why is my reconed jbl d130f quieter than the stock 15" eminence?

Discussion in 'Amps and Cabs' started by coolhand78, Sep 29, 2008.

  1. coolhand78

    coolhand78 Supporting Member

    Messages:
    3,578
    Joined:
    Oct 27, 2007
    Location:
    Melbourne, Australia
    i've got a 64 vibroverb custom and i've replaced the stock 15" eminence speaker with a re-coned orange frame JBL D130F and it seems to be a bit quieter? Is there some reason for this or just a common difference between different speakers?

    Also what was that power rating (watts) for the D130F?

    cheers
     
  2. kimock

    kimock Member

    Messages:
    12,604
    Joined:
    Mar 12, 2005
    Location:
    Where the Palm Tree meets the Pine
    I'm familiar with the JBL/Fender thing, and the JBL should be more efficient than the Eminence.

    Just guessin' now, but it would have to be the wrong impedance, not the stock JBL kit, maybe not the best re-cone work, needing remagnetization, with a bad connection between amp and spkr and polarity reversed or some combination of the above to really be a bit quieter than the Emi.


    Re: power rating.

    http://www.harpamps.com/micKspeakers/D130F-History.html

    peace
     
  3. coolhand78

    coolhand78 Supporting Member

    Messages:
    3,578
    Joined:
    Oct 27, 2007
    Location:
    Melbourne, Australia
    how would the polarity be reversed?
     
  4. kimock

    kimock Member

    Messages:
    12,604
    Joined:
    Mar 12, 2005
    Location:
    Where the Palm Tree meets the Pine
    I'll bet that Emi and the JBL fire in opposite directions when they're hooked up the same way.
    If the Emi was firing forward, the JBL could be percieved as deficient in comparison if you're sensitive to that kinda thing.

    Easy enough to check, just flip the speaker wires at the push terminals on the JBL and see if it makes any difference to you.
    If you can't tell it doesn't matter, but that **** drives me nuts.

    Har.
     
  5. pfflam

    pfflam Silver Supporting Member

    Messages:
    7,060
    Joined:
    Aug 26, 2005
    Location:
    PDX: The Rose City
    Does the recone come with a guarantee?

    Maybe the impedance?
    maybe it needs loosening up?
    Talk to the person who reconed it.
     
  6. coolhand78

    coolhand78 Supporting Member

    Messages:
    3,578
    Joined:
    Oct 27, 2007
    Location:
    Melbourne, Australia
    this wont damage the amp or speaker???

    it's not the impedance, the recone kit is a weber as you cant buy a JBL D130F recone kit anymore, and the recone work seems good... the speaker sounds good to me, maybe not as much of a difference as i had anticipated, just a little quieter than the emi.

    My amp tech told me that my amp which is rated at 40 watts actually puts out 50... which is why i was concerned with the power rating of the speaker but it should be fine as this is THE speaker for a 64 Vibroverb...
     
  7. kimock

    kimock Member

    Messages:
    12,604
    Joined:
    Mar 12, 2005
    Location:
    Where the Palm Tree meets the Pine
    No, not at all.
     
  8. johnzias

    johnzias Member

    Messages:
    859
    Joined:
    Jul 3, 2007
    Location:
    Tampa Bay Area
    A little off the point, but never swap a JBL or Altec for a Weber Neo or California. It's like swapping a Porsche for a Jetta. The drop in volume and low end clarity is profound.
     
  9. drbob1

    drbob1 Silver Supporting Member

    Messages:
    22,187
    Joined:
    Aug 9, 2004
    The JBL should be reverse polarity to the Emminence, try switching the +/- leads to the speaker around and see if that helps. It may just need to be broken in: the spider that supports the speaker cone does loosen up after time. It's also possible for even great shops like Weber to have problems, so if you're still not happy after you've broken it in for a couple of weeks, contact him....
     
  10. Tone_Terrific

    Tone_Terrific Member

    Messages:
    25,288
    Joined:
    Dec 26, 2004
    Location:
    Canada-GTA
    I have an Emi 15 and it is pretty darned efficient. A JBL may not be much better, at best.
     
  11. rhythmrocker

    rhythmrocker 1966 Battle of the Bands Supporting Member

    Messages:
    2,875
    Joined:
    Jul 19, 2006
    Location:
    City by the Bay, CA
    and here's a quote from Bosstone from another thread:
    "Another thing to know about JBLs is that the their "+" and (-) markings are done in the reverse of everyone else's. It doesn't matter if you are using only one speaker, which way you wire it or if all the speakers are JBL put they will be in "reverse polarity" if mixed with other brands of speakers and have to have the wires reversed."

    "we be jammin' man we be jammin'"
     
  12. johnzias

    johnzias Member

    Messages:
    859
    Joined:
    Jul 3, 2007
    Location:
    Tampa Bay Area
    What if you mix a JBL with an Altec?, which I am thinking of doing when I get my JBL back from the shop.
     
  13. pfflam

    pfflam Silver Supporting Member

    Messages:
    7,060
    Joined:
    Aug 26, 2005
    Location:
    PDX: The Rose City
    The polarity matters not at all as he is using only one speaker.

    If you are in Portland, OR area, Jamac Speaker repair does an EXCELLENT job reconing JBLs, and you can save money in shipping. he uses a lot of glue but it sure as hell works just jim-dandy. And he'll change specs for you as well.
     
  14. 57tele

    57tele Member

    Messages:
    924
    Joined:
    May 12, 2006
    This has been discussed numerous times here on tgp. The consensus seems that it also matters with one speaker, though some folks couldn't hear it and that the difference is more noticeable under some circumstances than others.

    http://www.thegearpage.net/board/showthread.php?t=323897
     
  15. coolhand78

    coolhand78 Supporting Member

    Messages:
    3,578
    Joined:
    Oct 27, 2007
    Location:
    Melbourne, Australia
    how can i tell if my speakers polarity is correct or not? i read thru that article but to be honest it went over my head, given that i've got a fender combo what would be the best way for me to check the polarity, given I'm no electrical technician here...
     
  16. myles111

    myles111 Member

    Messages:
    2,955
    Joined:
    Nov 19, 2003
    Location:
    Los Angeles CA
    Excellent info. A D130F is one of the most efficient speakers around and your problem indicates something wrong.
     
  17. Walter Broes

    Walter Broes Member

    Messages:
    358
    Joined:
    Aug 22, 2007
    Location:
    Antwerp, Belgium
    Those emi Legend 15's are unusually efficient speakers - maybe that's the only thing you're hearing?
     
  18. myles111

    myles111 Member

    Messages:
    2,955
    Joined:
    Nov 19, 2003
    Location:
    Los Angeles CA
    LEGEND 1518 SPECIFICATION [​IMG]Nominal Basket Diameter 15", 381mmNominal Impedance* 8 ohmsPower Rating [​IMG]Watts150W[​IMG]Music Program Resonance82HzUsable Frequency Range 60Hz-4kHzSensitivity***102.2Magnet Weight 59 oz.Gap Height 0.312", 7.92mmVoice Coil Diameter2", 50.8mm THIELE & SMALL PARAMETERS Resonant Frequency (fs) 82Hz
    [​IMG]
    Download PDF Spec Sheet ​


    DC Resistance (Re) 7.16Coil Inductance (Le) 0.86mHMechanical Q (Qms) 10.12Electromagnetic Q (Qes) 1.02Total Q (Qts) 0.93Compliance Equivalent Volume (Vas) 65.4 liters / 2.3 cu.ft.Peak Diaphragm Displacement Volume (Vd) 66ccMechanical Compliance of Suspension (Cms) 0.07mm/N BL Product (BL) 14.1 T-M Diaphram Mass inc. Airload (Mms) 55 grams Efficiency Bandwidth Product (EBP) 80 Maximum Linear Excursion (Xmax) 0.8mm Surface Area of Cone (Sd) 823.7 cm2 Maximum Mechanical Limit (Xlim)
     
  19. coolhand78

    coolhand78 Supporting Member

    Messages:
    3,578
    Joined:
    Oct 27, 2007
    Location:
    Melbourne, Australia
    is it a legend that comes stock in the CS 64 vibroverb Custom?
     
  20. johnzias

    johnzias Member

    Messages:
    859
    Joined:
    Jul 3, 2007
    Location:
    Tampa Bay Area
    Yes, with a Fender label. I used one in a Vibroverb for a while. It's a fine speaker, especially for the $$.
     

Share This Page