1. Win a Broadcaster or one of 3 Teles! The annual Supporting Member Giveaway is on. To enter Click Here. To see all the prizes and full details Click Here. To view the thread about the giveaway Click Here.

Speaker buzzing on low notes - help

Discussion in 'Amp Tech Center' started by WineCaster, Jul 17, 2017.

  1. WineCaster

    WineCaster Tele-Holic

    Posts:
    532
    Joined:
    Jul 12, 2012
    Location:
    Oshkosh, Wisconsin
    Hey folks. Here's the plot. I had a Celestion Gold G10 (10" 8ohm 40w) speaker that I had used in a cabinet with my THD Flexi 50 which I never ran above bedroom levels. I never noticed anything abnormal with it, just got bored and sold the speaker on Craigslist.

    The guy I sold it to contacted me shortly after and said there is a buzzing/minor crunching/static sound on the decay side of low E and A strings when played. I couldn't believe it but he was right. He was running two Princeton Reverb 68 Customs. I put the speaker in my cab that I brought to his house and played both amps separately through the speaker and sure enough, what he described was occurring-- both amps produced this sound.

    This is a relatively new speaker but I bought it used so I can't simply return it or have it replaced. Does anyone have any idea as to what the problem is? It was definitely not a vibration issue and it seemed to be coming directly from the speaker.
     
  2. robrob

    robrob Poster Extraordinaire Ad Free Member

    Posts:
    8,138
    Joined:
    Dec 29, 2012
    Location:
    United States
    Probably cone cry (cone rub). Sometimes mounting the speaker 180 degrees from original can eliminate it--if it's an extension cab just turn the cab upside down. If not it probably needs to be reconed.
     
  3. mherrcat

    mherrcat Tele-Holic

    Posts:
    725
    Joined:
    Dec 12, 2013
    Location:
    California
    This may not be the problem but I have heard that putting a "death grip" on the mounting nuts can distort the basket and possibly cause this. Just finger tighten the nuts then give them a quarter to half turn more with a nut driver. But Rob's suggestion is probably more accurate.
     
    robrob likes this.
  4. Milspec

    Milspec Poster Extraordinaire

    Posts:
    5,410
    Joined:
    Feb 15, 2016
    Location:
    Nebraska
    Sounds just like my spare Altec did last month....needed to be re-coned.
     
  5. WineCaster

    WineCaster Tele-Holic

    Posts:
    532
    Joined:
    Jul 12, 2012
    Location:
    Oshkosh, Wisconsin
    Does adding dope help with this issue?
     
  6. robrob

    robrob Poster Extraordinaire Ad Free Member

    Posts:
    8,138
    Joined:
    Dec 29, 2012
    Location:
    United States
    I've never heard of it helping.
     
  7. Snfoilhat

    Snfoilhat Tele-Afflicted

    Age:
    39
    Posts:
    1,396
    Joined:
    Apr 8, 2016
    Location:
    Oakland, CA
    @WineCaster, a guitar speaker I bought last year developed a frequency-dependent buzz shortly after I installed it. The cause was a small piece of hardened glue squeeze-out from when the dust cap was glued on at the factory, loose under the cap. Discovered this by gently shaking the speaker and resolved it by parting a portion of the cap away from the cone and letting the piece fall out then re-gluing. Don't know if this is as likely as a warped basket from over-tightenting or the other possible issues already mentioned. But easy to test.
     
    asnarski likes this.
  8. WineCaster

    WineCaster Tele-Holic

    Posts:
    532
    Joined:
    Jul 12, 2012
    Location:
    Oshkosh, Wisconsin
    Interesting! I'll report back!
     
  9. markeyd123

    markeyd123 Tele-Meister

    Posts:
    262
    Joined:
    Jun 27, 2017
    Location:
    USA
    I had this exact problem in a 68 custom Princeton RI and fixed it. If you play the offending low notes and push the face of the baffle just over the speaker does the buzz go away? It probably will . . .

    If so you need to reinforce the baffle. Get some 1"x1" square profile wood trim the length of the baffle. Glue it with construction adhesive inside the baffle above the speaker. Then take about 5 wood screws and screw in the trim. Reinstall baffle and you should be good.

    It is what was done here, but with wood, not metal and without a need for a router:

    http://www.tdpri.com/threads/the-cure-for-princeton-reverb-cab-buzzes.170032/
     
  10. markeyd123

    markeyd123 Tele-Meister

    Posts:
    262
    Joined:
    Jun 27, 2017
    Location:
    USA
    Also, if you change out the speaker for something bassier then the problem will be worse. When I put a Eminence Lil Buddy in there it was worse. I wound up putting the stock speaker back in and thinks it works better with this circuit anyway.
     
  11. JD0x0

    JD0x0 Poster Extraordinaire

    Age:
    30
    Posts:
    5,919
    Joined:
    Feb 22, 2009
    Location:
    New York
    Assuming it's not cab rattle. Sounds like a voice coil issue. Did anyone try to move the cone with their hand or other physical means? Did the screws get over torqued on the speaker when it was mounted?
     
  12. markeyd123

    markeyd123 Tele-Meister

    Posts:
    262
    Joined:
    Jun 27, 2017
    Location:
    USA
    See my posts above, but I chased this issue for 2 years, embarrassingly enough, convinced it was not cabinet buzz. I thought it was the speaker. Bought a new speaker and it was worse. If you press the top of the baffle and the buzz stops . . . it's cabinet buzz. Very easy to rule out. Push the baffle, and cabinet in different spots to easily rule that out or prove that point before going to more invasive extremes. I'll get off my soap box now.
     
  13. WineCaster

    WineCaster Tele-Holic

    Posts:
    532
    Joined:
    Jul 12, 2012
    Location:
    Oshkosh, Wisconsin
    I had the speaker in an external cabinet that i hooked up to each Princeton separately to test. That way we were able to eliminate the possibilities of loose hardware or a rattling cab. Mine is built from finger-joined pine and doesn't make a peep.
     
    robrob likes this.
  14. markeyd123

    markeyd123 Tele-Meister

    Posts:
    262
    Joined:
    Jun 27, 2017
    Location:
    USA
    My bad. Good troubleshooting though.
     
  15. Wally

    Wally Telefied Ad Free Member

    Posts:
    37,818
    Joined:
    Mar 17, 2003
    Location:
    Lubbock, TX
    Cone cry and 'rub' are two very different things. This problem is more likely to be a voice coil rub, which can be detected with the speaker out of the cab. Olace the speaker face side up on a stable surface. Place the fingers of both hands on opposite sides of the speaker....three fingers spread so as to depress the cone----lightly please--- and then letting the cone return to its "at rest" position. If there is voice coil rub, you will hear a gritty noise as the coil moves through its path. Sometimes rotating a speaker 180 degrees will help with this....most of the time it does not help. There are steps that can be taken to realign the voice coil.....possibility of a cure. If not, the speaker needs to be reconed.
    Cone cry occurs in otherwise perfectly good speakers when a strong signal is sent to the speaker with frequencies that occur above the 12th fret...usually. The cone shape distorts to create a howling that is not musical. Doping helps control this.
     
    JD0x0 likes this.
IMPORTANT: Treat everyone here with respect, no matter how difficult!
No sex, drug, political, religion or hate discussion permitted here.