Stainless Steel JBL 2307 & 2402 from Kenrick Sound

[JBLCarousel]

Does anyone have experience with or recommend any of these products from Kenrick Sound?

https://i.imgur.com/dUFTE15.jpg

https://i.imgur.com/5RWKfvQ.jpg

https://i.imgur.com/O4vB5un.jpg

https://i.imgur.com/FDmfaoV.jpg

[hjames]

Just polished - they do a lot of bespoke parts for folks willing to pay the extra bit of dosh for such as that.
I had seen them offering brass parts and some others in more precious metals.

I believe its like the difference between the 077 consumer slot tweeters with the Lucite wedge
and the 2405 pro slots tweeters with the metal wedges - functionally, there isn't really a difference, but visually there is.

I don't think the sound cares what metal color they are, but its sure shiny.

[Robh3606]

Eye Candy

Rob:)

[speakerdave]

To work the way it was designed, the 2307 should be covered with a lens anyway. If the horn is not black or dark gray, then visually both the lens and the horn should be the same color, I would think. I don't understand how anybody listens to those horns without the diffusor.

[Ian Mackenzie]

Does anyone have experience with or recommend any of these products from Kenrick Sound?

https://i.imgur.com/dUFTE15.jpg

https://i.imgur.com/5RWKfvQ.jpg

https://i.imgur.com/O4vB5un.jpg

https://i.imgur.com/FDmfaoV.jpg

To answer your questions No and No.

[Ian Mackenzie]

For uninitiated go to page 412
http://www.audioheritage.org/vbulletin/showthread.php?7852-Improvements-in-Monitor-Loudspeaker-Systems

The 2307 horn has a dispersion of 80 degrees but this narrows with increasing frequency. The 2308 lens maintains a wider horizontal dispersion with frequency. The function of the lens is such that the vertical dispersion narrows. This is not a concern is dry acoustic environments.

If you are more interested in cosmetics to match the retro appearance of a Yamaha integrated amplifier then none of this matters.

https://europe.yamaha.com/en/products/contents/audio_visual/hifi_components/hifi-history/integrated-amplifier/index.html

[hjames]

I would think the more relevent discussion would be which lenses to use, the original black plastic ones from JBL,
the wooden ones from various vendors, or the clear plastic ones like Toddalin has made for the bullets & slots?

8149581494

[Robh3606]

I would think the more relevent discussion would be which lenses to use, the original black plastic ones from JBL,
the wooden ones from various vendors, or the clear plastic ones like Toddalin has made for the bullets & slots?


Hello Heather

The originals. The other aftermarket parts need to be the exact same size and spacing, number of vanes, to have the same performance. The Kenrick are copies so they should work fine.

As far as slots and bullets just use the slot it was designed to match the 2307/2308 combo and was standard issue in basically all of the monitors. Also the lense isn't doing all that much at 10K and above so dropping one in front of a bullet won't get you much. If you want wide dispersion up to 20k use the slot or a 2404

Rob:)

[Ian Mackenzie]

There should be 11 plates btw. The image above has 8 plates.

[BMWCCA]

The originals. The other aftermarket parts need to be the exact same size and spacing, number of vanes, to have the same performance.
I assume there have been measurements made to back up this claim? This is how my 4345s from Rick look, though the first picture is actually of Rick's own, not mine. Nine thick, wood plates in these.

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=24870&stc=1&d=1178425923

These are mine, in the original owner's home before I picked them up:

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=30871&stc=1&d=1202495600

[Ian Mackenzie]

Love the rack!

[Robh3606]

Hello Phil

Happy Fathers Day

You do understand how they work?? The only measurements we should be concerned about are from the people selling these lenses that show that they match the original performance or are better. If you want original performance to match the JBL design your best bet is to use the originals. No different from cone kits. Those lenses look really nice doesn't mean they will work as well as the original. Do you really think if you swap the parts that started this thread with the originals it sounds better?? It's all cosmetics for them but not the lenses spacing, plate thickness, number of plates and size all matter.

Rob:)


http://www.lansingheritage.org/html/jbl/reference/technical/lens.htm

[hjames]

There should be 11 plates btw. The image above has 8 plates.
Right! The wood ones I showed were clones from a US firm that has long gone out of business
- it was the only wood lens image I could find quickly ...

My point was in support that chrome exponential horns don't make as much difference as lenses do!
And the wood lenses are a real nice touch!
(G'mornin' Phil!)

[BMWCCA]

And same to you!

I'm past the "original" design and, like those here who make their own "clones", we make adjustments, improvements, modifications, and kluges based on what's available or the opinions of others more knowledgeable—such as the original designer with his suggestions for networks and losing the gang switch. Often these are done intentionally to improve on the original. My cabinets were built by Rick, not JBL. My crossovers were built from one of Giskard's cc designs and I have no original networks with which to compare them, and the wood lenses came with the boxes. Easy enough to swap in plastic JBL lenses or KRS plastic reproductions but if the wood has any actual influence on the sound and I find I like it better with the wood than the plastic, I'm still gonna keep the wood. Heather had a good run with duck-billed wood horns and seemed to prefer them to the metal. I don't know if was an aesthetic decision, or based on sound. What I have sounds fine, most likely they guide and delay the path of the horn output in at least a similar pattern to the originals. I can imagine that plastic was easier and cheaper to work with. I like the way mine sound and it was you, Rob, who said they must be "the exact same size and spacing, number of vanes, to have the same performance." That sounds like a fair statement but you proposed it as fact. I don't know that those who crafted the wooden lenses ever made that claim. But you did, so I was just wondering what measurement you'd made to substantiate it? Just a question! I knew I wasn't getting "original performance" when I bought my 4345 reproductions. My hope was I was getting at least something as-good, if not better. I listened to them last night, as I've done nearly every night for the past nine-years. And I enjoyed it immensely.

. . . and the new Jennifer Warnes album is growing on me, or at least some of the tracks are.
:hurray:

Hello Phil

Happy Fathers Day

You do understand how they work?? The only measurements we should be concerned about are from the people selling these lenses that show that they match the original performance or are better. If you want original performance to match the JBL design your best bet is to use the originals. No different from cone kits. Those lenses look really nice doesn't mean they will work as well as the original. Do you really think if you swap the parts that started this thread with the originals it sounds better?? It's all cosmetics for them but not the lenses spacing, plate thickness, number of plates and size all matter.

Rob:)


http://www.lansingheritage.org/html/jbl/reference/technical/lens.htm

[Ian Mackenzie]

Ah

Here you are

https://www.sweetwater.com/insync/acoustic-lens/
Mhttps://www.tnt-audio.com/clinica/acoustic_lens.pdf

I think all Rob was saying is if you want the original performance stick original design of the lens.

Btw GT did not refer to any modifications to the lens or the drivers.

From the look of your wooden lens they are modified to allow line of sight to the Slot radiator off axis.

I think they look kind of cool.

Happy listening.

[toddalin]

Hello Heather

Also the lense isn't doing all that much at 10K and above so dropping one in front of a bullet won't get you much. If you want wide dispersion up to 20k use the slot or a 2404

Rob:)


Wanna bet?

https://youtu.be/zicT8bw1ZmM

[Robh3606]

Hello Toddalin

Happy Fathers Day

Not the entire range just the last octave 10-20K And if watch you own video you can see how the response 10-20K drops way off, almost off the scale, from on axis with or without your lense 4:28- 6:28 as an example.

Even on axis the last octave response 10-20K is down quite a bit not knowing what your scale is.

Like your lenses they look nice.

Rob:)

[Ian Mackenzie]

Okay,

Let’s look at JBLs own measurements of the 2307/2308.

Under magnification the last four plots are between -5 dB and -7 dB down at 30 degrees off axis. They are between -7 dB and -10 db down at 45 degrees off axis.

So above 10 khertz it’s got a dispersion of 60 degrees (ref -6 dB)

That is exactly why the slot radiator cuts in just below 10 khertz in the 4 way monitors.

The vertical dispersion narrows down to 30 degrees above 10 khertz (ref -6 dB) .

If time permits l will look at the effect of the lenses proximity on the off axis response of the 2405 (4345 baffle).

As a side note when l was using the 2344 bi radial l could always tell when the HF trim adjustment (above 10 khertz) was just right. Not enough and it sounded dull. Too much was too bright.

(I later sold them to Kent at Pass Labs after building my 4345 clones)