

Good luck, Richard

JeffW
09-18-2019, 01:02 PM
Hey, many thanks!
But... "EvilFuzz, you do not have permission to access this page."
I don't know, whats happened((

The file is in a section of the forum that was dedicated to a past private project that was pay to view.

85008
85009


85010

EvilFuzz
09-18-2019, 01:37 PM
The file is in a section of the forum that was dedicated to a past private project that was pay to view.


Thanks! Very interesting horns, something like Yuichi, as I understand? But I just asked plans from thread - 900 Hz Smith))
Thank you once again)

Kirill

JeffW
09-18-2019, 03:55 PM
Thanks! Very interesting horns, something like Yuichi, as I understand? But I just asked plans from thread - 900 Hz Smith))
Thank you once again)

Kirill

Right, I understand, but you said you couldn't view the link so I posted what was in the link.

I'm pretty sure the plans for the Smith horn & the JBL 2397(? I think that's the one) are both online, 2397 here:

http://www.audioheritage.org/vbulletin/showthread.php?28578-JBL-2397-Smith-Horn-drawings-needed-!

I have a pair of John W walnut horns, but really don't want to sell them.

Lee in Montreal (that's his user name here) made some nice MDF versions with aluminum fins, not sure if he still has any left.

EvilFuzz
09-19-2019, 02:25 AM
Right, I understand, but you said you couldn't view the link so I posted what was in the link.

I'm pretty sure the plans for the Smith horn & the JBL 2397(? I think that's the one) are both online, 2397 here:

http://www.audioheritage.org/vbulletin/showthread.php?28578-JBL-2397-Smith-Horn-drawings-needed-!

I have a pair of John W walnut horns, but really don't want to sell them.

Lee in Montreal (that's his user name here) made some nice MDF versions with aluminum fins, not sure if he still has any left.

Hmm... I can make 2397 or Westlake horns)

http://www.audioheritage.org/photopost/data//500/medium/IMG_3035.JPG


But I don't really understand scaling algorithm for higher frequency versions) Should I simply scale orig. 2397?

Thanks,
Kirill

richluvsound
09-19-2019, 04:09 AM
Hi ,


scaling is hit and miss .... it needs to be re-calculated .

Richard

EvilFuzz
09-19-2019, 04:40 AM
Hi ,


scaling is hit and miss .... it needs to be re-calculated .

Richard

Hi,

I supposed that:blink:. So, if I want to make 2397 for 1.5" drivers I must learn about calculation, or I must find a plans from John W (http://www.audioheritage.org/vbulletin/member.php?764-John-W))

Kirill

Robh3606
09-19-2019, 07:07 AM
I supposed that:blink:. So, if I want to make 2397 for 1.5" drivers I must learn about calculation, or I must find a plans from John W (http://www.audioheritage.org/vbulletin/member.php?764-John-W))

Why would you have to rescale the horn? All you are changing is the throat. You could just rescale the throat and leave the horn be as they are separate in the original design. You would also need to add the "lips".


Rob:)

EvilFuzz
09-19-2019, 07:36 AM
Why would you have to rescale the horn? All you are changing is the throat. You could just rescale the throat and leave the horn be as they are separate in the original design. You would also need to add the "lips".


Rob:)

Hi, Rob)

As I remember, Mr. Widget (http://www.audioheritage.org/vbulletin/member.php?3-Mr-Widget) said something like "never had success with 1.5" drivers with 2397". And in my first thread about Westie horns someone recommend John W project to me.

Many thanks, Kirill


PS: It seems I start to understand 'bout this calculation. All of parameters I can take from yggdrasil (http://www.audioheritage.org/vbulletin/member.php?1127-yggdrasil) XLS file!))
Sorry for my inattention..

Kirill

Robh3606
09-19-2019, 12:08 PM
As I remember, Mr. Widget (http://www.audioheritage.org/vbulletin/member.php?3-Mr-Widget) said something like "never had success with 1.5" drivers with 2397".

Odd have to see which ones they were, that horn could be set-up for a 1" driver different throat. Any of the modern large format driver like the 2450SL, 2451/2452 should work just as well as the older 2441/2445's.

Rob:)

EvilFuzz
09-19-2019, 11:46 PM
Any of the modern large format driver like the 2450SL, 2451/2452 should work just as well as the older 2441/2445's.

Nice! Only two things; I have none of this modern drivers, but I can use Altec 291, which I can take cheap now. And I have a dimension limit, 'cause this horn project for my friend system, 2397 too large for him)

Kirill

macsic
09-20-2019, 07:42 AM
Nice! Only two things; I have none of this modern drivers, but I can use Altec 291, which I can take cheap now. And I have a dimension limit, 'cause this horn project for my friend system, 2397 too large for him)

Kirill

Hello,
JBL 2397 is for me a very good horn for my listening room
One of my last experiences and change were with JBL 2397 (Smith Horn), this one has a 2 "with a 2328 (2327 for 1") adapter but I've never seen a 1.5 "adapter
If you have the choice, take the JBL 2450 (same motor of 2451 but with a 2 " demanding for the 2397) after that put the diaph of the SL, the Titanium Aquaplas SL is really better than the Titanium Ribbed normally used in the JBL2450, it's the choice after listening with very good results and really better than my previous 2441 references that I tried also with the 2397.
Note: Just my taste ;-) and sorry for my approximate english

https://nsa40.casimages.com/img/2019/09/20/190920044228953370.jpg (https://www.casimages.com/i/190920044228953370.jpg.html)

Mr. Widget
09-20-2019, 09:19 AM
Odd have to see which ones they were, that horn could be set-up for a 1" driver different throat. Any of the modern large format driver like the 2450SL, 2451/2452 should work just as well as the older 2441/2445's.

Rob:)I tried the 2397 with the 2327 1" adapter and a pair of LE85s... I didn't like the sound quality compared to the 2441s. The best sound I had with the 2397/Westlake version was with the TAD TD-4001. I never tried the newer JBLs.

Regarding the horn flare and adapters, the only 1.5" driver I tried was the TAD TD-4003 and that driver did not work with the 2328 throat and a 1.5" to 2" adapter that I tried.

Lastly regarding driver preferences between various "vintage" drivers. Most of the drivers available to us have been around the block and are likely far from spec so when you compare a 24XX with a 24YY, it is hard to say that one model is better than the other based on that comparison. I was fortunate enough to get my 2441s back when JBL was still JBL and I sent my pair to JBL and had them rebuilt at the factory. They were essentially new drivers when I had them. The TADs were also either new or in new condition.


Widget

Dr.db
09-20-2019, 11:51 AM
Beside the original JBL 2397, there are similar versions from Westlake Audio.
One version uses the 2328 adapter as well. Another version doesnīt and the horn seems to be a little higher, probably 2" like the exit of the horndrivers. But there isnīt much information on these versions on the internet... :(

EvilFuzz
09-21-2019, 03:11 AM
Hello,
JBL 2397 is for me a very good horn for my listening room
One of my last experiences and change were with JBL 2397 (Smith Horn), this one has a 2 "with a 2328 (2327 for 1") adapter but I've never seen a 1.5 "adapter
If you have the choice, take the JBL 2450 (same motor of 2451 but with a 2 " demanding for the 2397) after that put the diaph of the SL, the Titanium Aquaplas SL is really better than the Titanium Ribbed normally used in the JBL2450, it's the choice after listening with very good results and really better than my previous 2441 references that I tried also with the 2397.
Note: Just my taste ;-) and sorry for my approximate english


Hey, thank you for the Aquplas idea! My default drivers is 2446, and I just think 'about dia's replacement. I want Al Radian dia's, but Ti Aquaplas is very interesting.
Sorry for my English too, my is disgusting))



I tried the 2397 with the 2327 1" adapter and a pair of LE85s... I didn't like the sound quality compared to the 2441s. The best sound I had with the 2397/Westlake version was with the TAD TD-4001. I never tried the newer JBLs.

Regarding the horn flare and adapters, the only 1.5" driver I tried was the TAD TD-4003 and that driver did not work with the 2328 throat and a 1.5" to 2" adapter that I tried.

Lastly regarding driver preferences between various "vintage" drivers. Most of the drivers available to us have been around the block and are likely far from spec so when you compare a 24XX with a 24YY, it is hard to say that one model is better than the other based on that comparison. I was fortunate enough to get my 2441s back when JBL was still JBL and I sent my pair to JBL and had them rebuilt at the factory. They were essentially new drivers when I had them. The TADs were also either new or in new condition.


Widget

Nice to meet you, mr. Widget!
Thank you again and again for your priceless advices.
What you say 'bout Ti aquaplas, still didn't try?


Beside the original JBL 2397, there are similar versions from Westlake Audio.
One version uses the 2328 adapter as well. Another version doesnīt and the horn seems to be a little higher, probably 2" like the exit of the horndrivers. But there isnīt much information on these versions on the internet... :(

Hey)
Maybe I mistake, but early Westlake didn't have adapters at all? Mr. Hidley can attach driver directly to horn, as I saw at a few pics.
My adapters is simple wood plate with smooth inside transition, here's prototype, 22mm thickness:


https://nsm09.casimages.com/img/2019/09/21//19092112101925009716417221.jpg

Kirill