Psst... Ready to join TalkBass and start posting, make new friends, sell your gear, and more?  Register your free account in 30 seconds.

Speaker Mechanics question?

Discussion in 'Amps and Cabs [BG]' started by Gabu, Mar 4, 2004.


  1. Gabu

    Gabu

    Jan 2, 2001
    Lake Elsinore, CA
    Some speakers have large domes in the middle, and some do not. What is that for?
     
  2. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    The dome is just a dust cap, nothing more. It stops grit and dust from entering the vioce coil part of the speaker and settling in the gap. If anything gets into that gap, ic could prevent the speaker from moving freely.

    Big dust caps usually, but not always, means the speaker has a bigger voice coil. But nowdays it wouldn't surprise me if the dust cap is designed by the marketing department.
     
  3. notanaggie

    notanaggie Guest

    Sep 30, 2003
    Well the dust cap is often larger than the coil. it isn't only marketing, it affects highs.

    Depending on material, it can produce more, or damp them down, since the bulk of highs come from near the coil on the cone. If the cap is hard, and right on teh coil, it can produce a LOT of highs, usually an annoying amount, but maybe just right, depending.

    But when you see a huge one, often it is because it looks better. Particularly on car audio...............
     
  4. luknfur

    luknfur

    Jan 14, 2004
    DIXIE

    I wondered about that. I thought it was just me but the few speakers I've had with aluminum dust covers (Altec 423z [I think?] and JBL M151) were too brite, or maybe trebly would be a less ambiguous term, to suit my taste. I've since avoided aluminum dust covers at any rate.
     
  5. T. Brookins

    T. Brookins Supporting Member

    Larger dust caps can assist in the cone's rigidity. Because many speakers have wires to the coil (tinsel leads) that run from further up the cone's throat, to the cone apex and into the coil, the dust cap used is often large enough to cover these often fragile and sometimes unsightly wires.

    Larger dustcaps are also used to conceal cooling vents in the throats of some speaker cones.

    Smaller dust caps are used in applications that strive to yield lower moving mass, higher sensitivity and in those where rigidity is usually not as important.

    Some dust caps are even inverted; inadvertently, or intentionally.

    Another reason aluminum dust caps are chosen is for their heat dissipation properties.

    Plastic, pulp, paper, cloth, aluminum, et.al-

    Rejoice!

    Thank your dustcaps!
     
  6. Gabu

    Gabu

    Jan 2, 2001
    Lake Elsinore, CA
    I was wondering about this. I have a pair of old 15s with inverted dustcaps, (I guess!)... They are what got me to wondering why some of the domes on speakers are bigger than others.

    Does that mean that they were designed for more lows, if the dustcaps are inverted?