JBL drivers's comparison LE15,LE15A,LE15B

[citadel]

Dear,
I'm looking for some JBL LF drivers such as: LE15, LE15A,LE15B,136A. So, which one gives better LF?
Thanks,

[pos]

Hi citadel,

The 136A is the consumer version of the 2231a, and is similar in its T/S parameters to a 2235H, with an alnico motor and an older recone kit. You can install a 2235H kit on them but the alnico motor will still limit the maximum power they can admit (both for heat dissipation of the non-vented motor, and alnico demagnetisation reasons).

The Le15a is the consumer version of the 2215a, ancector of the 2231a, also with an alnico motor.
It is an underhung design, and as such should not suffer from alnico demagnetisation: http://www.audioheritage.org/vbullet...75&postcount=2

The Le15b is the consumer version of the 2216a, only used in the L200 (first version) and the 4325. It is similar to the Le15a, but with a cloth surround. Very efficient, but no real bass. Its T/S are unknown.


EDIT: I see you already knew all that: http://www.audioheritage.org/vbullet...6&postcount=10

[citadel]

Hi citadel,

The 136A is the consumer version of the 2231a, and is similar in its T/S parameters to a 2235H, with an alnico motor and an older recone kit. You can install a 2235H kit on them but the alnico motor will still limit the maximum power they can admit (both for heat dissipation of the non-vented motor, and alnico demagnetisation reasons).

The Le15a is the consumer version of the 2215a, ancector of the 2231a, also with an alnico motor.
It is an underhung design, and as such should not suffer from alnico demagnetisation: http://www.audioheritage.org/vbullet...75&postcount=2

The Le15b is the consumer version of the 2216a, only used in the L200 (first version) and the 4325. It is similar to the Le15a, but with a cloth surround. Very efficient, but no real bass. Its T/S are unknown.


EDIT: I see you already knew all that: http://www.audioheritage.org/vbullet...6&postcount=10

Thanks,

[dnewma04]

JBL LE15B (range of 4 drivers measured)

Re: 3.3-3.6 ohms
Fs: 24-26hz
Qts: .1633 - .1859
Qes: .1803 - .1950
Qms: 4.172 - 4.763
Le: .58 mH

Vas: measurements to follow.

[originaltubino]

The Le15b is the consumer version of the 2216a, only used in the L200 (first version) and the 4325. It is similar to the Le15a, but with a cloth surround. Very efficient, but no real bass. Its T/S are unknown.

I believe you when you say it has no real bass -- IN AN ORDINARY PORTED or SEALED BOX. In a very very large backloaded horn, it's a different matter.

On Saturday at AK Fest I bought a pair of dnewma04's LE15Bs and put them in these 30 cu ft (5' x 3' x 2') cabinets that night.




The bass is superb down into the 30s.

[robertbartsch]

I always like bass horns but the cabs are big and heavy.

[pos]

The Le15b is the consumer version of the 2216a, only used in the L200 (first version) and the 4325. It is similar to the Le15a, but with a cloth surround. Very efficient, but no real bass. Its T/S are unknown.

Some more info on this driver, thanks to Rob:
http://audioheritage.org/vbulletin/s...ad.php?t=24177

[originaltubino]

I always like bass horns but the cabs are big and heavy.

This is true... and I would hate to move them regularly. But years ago I managed to park this pair in my basement, and I'm just now getting them to work up to their potential. They are straightforward 3/4" plywood without much internal bracing, but... they work well! I toy with ideas to brace and load further... then I think about the day I would have to move them UP the stairs, and I spin another disc.

Back to the LE15B. Can anyone translate those sensitivity numbers into db/1w/1m?

[grumpy]

http://www.thielesmall.com/database.asp

query "JBL" and "15 inch" speakers to narrow the results... noting that
these numbers are 'contributed' but often good/reasonable.

[Mr. Widget]

Back to the LE15B. Can anyone translate those sensitivity numbers into db/1w/1m?

96dB/1w/1m

But at what frequency? Numbers like that are not particularly useful, but it a useful rough guideline.


Widget

[originaltubino]

96dB/1w/1m

But at what frequency? Numbers like that are not particularly useful, but it a useful rough guideline.

The hard-to-read footnote says a signal warbled from 100-500hz, and NOT the inflated 1Khz figure used by other manufacturers for drivers not intended for use over 800hz. My horn loading is probably keeping it up to that level below 100hz...

[vinny]

I have a LE15 hammer engraved B next to the LE15 and 16 ohms hammer stamped engraved just below it. It is foam surround version. Is there a reason why this particular pair we're done like this? Custom order? Different sonically?

[Earl K]

I have a LE15 hammer engraved B next to the LE15 and 16 ohms hammer stamped engraved just below it. It is foam surround version. Is there a reason why this particular pair we're done like this? Custom order? Different sonically?

Vinny,

How about posting a few pictures of what you're talking about?

According to info ( posted earlier in this thread ) a bonafide Le15B will read below 4 ohms.

JBL LE15B (range of 4 drivers measured)

Re: 3.3-3.6 ohms
Fs: 24-26hz
Qts: .1633 - .1859
Qes: .1803 - .1950
Qms: 4.172 - 4.763
Le: .58 mH

Have you measured the DCR of the voice-coils of your woofers ?

That's an important first step to figuring out what woofers you have there.