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Jorors DIY-Audio

Discussion in 'd.i.y.' started by jororaitchev, May 15, 2019.

  1. ^ A more to the project, for greater clarity of detail:
    [​IMG]

    "...... Did you CNC or hand route?"
    quote from first post: "...Not used "CNC" machine and 3D program".
    This is my copy center:
    [​IMG]
     
    orangeart and RichardH like this.
  2. h.g.

    h.g. pfm Member

    Nice project which must have taken major time and effort. The speaker has some similarities with the Nordic Tone which seemed to move to a Scan-Speak midrange to get reasonable sensitivity (would have likely been my choice also). Two insensitive SEAS midranges will likely have issues crossing to the tweeter arranged like that or have a narrow lobe if placed above and below. A single woofer will pull the sensitivity down significantly if you include a reasonable amount of baffle step. Are you still happy with the single woofer choice and how much baffle step correction did you go for?

    The drawings appear to show a sealed design but the gap in the photo suggests a possible lower port?

    Are the intersections of your matrix free to rub and damp or glued to get stiffness?
     
  3. ^Maybe, there is some discrepancy, my fault. The first photo in my post is another complete project with different speakers, my other publications are for a project I will be doing in the future - when, I have no idea!
     
  4. h.g.

    h.g. pfm Member

    You are building the speaker shown in post #21 with two midranges below the tweeter and two woofers in a separate cabinet below. That should give you a healthy sensitivity with plenty for the baffle step correction although quite how things blend in with frequency for the woofer/midrange crossover would require more examination.

    The first problem I would anticipate would be the large centre-to-centre distance from the tweeter to the lower midrange causing lobing issues through the crossover region. It is much more common to place the tweeter between when using a pair of midwoofers rather than a midrange to avoid this issue. There seem to be few purpose designed midrange drivers around these days just large numbers of midwoofers. There is the M15CH002 in the SEAS Excel range but the sensitivity is still a touch low.

    The second problem would be designing a crossover to avoid driving the very strong resonance of the magnesium cone. A notch is likely to be a must but also at high SPLs the third harmonic distortion component of the motor is going to get boosted by 15-20 dB to possibly become audible and unpleasant. Minimising this pushes the design in the direction of a low crossover frequency significantly below 1/3rd of the resonant frequency and the crossover slope up. Other design considerations will of course push in other directions. Crossovers for metal cones are a challenge.

    The use of a separate cabinet for the midrange/s and tweeter (passively isolated on something soft from the woofer cabinet?) is going to allow for relatively easy evolution of the design should you wish to do this.
     
    orangeart likes this.
  5. ^Thank you for your opinion! You have correctly noticed that the distances between the speakers are not good. This project will be developed, perhaps this way?

    [​IMG]
    I think it's better to talk about the project from the first post.
    Thank you all for your time and attention!
     
  6. h.g.

    h.g. pfm Member

    Yes that is the conventional way these days to use 2 midwoofers instead of one midrange in a 3 way speaker. It has advantages and disadvantages compared to a single midrange driver but on balance a single midrange tends to be preferred as reflected in almost all the top of the range designs from the larger commercial home and studio speaker manufacturers.

    The opening post seems to refer to graphs in a closed facebook group that nobody can see even the few here that are members of facebook. Are the graphs in a later post the ones being referred to?

    What is the configuration of the speaker in the first post?:

    - a pair of 10" 8 ohm metal woofers wired in parallel to give a nominal 4 ohm load or a single 10" metal 8 ohm woofer?

    - a pair of 5" metal midwoofers or a 5" midrange of some kind?

    - a 1" tweeter on a flat baffle?

    - a woofer cabinet and a tweeter/midrange cabinet passively isolated from each other?
     
  7. When everything is created by your hands, the pleasure is endless![​IMG]
     
  8. JimmyB

    JimmyB pfm Member

    This is the sort of thing I aspire to doing, awesome stuff, time to get my finger out after seeing this.
     
  9. Thank you for your comment!
    I was wondering if somebody in this forum would make a similar comment, DIY things like my , you can seen every day -fact!
     
  10. Mynamemynaim

    Mynamemynaim pfm Member

    If nothing else...it's good to know others share my dislike for Facebook/Twitter/ and any other "live your life online" crap that's out there...
     
  11. Wonderful! A matter of personal choice.
     

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