JBL L300/136a Help
- Thread starter Kazanski
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edgewound
JBL Pro Authorized...
The 2245H was first and foremost a subwoofer for studio monitors, 4345, and home hi-fi, B460. It was used in some pro audio applications...mainly Cinema Systems. The 2240H is the live sound counterpart. Foam surrounds are the most acoustically inert...but they do have a finite lifespan. Specialized items often have a finite lifespan. I've been toying with the idea of making a no-rot recone kit, at the expense of a few hertz of Fs. Might be worth the compromise.
Audiohound
Empiredude
I learned of the 2245h while working in several recording studios in NYC. I struck up a conversation with a JBL rep who informed me of the B460 for home use. Just like a version of the L-100s were were meant for the studio. Wanting that "Live" studio sound in my home I purchased a pair of L100s, and they are rocking still today, never a repair to the drivers. Although I have been looking into recapping the crossovers after reading some chatter, but I always go by the old addage "If it ain't broke, don't fix it" once a month or so I will take a penny and twist the two controls to extreme min to max and after 40 plus years, they don't make noise or scratch when turned, so I'm okay. The B460 for me was like most men and Sports cars, when you feel financially secure after lots of hard years trying to make your paper, so you treat yourself to a present..mine was the B460. I would still have it today, but the last reconing did it for me along with a new home location and the inability to find genuine parts. Again it was all about the foam surround. My personal opinion, had it been a cloth surround with dampening fluid, the woofer would have not needed constant reconing or refoaming
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They were pretty popular for a while out here in movie theaters because of their nice deep bass, but after a while, most of them ended up being reconed as 2240s, and always due to repeated surround failure. I agree totally about the lifespan thing. Stuff wears out.
As far as sacrificing a few Hz of FS for durability, most people would never know the difference, and would probably appreciate something that lasts longer. You can always add a little mass to the cone, or the end user can always add a little EQ. I'm not opposed to configurations that are different from what JBL offered 40 years ago.
That 2245 motor is too nice to waste as a doorstop.
edgewound
JBL Pro Authorized...
Actually...many were reconed with 2240H because over over-excursion, and impaled voice coils driven out of the gap. A larger foam surround would have exascerbated that. The 2245 voice coil is longer than the 2240. Apparently, bass hounds can't get enough until the subwoofer quits. Low cut filters are a thing for a reason.
The thing about changing a 2245H to a "non-factory" cloth surround design, is many won't go for that...unless it's proven to work well. It's funny that even if a design change is meant to gain some benefit, hardcore faithful users will never except it. Funny thing is...new JBL high-end drivers now have cloth surrounds. They've come full circle.
That's totally worth repeating. I might even be a little guilty of that myself.
lIt's up to us to gauge a customer's needs and steer them in the direction that our experience tells us will yield the most satisfactory results. Whether they are willing to listen or not is a whole other discussion.
Next time I order parts from you know who, I may get a 2240 cone and 2245 coil and do some experimentation. I have an empty basket and a couple of iterations of 4645 kicking around here taking up space.
BTW, what are you using for edge treatment on cloth/paper surrounds?
I would rather listen to my 2241s than my AlNiCo 2235s and assume that 2245s would be even worse. The 2241s are so much more realistic sounding than the 2235s. Sorry, but Greg Lake's bass does not sound right on 2235s. They are lifeless.
And while the 2235s may put out a bit more deep bass, they don't hold a candle to the way the 2241s handle an actual bass guitar.
And, when I made the Meman's I specifically did not use any speaker with foam surrounds to ever change. I ran them all through WinISD and the 2241 was the clear favorite for low frequency extension in a reasonable cabinet size.
And while the 2235s may put out a bit more deep bass, they don't hold a candle to the way the 2241s handle an actual bass guitar.
And, when I made the Meman's I specifically did not use any speaker with foam surrounds to ever change. I ran them all through WinISD and the 2241 was the clear favorite for low frequency extension in a reasonable cabinet size.
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I think he’s talking about LE15Bs with 2235 recones.
AlNiCo 2205s reconed as 2235s with factory kits and re-magged..., twice. Three of them no less.
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edgewound
JBL Pro Authorized...
LE15B should never be reconed with a 2235 kit. The motors are not interchangeable
Remagged twice?
I am curious, what did you find / measure that led you to having them re-magnetized? Everything that I have read recently regarding Alnico magnet speakers (primarily mids and tweets) indicates that under normal use / within design parameters there isn’t a high enough gauss from music input to change / degrade the Alnico magnets, were you able to measure or was the shop that re-magnetized them? I have some 416-8Bs that I’ve considered sending out to have them re-shot, but I have no indication that they’ve degraded, just that unknown with 40-year-old drivers.
I purchased three blown AlNiCo 2205s to have them reconed as 2235s and remagged to replace the 130As in the L200 cabinets and my center channel. I brought them home from Orange County Speaker and mounted them and was instantly displeased with the lack of life/midrange. I actually preferred the sound of the 130As though they lacked the bottom end. I pulled one out and Grumpy came over with WT-2 (Woofer Tester 2 from Parts Express) and we tested a speaker. For all intents and purposes the parameters were now similar to the 2235. But the BL came out just a hair low ~19.* out of 20.*).
The midrange is a product of the BL (control of the cone), so I took all three woofers back and they remagged them a second time for no charge. The BL now came up to over 21.*, a bit above factory spec. But they didn't gain any of the life I had hoped for.
If someone wants to recone a JBL as a 2235, my advise is to leave out the mass ring and just go as a 2234 to (hopefully) retain some life in the sound.
Thanks.
All three exponential horns have been replaced with the longer L300 horns and they all have original 2420 tangential diaphragms in their drivers.
turboyam
The Kenwood fan!
I agree with the leave-out the mass ring when reconing with a 2235 kit. Did it and regret it...
Nyjblbob
Hooked on Horn's and Tubes. Go big or go home
I was wondering if in the case of my 4350's, and 4343's, when Biamped,
where the 2230a's originally had aquaplas sprayed on them, with and I think unlike the later 2231's and 136a's
had plain cones, and the mass rings.. Their only used 0-250hz.
Or in the case of the 4435's, where one woofer only goes up to 100Hz, should keep the mass ring 2235, the other
full range 0-1,000 hz woofer would work better with out the mass ring 2234 .
FWIW just about all Le14's have the Aquaplas
where the 2230a's originally had aquaplas sprayed on them, with and I think unlike the later 2231's and 136a's
had plain cones, and the mass rings.. Their only used 0-250hz.
Or in the case of the 4435's, where one woofer only goes up to 100Hz, should keep the mass ring 2235, the other
full range 0-1,000 hz woofer would work better with out the mass ring 2234 .
FWIW just about all Le14's have the Aquaplas
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I presume this is when reconing the 2205s or what speaker are you reconing with 2235 kits?
I'm very happy with the (measured and subjective) response of the 136H reconed as a 2235 w/ the original kit and massring. I suspect that there are motors and applications that are not as well suited to a C8R2235 re-cone so responses should be specific.