Announcement

Collapse
No announcement yet.

Front and/or back of cabinet rigidly mounted?

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

  • Front and/or back of cabinet rigidly mounted?

    Hi all

    (zooming in on details for next build, of course…)



    I plan to mount the woofer (Dayton RS270-8) alone in a existing cabinet. My traditional baffle-mouting method has been to make the baffle ”float” on seals and secure the baffle with a number of tightly fastened screws (as in the pic. below). The back of the box is rigidly mounted.



    Now, the existing box is ”the other way around” that the baffle is glued in place and the back is demountable for access to the inside of the box. My plan is to work ”outwards” from the existing baffle and glue a 22mm board on it and on top of that, the baffle with the driver surface-mounted, glued in place. This will hopefully result in a very stiff baffle with a woofer secured to the box.



    But, and here comes my question, is it important tog glue the back of the box in place also? This will make things more difficult when mounting the driver, filling and other things. How will the sound be affected if the front and/or back of cabinet is rigidly/”floatingly” mounted?





    Best regards//lasse


    Click image for larger version

Name:	058.JPG
Views:	49
Size:	465.4 KB
ID:	1391272
    Perry Mason talking to his dentist:

    "Do you swear to take the tooth, the whole tooth and nothing but the tooth, so help you God?"

  • #2
    Lots of "vintage" speakers were built exactly this way. In the back there would be a frame with a gasket, and the rear panel was simply screwed into the frame. A perfect example is the heathkit AS-16, images below. It's not important for any part of a speaker cabinet to be rigidly connected, in fact it's probably better if they aren't.

    Click image for larger version  Name:	as_16_305855.jpg Views:	1 Size:	43.5 KB ID:	1391278

    Click image for larger version  Name:	26380444452_da23b5a3ee.jpg Views:	1 Size:	72.6 KB ID:	1391279
    "I just use off the shelf textbook filters designed for a resistor of 8 ohms with
    exactly a Fc 3K for both drivers, anybody can do it." -Xmax

    Comment


    • #3
      Originally posted by dcibel View Post
      Lots of "vintage" speakers were built exactly this way. In the back there would be a frame with a gasket, and the rear panel was simply screwed into the frame. A perfect example is the heathkit AS-16, images below. It's not important for any part of a speaker cabinet to be rigidly connected, in fact it's probably better if they aren't.
      I would disagree with that last part. I have heard and measured issues with screwed-on baffles that disappeared when rigidly mounted (glued). If enough screws were used, I'm sure there would be no issues, but then you're just approaching the optimum, which is an everywhere-restrained baffle (glued).

      Dan
      _____________________________
      Tall Boys
      NRNP Computer Sub
      The Boxers
      The Hurricanes
      The Baronettes
      Conneccentric
      UX3

      Comment


      • #4
        Agreed, every joint glued is best. Vintage cabs used screw and batten attachment of the back because drivers had no provision for front mounting. With front mounted drivers there's no reason not to glue the back.
        www.billfitzmaurice.com
        www.billfitzmaurice.info/forum

        Comment


        • #5
          Both of my speakers have the front and/or rear baffles screwed in place and they sound fine to me. It is very convenient when it comes time to make changes also...

          Comment


          • #6
            Hi,



            And thanks for all the feedback. Working both ways.



            My ”technical inuition” tells me from what you say that is is better for a driver to be as rigidly mounted as possibly can be. When the cone moves forward, it is probably not a good thing if the rest of the driver and the baffle moves in the other direction due to reaction forces and on top of that, influenced by a gasket with its inherent non-linear damping properties.



            The air volume inside the box push/pull a non-rigidly secured back side, contributing to the emitted SPL in a non-linear and phase-wrapped way but probably not as bad as a floating front baffle.



            It seems like the best way to go is to glue both baffles and accept the obvious down-sides of this arrangement, especially the limited access to the inner volume. (If, as in this case, there is a 10” hole in the front baffle, you can probably live with that)



            Best regards//lasse
            Perry Mason talking to his dentist:

            "Do you swear to take the tooth, the whole tooth and nothing but the tooth, so help you God?"

            Comment

            Working...
            X