Anyone tried the Troels Gravesen L112 upgraded crossovers ?

[andresohc]

I just read Troels Gravesen articles on modifying the L112 crossovers (http://www.troelsgravesen.dk/JBL-L112.htm), to clean up the midrange lobbing and muddling of the mids by the woofers and tweeters. I couldnt find any discussion of this on Lansing Heritage and wondered if anyone has taken the jump and how did it go? Worth the effort?

[Earl K]

Well, I haven't built anything of his but I do have huge respect for Troels Gravesen and all of his efforts .

His latest ( tip-of-the hat ) tribute to the 4345 is really quite inspired ( & very much an acknowledgement to JBL's prowess in it's 4-way designs ).

So, with all that glowing praise I would certainly try one ( or two ) of his mods on JBL's legacy products ( if I owned any ).

[andresohc]

Well, I haven't built anything of his but I do have huge respect for Troels Gravesen and all of his efforts .

His latest ( tip-of-the hat ) tribute to the 4345 is really quite inspired ( & very much an acknowledgement to JBL's prowess in it's 4-way designs ).

So, with all that glowing praise I would certainly try one ( or two ) of his mods on JBL's legacy products ( if I owned any ).

Yeah, his 43XX project looks delectable. In the L112 mods he basically redesigns the filters to decrease the overlap of the elements and decrease the lobes in the mids. Serious mods that no doubt cost quite a bit for new caps. He reports it sharpens up the midrange, makes it more discreet so that the imaging isnt so muddled. He also suggests building new front baffles with the elements aligned vertically. He has no love for the 044 tweeter which I have grown fond of. I grew up with JBLs on this site and was hoping to defer to the expertise here. Or maybe other suggestions a little less radical as an alternative. Maybe replacing the inductors with larger air core coils, newer midline caps etc.

[BMWCCA]

I've owned my L112s for about 37 years and have never heard anyone complain about the "defects" Troels mentions.

I also happen to like the 044. Apparently JBL did, too, since they updated it for the 250ti.

[1audiohack]

I noticed on Troels choices page he says over and over that functionally he cant know what you like and he wont hear the same as you will hear.

You couldn’t possibly know if you would like them more or less with his crossover networks unless you directly compared them.

That said, I am glad you like them as is, honest.

Barry.

[Robh3606]

I also happen to like the 044. Apparently JBL did, too, since they updated it for the 250ti.

Well what condition are his in?? After how many years who knows?? They don't look right based on his measurements. Do these have a foam pad as well or did they consider the phenolic self dampening and not need one??

Rob

[santashooter]

I only know Troels Gravesen based on his L100 century filters which have been very popular here in Denmark.
Having had 4 pairs of L-100 myself, restoring and showcasing them for friends and on forums i have heard more times that i like to, that "If you want them to sound better - make the Troels Gravesen filter".
While i do admire the filter Troels Gravesen makes and his way of working, the sound of the filters aren't for me - it takes away some of what i like about JBL. It might not be a "Theoretically correct" sound in terms of modern loudspeaker designs, and you can throw better crossover charts at me all day, but that doesn't change the fact that, in my mind, it takes away what i like about the sound. which leads me to my critique, because there is something I just simply cannot fathom in the approach:
If you don't like the sound of your speaker - why not buy a different speaker?


I love my JBL's for how they sound - with good and bad. There are a lot of people who love their original JBL's as well, and who has a hard time getting a pair that is still original, and in good condition.
Instead of modding or tricking out your speaker to become something else, why not sell it to someone who wants exactly that, and look for something that kills the itch? (Or buy all the components and build a clone )

and of course, i know it is fun to tinker, and that you don't necessarily harm any part of the speaker, trying a new crossover (As long as you take care with foilcals taking out the filter screws and keep the L-pads mounted since the new filter doesn't use them) - but still?
I often compare vintage audio with vintage cars - it seems counter-productive to make your old mustang into a vintage jaguar

[Earl K]

I only know Troels Gravesen based on his L100 century filters which have been very popular here in Denmark.
Having had 4 pairs of L-100 myself, restoring and showcasing them for friends and on forums i have heard more times that i like to, that "If you want them to sound better - make the Troels Gravesen filter".
While i do admire the filter Troels Gravesen makes and his way of working, the sound of the filters aren't for me - it takes away some of what i like about JBL. It might not be a "Theoretically correct" sound in terms of modern loudspeaker designs, and you can throw better crossover charts at me all day, but that doesn't change the fact that, in my mind, it takes away what i like about the sound. which leads me to my critique, because there is something I just simply cannot fathom in the approach:
If you don't like the sound of your speaker - why not buy a different speaker?


I love my JBL's for how they sound - with good and bad. There are a lot of people who love their original JBL's as well, and who has a hard time getting a pair that is still original, and in good condition.
Instead of modding or tricking out your speaker to become something else, why not sell it to someone who wants exactly that, and look for something that kills the itch? (Or buy all the components and build a clone )

and of course, i know it is fun to tinker, and that you don't necessarily harm any part of the speaker, trying a new crossover (As long as you take care with foilcals taking out the filter screws and keep the L-pads mounted since the new filter doesn't use them) - but still?
I often compare vintage audio with vintage cars - it seems counter-productive to make your old mustang into a vintage jaguar

Those are all good points ( & I believe they are well made ).

IME, the pursuit of imaging in my own projects can lead to sacrifices in "Tone" that are very hard to quantify ( & harder to rectify ).

I find it does end up being a balance between the two ( when not willing to just chuck the components and look for some that are less dynamic > or smoother sounding ).

In a nut-shell, I find that as one sharpens the image then one is also sharpening possible transient related audible annoyances that will also need some attention. It's truly a double-edged sword. So, many times it's just easier to soften the focus to retain the tone ( which I speculate JBL used to do ).

BTW, my budds original 4310's still sound great in their original form ( with great tone et al ).

[Ian Mackenzie]

My impression is it was a consumer sound Jbl wanted to portray at the time.
Therefore it is (was) what it is.

I actual recall hearing the L112’s. They were a Impressive bookshelf loudspeaker which was a popular category at the time but well above my budget.

The competition were Avid 103’s, ESS Tempest and the like in the West Coast Sound space to name a few. I mentioned the 103’s because l ended up with the Avid 102’s which were to my taste and budget at the time.

If today you compare an AR3 to an L100 or an L112 you will find the AR3 needs a lot more power.

In contrast Jbl Pro was exploiting the new bi radial monitors which were a true monitor if the dates in the L112 article are correct.

I agree with Earl in that tone wins over attempts to image. I recently heard a few live jazz sessions in Scotland and it’s about tone, instrumental clarity and vocal definition. That may sound like a line out of the 4343B brochure but that’s the real deal 15-20 feet from stage.

[Earl K]

I noticed on Troels choices page he says over and over that functionally he cant know what you like and he wont hear the same as you will hear.

You couldn’t possibly know if you would like them more or less with his crossover networks unless you directly compared them.

That said, I am glad you like them as is, honest.

Barry.

True all that!

Troels mentions that he he likes the voicing of the L112 but wanted to improve it's imaging abilities ( which he did > from his perspective ).

If better imaging is one's goal then try his mods ( if one has the money ) or reverse engineer his efforts ( fwiw, all the necessary info is actually on that page for those who have the talent and inclination ).

Well what condition are his in?? After how many years who knows?? They don't look right based on his measurements. Do these have a foam pad as well or did they consider the phenolic self dampening and not need one??

Troels consistently shows he has great respect for JBL's transducer designs ( he likely hasn't had enough of them pass through his fingers to create an opinion on JBL's QC abilities ) .

He's also the first ( serious ) speaker designer to offer up some very public shout-outs for the le20 ,le25 & le26 tweeters.

"Imaging" isn't for everyone ( & the lack of it in many of JBL's middlin home products hasn't really hurt JBL's sales in past decades ).

I kind of doubt that GT will come here to explain JBLs' reasoning behind releasing so many speaker systems into the market with muddled imaging ( & I suspect it's a subject that many of the JBL faithful don't really want to hear ).