/ Register

Ampeg B15N '65-'66 Jensen Speaker problem.

Discussion in 'Amps and Cabs [BG]' started by Ron Welby, Jul 21, 2021.

Tags:
  1. Jul 21, 2021 #1
    Ron Welby

    Ron Welby Supporting Member

    Mar 27, 2019
    Newport, RI
    Just reconditioned my Ampeg B15N in anticipation of selling it. It has a Jensen Concert 15" speaker in it. I bought it new around 1967. Final test of the amp worked well and sounded perfect until I pushed the volume over 12 o'clock to 3 o'clock. The speaker really crackles pretty badly. 1. Does that mean the speaker is broken? 2. If I need replace it what speaker would you recommend. I've looked at Eminence and Cellestian.
    Also just love it too much to let it go. JenSpeakerbak1.JPG
     
  2. Jul 21, 2021 #2
    beans-on-toast

    beans-on-toast

    Aug 7, 2008
    The EM1520 is an alnico speaker, desirable by guitar players in the used market. I have a ceramic EM1500 in my ‘63 and it doesn’t have the issue that you described.

    The crackle may not be your speaker. The wiring from the amp, through the connector, to the speaker needs to be checked, it could be arcing. The amp should also be checked. Check the speaker with another amp, connected at the speaker terminals to determine if it is the speaker.

    How to Fix Crackling Speakers: Top Tips and Solutions | Stereo Boombox

    As for a good replacement, consider the Eminence Delta 15A or the Eminence Beta 15A.

    BTW, the date on your speaker is 1967, 50th week.
     
    Ron Welby and anderbass like this.
  3. Jul 22, 2021 #3
    Ron Welby

    Ron Welby Supporting Member

    Mar 27, 2019
    Newport, RI
    Thanks so much. I checked out the speaker and I think the vibration from the higher volume maybe vibrating the male input from the head where it meets the female input inside the cabinate. I will probably go back to the original 3 or 4 prong input connection that came with the amp. Should I get a 3 or 4 prong male and female replacement? Again thanks for sharing your knowledge. I really appceate it!
     
    beans-on-toast likes this.
  4. Jul 22, 2021 #4
    AGCurry

    AGCurry Supporting Member

    Jun 29, 2005
    St. Louis
    IIRC, the stock wiring serves to protect the output transformer should the speaker not be connected. Mine is a four-pin Amphenol connection, which I believe is correct.
     
    Last edited: Jul 22, 2021
    beans-on-toast likes this.
  5. Jul 22, 2021 #5
    beans-on-toast

    beans-on-toast

    Aug 7, 2008
    There’s no reason why a jack can’t work, maybe the one that you have simply needs adjusting or replacing.

    If you want the original connector, I’d go with a 4-pin. The problem is, they are difficult to solder properly. The plastic that holds the contacts can melt with too much heat. The connector on the cable is particularly difficult to solder as space is tight.

    Replacement part numbers are: Switchcraft C4M and A4F.

    Additional details, including if using a jack on the chassis, are in the TalkBass Ampeg Portaflex Wiki: Technical - Speaker Cabinet | TalkBass.com