Good morning!
As the title of the topic suggest, I am looking for the Thiele/Small parameters for the woofer section of the G-600 Triax loudspeaker, with no luck so far.
Could anyone be so kind to search for them in his/her literature and pass them to me? That would be greatly appreciated! 🙂
I'm not 100% sure about this, but I have read that the woofer section of the G-600 is the same as the P15LL woofer, which is perhaps easier to find. So, should anyone have the T/S parameters for the P15LL, those would be extremely useful as well.
Thanks for helping...
As the title of the topic suggest, I am looking for the Thiele/Small parameters for the woofer section of the G-600 Triax loudspeaker, with no luck so far.

I'm not 100% sure about this, but I have read that the woofer section of the G-600 is the same as the P15LL woofer, which is perhaps easier to find. So, should anyone have the T/S parameters for the P15LL, those would be extremely useful as well.
Thanks for helping...
Greets!
Assuming you mean the G-610, correct. Specs vary of course, especially over time, but this woofer was marketed as the WE 752[?], so should have similar specs.
As always though, best to measure what one has as these now extremely old drivers typically measure different unless they’ve been exercised regularly with enough power to keep them relatively limber.
P15LL Plot and Parameters
GM
Assuming you mean the G-610, correct. Specs vary of course, especially over time, but this woofer was marketed as the WE 752[?], so should have similar specs.
As always though, best to measure what one has as these now extremely old drivers typically measure different unless they’ve been exercised regularly with enough power to keep them relatively limber.
P15LL Plot and Parameters
GM
No: G-600. The G-610 is a totally different speaker with an exponential woofer cone, which has nothing to do with the P15LL hardware.
Thanks for the link you posted, which data I already acquired in the past. Unfortunately it shows measurements (not factory data) of a P15LL replica made by Ted Weber, so it is not official Jensen data and it is not even a genuine Jensen speaker. Moreover, I still don't know for sure if the G-600 and the P15LL have anything in common, although they look very similar.
Nonetheless, I still could't manage to find anything better and I may decide to go with those figures in the next days. I'm very surprised by the total lack of literature about these highly regarded speakers, but so it is or so it seems. 😕
Many thanks for your reply anyway! 🙂
Thanks for the link you posted, which data I already acquired in the past. Unfortunately it shows measurements (not factory data) of a P15LL replica made by Ted Weber, so it is not official Jensen data and it is not even a genuine Jensen speaker. Moreover, I still don't know for sure if the G-600 and the P15LL have anything in common, although they look very similar.
Nonetheless, I still could't manage to find anything better and I may decide to go with those figures in the next days. I'm very surprised by the total lack of literature about these highly regarded speakers, but so it is or so it seems. 😕
Many thanks for your reply anyway! 🙂
does the G-600 have a single roll or double roll? because the I believe the P15LL is a double roll. The P15Q and some P15N's are a single roll and more of a full range driver. Is your G-600 a JAP? That's a high efficiency speaker. I may have a sales brochure, If I come across it, I'll scan and post it. But probably not for a week or so if I'm lucky enough to find it.
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Well, my P15LL has what appears to be a curvilinear cone with a double roll same as some tri-axs I've seen, ditto my LS15, both bought used in mid '60s, if that's what you mean by 'expo'.
WRT specs, I didn't read the site, just looked at the link I posted, but TW's 'P15LL' measures close enough to both my real P15LL and similar vintage Altec 515s to satisfy me.
FWIW, back then, driver's for a given frame size, performance range tended to be very similar, so that there was good interchangeability over a wide range of cab alignments since the driver-electronics interaction allowed significant frequency response shaping.
GM
WRT specs, I didn't read the site, just looked at the link I posted, but TW's 'P15LL' measures close enough to both my real P15LL and similar vintage Altec 515s to satisfy me.
FWIW, back then, driver's for a given frame size, performance range tended to be very similar, so that there was good interchangeability over a wide range of cab alignments since the driver-electronics interaction allowed significant frequency response shaping.
GM
That's weird.
The G-610's cone has the profile of a rotation surface, the surface itself being an exponential function, because the woofer cone is also the horn of the midrange compression driver. This is quite easily seen in this sectioned drawing:
In the G-600 an exponential woofer cone would be useless, as it has a coaxial but separated plastic horn to load the midrange driver. Thus, the woofer cone has the more common shape of a linear truncated cone. Both details should be quite well visible in this picture of a G-600 unit:
It seems very odd to me that the P15LL may have a "curvilinear" (exponential 😕 ) woofer cone, as it is not a coaxial speaker and thus I can hardly see any reason to use such an expensive and hard to manufacture profile on a totally conventional speaker. That would also contradict what I've read, that is: that the G-600 and the P15LL share the same cone, which seems reasonable. At the top of the folliwing linked thread (from another forum) there is a picture of a pair of what are said to be two P15LLs, with a nice photographic detail of the cone profile, and it looks to me rectilinear, not curvilinear or exponential:
Jensen - Page 8 - Audio Voice Acoustics
Impedance is said to be 16 Ohms, which is the same impedance of the G-600, which also speaks for a similarity between the two woofer sections.
The G-610's cone has the profile of a rotation surface, the surface itself being an exponential function, because the woofer cone is also the horn of the midrange compression driver. This is quite easily seen in this sectioned drawing:

In the G-600 an exponential woofer cone would be useless, as it has a coaxial but separated plastic horn to load the midrange driver. Thus, the woofer cone has the more common shape of a linear truncated cone. Both details should be quite well visible in this picture of a G-600 unit:

It seems very odd to me that the P15LL may have a "curvilinear" (exponential 😕 ) woofer cone, as it is not a coaxial speaker and thus I can hardly see any reason to use such an expensive and hard to manufacture profile on a totally conventional speaker. That would also contradict what I've read, that is: that the G-600 and the P15LL share the same cone, which seems reasonable. At the top of the folliwing linked thread (from another forum) there is a picture of a pair of what are said to be two P15LLs, with a nice photographic detail of the cone profile, and it looks to me rectilinear, not curvilinear or exponential:
Jensen - Page 8 - Audio Voice Acoustics
Impedance is said to be 16 Ohms, which is the same impedance of the G-600, which also speaks for a similarity between the two woofer sections.
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