Any opinion?

[pyonc]

Here are two pics of JBL PR8, passive radiator of early version of LE8T.
One on the top is intact, and the other one looks like broken or split (?).
Is this split thing okay? Any effect on the passive radiator?
Or is there any possibility that JBL produced the spiders cut like that for PR8 early version?
Thanks for your reply in advance.

[Mr. Widget]

The lower one looks purposefully modified by someone for a specific application. I would assume reducing the area of the spider would change the tuning.


Widget

[pyonc]

The lower one looks purposefully modified by someone for a specific application. I would assume reducing the area of the spider would change the tuning.


Widget

Thanks so much, Widget! I agree with you.
So, there is no possibility of JBL producing such a PR8 with the cut spider, right?

[Earl K]

Thanks so much, Widget! I agree with you.
So, there is no possibility of JBL producing such a PR8 with the cut spider, right?

I think both versions are indeed original JBL product ( sorry Widget ) / though my opinion is definitely simple conjecture.

Through the years I've noticed many of those cut versions ( & they're all cut similarly to the pic ).

I want to believe that if this was such a popular user modification from the past ( producing many cut-ups that have survived to present time ), we should have heard about the practice before now ( through the interwebz etc. ).

So goes my argument.

[Mr. Widget]

I didn’t mean to suggest that the mod wasn’t performed by JBL, but regardless of who did the mod, I do not think this PR is suitable for the LE8 as the original was intended.


Widget

[pyonc]

I think both versions are indeed original JBL product ( sorry Widget ) / though my opinion is definitely simple conjecture.

Through the years I've noticed many of those cut versions ( & they're all cut similarly to the pic ).

I want to believe that if this was such a popular user modification from the past ( producing many cut-ups that have survived to present time ), we should have heard about the practice before now ( through the interwebz etc. ).

So goes my argument.

Thanks for your feedback.
I have the very early 1964 model of C54 Trimline with LE8-1 (later LE8T), and this early PR8.
No spider cut like that on this PR. And I googled on this to check if there is PR8 with spider cut like.
Nothing. I wish I found one.
The one in the pic with the spider cut is an early version.
So, clearly someone seems to have cut it like that for some purpose, like Widget mentioned.

[jlyons]

I purchased a pair of Altec Bolero passive radiators with a neat factory appearance spider in that shape, with no provision for adding weight. I too am curious...

[Robh3606]

The one with the cut spider likely has a lower FS for a different application,

Rob

[Ed Kreamer]

Colleagues,

I can't speak about the PR 8, but I can for the PR 10. The PR 10's did indeed come cut out from the factory, ( I have 3 of them ) so perhaps the 8 came that way also. As to the Altec bolero they did not and as previously
mentioned there was no way of adjusting them like the PR 10 and the PR 15 did. I modified the altecs by fitting them with my own adjusting discs. It actually worked fairly well.

I'd go ahead and use them, and adjust accordingly

Ed

[pyonc]

Colleagues,

I can't speak about the PR 8, but I can for the PR 10. The PR 10's did indeed come cut out from the factory, ( I have 3 of them ) so perhaps the 8 came that way also. As to the Altec bolero they did not and as previously
mentioned there was no way of adjusting them like the PR 10 and the PR 15 did. I modified the altecs by fitting them with my own adjusting discs. It actually worked fairly well.

I's go ahead and use them, and adjust accordingly

Ed

Interesting. Do you have the pic of that PR10 with the cut-out spider?

[Ed Kreamer]

No I don't, but it looks like your lower PR8 photo. Except it has a bolt in the center where adjustment discs can be added or removed.