Speaker Asylum

General speaker questions for audio and home theater.

Return to Speaker Asylum

Message Sort: Post Order or Asylum Reverse Threaded

JBL L-112 Crossover rebuild

71.112.179.6
Posted on May 30, 2020 at 10:14:07
Batman
Audiophile

Posts: 4194
Location: Western Pennsylvania
Joined: March 31, 2000
Contributor
  Since: June 16, 2000
 I've owned these for over 30 years from my bachelor days.

Anybody tried this crossover rebuild kit (Link below)? Is it worth 500 Bucks?
Not sure I paid that much for the speakers back then. They have sentimental value to me.






 

Hide full thread outline!
    ...
RE: JBL L-112 Crossover rebuild, posted on May 30, 2020 at 12:16:12
vinnie2
Audiophile

Posts: 4481
Location: North Carolina
Joined: September 28, 2013
 That seems awful damn high for some caps and coils. Can't you just swap out the parts yourself?

 

RE: JBL L-112 Crossover rebuild, posted on May 30, 2020 at 14:02:38
airtime
Audiophile

Posts: 11287
Location: Arizona
Joined: February 4, 2003
 I looked at the board and they are offering some high quality parts on that crossover board.

However, as Vinnie stated why not just get a few good parts and rebuild it yourself?

From the looks of the original schematic there are only a few parts worth replacing.

Leave all the coils because they DON'T go bad.
The woofer has only a coil in the audio path - so leave it
The midrange has NO components in the audio path - just by decent bypass caps.
the tweeter has one 4uf cap. Buy yourself a nice ClarityCap for that one.
MAYBE buy a new 8ohm Lpad.
New wire, connections and solder and you're good to go

 

My understanding , posted on May 30, 2020 at 15:48:53
Batman
Audiophile

Posts: 4194
Location: Western Pennsylvania
Joined: March 31, 2000
Contributor
  Since: June 16, 2000
 Is that this is a total redesign of the crossover. Iron-core inductors replaced by air-core. Midrange and tweeter controls removed. There are no resistor values on the schematic.


 

+1 nt, posted on May 30, 2020 at 18:24:00
vinnie2
Audiophile

Posts: 4481
Location: North Carolina
Joined: September 28, 2013
 nt

 

That new crossover is going to change your speakers, posted on May 30, 2020 at 19:09:50
airtime
Audiophile

Posts: 11287
Location: Arizona
Joined: February 4, 2003
 don't forget that the new crossover will be changing rolloffs, impedance, phase,padding, etc....

The sound you're enjoying now will not be the same sound you'll be hearing with the new crossover.

From experience I've learned that those vintage drivers work better with the simplest of crossovers. Throw a second order or some filtering in there and things get muddy REAL fast. Been there dude!!!

 

Looks good!, posted on May 30, 2020 at 20:45:40
hawkmoon
Audiophile

Posts: 903
Location: cleveland
Joined: July 11, 2003
 Consider putting the crossover external to the speaker. Easier to work on and eliminates internal speaker sound from affecting the crossover.

 

RE: JBL L-112 Crossover rebuild, posted on May 30, 2020 at 21:33:32
rivervalley817
 in my experience this approach will come closest to keeping the speaker 'voicing' as the designer intended

so if you used to like it you'll still like it

be well,


 

RE: That new crossover is going to change your speakers, posted on May 31, 2020 at 05:16:39
vinnie2
Audiophile

Posts: 4481
Location: North Carolina
Joined: September 28, 2013
 Attached the +1 to the wrong post. It should have been attached to yours as I agree with you........

 

RE: My understanding , posted on May 31, 2020 at 16:47:34
B. Scarpia
 Iron core vs. air core is a matter of iron core delivering tighter bass in large values. Small value mids and tweeters, go air core.

Removing the level controls usually is an improvement keeping in mind the "0" position may well offer some resistance which you can measure and substitute a resistor.

a $12 meter will accurately measure the resistors but why replace them? $20 bucks gets you a good enough capacitance meter.

Z-Caps aren't that good, I've got a box full ;-} At that price point use Obbligatos.

Jantzen coils are excellent, right on spec, and even 16 ga. not that expensive.

 

Midrange signal path.., posted on May 31, 2020 at 20:12:18
Presto
Audiophile

Posts: 5957
Location: Canada
Joined: November 10, 2004
 ... lots of components there!

They just inverted the mid unit polarity.

Cheers,
Presto

 

RE: That new crossover is going to change your speakers, posted on May 31, 2020 at 20:43:11
hahax@verizon.net
Audiophile

Posts: 4306
Location: New Jersey
Joined: March 22, 2006
 No question this is a new, different crossover. Just go to Troels Graveson's web site and you can see the affect on individual drivers and overall response. It will sound different.

The overall response is smoother, flatter. More important to me the response of each driver and its crossover is way nicer which generally will make for more linear dynamics. I would do it but if you are just looking for a bit nicer version of the original speaker, I suspect this is essentially a new design even with the same cabinet and drivers. A crossover can be that important.

 

RE: That new crossover is going to change your speakers, posted on May 31, 2020 at 21:36:55
rivervalley817
 with all due respect,

I just want to reiterate that the closer the X over refresh is to the original design the truer it is to that designs voicing

and usually cheaper with better results

just as Airtime stated

both he and I learned from our mistakes

so you don't have to

[disclaimer]

I am sentimental about vintage gear so maybe a little biased

with regards,







 

RE: Midrange signal path.., posted on June 1, 2020 at 05:57:53
airtime
Audiophile

Posts: 11287
Location: Arizona
Joined: February 4, 2003
 opps, didn't notice that since I kind of rushed looking over the entire site. Still, just replace the caps and maybe a new metal film resistor in the audio path.

 

RE: JBL L-112 Crossover rebuild, posted on June 1, 2020 at 06:41:12
Ric
Audiophile

Posts: 364
Joined: October 14, 2001
 Hi, If you love your speakers and don't want to part with them, then why not? I have different speakers (open baffle) and decided to upgrade a few crossover parts with Jupiter caps and Pace Audio resistors. Huge improvement! You really don't know what your speakers are capable of until you use quality parts in the crossover. I can't comment on the specifics of parts quality/money/value--just my two cents. good luck!

 

RE: JBL L-112 Crossover rebuild, posted on June 1, 2020 at 07:46:45
Rpower
Audiophile

Posts: 280
Location: Northeast Georgia
Joined: October 27, 2000
 The L112 has already fixed the weakest point of the JBL100s, the paper cone tweeter. The JBL tweeter caps are pretty good already. If you like the sound of them, don't fix them if they aren't broke. The kit you are looking at will be an entire redesign of the original crossovers, with a completely new sound for the speaker, and pretty expensive to boot. They are built with quality components meant to last a lifetime, much better than most new speaker offerings.

 

Thanks, I came to the same conclusion, posted on June 1, 2020 at 08:00:39
Batman
Audiophile

Posts: 4194
Location: Western Pennsylvania
Joined: March 31, 2000
Contributor
  Since: June 16, 2000
 I was mostly looking for something to do during the lockdown but ruining my beloved speakers is not one of them.


 

One more thought..., posted on June 1, 2020 at 09:02:46
E-Stat
Audiophile

Posts: 37606
Joined: May 12, 2000
Contributor
  Since: April 5, 2002
 A weakness of that whole generation of JBL three ways was the choice to push the midrange considerably past its useful range in terms of consistent directivity. Where the current LSR6332 using virtually the same sized drivers crosses the 5" midrange at 2.2k, the L112 goes almost another octave to 3.7k. Ideally, the driver should not be asked to deliver a wavelength shorter than the nominal piston diameter or it will clamp down. 3.7k is 3.6 inches.

Consequently, there's a weird "hourglass" perspective to the directivity with respect to frequency. Wide at bottom and top and constricted at a particularly sensitive area.

Perhaps a newer crossover approach would fix it.

 

RE: That new crossover is going to change your speakers, posted on June 1, 2020 at 21:00:21
hahax@verizon.net
Audiophile

Posts: 4306
Location: New Jersey
Joined: March 22, 2006
 We basically agree, apples versus oranges. Like I said the Graveson crossover makes anew speaker. And I tried to show its pluses but you are losing what was probably what was liked in the original design.

 

RE: That new crossover is going to change your speakers, posted on June 1, 2020 at 21:21:19
rivervalley817
 all that & I'm a skinflint!

I thought those were tangelos?


with regards,


 

RE: One more thought..., posted on June 5, 2020 at 09:43:56
Davey
 The LSR6332 model is no longer current. JBL has moved much of their speaker lineup to (you'll love this) active systems. :)

Dave.

 

Easy to understand why, posted on June 5, 2020 at 12:14:48
E-Stat
Audiophile

Posts: 37606
Joined: May 12, 2000
Contributor
  Since: April 5, 2002
 the target audience for those would be satisfied with "onboard" active.

I was mainly observing how newer designs addressed the poor xover frequency choices from the Locanthi era.

 

Page processed in 0.032 seconds.

[ Top Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]
[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]