hi, I have a pair of JBL L100 Classics and they definitely needed a sub ( since they roll at about 70 hertz).
That 12" is more of a low mid driver than a real low frequency driver.
My 4312SE sounds much lower like 30hz and warmer.
I wonder what I can do to get to 30-40hz?
That 12" is more of a low mid driver than a real low frequency driver.
My 4312SE sounds much lower like 30hz and warmer.
I wonder what I can do to get to 30-40hz?
Move them closer to the wall(s) to get more low end gain from the room. The L100 Classic have a fairly good low frequency extension potential because the port are tuned somewhere between 30-40Hz.
Or you can EQ them above 30Hz to taste.
Or you can EQ them above 30Hz to taste.
That review didn't published the impedance response of the L100 Classic. But below is one from Audioholics. I don't see where it dips to 3.5 Ohms and at its lowest value, the phase angle is not high and in the mid- low-bass range (say below 90Hz) the impadance value is fairly high.
This is a very typical impedance load, nothing demanding for a modern amp IMO.
Edit: But it seems that this impedance measurement response is still not completely correct because the minimum impedance value (about 32Hz) of the vent tuning is not where the 0 phase angle (about 39Hz) is.
This is a very typical impedance load, nothing demanding for a modern amp IMO.
Edit: But it seems that this impedance measurement response is still not completely correct because the minimum impedance value (about 32Hz) of the vent tuning is not where the 0 phase angle (about 39Hz) is.
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Could this be the reason why it doesn't go below 70hz? (tight-punchy bass)
I have 4312SE with the same woofer and The bass is much warmer and bigger (boomy bass)
I have 4312SE with the same woofer and The bass is much warmer and bigger (boomy bass)
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The thing is the originals were ment to be hang from a wall, and rely on wall loading to get low bass. Without that, the bass start to roll off at 100Hz and is about 10dB down at 35Hz. That is a perfect slope for wall loading, not for freestanding speakers.
My uncle had those, and he hang them from the wall, at about 30cm (a bit less than a foot) from the ceiling near corrners, and so got a lot of bass out of it. I've seen the same way of using them in other houses in the 1980's as kid. It was a popular speaker (probally also because of the looks).
My uncle had those, and he hang them from the wall, at about 30cm (a bit less than a foot) from the ceiling near corrners, and so got a lot of bass out of it. I've seen the same way of using them in other houses in the 1980's as kid. It was a popular speaker (probally also because of the looks).
Trademark of "modern" JBL since they tailored they're products to the Japanese market with a leaner bottom end compared to the older speakers. There is also a lot less distortion compared to vintage drivers. So they have been designed to be like that on purpose by the JBL speaker engineers.
L100classic and 4312se use different drivers for highs, and bottom end.
The 4312SE use the 1200FE-8 transducer (audioheritage.org has the datasheet). And the 100 classic use the JW300PW-8.
Same frame, but the JW uses a double stack FE magnet.
That is some of the lowest distortion 12" midwoofers you can find, and the aquaplas damped cones tend to be smooth and well behaved.
4312se has a higher quality 'tweeter' 054 al/mg.
Midranges are the same in both.
Here is the 1200fe /jw300pw "stacked to see the difference clearly🙂
Will have more xmax, less excursion related distortion down low (a more constant BL(x) curve) then the 1200FE if everything else is equal.
So judging by the woofers alone the L100's woofer has the capability to go lower then the 1200FE.
Sounding "lean"/clean/anemic can also be the effect of less distortion.
While it is tuned higher then the original L100, in accordance with modern day JBL's, after all they're largest marketshare for "home use" is in Japan by far.
The L100 classic -F6 point is 4hz lower then the 4312se, with a slightly larger enclosure.
1200FE-8 info:
https://www.audioheritage.org/vbulletin/showthread.php?21713-1200fe-8
Will have more xmax, less excursion related distortion down low (a more constant BL(x) curve) then the 1200FE if everything else is equal.
So judging by the woofers alone the L100's woofer has the capability to go lower then the 1200FE.
Sounding "lean"/clean/anemic can also be the effect of less distortion.
While it is tuned higher then the original L100, in accordance with modern day JBL's, after all they're largest marketshare for "home use" is in Japan by far.
The L100 classic -F6 point is 4hz lower then the 4312se, with a slightly larger enclosure.
1200FE-8 info:
https://www.audioheritage.org/vbulletin/showthread.php?21713-1200fe-8
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HERE IS A DARING PROJECT FOR YOU
From memory, the cabinet width of the L100 is just slightly wider than the 12" woofer. So, this idea for a rear mounted sub-woofer is 12" limited.
What you do is find an Auto sub-woofer with moderate sensitivity, low Fs, low Qts, high Xmax and decent power rating > very doable these days.
You cut and mount the sub. reverse style > magnet out, on the back of the enclosure. (this slightly increases the enclosure volume)
Without changing any existing XO components, you drive this sub. with a high mH inductor that has high DCR. The rough start is 12mH @ 6ohm DCR.
Although experimentation is needed, like stuffing or blocking the existing port, what you have created is a "Large low frequency Power Assisted port".
The rear mounting not only provides 'out of sight' modification but can provide 'near room corner', some very low frequency gain.
This described scenario CAN provide quite astonishing lower-bass output & extension. The phase orientation of the rear sub. is audibly obvious.
PS.
Due to the high DCR of the inductor, price doesn't become prohibitive 🙂
From memory, the cabinet width of the L100 is just slightly wider than the 12" woofer. So, this idea for a rear mounted sub-woofer is 12" limited.
What you do is find an Auto sub-woofer with moderate sensitivity, low Fs, low Qts, high Xmax and decent power rating > very doable these days.
You cut and mount the sub. reverse style > magnet out, on the back of the enclosure. (this slightly increases the enclosure volume)
Without changing any existing XO components, you drive this sub. with a high mH inductor that has high DCR. The rough start is 12mH @ 6ohm DCR.
Although experimentation is needed, like stuffing or blocking the existing port, what you have created is a "Large low frequency Power Assisted port".
The rear mounting not only provides 'out of sight' modification but can provide 'near room corner', some very low frequency gain.
This described scenario CAN provide quite astonishing lower-bass output & extension. The phase orientation of the rear sub. is audibly obvious.
PS.
Due to the high DCR of the inductor, price doesn't become prohibitive 🙂
with just a 94 cm2 opening on the back ( I applied the 2πr law for a 12" cut 
) I would continue the line for making a TL
4 m indeed ( I applied the 1/4 wave ) for 30 Hz, less if tapered...
) I would continue the line for making a TL4 m indeed ( I applied the 1/4 wave ) for 30 Hz, less if tapered...