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Some good 18"s?

Discussion in 'Amps and Cabs [BG]' started by Tualatin, Jun 8, 2005.


  1. Tualatin

    Tualatin

    Feb 7, 2005
    Atlanta
    I'm thinking of replacing the oem speaker in my Mesa Diesel 18. What are some recomondations. I like big magnets.
     
  2. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    You can't just toss a driver into an enclosure and expect it to work properly. You must calculate the interior volume of the box, less that taken up by the driver and duct, and calculate the volume of the duct if it has one. You use that information in a speaker simulation program such as WinISD, along with the driver T/S parameters, to find if a particular driver under consideration is compatable with the box. That's the proceedure that Mesa used in the first place to decide upon the correct driver/cabinet combination. It may be possible to improve upon the original's performance. Then again, it may not. Without going through the above steps it's impossible to know.
     
  3. Reefer

    Reefer Guest

    Mar 9, 2003
    If your OEM is an EVM-18 you need to leave that in there. That's a great speaker and that cab was designed around it.
     
  4. pickles

    pickles Supporting Member

    Mar 23, 2000
    Ventura, CA
    Bag End makes a great 18.
     
  5. The Eminence Magnum series has different models that might suit your existing cabinet.

    Download my spread sheet, then compare the internal volume of your existing cabinet to the closest match in my sheet. Tune the cabinet accordingly and you will be there.

    Getting excited over big magnets is better suited for porn movies, not speaker cabinets. Select the driver that will do the job for your cab, not because it has The Big One.

    :D
     
  6. KPJ

    KPJ

    Oct 2, 2001
    Methuen, MA USA
    Thanks for a new signatue quote, Bruce!
     
  7. Wesley R

    Wesley R Supporting Member

    Why are you thinking of replacing it?

    If the driver is not living up to its potential, it might just need to be reconed. Is it the original driver?

    Best of Luck,
    Wesley R.
     
  8. Tualatin

    Tualatin

    Feb 7, 2005
    Atlanta
    It's sounding weak. How do I get it reconed?
     
  9. Tualatin

    Tualatin

    Feb 7, 2005
    Atlanta
    The only reason the magnet came to my attention was just a knee jerk reaction from an old job at a car audio store. Every year you would see bigger magnets on the back of the top shelf stuff.
     
  10. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    Reconing is done only if the cone or voice-coil is damaged. If it ain't broke don't fix it. As for sounding weak, any 18 is really only good up to 500 Hz or so, above that whatever midrange it's capable of has no dispersion. Consider adding a 1x10 or 2x10 above it to get some mids and highs.
     
  11. Wesley R

    Wesley R Supporting Member

    Way back when, if speakers started to lose their luster, if cones got mushy (and they would get mushy), the speakers would be reconed.

    Best of Luck,
    Wesley R.

    PS. Here in Minneapolis, we are blessed with a couple or more decent recone shops.
     
  12. Tualatin

    Tualatin

    Feb 7, 2005
    Atlanta
    How about 6x10?
     
  13. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    You don't need it when you already have the 18 on the bottom. I would recommend a 1x10 in a small sealed enclosure with a first order crossover at 300 to 400 Hz. That will add the mids that the 18 can't provide. The only reason for more than one ten is if you use them for the low end, and with an 18 already doing that you don't need more.