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amp crackles on "A" note.

Discussion in 'Amps and Cabs [BG]' started by Rick Martin, Mar 23, 2004.

  1. :meh: I bought a Hartke 1410 combo used. Thats the 1400 amp head with two ten inch aluminum speakers. I didn't noticed when I was trying it out at the store, but now that I have it home, it sounds great on all notes except the fourth and fifth fret on the E string. All three of my basses make the same static/crackle noise on A and Ab on the E string, even with the volume turned way down. All other notes sound great.
    I paid $250 for the amp and the store is too far away to return it. I am going to take it to a local repair shop but I thought I would ask for opinions/diagnosis/guesses here. What do you think?
  2. mine kinda does that too, 'cept on the B note :meh:
  3. Well I'll take a stab at this. I'm guessing from your description that you guys are suffering from over extended speakers. With the B, since it is so low, it has the most air to move. Most modern speakers are designed as vented speakers and the actual speaker vibrates the most above and below the frequency that the box is tuned to. There are many threads and perhaps FAQ that explain all this better. Anyway, So the B is probably vibrating below that box frequency where the speaker has little control over how much it vibrates. It just kind of flops around. As you go up in frequency and get to where the box is tuned, the speaker quits moving and the sound all comes out of the vent. (Try this. play down the scale with your hand by the vent and watch the speaker. You'll see the speaker stop moving at some point and the sound will come out of the vent.) Then the speaker starts moving again and the vent contributes less to the sound.

    Then as the frequency gets higher, the speaker has to move more air again. This is where the A string problem arises. So, depending on the speaker, the cabinet, and the bass, and how loud you are playing, and your EQ settings, you can "fart out" the speaker by overdriving it above or below the box tuning frequency.

    Maybe alll the speaker gurus out there can chime in on this one.

    I guess the moral of the story is turn down the amp or at least adjust the bass eq to cut some of the lowest fequencies. Bet you didn't want to hear that.

  4. No man, I don't wanna turn it down! I wanna turn it UP! I wanna play "Enter the Sandman" LOUD. When I'm playing loud, I don't hear the crackle on the A note so much. It's really more of a problem when I play softer. It also doesn't go away when I turn down the bass EQ. I'd like to try playing this amp through a different cab to see what that sounds like. I'm going to take it to a repair place on friday and see what they say. I thought I had such a great deal when I bought this for $250 cash at a store specializing in used stuff. The guy at the store let me play with it all I wanted and it sounded great to me in the store. I'm flummoxed!
  5. seanm

    seanm I'd kill for a Nobel Peace Prize! Supporting Member

    Feb 19, 2004
    Ottawa, Canada
    Have you tried going somewhere else and playing it? You might be picking up some weird noise from your place?
  6. Petebass


    Dec 22, 2002
    QLD Australia
    This is going to sound like a silly suggestion but humour me anyway.

    Take the amp into a different room and try it again. Chances are something in the room is picking up the frequency of the A note and resonating with it. I've seen smarter guys than me get caught out with this exact same thing. I've seen car audio enthusiasts returning perfectly good speakers because they heard distortion that was actually their license plate flapping around.
  7. I tried the amp in a different room and it still crackeled on the A note. I took it to a friends house (I blindfolded it so it wouldn't know where we were going) and damned if the static crackel noise wasn't significantly less. Still there, but less. The input jack is sloppy and I'm going to take it to the shop to get that replaced and see what the tech guy sez.
  8. It sounds like the speaker may be loose. Over time I've found that often the screws will be loose because of the vibration. It will rattle for certain notes and not others. While you at it you could check the wires and the driver itself. To check the driver gently and evenly push the cone in and out. Any scatching or scraping is bad. be carefull with the screwdiver. :smug:
  9. So I bring this Amp to the repair place, I plugs it in and it sounds just fine. No static no crackle, just a pure and lovely A note. I tried all of the frets on all strings to see if "it" moved and everything sounded sweet. The input jack is worn out and I left the amp there to have the tech replace that. I asked the boss to have the tech check the whole thing over and make sure everything is tight. I don't think they'll charge me a lot of money for this. Maybe the input jack is loose and the A note is the frequency that makes it screwy......but only at my house. Anyway, it looks like this Hartke 1410 is discontinued. I only see the 1415 offered. I wonder why???
  10. FunkyBeek


    Mar 23, 2004
    sounds like your box is resonating around the low "A". try just cutting some of the freqs @ 100Hz and less. i have run into this before, never to the point of distortion though. Question: did you use your bass to check it out at the shop??

    resonant frequencies are wierd.
  11. Yeah, I brought one of my basses to the shop and the amp sounded perfect. At home I got a crackeling A (like static) and at the shop no problem.
  12. ChildoftheKorn


    May 21, 2003
    well is it the bass you used for the crackling A noise? because maybe its the bass and not the speaker? just curious.
  13. All three of my basses made the A note crackle. I have three project basses. A Jazz, a P and a MM, all with Seymour Duncans.
  14. Mattski


    Jan 6, 2003
    Cleveland, OH
    Do you have a tweeter?

    I have had a problem with a crossover that gave me a crackle/static sound on g that was hard to identify. When I realized it was the horn vs. the speaker, it was easy to fix from there.

    If you have a tweeter in your system, try turning it off, or rolling off the highs a bit.

    Good Luck
  15. I got my Hartke 1410 back from the repair shop and it's fixed! It's boomin' clear as a bell. The teck guy said the input and return jack were both broken and the board that they are attached to was broken as well. He said the input jack was so wrecked, he was surprised it even worked at all. He replaced the two jacks, repaired the board (whatever that means) and cleaned the pots. He said everything else was nice and tight. The bill was $78 total. I'm happy.
  16. Petebass


    Dec 22, 2002
    QLD Australia
    Great news! Happy groovin!

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