Before going 1st order, I tried this...

[4343mod]

This is the exact circuit in the 4343 XO, minus provision for a rotary switch or L pads.

This crossover is built on a 1/4" thick piece of Aluminum, 24" x 16".
I built only one, though I have another piece of Al to build another one. After a few weeks of listening to this, I decided to abandon it and build the 1st order versions.

The price of the parts for this one XO was about the same as the parts to build 2 of the 1st order XO's that I use, since this XO has about twice the parts as one of my 1st order ones.

The sound is superior to the OEM XO, with greater transparency and detail. I still prefer the sound of the 6dB ones, they bring me in even closer. The only draw back between the two is the 1st order XO's really show the drivers inherent flaws.

The 2 inductors you see on the LF is due to a change I made after building this. I disconnected the 5mH air core and went with the 9mH ERSE laminated core.

What do you guys think? Is it over the top?

[4313B]

"The only draw back between the two is the 1st order XO's really show the drivers inherent flaws."

What flaws? Are you sure the filters are complementing the drivers properly?

"What do you guys think? Is it over the top?"

No. Good job!

[4343mod]

Originally posted by Giskard
"The only draw back between the two is the 1st order XO's really show the drivers inherent flaws."

What flaws? Are you sure the filters are complementing the drivers properly?

"What do you guys think? Is it over the top?"

No. Good job!

Thanks, Giskard. Well, I think JBL CD's are inherently "rough" sounding, at least compared to say, a Morel dome midrange like the MDM-55; and to make our CD's smoother requires more agressive filtering (like above) that diminishes transient response and detail. Of course, the MDM-55 is a different animal, and is a wimp compared to the 2420. Response of the '55 is like my 2420 with a sock stuffed in the horn.

If you or anyone can recomend a different coil and cap combo for a 1st order bandpass than the 9uF/2mH that I'm using, I'd certainly give it a try. Heck, I'll try anything! :)

[4343mod]

Bump
The 2121 uses a 2mH choke, the 2420 choke is .25 to .10mH, depending on the mood.

Clearing up a mistake I made 21 months ago. Still going stong and time indeed does fly when you having fun!

[Lancer]

I'd like to see a schematic so I could plug it all into a spice program to see what kind of voltage drives it yields.

[spkrman57]

I am a big fan of 1st order crossovers, my only limitations using them is the power handling ability is greatly reduced. That is unless you want to replace diaphrams often!
Ron

[stevem]

This crossover is built on a 1/4" thick piece of Aluminum, 24" x 16".

I might be wrong about this, but aren't you supposed to keep conductive metal away from inductors? Or does this just apply to ferrous materials? Would this crossover sound any different on a piece of masonite (or pegboard)?

[4343mod]

Here is the 1st order with current values in use. All resistors are 12W Mills. I also sometimes run the LF with a 12dB/octave XO, coming up...:)

[4343mod]

w/ 12dB/octave LF

[Lancer]

Pleasure. It's a great thread and will belongs here. Now, let's delete our chatter and clean things up... :DWhat?

Here is the 1st order with current values in use. All resistors are 12W Mills. I also sometimes run the LF with a 12dB/octave XO, coming up...:)Here's what it plays out like. Stock 4343 in gold.

[boputnam]

What?
Here's what it plays out like. Stock 4343 in gold.I'm not sure I should pay up for that response... :blink:

[4343mod]

Thanks for plugging that in Lancer, I appreciate you taking the time in doing so! I'm burning Man With The Horn on a Tascam 5000 right now, and it sounds wide and deep using the 12dB LF.

Can you reverse engineer and give values that look nice? I'll buy the parts, solder them up on new wood sheets, listen back and forth between the two and invite everybody over for a listening party after I have an opinion. You are all invited!

[edit] Ok I see the peak in the MF and the red is the 2405.
I dunno, what are you going to do with that 2121? Its like 88 or 89dB, in between a 98dB woofer and a 100+ dB CD, so you got to bring it up, IE no padding. You get the peak, but in the original 4343, tell me honestly- Has anyone heard the 10" even work in a stock cab? Mine was inaudible at close range before the new filters, and now when you listen to the baffle, you actually hear that driver sharing. the more I look at that plot, the more I nod and think "wow, yeah" The slot would be on fire if it was down much more, 2uF is pushing it. look at the MF, HF, and UHF- They still share parallel lines up to the apex. I could use a smaller shunt resistor on the UHF to heat it up, but the presence is actually pretty good here in RL. I would still like to try an optimised model.

Any tips for better value selections? Please? :applaud:
I think I'm done with my edits. *pew*

[Ian Mackenzie]

Firstly the original filters were design to provide bandpass (and stop bands) for the 4 drivers to work tightly together. Secondly the filters were adjusted to incorporate contours to flaten the combined response of the respective drivers and ensure the combined response was flat as possible.

The cruves are voltage drives not frequency response curves, as such they show the attenuated voltage to each driver.

While the 1st order slope may offer some benefits, note these drivers were not designed for 1st order crossovers.

Ian

[Lancer]

Can you reverse engineer and give values that look nice?

I no longer have any of the components you are using.

I dunno, what are you going to do with that 2121? Its like 88 or 89dB, in between a 98dB woofer and a 100+ dB CD, so you got to bring it up, IE no padding.

The 2121 should be a mid 90's driver, a tad more efficient than the 93-94 dB 2231. If you use 6 dB/octave filters and cross it over correctly you will probably loose a few dB of sensitivity.

I would still like to try an optimised model.

Yeah, it could be fun. Maybe you should think about picking up something like SoundEasy so you can dial in the slopes/crossover points you want and try them. Measure the results of what you are hearing.

I suspect Ian is right though. It could be tough to get these particular drivers to sound "right" with 6 dB/octave slopes. I think you need some test gear to help you.

I'd personally upgrade the 4343's to 4344's. I consider the 4344, 4345, and 4355 the end of the line for the 43xx series. My opinion is they had the most refined filter designs for those component types. No telling what someone with the time, inclination, and proper combination of software/hardware test gear could come up with for them today though.

[Ian Mackenzie]

Just to add a dollop of tomato sauce here I have found that biamping the 4344-45 requires a re think of the system voicing in terms of driver integration.

Subject to me running some detailed acoustic measurements the behaviour of the midrange bandpass filter (2122H in the 4344-45) alters in bi amp mode as its no longer a pure passive bandpass filter with customised 12db slopes but an 18 db electronic /12 passive bandpass.

To cut a long story short I had to pump up the 2122 a db or so to stop the horn from sounding like it was screaming its head off. Why? I really don't know but have a theory.

My reasoning, again subject to measurements of voltage drive is that bandpass filters typically have a specified Q, and as such the value of that Q can effect the shape of the filter response and even add some real gain at resonance. My hypothesis is that removing the passive low pass elemens has altered this balance and overall level slightly and some re alignment of the mid driver level is required to ensure overall system flatness.

Heck, I am sure most members just think they can plug and play and yeah biamping is always best and then we hear of mutterings of dissatisfaction, horns sounding like sea shells, poor imaging and worse listener fatique.

Frankly, pull passive mode is far more managable and more stable as a known set of variables.

Its a bit like asking yourself why do tiles fall of the Shuttle sometimes and not others or have they always been falling of but we weren't aware of it?

Well unfortunately with speaker system crossover design its all a careful balance and everything tends to react, so if you upset some aspect of the design it will mean adjustment is required elsewhere.

Hence if you start playing with 1 st order filters its a whole new world of hurt to deal with before sanity and order will be restored.

Ian

[Robh3606]

Hello Ian

I think your post is spot on. If you set-up in passive don't assume the biamp is a shoe in. You need to re-evaluate the entire system balance both the bottom and top as well as driver to driver. Things do changed from passive to biamp.

Rob:)

[Lancer]

My reasoning, again subject to measurements of voltage drive is that bandpass filters typically have a specified Q, and as such the value of that Q can effect the shape of the filter response and even add some real gain at resonance. True.

Frankly, pull passive mode is far more managable and more stable as a known set of variables.From the perspective that JBL already did the hard part for you with respect to the stock 4343 filter, yes.

Well unfortunately with speaker system crossover design its all a careful balance and everything tends to react, so if you upset some aspect of the design it will mean adjustment is required elsewhere.True.

Hence if you start playing with 1 st order filters its a whole new world of hurt to deal with before sanity and order will be restored.Without any kind of test gear it could, indeed, become a real mess.

[4343mod]

Thanks for your thoughts gentelmen. I'm flattered to have your participation in this. Though I'm more than a little intimidated in this group.
So without trying to sound curt, but to be blunt-

A: Please again what is wrong with the curve? Where? Why?

B: It would seem (in my fevered imagination) that plot is so bad you all have set subjective opinions on the system, and therefore conclude I'm trying to fix something or that I am unhappy. I'm looking for an improvement always, but if I don't find one, here it is then.

B2: At the risk of repeating what I have said on the other thread:
I would never put the stock XO back in for my own use, this sounds better to me, and all non-audiotypes around here agree without my asking. In my screwed room my 6dB tomato sauce plates sound purer and richer and faster and wider, deeper...More Meat on The Bone! Timbre they could not possibly produce with the stock XO. If it sounds better, it is better.

I'm just trying to get more. Always more.;)
Thanks again, keep em comming!

[B&KMan]

A: Please again what is wrong with the curve? Where? Why?




Hi, I just keep in fly this thread and try to expose my opignion in regards of my 4343 modification.

1--- in general the signal electrical is relatively good reflect of reality but is suppose the driver is stable....

In fact if you look my analyse of the original driver on thread 4343 modification, you look many driver have problem stability in lower and upper limit. so if you choose , for excellent reason, 1er order , your slope is not finish smooth than a spice software expose... so be carreful...

2--- the 1er order change the low and hi cut slope of driver and if you look at hf-uhf the slope is to close at max value and it is shure is create a bg overlap: result big notch on this area..

the rule is arround 4 db down at cross slope. 2 sound in equal power create a double power 90 dB and 90 dB = 93 db power sound...

in this rule , if you look your low: it is cut to fast and create a big hole arround 200K, it is not support by 2121 and you create a big hole in this area... of shure in normal time it is a problem but in your set-up amplified this situation...


if you run in the way of 1er order, your have a necessity to recalculate the ideal cross network and it is important to realise the problem of peak create by impedance or by natural eratic response on driver....

ex: the 2231 and or 2235 diaprham is really unstable arround 500K and realy push a peak and distortion.... so if you run in slope 1er order , (surprise..) the notch eratic response is too close on "working" response and expose more distortion and blurs fuzz in sound....


=========================

in one hand : you maintaint the network cut fr and you create a big hole in sound... other hand : you push a cut frq more higher and reaveal the section unstable of 2231/35 concluson ?? it is not easy to outperform the original design approach because the engeneer is test all parameter and set-up the optimum network in regards of limits of driver...


===========================


Your sound is "sound" great and better ???

of course, the original caps is dried (especilaly the big electrolytic) so immmediately after you change for fresh and better technologie you push realy higher your speakers in new blue sky....

------------------

but this upgrade is limited by the nature of driver and age. it is shure the original diaphram is too old for perform at high level with-out distortion...

if you play gentle :no problem, but for big "Pow Wa" it is a mess.

take time for put money in bank and scedule a fresh diaghram for all driver...


I hope this tips is helps you little bit...

:cheers:


Jean.

[Ian Mackenzie]

Thanks for your thoughts gentelmen. I'm flattered to have your participation in this. Though I'm more than a little intimidated in this group.
So without trying to sound curt, but to be blunt-

A: Please again what is wrong with the curve? Where? Why?

B: It would seem (in my fevered imagination) that plot is so bad you all have set subjective opinions on the system, and therefore conclude I'm trying to fix something or that I am unhappy. I'm looking for an improvement always, but if I don't find one, here it is then.

B2: At the risk of repeating what I have said on the other thread:
I would never put the stock XO back in for my own use, this sounds better to me, and all non-audiotypes around here agree without my asking. In my screwed room my 6dB tomato sauce plates sound purer and richer and faster and wider, deeper...More Meat on The Bone! Timbre they could not possibly produce with the stock XO. If it sounds better, it is better.

I'm just trying to get more. Always more.;)
Thanks again, keep em comming!

Nothing wrong with thinking outside the square.

Just make sure the square is actually square!

Ian

[DavidF]

Thanks for your thoughts gentelmen. I'm flattered to have your participation in this. Though I'm more than a little intimidated in this group.
So without trying to sound curt, but to be blunt-

A: Please again what is wrong with the curve? Where? Why?

B: It would seem (in my fevered imagination) that plot is so bad you all have set subjective opinions on the system, and therefore conclude I'm trying to fix something or that I am unhappy. I'm looking for an improvement always, but if I don't find one, here it is then.

B2: At the risk of repeating what I have said on the other thread:
I would never put the stock XO back in for my own use, this sounds better to me, and all non-audiotypes around here agree without my asking. In my screwed room my 6dB tomato sauce plates sound purer and richer and faster and wider, deeper...More Meat on The Bone! Timbre they could not possibly produce with the stock XO. If it sounds better, it is better.

I'm just trying to get more. Always more.;)
Thanks again, keep em comming!

To me, these (how to improve an existing design) are always tough questions to answer in the context of a forum. First, does a change you regard as an improvement negate some other design aspect that was important to the designer (every change usually results in a compromise somewhere else)? Second, does the change actually result in an improvement or just a difference in sound? Third, and most important, how do you the listener gauge what you hear as an improvement (we want to hear improvements so does this bias our judgment)? You have already said, I think, that you are happy with the change in design of the 4343 (though it no longer is a 4343, really). You are the best judge on what sounds best to you and that is the bottom line.



Your change really is a total redesign as opposed to a tweak or refinement. If you are looking for some reinforcement or constructive criticism on your efforts, it is really tough for someone to make any comments without some direct experience along the lines of your modifications. Alternatively, some general experience can point to some predictable results and I think some of the difficulties in reworking crossovers based on theoretical models alone are expressed above.



David F

[richard c.]

Do you add the inductance of the driver to the DCR value when modeling a crossover? I use Electronics Workbench (Multisim) and I find that treating a driver like a resistor doesn't give me the same response curve. I measure the Le with an RLC meter, and now that I bought the Woofer Tester II, I can get the inductance values all the way thru the passband. Knowing the Le also helps with designing the Zobal circuit - a lot less trial and error. I realize that a driver also looks capacitive during certain conditions.

I also bought Bassbox 6, which seems to be much better than other programs I have tried. I have never had a program where I could control box tuning.

Richard C.

[Lancer]

Electroacoustic models of the drivers are required to get the best results when modeling crossovers. We discussed this eons ago. Those discussions are buried somewhere in the forum.

Here are examples of voltage drives of a network using the standard JBL test fixture and then using actual driver loads. Last image is the frequency response of the system.

[B&KMan]

Electroacoustic models of the drivers are required to get the best results when modeling crossovers. We discussed this eons ago. Those discussions are buried somewhere in the forum.

Here are examples of voltage drives of a network using the standard JBL test fixture and then using actual driver loads. Last image is the frequency response of the system.


Hey very thanks for this network this info

but I'm tilt little bit....

the 4343 is 4 drivers and this schema curve expose 3 drivers.... :blink:

So (same as spock in start treck: euh I'm not understand this captain....)



:cheers:


Jean.

[Ian Mackenzie]

Subject to me running some detailed acoustic measurements the behaviour of the midrange bandpass filter (2122H in the 4344-45) alters in bi amp mode as its no longer a pure passive bandpass filter with customised 12db slopes but an 18 db electronic /12 passive bandpass.

To cut a long story short I had to pump up the 2122 a db or so to stop the horn from sounding like it was screaming its head off. Why? I really don't know but have a theory.

My reasoning, again subject to measurements of voltage drive is that bandpass filters typically have a specified Q, and as such the value of that Q can effect the shape of the filter response and even add some real gain at resonance. My hypothesis is that removing the passive low pass elemens has altered this balance and overall level slightly and some re alignment of the mid driver level is required to ensure overall system flatness.

Heck, I am sure most members just think they can plug and play and yeah biamping is always best and then we hear of mutterings of dissatisfaction, horns sounding like sea shells, poor imaging and worse listener fatique.



Ian

Okay everyone I did some fair accurate measurements in real time this morning and my hypothesis has proven correct.

To explain my test setup I feed a 600 hz pure sine wave into the speaker with the full passive crossover connected. I noted the input voltage from the amplifier with my multimeter and then took a read directly in front of the 2122H in near field using an SPL meter.

Noting these results I then connected the active crossover and re calibrated the input voltage to the speaker this time with bi amp mode to the passive crossover.

The SPL meter showed a net increase of 1 db from the 2122H in full passive mode over active mode. This proves that bandpass filters can add real gain in network design and must be accounted for to arrive at a flat response.''

While it may not seem much this is enough to throw the system balance completely out the window. The consequeces however are dire for the listener. The effect is to make the system sound bright and a tad glarey unless adjustments are made. Unfortunately unless you have a chamber and a very elaborate measurement set up 1 db is only a glitch and may go unnoticed on an FR graph.

The point is that to the uninitiated you would not know what was happening but might get the wrong impression about biamping or forever and a day wince at those plastic lenses that have gained a poor reputation! (This is not surprising particularly when using the original 2420 driver)

Tomorrow I will attempt some near field measurements comparing passive versus active crossovers of individual drivers and publish if time permits.

(I posted this here as it is relevant to any attempt at passive crossover design, full details will be posted in the 4344 upgrade thread in due course)

Ian

[B&KMan]

Okay everyone I did some fair accurate measurements in real time this morning and my hypothesis has proven correct.

To explain my test setup I feed a 600 hz pure sine wave into the speaker with the full passive crossover connected. I noted the input voltage from the amplifier with my multimeter and then took a read directly in front of the 2122H in near field using an SPL meter.

Noting these results I then connected the active crossover and re calibrated the input voltage to the speaker this time with bi amp mode to the passive crossover.

The SPL meter showed a net increase of 1 db from the 2122H in full passive mode over active mode. This proves that bandpass filters can add real gain in network design and must be accounted for to arrive at a flat response.''

While it may not seem much this is enough to throw the system balance completely out the window. The consequeces however are dire for the listener. The effect is to make the system sound bright and a tad glarey unless adjustments are made. Unfortunately unless you have a chamber and a very elaborate measurement set up 1 db is only a glitch and may go unnoticed on an FR graph.

The point is that to the uninitiated you would not know what was happening but might get the wrong impression about biamping or forever and a day wince at those plastic lenses that have gained a poor reputation! (This is not surprising particularly when using the original 2420 driver)

Tomorrow I will attempt some near field measurements comparing passive versus active crossovers of individual drivers and publish if time permits.

(I posted this here as it is relevant to any attempt at passive crossover design, full details will be posted in the 4344 upgrade thread in due course)

Ian

Hello Mr.. Mackenzie,

thank you for this explanation but I am curious to know some more, passive mode examined with the new fresh caps or the old caps in passif mode.


it is possible for the difference of 1 dB, it is due to a lack of precision of the apparatus. ??? it is a the same thing on other frequencies. ???


in other way, it is not a same history of L-Pad ???

the button of active network is not perfect and only with calibration the real position is obtained ???

I believe that for a high degree of accuracy, it should allways be pushed the calibration as you did.

it is the price to pay for more powerful and, on many aspects, better but definitely more complex to put in operation.

:cheers:

[Ian Mackenzie]

I have no idea what you are talking about.

There are plenty of references to bandpass gain, try a search on google.

[B&KMan]

Thanks for plugging that in Lancer, I appreciate you taking the time in doing so! I'm burning Man With The Horn on a Tascam 5000 right now, and it sounds wide and deep using the 12dB LF.

Can you reverse engineer and give values that look nice? I'll buy the parts, solder them up on new wood sheets, listen back and forth between the two and invite everybody over for a listening party after I have an opinion. You are all invited!

[edit] I would still like to try an optimised model.

Any tips for better value selections? Please? :applaud:
I think I'm done with my edits. *pew*

Hello, I send link of my experience in real 2121 on my upgrade 4343.

http://www.audioheritage.org/vbulletin/showpost.php?p=51750&postcount=101

the first response in pict is my 2121 with original caps and back switch peakers for single or bi-amp. the big correction is due to the leakage of switch and is expose better response. If you look in compare as your curve , your 2121 is too small response and go not in low fr.

Unfortunately I'M realize now the problem of L-Pad too so before put some time and energy in optimize your design be shure the pad and switch is clean and perform correctly.

if problem continue, change value for your 2121 is go more down...


I hope this is help you.

:cheers:

[4343mod]

I meant to reply over the weekend, but she had other plans, so...

[DavidF:]
To me, these (how to improve an existing design) are always tough questions to answer in the context of a forum. First, does a change you regard as an improvement negate some other design aspect that was important to the designer (every change usually results in a compromise somewhere else)?

Absolutely. Power handling & maximum SPL are certainly reduced, as is convenience in adjustment. Reliability is diminished, since anyone could easily smoke a diaphragm if not careful. (I'm lucky so far, but I don't need or want to listen as loud as I used to when I first bought them) Originally, they had a warmer sound, though that "warmth" may have been noise/distortion. The only other drawbacks I can think of are the miserable measured result, and a loss in monetary value.

Second, does the change actually result in an improvement or just a difference in sound?

Of course, that is in the eye- er, ear of the beholder. To me there is a significant subjective difference in sound that brings an enormous improvement in my room, to my ears. It has been years since I heard them in stock trim, so it is difficult to make accurate before/after judgements today. Audio hindsight is not 20/20! :)

Third, and most important, how do you the listener gauge what you hear as an improvement (we want to hear improvements so does this bias our judgment)?

Ah, to quantify personal subjective values; a slippery slope. I believe our subjective judgement is biased by several factors, and nobody, I say nobody is immune unless listening blind, and then ones subjective judgement gets distorted in other ways, leading to poor choices in the real world. Some listeners (like me) may be biased toward "wanting to like" the sound of JBL comp. drivers, while others are biased toward/against comp. drivers all together, or tubes, or SS, digital, analog, sat/subs, copper, silver, SE, balanced, on and on. I'm biased against the people who are biased against our drivers! :)

You have already said, I think, that you are happy with the change in design of the 4343 (though it no longer is a 4343, really). You are the best judge on what sounds best to you and that is the bottom line.

No, it's not a 4343 system anymore. They are merely hybrid versions of their former selves. 4343Borg?

Your change really is a total redesign as opposed to a tweak or refinement. If you are looking for some reinforcement or constructive criticism on your efforts, it is really tough for someone to make any comments without some direct experience along the lines of your modifications. Alternatively, some general experience can point to some predictable results and I think some of the difficulties in reworking crossovers based on theoretical models alone are expressed above.

Well said, I understand. Naive' of me to assume otherwise. It is frustrating to wonder if the ideal theoretical XO existed, and I built it, and I plugged it in, would I say "wow, this even better"? I better do more learning so I can begin to understand half of what is discussed here. ;)

Thanks you guys,
-Andy

[Ian Mackenzie]

Yeah well the funny thing is speaker builder designers can be their own best and worst enemy. The human brain can and does play tricks on us all...the more we hear, the more we like it. Perhaps that is where science and art cross paths, the instruments lead us in the right direction but the ears are the deciding factor.

Of course there are bad examples of those who profess to belong and indulge so much in one camp or the other that they loose sight of the big picture. There we have a very clinical and detailed sound, etched and lifeless and the other extreme full of bloom, romantic and engaging but never truely accurate.

I tend to trust less those who love to play all day long with their fancy analyers, screwing around with optimisiers late at night looking for that perfect crossover design.

Perhaps the better way is to approach it empirically with a few simple objectives. Listen first then do some measurements and make some changes, then listen again.

Then invite some friends to hear it.

[B&KMan]

Hi Jean,
All L-pads and Bi-amp switches are long gone, so no problem there. ;)
Do you mean to shift the 2121 down in frequency, or to change a cap/choke to a lower value? Thanks!

-Andy

Hello again,

first (keep in your mind my english is poor so try to understant inter-line If you have doubt please ask...)

second : I'm not a electronical formation. So I'm suggest modification in regards of theorical parameters but I dont know what is exact value...

in this case other members is easly help you...

OK first in according in my experience of my 4343 original, your 2121 have too small hight platform because the 1 order is cut too slow...

if you look my addition in schema , your remark 2 point the 2231 is start drop too fast and the 2121 is begin to hight for good cross network in according of 1er order... so you loose in this area arroud 7 db. it is more than double power of sound in this area !!! look red line

the better compromise is you put down 2121 cross network frec in regard of the inpedance your 2121 is support more than you put down response than you put the 2231 up... the 2231 is fastest eratic in hight frec and because you run in first order you risk to hearing the phenomenon.

but i Dont know is close box arround 2121 is support this frec. ???

http://www.audioheritage.org/vbulletin/showpost.php?p=51417&postcount=52
http://www.audioheritage.org/vbulletin/showpost.php?p=51311&postcount=43

I hope this is put something light in your project.

By the way the 2420 is extremely eratic in dow frec and you are probably fatigue fastest the diagragm if you run in first order + maybe more distortion listenable than if you add more part in your circuit for control this effect.


I repeat many other members write : this selection driver is not optimised for 1 order network .... be shure you understand the level of distortion and eratic response you put on response with this approach...

I know the simple apparch the better result and it is the succes of the 1 order but the advantage is rapidly destroy by other parameter...


In feeling calculate 1/3 octave below frec net of 2121 and 1/3 octave frec upper in 2231 and maybe it is better flat response but introducce more distortion in extreme response of each driver... probably just try is fell the right response acceptable... sorry.
:cheers:

Jean.

[4343mod]

OK, now I understand. The plot shows the crossover point between the LF and MF is over 6dB down compared to stock, as is the response at those frequencies. Funny thing is as I remember, the 2121 was almost mute before the mods, and now is a real working player among the group. Strange.

Lancer- If it's not too much to ask, could you please be so kind as to plug the second schematic with the 12dB/oct. LF filter into the modeler? If I'm not mistaken, the LF filter will have an effect across the whole spectra, no?

-Andy