Announcement

Collapse

Midwest Audio Fest

It’s that time audio enthusiasts! Registration for the 2019 Speaker Design Competition is now open! Visit midwestaudiofest.com for details and to list your speaker project. We are excited to see all returning participants, and look forward to meeting some new designers this year, as well! Be sure your plans include a visit to the Parts Express Tent Sale for the lowest prices of the year, and the Audio Swap Meet where you can buy and trade with other audio fans. We hope to see you this summer! Vivian and Jill
See more
See less

Understanding Sub-woofer SPL

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • STIchris722
    started a topic Understanding Sub-woofer SPL

    Understanding Sub-woofer SPL

    I am in the process of designing some PA sub-woofers and I am not understanding the results that my modeling software is spitting out. With one (1) B&C 18TBW100 in an 8ft^3 cabinet tuned to 38Hz, I am hitting 129dB @ 50.7Hz. If I make a cabinet with two (2) 18TBW100 in an 16ft^3 cabinet tuned to 38Hz, I am hitting 134.8dB @ 50.7Hz. I always thought (and forgive me if I'm wrong), that every time surface area is doubled, there is a 3dB gain. Should I not be doubling the input power to 3KW when using the two (2) speaker method? I feel as thought I am missing something very simple here and need a sanity check from my fellow members. Any help would be greatly appreciated!
    two (2) 18TBW100 in a single box @3KW one (1) 18TBW100 in a single box @1.5KW

  • STIchris722
    replied
    Originally posted by billfitzmaurice View Post

    Post them on my forum. Thanks.
    Done. Thank you

    Leave a comment:


  • billfitzmaurice
    replied
    Originally posted by STIchris722 View Post

    I tried to send you a PM, but it wouldn't allow me to. I have some questions regarding a set of Tuba plans I purchased from you.
    Post them on my forum. Thanks.

    Leave a comment:


  • STIchris722
    replied
    Originally posted by billfitzmaurice View Post
    Because bigger and more expensive is always better, and in the words of a high end cable executive, 'As long as people are stupid enough to buy what we're selling we'll keep selling it'.
    I tried to send you a PM, but it wouldn't allow me to. I have some questions regarding a set of Tuba plans I purchased from you.

    Leave a comment:


  • billfitzmaurice
    replied
    Originally posted by STIchris722 View Post
    why would anyone purchase a 21" over an 18"? !
    Because bigger and more expensive is always better, and in the words of a high end cable executive, 'As long as people are stupid enough to buy what we're selling we'll keep selling it'.

    Leave a comment:


  • STIchris722
    replied
    So I contacted a B&C rep and they told me that the reason a 21" speaker doesn't have anymore output than an 18" is due to the additional mass of the cone being moved. If this is the case then why would anyone purchase a 21" over an 18"? I have been so intrigued with the 21" speaker because of the Tim Allen tool time mentality of bigger is better, but after modeling them, they look terrible. I can post some pictures if anyone is interested, but so far this B&C 18TBW100 is kicking more butt than anything else I can model. If someone could shed some light on this I'd appreciate it. Cheers!

    Leave a comment:


  • filmslayer
    replied
    Originally posted by STIchris722 View Post

    That looks outstanding. What is it tuned to? Does it sound good? I like the design!


    IIRC it was a couple years ago . it was tuned low 20's and could handle 3600w before X-max became an issue . the sound was clean and amazing . not a cheap though .... https://www.parts-express.com/bc-21s...4-ohm--294-689

    Leave a comment:


  • donradick
    replied
    Originally posted by STIchris722 View Post

    What is this supposed to mean?
    Wayne's World - a comedy sketch on Saturday Night Live with Dana Carvey (as Wayne) and Mike Myers (as Garth)
    The proper response is "rock on Garth!"

    It means, have fun, enjoy yourself.

    Leave a comment:


  • Pete Schumacher
    replied
    Originally posted by STIchris722 View Post

    What is this supposed to mean?
    Wayne’s World

    Party on Garth

    Leave a comment:


  • STIchris722
    replied
    Originally posted by Paul O View Post
    You're comparing a top shelf driver to a mid level driver so they're not really in the same ballpark, even a Definimax doesn't compare to the B&C when it's being pushed. Have you modeled the 18TBX100? I'm also seeing 5.5 cu/ft per driver as the optimum for power handling.
    Paul -- That's precisely why I am asking the question. I know nothing about B&C and wasn't sure if their price point was due to being imported from Italy rather than being produced in the US such as Eminence. I am going to model that driver per your recommendation. Thank you for the advice!

    Leave a comment:


  • STIchris722
    replied
    Originally posted by filmslayer View Post
    i've not heard any of B&Cs 18's , but this is Jbrunner's B&C 21 in 13^3ft . it was amazing !

    Click image for larger version

Name:	joshs21_zps5o63fsnh.jpg
Views:	1
Size:	52.1 KB
ID:	1380351
    That looks outstanding. What is it tuned to? Does it sound good? I like the design!

    Leave a comment:


  • STIchris722
    replied
    Originally posted by donradick View Post

    Fair enough, rock on Wayne
    What is this supposed to mean?

    Leave a comment:


  • Paul O
    replied
    Originally posted by STIchris722 View Post
    I am designing a set of 18" PA sub-woofers right now and am torn between the Eminence KappaProLF 18" vs the B&C mentioned earlier.
    You're comparing a top shelf driver to a mid level driver so they're not really in the same ballpark, even a Definimax doesn't compare to the B&C when it's being pushed. Have you modeled the 18TBX100? I'm also seeing 5.5 cu/ft per driver as the optimum for power handling.

    Leave a comment:


  • filmslayer
    replied
    i've not heard any of B&Cs 18's , but this is Jbrunner's B&C 21 in 13^3ft . it was amazing !

    Click image for larger version

Name:	joshs21_zps5o63fsnh.jpg
Views:	1
Size:	52.1 KB
ID:	1380351

    Leave a comment:


  • donradick
    replied
    Originally posted by STIchris722 View Post

    I appreciate the advice, but I don't have any interest in horns or scoops. I don't care for their directivity and complexity in construction. I will not disagree that you can get a lot of output out of a horn with a small speaker, but I don't care for the response curve or directivity. This is not a slam on Bill or anyone else that uses these products. I simply prefer direct radiating.

    I am looking for some advice on driver selection at this point.
    Fair enough, rock on Wayne

    Leave a comment:

Working...
X