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Thread: How to choose rossover coils?

  1. #31
    Senior Member Ian Mackenzie's Avatar
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    Quote Originally Posted by scombridae View Post
    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.

    Ari
    Hi Ari,

    A bit about me.

    I treat a new forum member like the customer and l am here to sell you the JBL legacy experience, authentic and bring it to life. To do that you have to have lived with the product(s) for a long period of time and be invested in a growth mindset to explore and understand how these systems work in great detail.

    More recently l worked closely with Greg Timber’s, Nelson Pass with feedback from Lor Kramer on some further developments in the field of Biamping JBL Pro and Consumer Loudspeakers Systems. Much of the new insights are learnings from Greg Timber’s long experience and expertise. I refer to these insights as the unknown unknowns. Things even experienced professionals aren’t aware of that when carefully considered bring world class loudspeakers to fruition. As Greg Timber’s says, “Everything thing matters in Audio” and to that end l apply a lot more attention to detail than may seen necessary. The end results have been described as spectacular by those who l have work with closely.

    When this Covid situation calms down and we all start to resume normal calm lives l hope bring some new products to market. These products will appeal to what Nelson Pass refers to as the “Think Cap” customer who is curious and wants to explore and push the envelope with his or her audio system.

    Both consumer and audio amateur will be provided with comprehensive technical support from set up guidance to engineering / technical support for large format project loudspeakers and selected JBL pro legacy and consumer loudspeakers.

    Pivotal to that will be an emphasis on listening carefully to our customers and answering all their questions while providing a comprehensive awareness on the key elements associated with reaching the pinnacle of performance with his or her sound system.

  2. #32
    Senior Member Ian Mackenzie's Avatar
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    Hi RMC,

    Please accept my apology for that unfortunate post recently. Hopefully we can put our differences behind us and move forward in a collaborative way.

    To that end l would like to extend an opportunity to you to be able to make contact with the key engineers behind the JBL Subwoofer article subject to their availability. I think it would really great for you to communicate with the engineers on the design detail which are so invested with bass reflex subwoofers.

    Leave it with me.

    Ian

  3. #33
    Administrator Robh3606's Avatar
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    "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 that’s really the best option."

    Hello Ari

    I would price out soundcard, microphone and software. I have been using CLIO Pocket. It's not the cheapest option but it works very well. I used Pocket to do my last DIY speaker and it was a pleasure to use. The advantage is it's a proven system the self calibrates so no issues with software and hardware. You purchase your done.

    Rob
    "I could be arguing in my spare time"

  4. #34
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    Quote Originally Posted by Ian Mackenzie View Post
    Hi Ari,

    A bit about me.

    I treat a new forum member like the customer and l am here to sell you the JBL legacy experience, authentic and bring it to life. To do that you have to have lived with the product(s) for a long period of time and be invested in a growth mindset to explore and understand how these systems work in great detail.

    More recently l worked closely with Greg Timber’s, Nelson Pass with feedback from Lor Kramer on some further developments in the field of Biamping JBL Pro and Consumer Loudspeakers Systems. Much of the new insights are learnings from Greg Timber’s long experience and expertise. I refer to these insights as the unknown unknowns. Things even experienced professionals aren’t aware of that when carefully considered bring world class loudspeakers to fruition. As Greg Timber’s says, “Everything thing matters in Audio” and to that end l apply a lot more attention to detail than may seen necessary. The end results have been described as spectacular by those who l have work with closely.

    When this Covid situation calms down and we all start to resume normal calm lives l hope bring some new products to market. These products will appeal to what Nelson Pass refers to as the “Think Cap” customer who is curious and wants to explore and push the envelope with his or her audio system.

    Both consumer and audio amateur will be provided with comprehensive technical support from set up guidance to engineering / technical support for large format project loudspeakers and selected JBL pro legacy and consumer loudspeakers.

    Pivotal to that will be an emphasis on listening carefully to our customers and answering all their questions while providing a comprehensive awareness on the key elements associated with reaching the pinnacle of performance with his or her sound system.
    Hello Ian,

    The groundwork you have done and are doing is impressive just from what I've read on this forum. I am all in on what you are doing and you have my support.

    I have only owned 4411 and L220 speakers for the last 20 years as they are some of the the more reasonably priced models. About 15 years ago I built a B460 clone which I will use with my 4344s. It's works very well with the L220s and is incredibly musical for an 18" subwoofer. Recently I built charge coupled crossovers for the L220s. What a difference! I almost feel like they are new speakers. I've always thought the LE5 speaker to be grainy and weak point in these systems. I wonder if there's a way to deal with this in capacitor choice. Anyway after that experience I decided to finally loose all my marbles and actually build the 4344 thanks to you inspiring me.

    I believe it will be a long journey but it has taken me almost 20 years of reading this forum to post. That's how good the information is on this website and how much I respect it.

    I imagine I will be full of questions when I get these up and running. The anticipation is unbearable sometimes, but then I take a deep breath and simply focus on the next step to not mess it up. One step at a time and do it well. I have this imagination that keeps creeping in that I will get them up and running and everything will be sounding wrong and disjointed. It's almost an expectation at this point with 8 drivers. When I look at the crossover I just think, go over everything 10 times and remember the woofer is reverse polarity... just like the L220. Why couldn't JBL just make black negative and red positive? Your Ferrari reference is quite appropriate here!

    Thank you for all you do and all the contributors to this forum! It is making it possible for an engineer of nothing to build these speakers.

    Ari

  5. #35
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    Quote Originally Posted by Robh3606 View Post
    "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 that’s really the best option."

    Hello Ari

    I would price out soundcard, microphone and software. I have been using CLIO Pocket. It's not the cheapest option but it works very well. I used Pocket to do my last DIY speaker and it was a pleasure to use. The advantage is it's a proven system the self calibrates so no issues with software and hardware. You purchase your done.

    Rob

    Thanks Rob for the tip! It looks very interesting and may be in my future.

  6. #36
    Administrator Mr. Widget's Avatar
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    Quote Originally Posted by scombridae View Post
    Thanks Rob for the tip! It looks very interesting and may be in my future.
    Ditto!

    Rob, do you know of anyone who calibrates these mics and if Pocket CLIO accepts calibration files?


    Widget

  7. #37
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    In terms of software Smaart is the industry standard for live audio measurement and it costs real money. For home hi-fi measurement REW ( Room EQ Wizard ) is very serviceable software for free as well as Open Sound Meter again for free. All three of these have Mac versions which is what I run. Spectra Foo was the original Mac based audio measurement software but they have yet to make it able to run in 64bit OS versions. Just one more reason it'll be a long time before I move beyond OS 10.14.

    USB audio interfaces with mic inputs that can power measurement mics are too numerous to count. My most basic one is a Focusrite Scarlett 2i2. A USB audio interface is a handy thing across the board and for measurement use the most you need is a two channel unit with at least one XLR mic input.

    Measurement mics are again numerous. I own several including an Earthworks M23, a Superlux ECM 99, an Audix and a couple others ( maybe a Behringer I'm embarrassed to admit ) I don't even remember the make of. I've measured the response differences between the Earthworks ( the serious money mic ) and the cheap, under $100 Chinese mics and found that in the mid band 100 - 10k hz range the response is identical and at the frequency extremes it never gets worse than 1.5db off. More than close enough for evaluating the response of any loudspeaker as moving the mic a foot left or right from a given measurement position will make a greater change in response at those extremes than 1.5db. I've long suspected that the various Chinese mics all came from the same factory and simply get the brand name applied at the end of the production run but that may be a bit over the top.

    The trick of course is learning how to use it all and there is a substantial amount of training material on the Web and on Youtube explaining how to make audio measurements. The makers of Smaart are prolific in training live audio engineers in how to use their products and anyone interested in understanding how sound measurement works and how it informs your listening experience can benefit from them. There are threads on the AV Nirvana forum with instruction and Q&A about using REW.


    Quote Originally Posted by scombridae View Post
    Riley Casey,

    ... Could you suggest some good microphones and external sound cards? I happen to be Mac based but I have a pc if that’s really the best option.

    thanks,
    Ari

  8. #38
    Administrator Mr. Widget's Avatar
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    Quote Originally Posted by Riley Casey View Post
    Measurement mics are again numerous….

    The trick of course is learning how to use it...
    Agreed, learning how to gather meaningful data is key and takes a bit of time as well as reading and/or watching instructional videos.

    Smaart is the industry standard for setting up live sound and can be useful in a home system as well. CLIO, MLSSA, LEAP, and other newer products are better for designing loudspeakers. In the right hands they can all be useful.

    FWIW: If anyone wants a free USB calibration mic with compact mic stand, I have several NOS Anthem ARC mic kits. Just pay the shipping.


    Widget

  9. #39
    Senior Member RMC's Avatar
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    Hi RMC,

    Please accept my apology for that unfortunate post recently. Hopefully we can put our differences behind us and move forward in a collaborative way.

    To that end l would like to extend an opportunity to you to be able to make contact with the key engineers behind the JBL Subwoofer article subject to their availability. I think it would really great for you to communicate with the engineers on the design detail which are so invested with bass reflex subwoofers.

    Leave it with me.

    I accept the apology and thank you for it.

    On the other hand have a busy autumn with too many things to do, less availability, making it difficult to plan for a Timbers/Kramer conversation.

    Worst, some signs of a possible early winter, like previously, are in the air (= even more work to do): noisy migrating birds already going south US for the winter! and nights around 7°C coming our way, sooner, both typical signs of cold on the way.

    I need Bora Bora in the Pacific...

  10. #40
    Senior Member Ian Mackenzie's Avatar
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    Quote Originally Posted by RMC View Post
    I accept the apology and thank you for it.

    On the other hand have a busy autumn with too many things to do, less availability, making it difficult to plan for a Timbers/Kramer conversation.

    Worst, some signs of a possible early winter, like previously, are in the air (= even more work to do): noisy migrating birds already going south US for the winter! and nights around 7°C coming our way, sooner, both typical signs of cold on the way.

    I need Bora Bora in the Pacific...
    Okay no worries.

    Ian

  11. #41
    Senior Member Ian Mackenzie's Avatar
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    DIY Audio Measurement Primer
    For diy purposes please find below some recommendations:

    1.Measurement software/ systems
    In diy the de facto loudspeaker measurements tool is REW.

    It’s well supported and can accept mini Dsp calibrated mics for only about $100 on a Mac Pro laptop.
    It will run on a Mac laptop or Windows.
    GT said he prefers REW to LMS these days.

    Dayton Audio also produce a relatively inexpensive measurement set up which is very well supported.

    2.Measurement for the 4344mk2

    If you are new to loudspeaker building here is a low cost way to set up your 4344mk2 project without a lot of expense or head scratching. It’s simple with very little additional knowledge required.

    If you make the 4344mk2 network to the letter then you have a number of Lpad calibration options.

    Grab a Radio Shack analogue spl meter or other brand low cost spl meter. You might find these on EBay or a simple spl meter with a frequency response of 300-10,000 hertz.

    There are other low cost spl meter available from electronics suppliers.

    Relative Sound Level Measurements

    To set the zero position of the L pad we can rely on the manufacturers attenuation levels on the L pads plate. However the Lpads are sloppy and should not be used for precision level matching.

    I have found that using the L pad max level as a reference and the -1.5 dB of measured attenuation an overall uniformly flat response can be obtained. This is referred to as a Relative SPL Measurement where we are only concerned with the SPL difference in one measurement to another at a specific frequency.

    By placing the measurement microphone close to the driver most of the interference from the room can be reduced to a small amount or ratio of the direct sound from the driver.

    We can therefore adjust the spl range on the meter to range where differences in 1.00 dB can easily be identified on the analogue scale

    This approach is good place to commence adjustment of your L pads and does not involve expensive test equipment or a lot of software program learning.

    The key is obtaining a reliable and precise measurement.

    Note it is assumed that as you are building a jbl designed clone the manufacturer has engineered the system to have a frequency response which is flat within a known tolerance typically -+-3 dB or +-2 dB, lts unlikely an audio amateur a high degree of competency will be as able to validate the manufacturers specifications without ideal measurement conditions.

    If you are an experienced audio amateur with a spl frequency response measurement instrument then you can proceed to make your own measurements if you wish. I do not recommend attempting to equalise the response with external dsp based analysers before setting the L pad levels.

    Note. Under optimal conditions l have measured the overall system response to within +-3 dB from 32-20,000 hertz on axis. A smoother response can be obtain slightly off axis.

    Note. If you attempt to equalise the response adopt the 5 or 7 position spl test practice outlined in the Dirac software application.

    3 Procedure

    Down load an audio tester application on your laptop that can create sine wave audio outputs via the audio output on the laptop or from your smart phone. Plug the output lead into the input of your pre amp auxiliary input.

    Adjust your power amplifier output so the sine wave is audible. Do not have it too loud.

    Mount your spl meter on a camera or telescope tripod with the mic 1-2 inches from the centre of the 2123 mid cone

    Run sine wave test tones at 800hertz (2123) 4000hertz (2425) and 10,000hertz (2405) with the meter reading 00.00 dB with the L pads up full and the mic in a close near field location to each driver for individual tests.

    Do this step for each driver.

    Then turn down the Lpads for each driver down -1.5 dB on your spl meters analog scale ( per the 4344mk2 markings on the Lpad plate).

    Repeat for each driver with the mic directly in front of the driver. You will need a tripod and a means of holding the meter in place.

    Once done your going to have spl matching on the mid, horn and slot to a reasonably good tolerance within +-1.5 dB matching of drivers in the other enclosure which is also important. This procedure will take an afternoon so best to do it while the family is out.

    Note you can do the above Relative SPL Measurements with REW which is free. I did this on a home visit for someone in LA.
    He was very pleased with the overall results.

    Note : Attempts to do this in the listening position for driver spl level matching is in accurate because you won’t see the resolution with the room interference. So don’t bother.

    Woofer Midrange Balance
    Now you can then match the woofer to the mid- high frequency array by ear much more easily.

    Pink Noise measurement
    Or you can run a one octave band of pink noise centred at 300 hertz at 1 metre with the drivers electrically in phase (2nd order Electronic Crossover Slope) or out of phase ( with 4th order LR Electronic CrossoverSlope) and the mic central to the drivers. Adjust the level of the woofer signal until you see a uniform notch about 300 hertz. The woofer and midrange will then be close to 1 dB match in spl.

    I will need to refer to my notes but that is essentially a good place to start with matching the drivers.

    Outdoor Measurements
    You can also do outdoor ground plane measurements at 2 meters and get high resolution measurements with the enclosure laid on its side on a smooth concrete surface (not rough stone finish)

    I have run LMS frequency sweeps with a measured 1 dB changed in Lpad adjustment with 1/2 octave smoothing and obtained very good results.

    You can also look at matching of the voltage drives. This can be done with REW amd a USB interface like Focusrite.

    This is the thing.
    You have 3 drivers in the mid, horn and slot that need to be closely match to each other and each channel. If this is not done the subjective performance is diffuse and tonally warped if that makes sense.

    It’s like comparing a cheap Riaa phone to a top of the line one which has much high matching of the Riaa curve.

    The next step is off axis measurements which come into their on where you toe in the enclosures at a defined angle. Dirac or other room EQ systems may be used. Refer to the Dirac mic measurement procedure of 5 or 7 mic measurement locations.

    These 4344mk11 systems are very finicky but once you get to know your way around them they pull you in closer to the music than any comparable loudspeaker l am aware of.

    This a a simple instructional guide for loudspeaker builders (4344mk2)

    Enjoy your tinkering…

    Ian

    Attached spl graph of 4344mk11clone passive network (this is an old measurement 10 dB division. The LF bump is a nearby building. Overall not a bad response, 1/2 octave smoothing Linear X LMS - woofer 2235H)

    Ian Mackenzie Audio copyright 2021
    Attached Images Attached Images    

  12. #42
    Senior Member Ian Mackenzie's Avatar
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    Other tips

    By far the most issues clone builders face is with used drivers not meeting specifications.

    Typically builders assume their drivers are good but unfortunately this is not always the case. The 2425 and the 2405 can have low output or unmatched outputs or distorted outputs. There is nothing worse than the disappointment of the project not working as expected at the end.

    So first things first invest in having your drivers checked out by a jbl technician who has certification or testimonials to validate their work. You will need to do this yourself. In the USA Ken Haaer at Upland Loudspeaker Repairs is highly recommended with numerous international clients

    One guy affectionately became known as my other wife because of the emails that would flow back and forth snd the phone calls trying to sort out his diy clone. You could hear the suffering in his voice. As it turned out all his drivers had problems. The woofer recones was in the wrong baskets, the diaphragms in his Horn drivers were faulty and one of his slots has low output. Of course he refused to believe this unless it was the last possibility to check…Lol

    The Crossover
    The crossover is only as good as the way it was assembled.

    The second area of mishaps is the crossover.

    Use ONLY the specified parts. If it does not work right you are only to blame.
    Pay someone to build it if you are not confident.
    Check your work and re check your work.
    REW with a USB interface can help you validate the voltage driver. But if your work is checked it will work fine.

    LPad wiring and polarity.
    All the midrange, high and slot drivers are wired in phase.
    The woofer is wired out of phase.

    Many builders get this wrong ��, Follow the schematic and it will work as intended.
    The L pad wiring can be downloaded.

    Parts.

    The crossover is only as good as the parts,
    Order the matching parts. This applies to resisters, inductors specifically. Do NOT substitute parts off EBay because they are cheap. The odds are they are not within the specifications required.

    Assembly.

    Take a methodical approach to assembling your crossover within the enclosure. Label all cables and terminations. This will safe a lot of time, frustration and disappointment.

    Often mistakes are made because the builder mixed up a cable connection. Or wired up the L pad incorrectly. Check and recheck your work the next day. Arranging someone to check your crossover for faults can be time consuming and costly.

    I can honestly say l have found second and third clone owners who have reported problems only to find wiring mistakes in the crossover and wiring.

    This does not reflect well on the expectations of the owner towards the cloned system.

    So l tend to adopt a fairly regimented approach to assembly with clone builders. It’s not for the faint hearted and some can take years to complete. Hand holding, lots of patience and understanding is required.

    Your work is only as good as your last job!

  13. #43
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    Quote Originally Posted by Ian Mackenzie View Post
    DIY Audio Measurement Primer
    For diy purposes please find below some recommendations:

    1.Measurement software/ systems
    In diy the de facto loudspeaker measurements tool is REW.

    ItÂ’s well supported and can accept mini Dsp calibrated mics for only about $100 on a Mac Pro laptop.
    It will run on a Mac laptop or Windows.
    GT said he prefers REW to LMS these days.

    Dayton Audio also produce a relatively inexpensive measurement set up which is very well supported.

    2.Measurement for the 4344mk2

    If you are new to loudspeaker building here is a low cost way to set up your 4344mk2 project without a lot of expense or head scratching. ItÂ’s simple with very little additional knowledge required.

    If you make the 4344mk2 network to the letter then you have a number of Lpad calibration options.

    Grab a Radio Shack analogue spl meter or other brand low cost spl meter. You might find these on EBay or a simple spl meter with a frequency response of 300-10,000 hertz.

    There are other low cost spl meter available from electronics suppliers.

    Relative Sound Level Measurements

    To set the zero position of the L pad we can rely on the manufacturers attenuation levels on the L pads plate. However the Lpads are sloppy and should not be used for precision level matching.

    I have found that using the L pad max level as a reference and the -1.5 dB of measured attenuation an overall uniformly flat response can be obtained. This is referred to as a Relative SPL Measurement where we are only concerned with the SPL difference in one measurement to another at a specific frequency.

    By placing the measurement microphone close to the driver most of the interference from the room can be reduced to a small amount or ratio of the direct sound from the driver.

    We can therefore adjust the spl range on the meter to range where differences in 1.00 dB can easily be identified on the analogue scale

    This approach is good place to commence adjustment of your L pads and does not involve expensive test equipment or a lot of software program learning.

    The key is obtaining a reliable and precise measurement.

    Note it is assumed that as you are building a jbl designed clone the manufacturer has engineered the system to have a frequency response which is flat within a known tolerance typically -+-3 dB or +-2 dB, lts unlikely an audio amateur a high degree of competency will be as able to validate the manufacturers specifications without ideal measurement conditions.

    If you are an experienced audio amateur with a spl frequency response measurement instrument then you can proceed to make your own measurements if you wish. I do not recommend attempting to equalise the response with external dsp based analysers before setting the L pad levels.

    Note. Under optimal conditions l have measured the overall system response to within +-3 dB from 32-20,000 hertz on axis. A smoother response can be obtain slightly off axis.

    Note. If you attempt to equalise the response adopt the 5 or 7 position spl test practice outlined in the Dirac software application.

    3 Procedure

    Down load an audio tester application on your laptop that can create sine wave audio outputs via the audio output on the laptop or from your smart phone. Plug the output lead into the input of your pre amp auxiliary input.

    Adjust your power amplifier output so the sine wave is audible. Do not have it too loud.

    Mount your spl meter on a camera or telescope tripod with the mic 1-2 inches from the centre of the 2123 mid cone

    Run sine wave test tones at 800hertz (2123) 4000hertz (2425) and 10,000hertz (2405) with the meter reading 00.00 dB with the L pads up full and the mic in a close near field location to each driver for individual tests.

    Do this step for each driver.

    Then turn down the Lpads for each driver down -1.5 dB on your spl meters analog scale ( per the 4344mk2 markings on the Lpad plate).

    Repeat for each driver with the mic directly in front of the driver. You will need a tripod and a means of holding the meter in place.

    Once done your going to have spl matching on the mid, horn and slot to a reasonably good tolerance within +-1.5 dB matching of drivers in the other enclosure which is also important. This procedure will take an afternoon so best to do it while the family is out.

    Note you can do the above Relative SPL Measurements with REW which is free. I did this on a home visit for someone in LA.
    He was very pleased with the overall results.

    Note : Attempts to do this in the listening position for driver spl level matching is in accurate because you wonÂ’t see the resolution with the room interference. So donÂ’t bother.

    Woofer Midrange Balance
    Now you can then match the woofer to the mid- high frequency array by ear much more easily.

    Pink Noise measurement
    Or you can run a one octave band of pink noise centred at 300 hertz at 1 metre with the drivers electrically in phase (2nd order Electronic Crossover Slope) or out of phase ( with 4th order LR Electronic CrossoverSlope) and the mic central to the drivers. Adjust the level of the woofer signal until you see a uniform notch about 300 hertz. The woofer and midrange will then be close to 1 dB match in spl.

    I will need to refer to my notes but that is essentially a good place to start with matching the drivers.

    Outdoor Measurements
    You can also do outdoor ground plane measurements at 2 meters and get high resolution measurements with the enclosure laid on its side on a smooth concrete surface (not rough stone finish)

    I have run LMS frequency sweeps with a measured 1 dB changed in Lpad adjustment with 1/2 octave smoothing and obtained very good results.

    You can also look at matching of the voltage drives. This can be done with REW amd a USB interface like Focusrite.

    This is the thing.
    You have 3 drivers in the mid, horn and slot that need to be closely match to each other and each channel. If this is not done the subjective performance is diffuse and tonally warped if that makes sense.

    ItÂ’s like comparing a cheap Riaa phone to a top of the line one which has much high matching of the Riaa curve.

    The next step is off axis measurements which come into their on where you toe in the enclosures at a defined angle. Dirac or other room EQ systems may be used. Refer to the Dirac mic measurement procedure of 5 or 7 mic measurement locations.

    These 4344mk11 systems are very finicky but once you get to know your way around them they pull you in closer to the music than any comparable loudspeaker l am aware of.

    This a a simple instructional guide for loudspeaker builders (4344mk2)

    Enjoy your tinkeringÂ…

    Ian

    Attached spl graph of 4344mk11clone passive network (this is an old measurement 10 dB division. The LF bump is a nearby building. Overall not a bad response, 1/2 octave smoothing Linear X LMS - woofer 2235H)

    Ian Mackenzie Audio copyright 2021

    Ian,

    This is very helpful and much appreciated! I anticipate having more questions as I begin that process, but as I am right in the middle of construction and there are other fish to fry at the moment. I've been going through the CC vs. high quality capacitors posts to gain an education. I may decide to switch from CC to the Mundorfs you show in the initial photo on this post's string. I've seen Kenrick use them as well and there must be good reasons for that. Currently I plan to power the midrange, HF and UHF with a Mcintosh 275 tube amp. The 2235H will be powered by an Emotiva BasX 2 channel 160w x 2. Do think think there would be a cap choice in this setup that is beneficial? I realize I most likely will have to do my own research but maybe you have some thoughts?

    I am truly amazed with the information you have worked hard at gathering and discovering. We are lucky to have someone as generous with their hard earned knowledge and willing to share it for the benefit of us who can't give much back to the forum other than asking questions that others may learn from.

    But just a couple quick questions. Once everything is up and running correctly, should I wait to burn in the crossovers/drivers for some time before calibrating the Lpads? Or maybe calibrate them immediately and then check again after say 50hrs? Also when monitoring the horn db level should that be done with the lens on or off?

    Thanks,
    Ari

  14. #44
    Senior Member Ian Mackenzie's Avatar
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    Quote Originally Posted by scombridae View Post
    Ian,

    This is very helpful and much appreciated! I anticipate having more questions as I begin that process, but as I am right in the middle of construction and there are other fish to fry at the moment. I've been going through the CC vs. high quality capacitors posts to gain an education. I may decide to switch from CC to the Mundorfs you show in the initial photo on this post's string. I've seen Kenrick use them as well and there must be good reasons for that. Currently I plan to power the midrange, HF and UHF with a Mcintosh 275 tube amp. The 2235H will be powered by an Emotiva BasX 2 channel 160w x 2. Do think think there would be a cap choice in this setup that is beneficial? I realize I most likely will have to do my own research but maybe you have some thoughts?

    I am truly amazed with the information you have worked hard at gathering and discovering. We are lucky to have someone as generous with their hard earned knowledge and willing to share it for the benefit of us who can't give much back to the forum other than asking questions that others may learn from.

    But just a couple quick questions. Once everything is up and running correctly, should I wait to burn in the crossovers/drivers for some time before calibrating the Lpads? Or maybe calibrate them immediately and then check again after say 50hrs? Also when monitoring the horn db level should that be done with the lens on or off?

    Thanks,
    Ari

    On the L pads no that burn in is not going to effect an objective measurement.

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