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From bookshelf to floorstander, no XO change

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  • mga2009
    started a topic From bookshelf to floorstander, no XO change

    From bookshelf to floorstander, no XO change

    Hi,

    I would like your opinion on changing the design of a TM speaker, and convert a bookshelf speaker to a floorstander/column, without changing the XO design.

    The cabinet would have more volume, so I need to re-measure the port and tune it again, maybe to a lower frequency (modelling needed of course...)

    Components location in the baffle would be exactly the same.

    What about the XO? Do I need to modify it? Or I may use the same XO?

    Thanks in advance.

  • xmax
    replied
    Originally posted by mga2009 View Post

    OK. Will aim for mid/upper 40's and see how does it measure... I already have nearfield measurements of the sealed version.

    Thanks for your help!
    It might be fun and informative to try 3 port sizes and measure all 3 before you glue the port.
    (if you were planing to glue it)

    Leave a comment:


  • mga2009
    replied
    Originally posted by Chris Roemer View Post
    Yeah, I'd prob'ly go somewhere in-between: 3"id x 7"long, maybe 6" (mid to upper 40s Fb).
    Most (average) music gets down to the lower 40Hz range.
    OK. Will aim for mid/upper 40's and see how does it measure... I already have nearfield measurements of the sealed version.

    Thanks for your help!

    Leave a comment:


  • Chris Roemer
    replied
    Yeah, I'd prob'ly go somewhere in-between: 3"id x 7"long, maybe 6" (mid to upper 40s Fb).
    Most (average) music gets down to the lower 40Hz range.

    Leave a comment:


  • xmax
    replied
    Yes you will be fine, you might like the 60hz tuning better, I would make a 2.75", 6" and 9" port and see what
    sounds best in your room.

    Leave a comment:


  • mga2009
    replied
    Originally posted by xmax View Post

    I would think the floor stander should sound much better than the sealed version, if you are using a 3" port, give yourself the
    ability to make it as long as 9" for a tuning in the low 40s (2.75" for 60hz) with a 60hz tuning they might get a little boomy.
    I though tuning it to the lower 40's would give me over excursion with low power, but the speaker has a XMAX of 5.25mm and a Xdamage of 13.15mm, so it seems I can do some "safe" over excursion.

    Anyway, my listening habits are with moderate volume.

    https://1drv.ms/u/s!AoNwvVYR7XiOhmU-QtJFao9It9SJ

    Leave a comment:


  • xmax
    replied
    Originally posted by mga2009 View Post

    This particular design has a Q of .707

    I am planning on a 28 liters (net volume) tuned to 60hz

    Driver is a FaitalPRO 6FE100 crossed over @ 2400hz to a Denovo DNA-150 CD mounted in an EOS6 waveguide.
    I would think the floor stander should sound much better than the sealed version, if you are using a 3" port, give yourself the
    ability to make it as long as 9" for a tuning in the low 40s (2.75" for 60hz) with a 60hz tuning they might get a little boomy.

    Leave a comment:


  • mga2009
    replied
    Originally posted by xmax View Post
    If you know the Q of the sealed alignment that would be helpful, often smaller sealed boxes
    are tuned with a Q higher than .707, if this is the case it might make sense to choose
    BB4 or QB3 alignment or system balance could be compromised. I would choose a
    porting scheme that allows you to change the port tuning for preference.
    This particular design has a Q of .707

    I am planning on a 28 liters (net volume) tuned to 60hz

    Driver is a FaitalPRO 6FE100 crossed over @ 2400hz to a Denovo DNA-150 CD mounted in an EOS6 waveguide.

    Leave a comment:


  • PWR RYD
    replied
    BB4 or QB3... the 90's want their LSDC back LOL!

    Leave a comment:


  • xmax
    replied
    If you know the Q of the sealed alignment that would be helpful, often smaller sealed boxes
    are tuned with a Q higher than .707, if this is the case it might make sense to choose
    BB4 or QB3 alignment or system balance could be compromised. I would choose a
    porting scheme that allows you to change the port tuning for preference.

    Leave a comment:


  • mga2009
    replied
    Originally posted by a4eaudio View Post
    You could sim the box volume and tuning and if it is better with more volume then use the new tuning and port. If it isn't better (maybe the original design was pretty optimal) then you could just separate the top of the cabinet to keep the volume the original and have the bottom just an empty/unused compartment .
    Actually I am going from sealed to ported... using the same XO and bigger enclosure.

    The speaker designer told me there would be no problem regarding the sealed to ported modification, only do the correct sim in WinISD or similar and get the correct tuning and port lenght. I forgot to ask the enclosure size, and that's why I am asking the experts here.

    Thanks

    Leave a comment:


  • a4eaudio
    replied
    You could sim the box volume and tuning and if it is better with more volume then use the new tuning and port. If it isn't better (maybe the original design was pretty optimal) then you could just separate the top of the cabinet to keep the volume the original and have the bottom just an empty/unused compartment .

    Leave a comment:


  • mga2009
    replied
    Originally posted by jhollander View Post
    Assuming the baffle width and driver placement is the same and you extend the cabinet to the floor, there would be minor changes in the baffle step but the original x-o would work.
    Thanks! Yes, driver placement and baffle width would be exactly the same, just extending the cabinet to the floor.

    Well, it seems that I will proceed then! Thanks

    Leave a comment:


  • jhollander
    replied
    Assuming the baffle width and driver placement is the same and you extend the cabinet to the floor, there would be minor changes in the baffle step but the original x-o would work.

    Leave a comment:

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