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Amp dislikes the note D

Discussion in 'Amps and Cabs [BG]' started by Laguna J., Jul 25, 2005.


  1. Laguna J.

    Laguna J.

    Dec 10, 2002
    Liverpool, UK
    Hi, wondering if anyone here can help with a bit of an odd problem.

    I've got a Peavey BAM210 combo that i've had for just under two years, and it's been gigged heavily, but lately i've noticed that it distorts whenever i play a D in any octave. A semi-tone either up or down buzzes slightly and anything more than a tone away from a D is fine.

    I'm told this means the speakers are on the way out, basically. Can anyone clarify this?

    Thanks
     
  2. This could be a loose screw or something loose in the amp, im pretty sure D is the note that usually tends to make things rattle

    Its either D or A, but its almost midnight and i dont think anyone would appreciate me fireing up my amp to find out
     
  3. Lonnybass

    Lonnybass Supporting Member

    Jul 19, 2000
    Minneapolis by way of Chicago
    Endorsing Artist: Pedulla Basses
    Sounds like your speakers are going, and the note you are hearing is the frequency that is corresponds to the weakening of the cone.

    Lonnybass
     
  4. Selta

    Selta

    Feb 6, 2002
    Pacific Northwet
    Total fanboi of: Fractal Audio, AudiKinesis Cabs, Dingwall basses
    Yeah... just cos you might move the fundamental up an octave, the harmonics are still there, and can be very low also. Lonnybass nailed it though, I do think. Try testing the speakers, see if you can't find anything wrong with them.

    -Ray
     
  5. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    Something is sympathetically vibrating at the same frequency as that note. It might indicate a potential problem but more likely means something is simply loose.
     
  6. Laguna J.

    Laguna J.

    Dec 10, 2002
    Liverpool, UK
    Hmm, ok, thanks for the replies. Will check it out.
     
  7. Templar

    Templar Supporting Member

    Interesting thread. I'm experiencing a similar phenom with my new YBA 200 head....

    Any A440 note sounds a bit weaker than all other notes, most noticable on the lowest octave, regardless of which string.

    Anyone ever hear of such a thing?

    Anyway, I ordered a set of JJ KT-88's to replace the stock Sovteks. I'm hoping the 440 anomoly will disappear when the 88's arrive.
     
  8. Take the speakers out, and check the internal bracing in the cabinet and all the joints. Push gently on every brace, try to separate it from the wall its on.

    I had a brace glued to the back, it broke off, took a slice of the back with it, would vibrate at one freq. It was VERY hard to see that it had pulled off, cause it was still pressed against the back. Only when I pushed on it and saw motion did I notice.

    More glue, a screw or two to hold in place, vibration gone.

    Speakers tend to be more expensive also....

    Make the the speaker screws are all tightened evenly, and remember how tight they were, I don't "think" you're supposed to crank them super duper tight, but they should be pretty snug.

    Randy
     
  9. Plain Old Me

    Plain Old Me

    Dec 14, 2004
    Sounds more like a cab problem... Try to EQ it out, but it might also be the room you are in. I remember at one recent gig, I was in a room where I had to turn my Mesa's graphic EQ on and just cut one freq because it was twice as loud as the others.
     
  10. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Gold Supporting Member Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    I had something similar a few years ago. It turned out my 15" had a crack in its frame, and it needed to be replaced. There was also a broken brace inside the cab, which points to a fall as the likely culprit.

    What's odd is that someone had accidentally knocked my cab over onto its face a few months earlier, but it didn't sonically show any symptoms of damage until later.
     
  11. Selta

    Selta

    Feb 6, 2002
    Pacific Northwet
    Total fanboi of: Fractal Audio, AudiKinesis Cabs, Dingwall basses
    Now that you bring up internal bracing, I did have a Peavey combo once that did that to me also. It's always hard to tell where that's coming from also, IIRC, cos it's inside the cab. Good luck solving it.

    -Ray
     
  12. nt40lanman

    nt40lanman

    Jul 25, 2005
    I had that happen to me with a Peavey Basic 112. It was a bad glue joint in the cabinet. Take the grille off and "A" it to make the noise. Put a little pressure on one speaker cone and then the other. That may show you a bad speaker. Continue playing your A and push and squeeze different parts of the cabinet until you get the noise to lessen.
     
  13. Templar

    Templar Supporting Member

    I got a new 410 cab today, still have the weak 440 notes with the Traynor, tho. I did however, manage to tame a wolfish F# by switching cabs, so that's good.

    Funny thing is that my PLX/Demeter rack does not do this. Makes me think it's the head somehow. I will experiment with different rooms this week.