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Thread: JBL L200B with 2216nd, LE85/H91, and 077. Crossover recommendations.

  1. #31
    Senior Member alskinner's Avatar
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    Quote Originally Posted by Mr. Widget View Post
    Iíd love your opinions of the various woofers.


    Widget
    The 136a and the 2235 are very similar in sound. The 2235 does a very good job in my 4344 clones crossed at 290hz. however both these woofers seemed to struggle to meet the 800hz cutoff to reach the LE85 and HL92 Horn in the L300. Building the Nelson Pass Crossover improved this a lot but I could still detect it could be improved upon. Not that the speaker was bad at all and I was fairly satisfied.

    Thanks to Heather I found the 2216nd was back in stock and ordered them intending at some point to build a M2 clone. I decided to try them in the L300. I was very pleased to find the new woofer was almost seamless with the horn. The bass is also more articulate in that low bass notes can be heard without any muddiness. Also being very light to handle doesn't hurt. The sound may change somewhat when the woofers break in. I am sure it could be even better in a cabinet redesign and crossover designed for it, but for now I am well pleased.

    I wish had the test equipment some of you have to verify my suppositions. But for now I rely on people like you and the others on this forum.

  2. #32
    Administrator Mr. Widget's Avatar
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    Quote Originally Posted by alskinner View Post
    The 136a and the 2235 are very similar in sound. The 2235 does a very good job in my 4344 clones crossed at 290hz. however both these woofers seemed to struggle to meet the 800hz cutoff to reach the LE85 and HL92 Horn in the L300. Building the Nelson Pass Crossover improved this a lot but I could still detect it could be improved upon. Not that the speaker was bad at all and I was fairly satisfied.

    Thanks to Heather I found the 2216nd was back in stock and ordered them intending at some point to build a M2 clone. I decided to try them in the L300. I was very pleased to find the new woofer was almost seamless with the horn. The bass is also more articulate in that low bass notes can be heard without any muddiness. Also being very light to handle doesn't hurt. The sound may change somewhat when the woofers break in. I am sure it could be even better in a cabinet redesign and crossover designed for it, but for now I am well pleased.

    I wish had the test equipment some of you have to verify my suppositions. But for now I rely on people like you and the others on this forum.
    Thanks for the mini review... it aligns with my experience and expectations of the new driver in that enclosure.

    My guess is that the best results would be from adding a DSP on the woofer. Actively crossover to the horn and bump up the very bottom a bit.

    But at the end of the day, if you are pleased, it is a winner!


    Widget

  3. #33
    Senior Member alskinner's Avatar
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    2216nd EQ

    Thanks Widget

    You are correct on the bottom end. I had already bumped up from 30hz to 60hz about 4 decibels it does need it this cabinet. I will keep the DSP option in mind.


    Regards
    AL

  4. #34
    Senior Member maxwedge's Avatar
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    I would switch the polarity at the ND2216 so it is in phase in the crossover region with your compression driver. The 2235 and 136a are both negative polarity drivers and the ND2216 is positive.

  5. #35
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    I donít know. Itís like all these things of it measures the same it will sound the same. Just like amplifiers. Blah blah 😕

  6. #36
    Senior Member maxwedge's Avatar
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    Quote Originally Posted by maxwedge View Post
    I would switch the polarity at the ND2216 so it is in phase in the crossover region with your compression driver. The 2235 and 136a are both negative polarity drivers and the ND2216 is positive.
    Quote Originally Posted by Ian Mackenzie View Post
    I donít know. Itís like all these things of it measures the same it will sound the same. Just like amplifiers. Blah blah 😕
    I agree but OP says he doesn't measure and the ear is very adaptable to sound, whether in phase or not, and can lead someone to think it sounds good when in fact it's not quite right. It was just a suggestion to try but if he likes it as is then that's fine.

  7. #37
    Administrator Mr. Widget's Avatar
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    Quote Originally Posted by maxwedge View Post
    I agree but OP says he doesn't measure and the ear is very adaptable to sound, whether in phase or not, and can lead someone to think it sounds good when in fact it's not quite right. It was just a suggestion to try but if he likes it as is then that's fine.
    +1

    Certainly should be tried.


    Widget

  8. #38
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    Making basic response measurements is pretty easy these days.

    There are some pretty Hi-Rez Smartphone apps ( some are free and are mostly 1/3 to 1/6 octave RTA's ) that allow one to see ( at the very least ) how things mesh together at crossover ( and additionally, what LF + HF extension is like ).

    Most of Apple's more recent smart phones have a pretty linear built-in mic // making those iPhones the better choice for ad-hoc, on the cheap measurements.

    Here are some internet comparisons for older iPhones;

    Attached Images Attached Images   

  9. #39
    Senior Member alskinner's Avatar
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    Maxwedge
    I didn't realize that the 2216nd was positive cone forward. I will definitely swap polarity and see what effect it has. It may be an improvement or maybe not. Nelson Pass reversed polarity on the mid range driver on his L300 crossover and found he liked the sound better.

    Earl
    Thanks for the information on the Iphone apps available. I have an Iphone 11 and will see what's available. As soon as Thanksgiving is over I will try to measure the speaker with the woofer wired in both polarities and report back.

    Thanks to all and have a great Thanksgiving
    Al

  10. #40
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    Red face

    Haaa,

    Please donít make me think.

    Letís see.
    According to a sketched diy plan of the 2397 the horn on Google the horn protrudes 6.87 inches behind zee baffle.
    Then the 2428 adapter 4 inches
    And the depth of the driver to the diaphragm. perhaps 3 inches
    That about 14 inches behind the baffle

    The 2216 is about 4 inch deep. 14 - 4 = 11 inches

    Thatís about a difference of 11 inches difference in the physical acoustic centres
    In metric thatís 280mm difference.

    A 800 hz crossover point has a wavelength of 430 mm
    So therefore this offset will have a lagging phase shift at the crossover point of 234 degree @ the 800 hertz crossover. As 180 degrees is the same as opposite electrical phase it could potentially help to wire both drivers in phase. Try it and see.

    The rest is small movement of the horn of around 2 inches to obtain a good in phase situation which will make or break it subjectively.

    This will depend of the amount of phase shift in the horn at the crossover point. I recall the 2397 extends down to three or four hundred hertz.

    I donít recall that Nelson came up with. I would borrow an Ashly 24 db active crossover with the adjustment to start with that as itís a simple thing to set up and see what happens. Then make a passive crossover if desired using the active best case scenario (measured)

    You are poking around in the dark with a passive crossover from scratch without measurements. It never is quite how it should be unless run in a sim with solid data.

    Those horns have a nice open midrange. Iíd put the slot in the baffle on the inner listening side under the horn so the air in the top end above 7000 hz is focused between the loudspeakers. The 2397 of diffraction limited as l recall by the 50 mm horizontal slot in the horn.

    Have fun.

  11. #41
    Senior Member alskinner's Avatar
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    Ian

    As always I respect your input and guidance. Right now I am not working on the 4344s I am working on the L300s with the 2216s in them with the LE85s and HL92s. So I am not sure what effect the length of the horn and the depth of the 2216 will be on the needed polarity.

    A little history on my L300s. I bought them for $1100 dollars many years ago. They were not pristine but in good shape cosmetically. I had the woofers reconed and assumed the LE85 and 077 were in good shape (bad assumption). Upon building the Pass L300 crossover the speaker sounded better but not just right. I took the back cap off the LE85 only to discover someone had put phenolic diaphragms in them. I had a spare set of 85s and it made a lot of difference in them for the better. I started enjoying them again. This taught me not to assume anything about anything used and sometimes new. When I ordered the 2216s I didn't intend to use them in them in the L300s but wanted to test them to insure there were no defects. But the more I played them the better I liked them.

    You all are absolutely correct in that I will need to get some measurement equipment as I have spent countless hours trying to make the 4344s work with the Westlake style horn and 2241 driver and never got them to sound just right so I went back to the 2307, LE85 and 2405 and am fairly satisfied with them. I really like the sound of the 2441 and Westlake horn but without accurate measurements and a crossover redesign I'm dead in the water. Early on I did use an Ashly 4001 and while the results were good I really wanted a passive crossover with just one amp.

    I did find an Iphone app for rudimentary measurements, I am looking for a calibrated mic and some good measurement software. If anyone knows of a good reasonably priced setup please let me know.

    Regards
    Al

  12. #42
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    Hi Al,

    Thank you for outlining your journey. I had similar impressions with the 2397 stop my 4345 clones.

    Bring up the condition of compression drivers is a good point when trying different components. It pays to know whatís going on.

    My earlier post was to give some insights on what can happen with a reasonably long horn. The horn in the L300 with the LE85 has a depth in the same ballpark as the 2397.

    I do have an iPhone Dayton mic but l have never used it.

    The thing with the L300 is we donít have the flexibility of being able to move the horn back and forth to modify the response in the crossover region. I would try out the 2216nd and simply listen with the polarity either way. With any luck one way with offer an obvious ďthatís itĒ impression. There are more scientific approaches to obtaining a descent crossover transition in such situations like the L300 with a passive crossover and the long horn but itís a deep topic to explain and would require a whole thread.

    Over on my forthcoming website (under construction) l will be publishing some project systems such as the L300 with advanced passive crossover design techniques aimed at further improvements with stock components and alternative drivers.

  13. #43
    Senior Member alskinner's Avatar
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    Update

    I did indeed had the 2216s wired out of phase. Testing the woofers with my trusty 1.5v battery the cone does move outward with positive voltage to the red terminal. The sound is now more centered with more coherent bass rather than coming from each speaker separately. I have run test wires from the crossover to the speakers out the port hole so that I can change polarity rapidly without taking the speakers in and out.

    I did get AudioTools from Studio Six Digital measurement software for the Iphone. Although I can get readings using the internal Iphone mic, I doubt the mic is very accurate. I have ordered a miniDSP UMIK-1 mic which should give more accurate readings. I will also be able to use REW and TrueRTA software to compare results. I know there will be a learning curve before I can get real accurate readings but it's a start.

    Regards
    Al

  14. #44
    Administrator Mr. Widget's Avatar
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    I use Studio Six Digital with the built in mic and for many tasks it is pretty close my more accurate methods of measuring.

    My guess is that at least some of the added coherence from the rewired woofers is due to confirmation bias, but it is probably the ďrightĒ way to integrate them into your design.

    I am confident that the 2216Nd woofers are an upgrade and may go that way if I ever get around to my own ďL200Ē project. I only bring up confirmation bias because it affects us all and needs to be taken into account as we stumble towards excellence.


    Widget

  15. #45
    Senior Member alskinner's Avatar
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    Mr. Widget

    Understand what you mean by confirmation bias. That's why I left the test leads so I could change the polarity back and forth. So that when I can measure what I think I'm hearing and apply some equalization I may prefer them out of phase. I have a small room to play them in and there are other factors that can influence the final sound heard. The last thing I want to do is to have others follow my subjective impressions without something to back them up with.

    The L300 by today's technology is pretty ancient, but damn they're fun to listen to. My goal is to make them sound the best they can be with what I have to work with.

    I do have one question. What source is used to test speakers with. I mean would one use white noise or is there a standard source? Forgive me if this is covered elsewhere on the forum.

    Regards
    Al

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