2397 taper and lip

[Mr. Widget]

...it would be great if among the readers of this thread (who might have 2397s or westlakes) some would make some measurements for a more wide perspective.

I agree... I see you have one of my plots posted above, I will caution that measurement I made of the 2397 was among the very first audio measurements I ever did using CLIO and may not be as useful or accurate as my later measurements... here is an example of a later on axis measurement comparing a TAD TD-4001 and JBL 2441 both on the Westlake horn and a TAD TD-4003 on a TAD TH-4003 horn. Even this measurement was fairly early in my measuring and I was just getting the hang of time windowing... I wouldn't trust the curves below about 1K to 1.5KHz... the windowing has likely clipped some information and overly smoothed the response.

I would offer to make additional measurements on both the Westlake with 2328 throats and the 2397 horns that I have in storage, but I do not have any 2" drivers to put on them.


Widget

[yggdrasil]

@jf65 - what are your crossover frequencies?

[jf65]

@jf65 - what are your crossover frequencies?

The Iwata is crossed at 600 Hz in a 3 way system.
I bought a pair of 2123H and moving to 3way, the horn (Iwata or 2397) is now crossed at 1200 Hz.
That's why i thought of the 2397 after reading this thread , because it's smaller than the Iwata used at the moment. But now i hesitate.
The tweeter is crossed at 8000 Hz.

[reVintage]

Don´t know if this has been mentioned earlier in the thread but:
2397 should be used with 2328 and old style 2"(with short horn inside the driver) as these together has a flare of 160Hz. The horn is then cut at 800Hz mouth-area if I remember it right.

[jf65]

Don´t know if this has been mentioned earlier in the thread but:
2397 should be used with 2328 and old style 2"(with short horn inside the driver) as these together has a flare of 160Hz. The horn is then cut at 800Hz mouth-area if I remember it right.

Could you explain the "flare of 160Hz" ? i have the 2328 on this horn.

[4313B]

Widget, with the experience you now have regarding the array1400, S9900 and D66000, do you still find the smith horn superior to the biradials? (when used with a supertweeter)

The 1400 Arrays are in my living room playing as I type this. My 2397s and my beautiful Westlake clones are tidily packed away in my attic.

That is such a nice, polite answer!

I agree... I see you have one of my plots posted above, I will caution that measurement I made of the 2397 was among the very first audio measurements I ever did using CLIO and may not be as useful or accurate as my later measurements...

If I'm not mistaken, once saved, the CLIO files can be manipulated whenever desired, including windowing. The biggest factor appears to be getting anything meaningful below ~ 1 kHz in the typical home room or garage.

[Mr. Widget]

If I'm not mistaken, once saved, the CLIO files can be manipulated whenever desired, including windowing.

True, however I saved very few of my actual MLS files.

The biggest factor appears to be getting anything meaningful below ~ 1 kHz in the typical home room or garage.

In my old 30' by 25' by 10'+ room once I learned what I was doing I was able to get accuracy down to about 500Hz if I was only measuring a single horn... I could mount the horn five feet from the floor and it would be almost five feet from the ceiling as well. With a larger speaker this obviously isn't physically possible. (This info pertains to measurements using time windowing. Most of the response plots that we see posted by individuals can not be time windowed due to the near by reflective surfaces and are therefore only indications of what the response is in a single location in a particular room at a particular time.)


Widget

[Ruediger]

Far from that, the farther you go the flaws of each horn grow bigger. To show you i join the measurements made at 2 meters, still in the garden.

Attachment 50762

The 2397 response looks like a comb filter response. All sound waves which are reflected by the ground and reach the microphone are delayed by the same amount of time and thus by a different phase. This is consistent with Your observation, that the bigger the distance the bigger the effect (more reflections). What is the vertical coverage of the iatwa horn?
Ruediger

[reVintage]

jf65,
Must ask you about your measurements. Did you use the 2328-adapter on the 2397?

[pos]

Widget, with the experience you now have regarding the array1400, S9900 and D66000, do you still find the smith horn superior to the biradials? (when used with a supertweeter)

The 1400 Arrays are in my living room playing as I type this. My 2397s and my beautiful Westlake clones are tidily packed away in my attic.

That is such a nice, polite answer!

And where are the TH4003 ?

[jf65]

The 2397 response looks like a comb filter response. All sound waves which are reflected by the ground and reach the microphone are delayed by the same amount of time and thus by a different phase. This is consistent with Your observation, that the bigger the distance the bigger the effect (more reflections). What is the vertical coverage of the iatwa horn?
Ruediger

You're right, I didn't measure the vertical coverage, i add it to the things i will do when i measure again.
By looking at the horns it would seem that the Iwata vertical coverage should be bigger, but it will be interesting to verify it.
I measured the horizontal coverage (but didn't post it as it looks like Widget's graph) and the 2397 is wider than the Iwata, not a surprise.

[jf65]

jf65,
Must ask you about your measurements. Did you use the 2328-adapter on the 2397?

Yes, how could i put the driver without it? is there another way?

By the way, i see something "wrong", at least for me, in the shape of the 2328: it grows bigger then narrows at the end on the horn, kind of like in the Altec 511 if not exactly the same. Maybe there's a reason, but it could produce some more accidents. In l'Audiophile someone fixed this and said it was better: i didn't try it as i discarded the 511s.

[Mr. Widget]

And where are the TH4003 ?

In a different league.

Yes, how could i put the driver without it? is there another way?

In later Westlakes, they just bolt the driver right onto the horn with a thick round holed plate. They also increased the height of the horn.

By the way, i see something "wrong", at least for me, in the shape of the 2328: it grows bigger then narrows at the end on the horn, kind of like in the Altec 511 if not exactly the same. Maybe there's a reason...

I don't know the history or the reasoning, but both the Altec radial horns and the JBL 2328 throat adapter do seem to share a somewhat similar geometry... a geometry that is quite difficult to manufacture, so they must have had a pretty good reason to go that way.

The 2397 response looks like a comb filter response.

I agree. I did find that for the 2397 or the Westlake to sound good, the room really needed a fair amount of treatment... i.e. they sounded far better in a dead room. I attributed this to the wide dispersion, but your point about the comb filtering could also be part of the reason.


Widget

[reVintage]

Yes, how could i put the driver without it? is there another way?

You could for instance have made something less good by yourself......
So one could suspect that there was something wrong

Still the horn measurements indicates it is not the best horn you could live with.

Have seen quite a lot of smaller horns in the same style, or full radial, without a necessary round to radial adapter.

[jf65]

Yes, how could i put the driver without it? is there another way?

You could for instance have made something less good by yourself......
So one could suspect that there was something wrong

Still the horn measurements indicates it is not the best horn you could live with.

Have seen quite a lot of smaller horns in the same style, or full radial, without a necessary round to radial adapter.

Yes i understand, it was the real complete horn. As for round adapter , here's a comparison made on Iwatas (not by me):