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replacement speaker options for GK150MBE

Discussion in 'Amps and Cabs [BG]' started by basss, Jun 26, 2003.


  1. basss

    basss

    Aug 27, 2001
    NYC
    I have a GK 150MBE combo amp that I really like for its portablility. It sounds great when I plug in an extension cab that extends the limited frequency response of the speaker included in the combo. Would replacing the speaker in the combo give me a better sound when not using an extension cab? I was curious as to if there are any replacement speakers on the market that would work in a small sealed box and improve the performance of this combo. Anyone try this?
     
  2. B String

    B String Supporting Member

    Apr 11, 2002
    Los Angeles
    I've got the older 200mb, which is about
    the same as the 150mb. The previous owner
    put an EV force 12in in the amp. The specs
    on the EV are much better than the stock
    speaker. BUT!!! Years ago, gk told me no
    other speaker would fit in the box. Bob
    Gallien, recently told me the stock speaker
    is made to work with that box and no other
    speaker would sound right. Go figure.
    Even with the EV, I could use more lows
    and highs. The EV adds about 3 extra lbs too.
     
  3. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    GK are right, to a point. The volume of the cabinet and the porting (if any)are pretty important to the final sound, especially in the low frequencies.

    Replacement speaker can work, but only with some careful planning and maths. Ideally you'd need to post the dimensions of the cab. We'd have to work out the volume, then hunt around for a driver designed to work in a box that size. It's a sealed cab so we'de need to make sure the speaker we choose has a QTS of at least 0.4.
     
  4. basss

    basss

    Aug 27, 2001
    NYC
    Thanks so far
    the dimensions are
    13.75 height x13.75 width x 13.75 depth (inches)

    Who are some good speaker manufacturers to check out? I looked at eminence already but they seem to only make speakers for vented boxes.
     
  5. tripwamsley

    tripwamsley

    Jan 31, 2002
    Sulphur La,
    "Bob Gallien, recently told me the stock speaker
    is made to work with that box and no other
    speaker would sound right. Go figure"--quote


    As someone who used to work for him I can tell you that Bobster hears things one way; His. I always thought the speakers in the MBs were too dark for bass guitar. For upright I thought they were fine. (I don't play upright anymore so what the heck do I know about that.) I would say that if you put another speaker in there judge for yourself whether it sounds great or not. Good brands abound, JBL, EV, Eminence, there are also all kinds of hi-fi speakers that you could try in that thing.
     
  6. B String

    B String Supporting Member

    Apr 11, 2002
    Los Angeles
    Right on Tripster.
    The idea that other speakers may fit
    in the box opens the way to finding
    the sound that YOU like. But realize
    that some great speakers may sound
    awfull in that box because of size
    and materials. As its been said...
    "Your milage may vary"
     
  7. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    Whoa - a perfect cube???? You don't see that too often. The reason the rectangle is so popular is because it's better at keeping standing waves under control. And because it's a cube, there's probably no where else to put the the speaker other than dead centre - another recipe for standing waves.

    Question, does this cab have a lot of stuffing inside? My guess is that it will (or should).

    By my calcs that's a 35.69 litre box (1.26 cu.ft). Im gonna have to get back to you on some drivers. This is not your standard speaker hunt.
     
  8. basss

    basss

    Aug 27, 2001
    NYC
    OOPS!
    its actually 13.75 x 13.75 X 7.75
    I posted the other ones pre-coffee this morining.:p
    I haven't looked inside the cab- don't know about stuffing.
     
  9. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    19.17litres (0.68cu.ft)That's tiny! It is a 12" speaker right? Just checking.......
     
  10. It's actually 13.7x13x8.5.

    I have another suggestion though. GK is going to be releasing the MB150 head pretty soon so you can plug it into any speaker cabinet you want.

    There is no stuffing inside it.
     
  11. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    You know what, that may not be a bad suggestion. I haven't exhaused all avenues yet, but so far that speaker hunt has yielded nothing suitable.

    I'll keep trying.......
     
  12. B String

    B String Supporting Member

    Apr 11, 2002
    Los Angeles
    Just put a carvin ps-12 speaker in
    my old 200mb. For the cost ($67.00)
    it seems like a good deal. The speaker
    is made by emenince with resonse of 50-
    4.5k. The stock speaker is 80-2k
    Its lighter than the ev I had in there
    and seems to have more highs and perhaps
    more lows. I think it sounds better than
    the original speaker. jmho
     
  13. tripwamsley

    tripwamsley

    Jan 31, 2002
    Sulphur La,
    Well you go! I always thought that unit could use more highs.:)
     
  14. basss

    basss

    Aug 27, 2001
    NYC
    Thanks all.
    Ive been looking around and it doesn't look like I'm going to find anything made specificly for a box like this besides the stock GK speaker. What can I put in that might not be designed for this but would sound ok anyways? I was looking at
    this
    I know the frequency response would get squashed if I put this speaker in the smaller box but it might still be better than the stock speaker. Would there be any other reasons not to do this?
     
  15. Eric Moesle

    Eric Moesle Supporting Member

    Sep 21, 2001
    Columbus OH
    If you moved up to an Eminence Delta 12 instead of the Beta 12, you'd get more low end, but the efficiency would suffer a tad. Its a shame you couldn't just try them both and send one back after A-B'ing them. If only this were a perfect world . . .
     
  16. tripwamsley

    tripwamsley

    Jan 31, 2002
    Sulphur La,
    If only...indeed.:(
     
  17. basss

    basss

    Aug 27, 2001
    NYC
    I picked the BetaLT because it has that neato little extra cone thingy that extends the highs a few thousand herz. Also I figure if I go this route the published specs are going to go out the window but Im guessing it would be better than the stock speaker.
     
  18. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    I'm at work so I don't have my speaker modeling tools with me.

    But the general rule about putting a speaker into a smaller box is that it creates a hump in the midrange. That's how the Eden cabs work, but Eden spent some time and effort ensuring the hump is exactly where they wanted it to be.

    Midrange can be anywhere between 200Hz and 2K nowdays, so where exactly that hump will be is anyones guess.
     
  19. basss

    basss

    Aug 27, 2001
    NYC
    Hmmm thanks. More mids are exactly what I don't want. Anyone know what kind of speaker the stock GK speaker is? Could be a good reference point.
     
  20. B String

    B String Supporting Member

    Apr 11, 2002
    Los Angeles
    I could be wrong, but I believe
    that gk told me the stock speaker
    is made by eminence. The carvin
    speaker (sp12) I used is also made
    by eminence. This speaker is working
    better than the ev force12 That was
    in the amp when I got it. REMEMBER!!
    This is a small amp that is made to
    be light and used for low volume
    applications. Perhaps the fact that
    the stock speaker is rated at 80hz,
    gives it the low end that the box
    can handle. But the 4.5 top end seems
    to be plenty for this box.
    "your milage may vary"