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Thread: How to choose rossover coils?

  1. #16
    Senior Member Ian Mackenzie's Avatar
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    Quote Originally Posted by scombridae View Post
    Ian,

    Please correct me if I am wrong but the woofer can be wired directly to the amp because I'm using an active crossover right? The only crossover I am building is for the MF, HF and UHF.

    What is SOA circuitry?

    Thanks,
    Ari
    That’s right. Your woofer amplifier obtains its signal from the low output of the active crossover.

    You only need the midrange, horn and uhf passive crossover.
    In Biamp use the 72uf+72uf capacitor is not required or the input resister.

    SOA = state of art. High quality parts such as Linear Systems Jfets and Sparko studio quality discrete opamps. Most consumers electronics are mass production with integrated circuits which are compromised due to compact size for hi end audio. The Sparko discrete opamps can achieve much high output voltage and signal current into low impedances to deliver lower distortion levels and lower noise floor than mass produced ics.

    The result is a more transparent sound reproduction which is important as these loudspeakers tend to be very analytical.

    You don’t want to be listening to brick and mortar presentation of low cost electronics which these loudspeakers will sound like.

    What you put in is what you hear.

  2. #17
    Senior Member RMC's Avatar
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    Most of your questions are related to your 43 series project and as i mentioned earlier the 43 series isn't really my thing. So i'll let others deal with the 43 specifics.

    As for the impossible aspect of adjusting a two-way electronic crossover without measuring setup and software i think its an exagerated statement. Its been done for decades in absence of the newer measurement/software gadgets. Btw the Ashly came with a user manual giving some hints. They might also have an application note for this, i haven't checked.

    On the other hand you have two of the most practical assessment tools: your own two ears, unless you don't trust them.

    Trial/error and personnal preferences are part of the process. inevitable. What is worth a sophisticated setup if you don't think its worth the money spent and/or don't really like how it sounds or is different than expected? Don't forget you build boxes to please yourself first and foremost, not the neighbor or the crowd...

  3. #18
    Senior Member Ian Mackenzie's Avatar
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    Looking at the voltage drive of the 4344mk11 with the drivers connected (not the 8 ohms test load) the woofer is a damped 2nd order filter. The midrange crossover is in fact a 2nd bandpass filter with something like 9 dB per octave slopes.

    If you were looking at a customised active crossover a 2nd order Linkwitz crossover at about 320 hertz will sum perfectly flat with the electrical phase of the mid/horn array reversed.

    These filters have a more gradual knee than the Butterworth filter while still having 12 attenuation per octave. On paper the drivers start to gradually roll off with a wider overlap in the crossover region. However both drivers sum flat and do they blend perfectly.

    A 4th order Linkwitz filter will work but you may find the transition too narrow for optimal tonal balance. The 4th order filter has inferior transient performance to the 2nd order Linkwitz filter.

    I use this kind of filter on my 4345 when l use the 2123 mid and itís a superbly natural transition from the 18 inch woofer to the 10 inch mid driver. You really canít pick the crossover point.

  4. #19
    Senior Member Ian Mackenzie's Avatar
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    The complication is that these are 4 way and most people find it difficult to obtain a satisfactory result by ear.

    I have prescribed else where a method of obtaining a highly accurate match in the levels. It make a huge difference in the tonal balance and sound stage.

    Both Rane and jbl crossover manuals detail a procedure for setting up their analog active crossover. Itís not done by ear. Itís a case of doing it correctly or not at all if you want the best possible results.

  5. #20
    Senior Member RMC's Avatar
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    Since Rane crossover manual was mentioned, i happen to own for years two Rane crossovers, along with the Data Sheet (4 pages, including an application note) as well as the 19 page Manual, both provided in Rane's packaging at time of purchase.

    There's nothing rocket science or sophisticated seen in this regard, in fact the explanations given are pretty simple and straightforward.

    As for matching of the levels the manual details different procedures alluded to on pic.

    A number of meanings were attributed to SOA, however in the audio field more often than not it was used to describe Safe Operating Area e.g. in relation to amp output stage.

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  6. #21
    Senior Member Ian Mackenzie's Avatar
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    Thumbs up

    Hi Richard

    I must have had a seniors moment.

    Too bad you actually went to the trouble of looking for nothing.

    Besides you said the 43xx was not your thing? So why are you in this thread?

    I look forward to you publishing a long thread on your own loudspeaker design with references to the way back machine.

    Attached is a screen dump of an official JBL 4350 manual referring to the Biamp balance procedure.

    As l mentioned earlier the mater of obtaining the correct tonal balance using the Lpads is much more involved in the 4343-4345. One would assert if you in fact owned one of these systems you would not be gum slapping over this. But of course you formally stated the 43XX are not your thing. Your just here to stir up trouble like you always have. So kindly leave this thread to those directly involved.
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  7. #22
    Senior Member RMC's Avatar
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    The usual rhetoric when one doesn't swallow all that is said or his things catch up with him.

    Seems something was forgotten, "the 43 series isn't really my thing, i intervene in 43xx related threads occasionaly, not much more."

    When newcomer OP posted i waited to see if others would take care of him, nobody showed up. I did and was here before Mackenzie, while he stood on the sidelines. The OP thanked me for helping him and others:"This information is very helpful! Thank you for taking the time and effort to help me and anyone else that has these questions."

    Had signalled i would not stick around long, but when i saw the Ashly not being so good anymore i decided to stay a little longer considering the previous comments in post 13:

    "Your Ashley crossover will give a competent crossover region with some trial and and error adjustments."

    "I recommend you tweak the Ashley crossover for best subjective performance for now," by ear obviously. Both statements not disputed.

    The wind changed direction in post 19, with an alleged procedure he raised re the Rane Manual, also shooting an arrow in my direction that "Itís not done by ear. Itís a case of doing it correctly or not at all..." Turns out Rane appeared to have a different view (pic posted), himself too in the above statement.

    Instead of explaining his disagreement with manufacturer position he prefers to attack me. When one prefers the latter its a sign the case might be weak.

    Having both Ashly and Rane xo i'm certainly interested in what is said about these, inquiring is relevant plus these are not even 43 series gear. That members are provided with different and relevant manufacturer or expert info is an asset in making one's own decisions.

    Men who screw up assume, correct and move on, while here its "assume" and leave the thread! Looks like trying to take control of the narrative and of any info given as if he owned this thread, though he waited for someone else to "break the ice" first, now claims to be "those directly involved!

    When a player plays fair game there's less reason to jump in or stick around. At this time there's no justification to leave, or to stay for that matter.

    Will continue to look at threads, including this one and others, and post as i see fit or the situation requires.

  8. #23
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    Quote Originally Posted by RMC View Post
    The usual rhetoric when one doesn't swallow all that is said or his things catch up with him.

    Seems something was forgotten, "the 43 series isn't really my thing, i intervene in 43xx related threads occasionaly, not much more."

    When newcomer OP posted i waited to see if others would take care of him, nobody showed up. I did and was here before Mackenzie, while he stood on the sidelines. The OP thanked me for helping him and others:"This information is very helpful! Thank you for taking the time and effort to help me and anyone else that has these questions."

    Had signalled i would not stick around long, but when i saw the Ashly not being so good anymore i decided to stay a little longer considering the previous comments in post 13:

    "Your Ashley crossover will give a competent crossover region with some trial and and error adjustments."

    "I recommend you tweak the Ashley crossover for best subjective performance for now," by ear obviously. Both statements not disputed.

    The wind changed direction in post 19, with an alleged procedure he raised re the Rane Manual, also shooting an arrow in my direction that "It’s not done by ear. It’s a case of doing it correctly or not at all..." Turns out Rane appeared to have a different view (pic posted), himself too in the above statement.

    Instead of explaining his disagreement with manufacturer position he prefers to attack me. When one prefers the latter its a sign the case might be weak.

    Having both Ashly and Rane xo i'm certainly interested in what is said about these, inquiring is relevant plus these are not even 43 series gear. That members are provided with different and relevant manufacturer or expert info is an asset in making one's own decisions.

    Men who screw up assume, correct and move on, while here its "assume" and leave the thread! Looks like trying to take control of the narrative and of any info given as if he owned this thread, though he waited for someone else to "break the ice" first, now claims to be "those directly involved!

    When a player plays fair game there's less reason to jump in or stick around. At this time there's no justification to leave, or to stay for that matter.

    Will continue to look at threads, including this one and others, and post as i see fit or the situation requires.
    Richard and Ian,

    Thank you both for your input and sticking your necks out in this jungle forum. Your contributions have helped me tremendously here. This is all excellent stuff!

    I'm sure with the correct measurement tools and such, balancing a 4 way speaker in a room with less than ideal acoustics would help a lot. That said, there's something to be said about being able to tune a guitar by ear. I once took a guitar class in junior college and at the first meeting the teacher went around and tuned everyone's guitar in about 15minutes. I think there were 30 people in class, so we are talking 30 seconds to tune the guitar. It was the kind of teacher/student introduction that immediately established great respect for the teacher. It's enjoyable to tune and play a musical instrument. The funny thing is, as soon as one gets close to tuning in key, the sound changes and a retune is needed. What was once "flat or neutral" is slightly different. Making music is like that. And part of the enjoyment in making it is the organic nature of all this process. As much as we all love making and tuning speakers, in the end we all LOVE music.

    You are both teachers with different styles. I am a student like many on this forum who are learning. We are all blessed to have this forum with access to experienced teachers as yourselves. 25 years ago I wouldn't have a clue on how to build these speakers and any access to help. We are all fortunate that this forum allows all of us to contribute and learn from each other, so please don't chase each other off. It's doesn't benefit the students. I really appreciate both Richard's and Ian's help on this and you both provide very valuable information!

    Back to the subject, I'm guessing there are many a sage speaker enthusiast who can get very close to tuning a 4 way by ear. I am guessing I am not that person for I don't have any experience with the 43XX 4way series. But I am enjoying making the speakers, though it is a beast of a project. I'm assuming it will be very difficult to get all the drivers to sound or blend in a neutral way especially because I've never heard this species before and have no idea what it "should" sound like. Most likely I will play with all the knobs, put on familiar music, adjust, adjust, get closer and then decide months from now I will need to purchase mics and software and see how far off I really am.

    I guess what I'm trying to say is whatever lines have been crossed in the past or mud slinged, it is most important to see that both a scientific method and more organic approach are equally valuable and needed. And I'm assuming like most humans you both engage in both methods of speaker tuning and you both use a more scientific approach to finalize the product.

    I welcome both of you to continue to contribute on this thread and if you have any other "metaphysical" tips to tuning these monsters to tie me over until I get up the courage to do it more scientifically, it will help me and a large chunk of followers.

    Thank YOU Both!

  9. #24
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    Quote Originally Posted by Ian Mackenzie View Post
    Hi Ari and scombridae,

    If you wish l can provide a detailed approach to the level settings that Greg Timberís has recommended for his top Everest loudspeaker designs. There are also other approaches for precision level settings l can describe.

    I am not going to elaborate here due to the ongoing interference and general confusion as a result.
    A number of forum members have contacted since posting in this thread with their own questions and other things they needs advice on. So l can work with you on your specific scenario, your questions and help you most efficiently that way.

    Thereís just too much interference, debate, ramblings and confusion to make it worthwhile posting on detailed topics here.

    PM me and l will take from there via email.

    Ian

    Hi Ian,

    As much as I would like to contact you directly, I really think it is a huge benefit to continue to post to this forum. I have gained so much knowledge from reading this forum for the last decade and a half. Any questions I have will be probably benefit many others if they are answered here out in the open. And probably because I'm interested in 43xx, you Ian in particular have been my hero. I thank you for all you have done in this venue.

    I am very interested in Timber's detailed approach to tuning the Everest series so if you have info, a link or anything else I would love to see it.

    Ari

  10. #25
    Senior Member RMC's Avatar
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    Hi scombridae,

    RE I welcome both of you to continue to contribute on this thread...

    I understand your point but it seems unlikely to happen. Obviously distortion and noise are too high for any discussion.

    Among all the noise, simply remember what design engineers do. When they're done with the initial protoptype they listen carefully to the speaker they just engineered. In spite of that may hear things they might not like (it can be anything, e.g. mid level perceived as too prominent or too low). Then tweak it some more, and what happens next, they listen again to confirm if its a go or a no go...Yup, has to pass the ear test. This is what i alluded to in post 17. Regards,

  11. #26
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    Quote Originally Posted by Ian Mackenzie View Post
    Hi Ari,

    You can attempt to set the loudspeaker by ear. However this is not a simple two way loudspeaker.

    There are four drivers in each enclosure so you need to set a total of eight driver levels. This is so they not only have the correct tonal balance but also match left and right precisely.

    The Lpads are not calibrated reliably for any kind of accurate adjustment. They never were and they never will be. References provided below for Rane and JBL guide to level adjustments. You will note these references are over 30 years old. In recent times free down load software such as REW and Dayton Audio test equipment eclipses these old style spectrum analysers and are now affordable to diy audio amateurs. A foundation skill set and understanding of measurements and the internal loudspeaker crossover is required. Otherwise your walking in the dark and might get lost.

    I can offer you technical guidance in obtaining useful measurements and how to set the levels within 1.00 dB.

    Most spectrum analysers only have resolution of +-3 dB and are used for pro sound reinforcement setup. A loudspeaker studio monitor requires a resolution of +-2.00 dB or better for accurate adjustments.

    Imagine the left loudspeaker is set within a tolerance of +-2.00 dB and the midrange is actually set at +2.00 dB the resolution of the analyser. The right loudspeaker midrange is set to -2.00 dB which is within the resolution of the analyser. But you have a discrepancy of 4.00 dB in midrange level with the left and right midrange drivers. This will result in a tilt in the tonal balance of each enclosure in opposite directions and displacement of the stereo image.

    This situation also applies to the horn and the slot radiator and the woofers where careful balance of both channels had not been tested. Using specific techniques high resolution level testing can be made. This requires a deeper understanding of the techniques involved and is beyond the scope of posting on forums.

    The notion that you can do that reliably by ear is not realistic and users have struggled with this for decades.

    I am not going to waste any more of my time on this kind of topic on a public forum. Itís relatively involved and requires a detailed explanation.

    Those who are serious and invested in their project and want to get it right without trawling through post after post of opinions based on opinions night after night or for months contact me directly.

    Iím not interested in a debate, an argument when thereís nothing to debate or argue. Unfortunately there are those whoís sole cause is to engage in anti social behaviour rather than collaborate and work together. The moderators here have a view itís a jungle and that what for the problem to get out of hand before dealing with it. Nor am l going to be the subject of ongoing criticism, trolling and agitation by those who are here only to get off on abuse towards myself and others. The day RMC arrived on these forums he declared non of us had any idea of what we were talking about and made a vow to make this place a toxic culture with personal attacks towards Greg Timberís, myself snd others. This guy is a narcissistic personality. Itís not okay and it will never be okay. I donít have to put up with scene where those types of people are welcome.

    Here in Australia we have laws against those behaviours and the government has taken Facebook head on to deal with that and many other issue related to online social media. The USA is riddled with social divisions, racism and other appalling crimes. The people behind this place are are obviously tolerant of those kinds of behaviours because they live in it and they have grown to accept. Thereís no respect.

    ************************************************** ****

    ďWhy have l spent five years trying to figure something out by ear?Ē

    That was the comment from a hi end project loudspeaker user in China after l spent an afternoon with him.

    While there are a number of contributions to the forums itís not an environment where you can ask specific questions relating to your specific scenario and get one answer from on poster that will cover everything correctly. Itís a really inefficient means of communication. What you end up with is a lot of generalities that donít address you questions.

    So why do that?

    The other guy here has no direct experience with these systems nor has he demonstrated any detailed understanding of these systems. What you get is read this page in this book and then you will understand.

    Thatís absolutely rubbish because you still donít have the skills to use the tools for measurements or a detailed understanding of exactly how these things work. They are really complicated things to figure out and work on.

    The other guy isnít doing any work. Instead heís handing the problem back to you to figure out for your self. Your on your own.

    Reference to a document is NOT proof that you are a credible source of information or an understanding of the question and the answer being raised.

    This guyís posts are only generalisations and opinions. Heís only here to make a noise.

    Thatís why the Ferrari owner goes to a Ferrari service centre instead of calling Lubemobile so he knows itís going to be worked on by a Ferrari trained mechanic.

    The approach to moderation here is very laid back and that in itself is not conducive to a place that was originally intended as a factual source of information on JBL legacy systems. Most of the truly invested people in this area have left and or no longer choose to post here. I can reliably point to that as fact given the volume on user enquires l receive annually.

    They have the responsibility to lift their game or just get out of this type of forum. Sell to someone who is invested in making it work. There are other excellent forums much larger th as n this such as Diyaudio.com that have gone from strength to strength in the way they manage forum membership while the Lansing Heritage Forum remain dormant.

    At this point in time l an touring in Outback Australia where internet coverage is virtually non existent. I hardly have time or the means to post on the LHS.


    See edits to content and attachments- measurements

    Reference to level adjustment Rane, JBL
    https://www.ranecommercial.com/legac...ac23bman03.pdf

    Pages 14-15 level adjustments


    https://vdocuments.mx/reader/full/jbl-5235-manual

    Section 3-5,3-6, 3-7 level adjustment
    Ian,

    Thank you so much for posting this material with links to the documents AND for doing this while you are in the outback. I really appreciate your dedication to the cause. It will take me some time to read the manuals and I'm about 2-3 months away from finishing the speakers, so there is no rush at all. This will give me a great start in powering up the system safely and adjusting it.

    In the meantime, take care and I will be in contact if I have further questions once the system is up and running.

    I'd rather not comment on the politics of this forum or the world, but just for the record, I believe in science, vaccines, good old fashioned common courtesy, and looking out for others. Just think how far we would get if the majority did that?

    Thanks again,
    Ari

  12. #27
    Senior Member Ian Mackenzie's Avatar
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    Hi Ari,

    Your right but it would be naive to believe anything will change If it was going to grow into something better it would have already.

    In the meantime a group of like minded JBL enthusiasts are preparing a more appropriate platform to deal with technical aspects of JBL 43xx designs, Biamping JBL systems including the Everest 65000-67000, building clones and upgrades. Threads updated and rewritten by Ian MacKenzie with the latest upgrades, project journey guides for JBL amateur loudspeaker builders, questions that will be answered in real time, real schematics, crossover layouts, over 1000 unpublished jbl driver measurements, webinars on key topics and articles written by guest contributors and more.

    The inspiration came from a number of Lansing Forum members l have met personally and the dozens of people who have come to me for advice over the past five years.

    It will be a private platform by invitation with exactly what your looking for.

    More information will be forthcoming.

    Ian

  13. #28
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    Quote Originally Posted by Ian Mackenzie View Post
    Hi Ari,

    Your right but it would be naive to believe anything will change If it was going to grow into something better it would have already.

    In the meantime a group of like minded JBL enthusiasts are preparing a more appropriate platform to deal with technical aspects of JBL 43xx designs, Biamping JBL systems including the Everest 65000-67000, building clones and upgrades. Threads updated and rewritten by Ian MacKenzie with the latest upgrades, project journey guides for JBL amateur loudspeaker builders, questions that will be answered in real time, real schematics, crossover layouts, over 1000 unpublished jbl driver measurements, webinars on key topics and articles written by guest contributors and more.

    The inspiration came from a number of Lansing Forum members l have met personally and the dozens of people who have come to me for advice over the past five years.

    It will be a private platform by invitation with exactly what your looking for.

    More information will be forthcoming.

    Ian
    That sounds very exciting. Iím definitely interested. Count me in.

    Ari

  14. #29
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    It might help to remember that an under $100 microphone, a $150 USB audio interface and some free software will give you better tools for analyzing the characteristics of your home built 4350 or similar speakers than any tools that the JBL engineers had at their disposal when these speakers were designed back in the 1970s. Well aside from the engineering degrees, decades of experience and trained ears. Nonetheless the idea that you can tune a four way loudspeaker system with slightly different components than stock particularly with all of the iteration that passive network design add to the process with tuning a guitar is pretty far off base. You might be closer to that by ear ideal if you were quad-amping the speakers as your options at least with a DSP based crossover are pretty limitless and can be addressed in real time but all in all it's just not realistic to think that you can build from a cold start a usable set of passive filters for any drivers other than those originally used by JBL and by following exactly the original networks then in use. Golden ears are certainly ideal for the 'finishing touches' in speaker tuning but there is too much in-between the pile of plywood stage final listening assessment stage to rely on that all the way thru.


    Quote Originally Posted by scombridae View Post
    Richard and Ian,

    ...

    I'm sure with the correct measurement tools and such, balancing a 4 way speaker in a room with less than ideal acoustics would help a lot. That said, there's something to be said about being able to tune a guitar by ear. I once took a guitar class in junior college and at the first meeting the teacher went around and tuned everyone's guitar in about 15minutes. ...

    Thank YOU Both!

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    Quote Originally Posted by Riley Casey View Post
    It might help to remember that an under $100 microphone, a $150 USB audio interface and some free software will give you better tools for analyzing the characteristics of your home built 4350 or similar speakers than any tools that the JBL engineers had at their disposal when these speakers were designed back in the 1970s. Well aside from the engineering degrees, decades of experience and trained ears. Nonetheless the idea that you can tune a four way loudspeaker system with slightly different components than stock particularly with all of the iteration that passive network design add to the process with tuning a guitar is pretty far off base. You might be closer to that by ear ideal if you were quad-amping the speakers as your options at least with a DSP based crossover are pretty limitless and can be addressed in real time but all in all it's just not realistic to think that you can build from a cold start a usable set of passive filters for any drivers other than those originally used by JBL and by following exactly the original networks then in use. Golden ears are certainly ideal for the 'finishing touches' in speaker tuning but there is too much in-between the pile of plywood stage final listening assessment stage to rely on that all the way thru.

    Riley Casey,

    Point well taken. Iím a total greenhorn when it comes to this stuff. And when a rookie opens his mouth thereís no hiding! Haha!

    Iím pretty much cloning a 4344 Mk2 drivers, enclosure, and crossover so Iíll leave it up to my ability to get close to the original. Iím sure it wonít be a perfect match as the horn and woofer are not exactly the same, but my substitute drivers are close.

    Most likely I will be visiting the tuning rabbit hole eventually. Could you suggest some good microphones and external sound cards? I happen to be Mac based but I have a pc if thatís really the best option.

    thanks,
    Ari

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