L100T vs L100T3

[duaneage]

Picked up a pair of L100T speakers from Big Yank ( thanks a million! ) and I was wondering if anyone knew what the difference was supposed to be between the T and the T3.

Both systems use the 104H-2 midrange. The T crosses the mid to the HF a bit lower and the woofer to mid is a bit higher. The Woofer and tweeter have slightly different part numbers. So my question is are the 2214h-1 and 2214H woofers so different?

Are the 035Ti and 035Tia tweeters different animals as well?

Why did JBL make these changes to the L100T series?

[Miss Orchid]

Why did JBL make these changes to the L100T series?

The L100t3 sounds better.

035Ti and 035TiA are functionally equivalent.

2214H and 2214H-1 are functionally equivalent.

[duaneage]

If the drivers are the same then the crossover network holds the key?

I doubt that very much but it is easy enough to try. Sounding better is object though, someone always likes the other version better.

New Coke was so well received in Japan that they don't sell Coca-cola classic there.

[johnaec]

I thought I also heard something that the T3 cabinets were more solid than the original T versions...

John

[Miss Orchid]

If the drivers are the same then the crossover network holds the key?

That is correct.

We did direct comparisons of the L100T and L100t3 in several environments and the conclusions were unanimous.

[Michael Smith]

Afternoon
When the model change happened the "JBL speak' was that 'We have REVOICED THEM by changing the X/over points"
If you AB you will find that the T3 has much better mid range,more foward than 100T.
I'm must be getting old that's nearly 20 years ago,think I better have a nap
Regards
Michael

[duaneage]

This is interesting.
If the difference between the L100T and the L100T3 is related to the crossover points, I will use my crossover substitution box to A-B test the two networks side by side and see how it goes.

It may be unanimous after all. Have any forum members so modified their L100T into L100T3 by changing the crossover points? This should be a fairly inexpensive modification to do.

[duaneage]

I thought I also heard something that the T3 cabinets were more solid than the original T versions...

John

Outside of thicker material, did they add additional bracing material and if so where was it added?

[johnaec]

Outside of thicker material, did they add additional bracing material and if so where was it added?That I couldn't tell you - I own neither. But I'm sure I read a thread here some time ago that did mention the T3 cabinet was better. A diligent search may turn it up...

John

[Michael Smith]

I've had my nap and I feel better now.
When the L100T came out,Sidney had invested a shit load of bugs bunny on a new german wood working machine and in conjuction with a newly discovered veneer called from memory Endriana was able to make a box using only two pieces of timber as the veneer was easy to work with.
I think the five planes were in one piece and the front was then put on/in.
This was going to save $$$$$ and it did compared to the previous range.
I have over the years added braces to L110T boxes with a good result,also changed the caps in the X/over in the 80s' using 250v Metallised Polypropylenes', they worked a treat.
I cannot remember the inners of L100T3 maybe some one has both and can check.
Michael

[duaneage]

Despite some comments I read a while back about this series that disparaged them I am impressed with the wood grain matchup. I was planning to make a pair of these having gathered the drivers and I was debating the crossovers when an opportunity came to buy these. I was impressed enough with the woodwork to ditch the homebrew plans. I don't think I could do as good a job myself with thin veneer as these.

I plan to sweep the speakers with signal generators as part of my croissover experiment and if I find a resonance I don't like I will brace or damp it out.

I'll update everyone on what comes of it.

[jim3860]

Why did JBL make these changes to the L100T series?

The L100t3 sounds better.

035Ti and 035TiA are functionally equivalent.

2214H and 2214H-1 are functionally equivalent. i would have to agree on Miss Orchids thoughts i own a pair of L100ts and a pair of L80t3s the L100s play louder 91db rating versus 90db for the L80t3s but i like the sound of the L80t3s much better more musical and better sounding bass in my opinion not as deep as bass as the L100ts but richer more musical to my ears a little faster response also in the L80t3s that could be because the L80 t3s use a 10 inch woofer versus a 12 inch though i think it is due to a better crossover in the L80t3s rather than the cabinents the L100t3s use a slightly smaller cabinent than the L100ts also around 20 lbs difference there same with the L80ts and L80t3s i have listened to both the L80ts and my L80t3s and the L80t3s win hands down so in mho i think a crossover change might make a world of difference either way L100ts are very nice speakers noyhing to turn your nose down at considered by many as the refernce rock and roll speaker that others are measured by certainly at the price anyways CONGRATS on the nice score from BIG YANK they will only go up in value from here :applaud: jim3860

[johnaec]

i would have to agree on Miss Orchids thoughts ...... CONGRATS on the nice score from BIG YANK they will only go up in value from here :applaud: jim3860jim that has to be the hardest to read paragraph i've ever had the exasperation of reading on the internet don't you ever use capitalization or punctuation so people can read your messages as coherent thoughts instead of just a stream that rambles on and on until you just give up trying to read it:banghead:

Seriously! Many people won't go farther than the first few words with something like that. I'm not going to go back and try to figure out what you said, and I think you'll lose the attention of other readers too. Punctuation isn't that hard...

John

[jim3860]

jim that has to be the hardest to read paragraph i've ever had the exasperation of reading on the internet don't you ever use capitalization or punctuation so people can read your messages :) as coherent thoughts instead of just a stream that rambles on and on until you just give up trying to read it:banghead:

Seriously! Many people won't go farther than the first few words with something like that. I'm not going to go back and try to figure out what you said, and I think you'll lose the attention of other readers too. Punctuation isn't that hard...

John my apolgies john, for the badly written incoherent ramblings. i will try to use some punctuation marks etc, in future posts. i'm not sure where to put the things you mentioned, exactly. i never made it past the 4th grade in school. but i will attempt to do better THANKS for bringing this shortcoming to my attention:)

[johnaec]

i never made it past the 4th grade in school. but i will attempt to do better THANKS for bringing this shortcoming to my attention:)OK - one last lesson. Sentences, (and the letter I, when used personally), usually begin with capital letters. ;)

'Just trying to help out...

John

[bigstereo]

I am wondering....
How does one visually tell the difference between a L100T and a L100T3
Is there a marking on the cab? Label? Visual difference in a driver?

RJ

[Don C]

The emblem on a T is the square metal one. The emblem on the T3 is rectangular, much wider, made from plastic.

[bigstereo]

I have been curious about that for a long time as I have been hoping to run into a good deal on a set of T3's

RJ

[GordonW]

The emblem on a T is the square metal one. The emblem on the T3 is rectangular, much wider, made from plastic.

Also, most L100Ts are a light-walnut finish, while the T3s tend to be a darker, redder finish, like rosewood or similar.

IIRC, the L100T has a "stand-off" grille, while the T3 has a grille that "hugs" the face of the speaker (ie, sits against the face, instead of being spaced off like 3/4"). That may have only been for some of the "S" military models, but I seem to remember a difference...

Regards,
Gordon.

[bigstereo]

Armed with the info given here, I also searched the tech sheets and noticed the the emblem on the T is on the top right, while the T3 emblem is on the top left.
Thanks for clearing this up for me guys. This model may very well be my next acquisition as I can't see my self being able to afford a set of 4333's or L300's anytime soon.

RJ

[bigstereo]

One more question and then I will have all that I need, as I can now visually identify the different models.
There is no tech sheet here for the L100S.
Are the components the same as in the T3?

RJ

[Robh3606]

The S is vinyl clad and there is a size difference between the T and T3

Rob:)

[johnaec]

If the labels are still on the back of the cabinets, they absolutely say either L100T or L100T3 - I believe the emblems on the front do likewise.

John

[bigstereo]

Thanks guys for the info. Very much appreciated.

:cheers:

RJ

[bigyank]

Duanage, how goes this project? Wondered how the L199t's were holding up. Sometimes I miss 'em!

Yank

[duaneage]

I bought a pair of L100T crossovers to experiment with but have not done anything yet, too much bicycle riding lately and I restored that Honda you saw me riding last spring to perfect condition.
As soon as the heat breaks I want to make a pair of 4406 style speakers and a 3-way studio monitor with 2214H in the style of the 4312 series.

I will get to the crossover mods for the L100T eventually

[Likeit Loud]

I have had a pair of L100S that I bought directly from JBL in Northridge in the early 90's. I've never been able to figure out what the difference is between them and L100T or L100T3's other than they are vinyl clad. I just had the 2214's re-coned and still appreciate them as great rock 'n roll speakers. I have just recently purchased a set of L300's and while i miss the low end punch of the L100s, the overall clarity and crispness and balance of the L300's are awesome. However for the prices I've seen for used L100t and L100t3's I don't think they can be beat for their sound/value equation. I'd appreciate any info on the L100s.

[Don Mascali]

However for the prices I've seen for used L100t and L100t3's I don't think they can be beat for their sound/value equation. I'd appreciate any info on the L100s.

I have a pair of L100t3 in my Living Room system and I have to agree that they are an outstanding value. I recently added my B380 clones to that system and as good as the low end was, they are serious now.

(X-over @ 80hz to a Crown XLS-602 amp)

[transducergeek]

I just purchased a pair of L100S units, I have read some threads, but don't know if they are closer to the T3 or plain T? Are they identical to either, besides the vinyl cladding? What's the exact story? No info from JBL. Thanks Guy's...!

[Don Mascali]

I don't really know but;

My L100t3's measure 14 1/2" wide x 13" deep and 35 3/8" tall on the outside of the box. The L100t's are a different size.

Please let us know here for the next guy that searches it.:)

[Blaster]

I have a pair L100T and a pair of L100t3. They are both the same height. The L100T are gloss black and measure 13 1/2" deep X 16" wide X 35 3/8" tall. The L100T3 are walnut and measure 13" deep X 14 1/2" wide X 35 3/8" tall. I don't have any L100S cabs to compare.

[pos]

Considering the difference in cabinet size (and especially the width of the front baffle), do you think it is a good idea to upgrade a L100T crossover to the L100T3 specs?
I mean, if the baffe is norrower on the T3 then the crossover has to be different to take the baffle step into account.
Does anyone has direct experience with doing this?

Also, has anyone mesured the DCR of the selfs of the T3?


http://manuals.harman.com/JBL/HOM/Technical%20Sheet/L100t%20ts.pdf
http://manuals.harman.com/JBL/HOM/Technical%20Sheet/L100t3%20ts.pdf

[duaneage]

I don't think any cabinet variations would be that much of a concern. The big difference is the efficiency of the two drivers and the crossover from the mid to the woofer. The distance between them would affect it more.

I modified a set of crossovers for Evans224 a few weeks ago and tested them in my set. The midrange has different presence and the balance is smoother. In a different room with various source material it becomes a matter of choice.

I can modify a set for someone else if interested, I have extra parts and a spare set of crossovers to perform exchange with.

[hjames]

Just got back from picking up a pair of L100T -
seller is headed out of town and just wanted to get rid of them - (stereo shown not included in sale)
of course, the woofer surrounds are gone ... but the price was nice

They look to be REALLY clean - but - I had no idea these things were so darned HUGE!
(what do I know, I've had L20T and L60Ts in the past)

Anyway I just got them home and need to head to bed -
but I'll post more specifics tomorrow once I get into them them and get specifics of the drivers and crossovers and such!

[opimax]

good deal, look good from the pictures. what are you going to do with them?

Mark

[hjames]

good deal, look good from the pictures. what are you going to do with them?

Mark
Get them working first (refoam), then possibly upgrade the crossover, smooth them out ... Afterwards - not sure yet ??

They have rear-firing ports, and I know how to cure that, but they are too big for the TV room,
and redundant upstairs with the L200 3ways ...

But at least they aren't L5s ... all that Black ash - yeesh!

(just kidding guys, relax!)


Why?

[opimax]

Inquiring munds want to know, nothing else! Really! :)

I would like to hear them sometime, after all they are JBL

Mark

[hjames]

Inquiring munds want to know, nothing else! Really! :)

I would like to hear them sometime, after all they are JBL

Mark

http://audioheritage.org/vbulletin/attachment.php?attachmentid=38871&stc=1&d=1240878990

Well, I put this pix in another thread but - darned - these puppies are larger than I had imagined from the pictures ...
In those pix they kinda looked cute, like the L20T - but when we got there and checked them out -
wow, they are 3 foot tall! Look at them next to my L200!
Rock'n'Roll indeed (where's that Tempest CD??)

I'll have to build some wheeled bases for them like I did for the L200s and 4341s.
I ordered a Rick Cobb 2214H foam kit early yesterday!
Busy weekend coming up, but maybe I'll get to them by the 9th
( I still have to find time to get the H92 long-horns into the L200s,
and get the aquaplassed 2425 drivers into the 4341s!!)
But its summertime - big speaker work can wait for either the dog days of summer, or for the winter!


http://audioheritage.org/vbulletin/attachment.php?attachmentid=38872&stc=1&d=1240878998

[bigyank]

http://audioheritage.org/vbulletin/attachment.php?attachmentid=38871&stc=1&d=1240878990

Well, I put this pix in another thread but - darned - these puppies are larger than I had imagined from the pictures ...
In those pix they kinda looked cute, like the L20T - but when we got there and checked them out -
wow, they are 3 foot tall! Look at them next to my L200!
Rock'n'Roll indeed (where's that Tempest CD??)

I'll have to build some wheeled bases for them like I did for the L200s and 4341s.
I ordered a Rick Cobb 2212H foam kit early yesterday!
Busy weekend coming up, but maybe I'll get to them by the 9th
(and I still have to find time to get the H92 long-horns into the L200s!)

http://audioheritage.org/vbulletin/attachment.php?attachmentid=38872&stc=1&d=1240878998

I hope you meant to type 2214H Heather! :D I always liked the bass from these woofers but personally never thought the rest of the system could keep up!

[hjames]

I hope you meant to type 2214H Heather! :D I always liked the bass from these woofers but personally never thought the rest of the system could keep up!

yep - early AM slippery fingers ...
Checked the order and 2214H it is!

[evans224]

The L100T's work great in my HT setup. Like Bigyank said, the 2214H's are impressive. I was not happy with the rest of the system either. After Duanage modified the x-overs, the mids backed out of my face a bit and the highs lost that really sharp edge. However, the best thing for them was to get them out of the hard-surfaced room they were in. By the way, here are some before and after pics here-I finally got around to finishing them. Yours are in much better shape than mine were.

[bigstereo]

Congrats Heather. I've been loving a pair of L100t3's for the past 3 years.

Bet you wish you had a spare set of 035TiA's laying around now eh? Just in case. ;)

RJ

[hjames]

Congrats Heather. I've been loving a pair of L100t3's for the past 3 years.

Bet you wish you had a spare set of 035TiA's laying around now eh? Just in case. ;)

RJ

Yeah, why oh why did I ship them t'ings to NY??

Funny thing is - when I arrived at the sellers house he started to play them for me with some kind of thumpy rock music - even with the blasted foams.

I had him turn them off quickly, but it did sound like there mids and highs present ... I'd hate to gut my L20Ts to get these things working!

So, maybe next weekend after I get the refoams installed I'll have some idea of what I've gotten.

My living room is a fright now anyway, with these big things next to the L200s, a pair of H82 long horns on the coffee table, and next to those a clean pair of 2425Hs with fresh aquaplas ti diaphrams ...
I ought to be able to get some good sounds going with all of that laying around!

[pierce]

I'm curious about the differences in the crossovers, i started a thread elsewhere in this forum w/ the schematics of the L100T and T3 crossovers, both speakers claim 800Hz and 4500Hz crossover points and 12db/octave. I can see the two circuits are the same topology but have somewhat different component values but don't remember enough of my college electronics to be able to say what that means.

Also, interesting, looking at these two wiring diagrams, it -appears- if the L100T and T3 have all three speakers reversed in phase relative to each other...

http://manuals.harman.com/JBL/HOM/Technical%20Sheet/L100t%20ts.pdf
http://manuals.harman.com/JBL/HOM/Technical%20Sheet/L100t3%20ts.pdf

[duaneage]

The phase reversal has to do with the type of network and how the filters sum at the crossover point. Without reversing the phase there would be a hole or peak in response at crossover. These are typical 2nd order networks that sum flat electrically at the crossover point only if the middle driver is out of phase.

The midrange and woofer interact above and below the crossover point. No crossover frequency is a hard value, there is content from both drivers above and beyond the frequency. The difference is how the polar response works along with the level of each driver. Subtle changes in the crossover components can have marked results and usually do not agree with calculated values. Many of JBL's designs violate rules for crossovers but that is because they leverage the natural response of the drivers. Many times the designer goes for a typical "sound" versus an absolute flat response.

THe T3 circuit also dampens the high frequency to soften the tweeter response. Metal domes can be a bit harsh so this is an improvement. The midrange is where the music is anyway so the tweeter augments the midrange without overpowering it.

Essentially what the T3 network does is create a "hole" in the transistion between the woofer and midrange by lowering slightly the woofer's crossover point and raising the midrange crossover point while still being centered on 800 hz. . The 2214H has a rise in response above 1.2 Khz so this reduces that peak. The midrange is raised a little and that isolates it a bit from the woofer while tweaking the loudness slightly.

The result is a bit smoother midrange, less shrill highs, and the bass seems clearer. With some tweaking other JBL designs could be helped this way too but we have a production standard that can be duplicated which has the blessing of the JBL design engineers.

There is a host of other things going on too like driver spacing, time alignments, impedance, phase response, edge diffraction, and temperature changes too but in the end the T3 network is a bit nicer to listen to and that is all that matters.

[pierce]

The phase reversal has to do with the type of network and how the filters sum at the crossover point. Without reversing the phase there would be a hole or peak in response at crossover. These are typical 2nd order networks that sum flat electrically at the crossover point only if the middle driver is out of phase.

absolute phase has always bothered me. if all three drivers are the same inversion, relative to the other version, and the crossover networks are essentially the same design albeit slightly different frequency rolloffs, I'm still not sure I understand why + vs - makes any difference.


The midrange and woofer interact above and below the crossover point. No crossover frequency is a hard value, there is content from both drivers above and beyond the frequency. The difference is how the polar response works along with the level of each driver. Subtle changes in the crossover components can have marked results and usually do not agree with calculated values. Many of JBL's designs violate rules for crossovers but that is because they leverage the natural response of the drivers. Many times the designer goes for a typical "sound" versus an absolute flat response.

sure, I've always assumed that crossovers use the speaker as an active element of the circuit, and are designed around the speakers natural characteristics and limitations. The extreme case is the simple 2-way crossover that consists of just a capacitor in series with the tweeter... thats relying on the natural lowpass of the woofer, and that capacitor + the tweeter's voicecoil/inductor comprise a single-pole L-C filter.


The T3 circuit also dampens the high frequency to soften the tweeter response. Metal domes can be a bit harsh so this is an improvement. The midrange is where the music is anyway so the tweeter augments the midrange without overpowering it.

I wonder if I couldn't simply add a small value resistor in series with the 035Ti to achieve some of this rolloff? Although, with my 55 yr old rock-damaged hearing, they don't sound too bright to me :p


Essentially what the T3 network does is create a "hole" in the transistion between the woofer and midrange by lowering slightly the woofer's crossover point and raising the midrange crossover point while still being centered on 800 hz. . The 2214H has a rise in response above 1.2 Khz so this reduces that peak. The midrange is raised a little and that isolates it a bit from the woofer while tweaking the loudness slightly.

The result is a bit smoother midrange, less shrill highs, and the bass seems clearer. With some tweaking other JBL designs could be helped this way too but we have a production standard that can be duplicated which has the blessing of the JBL design engineers.

There is a host of other things going on too like driver spacing, time alignments, impedance, phase response, edge diffraction, and temperature changes too but in the end the T3 network is a bit nicer to listen to and that is all that matters.

the driver spacing is nearly identical, as are the time alignments (after all, both speakers are planar, and not stepped back like time coherent designs such as Vandersteen). Both L100T and T3 speakers have the same sharp cabinet edges, and the same impedance drivers. I know the T3 is a little deeper, and there was some conjecture on one of these threads that it was a little sturdier (I'd love to see some actual evidence of this, as when I first saw the T3 in a store a couple years after buying my T, I got a distinct impression it was a little cheaper construction, the cabinet felt lighter).

anyways, thanks for the analysis.

[duaneage]

absolute phase has always bothered me. if all three drivers are the same inversion, relative to the other version, and the crossover networks are essentially the same design albeit slightly different frequency rolloffs, I'm still not sure I understand why + vs - makes any difference.
Because drivers have voltage and current lags that affect the interaction with reactive components like capacitors and inductors. The result is a change in output as the frequency changes through the crossover. In actual practice the midrange and/or woofer is complementing the acoustic output of the other driver. If they are in phase in some networks they compliment too much causing a ringing effect at the crossover point.


sure, I've always assumed that crossovers use the speaker as an active element of the circuit, and are designed around the speakers natural characteristics and limitations. The extreme case is the simple 2-way crossover that consists of just a capacitor in series with the tweeter... thats relying on the natural lowpass of the woofer, and that capacitor + the tweeter's voicecoil/inductor comprise a single-pole L-C filter.

Actually the simple 2 way capacitor only design is far from extreme, it's preferred by many. The problem with a simple capacitor is not so much the response (in fact it's simplicity is a major advantage) but the lack of driver protection because too much low frequency information makes it to the tweeter. I don't like woofers run wide open this way because they make lousy tweeters and cause two point sources in the midrange. The L100 is a classic example of this and I have never liked the sound of this system because of the crossover network, or lack of one really.

I wonder if I couldn't simply add a small value resistor in series with the 035Ti to achieve some of this rolloff? Although, with my 55 yr old rock-damaged hearing, they don't sound too bright to me :p

Sure, an L-pad would be better since it could control the output for the room. In the T3 versions, the shunt resistor remains 20 ohms while the series doubles to 2.4 ohms. The series capacitor changes to reflect the increased resistance seen by the 4 uf cap. If the cap was not changed the crossover frequency would drop as the total load was a little higher than before. Small detail maybe, but if you want to protect the tweeter while keeping it in the proper operating range you have to account for it.

the driver spacing is nearly identical, as are the time alignments (after all, both speakers are planar, and not stepped back like time coherent designs such as Vandersteen). Both L100T and T3 speakers have the same sharp cabinet edges, and the same impedance drivers. I know the T3 is a little deeper, and there was some conjecture on one of these threads that it was a little sturdier (I'd love to see some actual evidence of this, as when I first saw the T3 in a store a couple years after buying my T, I got a distinct impression it was a little cheaper construction, the cabinet felt lighter).

anyways, thanks for the analysis.

Crossover networks can compensate for time alignments to a certain degree, the offsetting of the drivers from center helps with edge diffraction. I doubt the cabinets have much effect on the crossover action, but one never knows. The mid and tweeters are at ear level while sitting, that makes a huge difference compared to lower placement.

I think the L100T and T3 speakers are excellent systems which have huge potential for experimenting and reward. They are still relatively affordable and when you look at the drivers used they are a great bargain. Not everyone likes the full veneer look, I happen to like it very much.

[pierce]

Actually the simple 2 way capacitor only design is far from extreme, it's preferred by many. The problem with a simple capacitor is not so much the response (in fact it's simplicity is a major advantage) but the lack of driver protection because too much low frequency information makes it to the tweeter. I don't like woofers run wide open this way because they make lousy tweeters and cause two point sources in the midrange. The L100 is a classic example of this and I have never liked the sound of this system because of the crossover network, or lack of one really.

FWIW, if you look here http://www.audioheritage.org/vbulletin/showthread.php?t=24894 you'll see the *original* L100 century had a multi-pole crossover, while the L100A "Late" had a simplified cap-only crossover. Now, the L100's wasn't as complex as that on the T's, notably, the woofer is still running wide open, and if I read that right, the mid and tweeter are both strictly high-passed, but at least its an L-R-C network and not just a C...

anyways, obviously I concur with your eval of the L100T/T3... I own a set :) When I bought them, circa 1988(?), I took 5 CDs to about a dozen audio parlors and auditioned the a specific track off each disk on each system I was interested in in the $1000-2000 range. The L100T was the first and last system I listened to, and I bought them based on what I'd heard. I think I paid $800 for the as-new demonstrators in this small audio store in my town, after having been to all these fancy places in/around Silicon Valley, listening to Klipsch, Kefs, and all manner of $2000 speakers what I can't remember.

The one pair of speakers I've heard since then that really sounded significantly better to me across a wide range of source materials (and weren't in the ludicruous-$$$ <cough>B&W 801</cough>) were Vandersteen 2c's. Setup right in a big open room, they had an amazing stage presence and clarity whether playing a folk string quartet, or choral harmony or a live rock concert at full tilt.

[duaneage]

The midrange used in the original L100 is worlds apart from what the L100T ended up with. Lower FS, smoother response curve, better cone materials. The L100 essentially was the home version of a studio monitor JBL designed to replace Altec in the studio. The sound they were going for was specific.

[evans224]

I understand some of the discussion on crossover theory. What I understand better is the way that the L100T's sound after having the crossovers updated and modified to L100t3 specs (Duanage does good work!). The result is a much smoother upper/midrange and a more defined. less muddied low end. I suggest you give it a try. I actually have a spare set of L100t crossovers that I am going to put in and I will A/B the speakers.

[pierce]

Duneage, you mod these crossovers for folks? Interesting. Actually, I'm pretty good with a soldering iron and have a weller temp controlled soldering station, so if I can source the parts, I could do it myself (I'm on a real tight financial leash this year, my wife has been unemployed from her tech-writer career about a year, a kid goes to college next year, work is downsizing, eeeek).

Think I can get away with eyeballing the 'type' of the parts in my existing crossover, then ordering the alternate values from digikey or mouser?

It strikes me that the inductors will be the hard ones, do you custom (re)wind them ? for instance, in the woofer section, L1 goes from 3 to 3.2mH, C1 from 40 to 44uF, and the R goes from 39 to 41 ohm (via 2x82ohm in parallel). in the mid, C3 goes 17 to 15uF, L2 0.5->0.6mH. In the tweet, C7 goes 3 to 4uF, and R4 goes 1.2 to 2.4ohm.

Do you think the R and/or C values could be tweaked to keep the L values the same?

[duaneage]

I did evan224's crossovers, I have a spare set I can exchange with. I did not change the shunt resistors across the woofer because they are so close in value to each other tolerances pretty much make them the same. I replaced the electrolytic capacitor in the midrange circuit with a high quality poly cap and used poly caps for the high pass as well. The resistors in the mid and high pass were changed as well.

The inductors I sourced were too big for the board so I extended the two coils with appropriate gauge wire and verified the values to within 1%. Then I reassembled the boards and tested them in my L100T speakers as well as bench checked them to make sure all was well. I also replaced some connectors with new ones because they were a little corroded.

I'm toying with the idea of offering this as a service, I can do single day turnaround because I have a set to core with. I need to determine what the parts and time costs are and see if it is worth doing. I spent about 1.5 hours on Evan's networks doing the work and another hour testing and evaluating them.

So a short answer is yes, there is no reason why the crossovers could not be modified provided you source replacement parts, have a selection of coil wire handy, the proper tools to solder with, and a means of testing the inductors (or replacing them) to make the switch. Along the way an enterprising engineer might want to replace all the electrolytic s with better caps for durability and quality.

[cosmos]

I'm toying with the idea of offering this as a service, I can do single day turnaround because I have a set to core with. I need to determine what the parts and time costs are and see if it is worth doing. I spent about 1.5 hours on Evan's networks doing the work and another hour testing and evaluating them.

Interesting.. have you gone any further with this idea? I have a set of L100T that I am toying with upgrading...

[duaneage]

Interesting.. have you gone any further with this idea? I have a set of L100T that I am toying with upgrading...

I have worked on streamlining the process a bit and identifying suppliers for the parts. I guess the real questions is what levels to offer for this. I could replace the electrolytics with different value electrolytic capacitors for an economy upgrade but most people prefer high quality capacitors instead. Replacing the midrange and high pass caps with polys and simply adding a poly cap to the low pass is a step up in performance.

Replacing all the electro caps with poly would cost quite a bit more and there may be space limitations on the boards, the poly caps are larger by a significant amount. This might require new circuit boards and that gets complicated.

Finally I've been asked about a CC biased version. I could make a CC version of this network but it would definately require a new board, all new capacitors, and additional parts as well. This would be the Lexus level and probably cost as much as a pair of T3 speakers used.

So if I buy large quantities of the parts and keep it simple I can do 3 levels of upgrade.

1. Simply replace the caps with different values, rewind and test the inductors, new resistor for the high pass and test the results.

2. Poly caps for new values, same tasks as above.

3. Poly caps all around, same tasks as 1 and 2.

Once I get an idea of costs and benefits I'll post something. In the meantime contact me by PM if you want to do something and we can discuss.

[JSF13]

I understand some of the discussion on crossover theory. What I understand better is the way that the L100T's sound after having the crossovers updated and modified to L100t3 specs (Duanage does good work!). The result is a much smoother upper/midrange and a more defined. less muddied low end. I suggest you give it a try.


I'll second that. I just picked up Heather James L100T's with crossovers upgraded by Duaneage :D and I have to say, having owned L100T's before, that I totally agree with the above. Any of you out there with L100T's should definitely think about doing this upgrade. You won't be sorry.