Why Can't I get a good signal from Bass to Mixer?

Discussion in 'Live Sound [BG]' started by dbogart, May 18, 2011.


  1. dbogart

    dbogart

    Joined:
    Sep 16, 2008
    Hi guys,

    Can you tell me why I can not get a clean signal from my bass to my mixer?

    I keep having to crank the gain up on my channel on the board to even get the light to blink.

    I have tried the output (DI) from my bass amp to the board, i have tried a seperate direct input box, and then i finally tried just plugging my bass directly into the board...still without a good signal.

    I am using a Dean 5 string that uses a 9volt battery in the back. i guess that is an active bass?

    My mixer is a Mackie DFX-12.

    Thanks for any thoughts or help.

    Dave
  2. mambo4

    mambo4

    Joined:
    Jun 9, 2006
    Location:
    Seattle
    either some equipment is failing or yer doin it wrong, but from your post there's not enough info.

    -does your bass work fine otherwise?
    -do other signals (guitars, mics) work fine in the mixer?
    -have you tried many channels, or just one?

    If your bass works fine thru the amp, and you haven't succeeded with getting ANY signal out of the mixer:

    -have you read the manuals and understand how signals are routed through a mixer, and what you need to do to get sound coming out?

    Mixer are not like your amp, where you just plug in, turn on a noise comes out. Mixers are complicated signal routing devices and you need to make sure you understand what each switch on the channel strips and returns actually does, and how to assign them to the mix correctly. There are also a LOT of input/s outputs, easy to confuse what should plug in where.
  3. dbogart

    dbogart

    Joined:
    Sep 16, 2008
    yeah i read the manual nine ways to sunday. if im on here i need help. bass guitar works fine through amp. other signals-mics, guitars, work fine in mixer. although mic'ed in guitar from 2nd guitarist seems to take a lot of gain as well. i have tried other channels and all suck. using correct inputs. tried both XLR from amp and seperate direct input box out via XLR as well as 1/4" and directly in from instrument.

    dont get me wrong, i can get that level light to start blinking but the gain is cranked way up, like almost to max.

    and it sounds like crap. but could that be from using passive main PA speakers rather then powered?
  4. TimmyP

    TimmyP

    Joined:
    Nov 4, 2003
    Location:
    Indianapolis, IN
    Where do you run the gain control on the vocal channels to get a "PFL 0" level?
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  6. BogeyBass

    BogeyBass

    Joined:
    Sep 14, 2010
    Depends on what is powering your speakers.

    The DFX12 is not a powered mixer, its just a mixer

    You need powered speakers, or a power amp to run your monitor
    or mains speakers.
  7. uhdinator

    uhdinator

    Joined:
    Apr 20, 2010
    Location:
    Maine
    I think you may have something here :eyebrow:
  8. Never_grew_up

    Never_grew_up

    Joined:
    Sep 2, 2006
    Location:
    Roswell, GA
    But the OP's post is about gain/signal level into the mixer. (blinky lights). I don't know that particular mixer very well, but is there a mic/line button or a pad button near the gain knob at the top of the channel strip? Are channel volume & gain both up?
  9. staindbass

    staindbass Gold Supporting Member

    Joined:
    Jun 9, 2008
    if the bass is active ,did you open the bass cavity to see if there is a trim pot inside the guitar? im sure you checked the battery.. johnny a.
  10. Never_grew_up

    Never_grew_up

    Joined:
    Sep 2, 2006
    Location:
    Roswell, GA
    Also (not to be insulting) when you plug your bass directly into the board you're not plugging into the insert are you?
  11. Calaverasgrande

    Calaverasgrande

    Joined:
    Apr 22, 2006
    Location:
    East Oakland, California
    You need to go back to using the DI box. There is a reason why every recording studio and club stage uses these beyond turning 1/4" plugs into xlr plugs. It changes the impedance relationship as well. A bass straight into a mixer is "seeing" too low of an impedance so the tone will be off even if the signal is hot enough.
  12. dbogart

    dbogart

    Joined:
    Sep 16, 2008
    timmy: can you explain the PFL question. if your asking me when does the signal light start blinking on the vocal channels without the fader turned down, i would say about 65% of the way turned up.

    bogeybass (nice name): the main PA speakers are powered by a seperate crown amp.

    nevergrewup: here is a pic of my board:

    http://www.woodbrass.com/images/woodbrass/mackie dfx12 mixer analogique 12 entrees.JPG

    when i was trying to get the signal to blink the fader was all the way down. like i said-it will blink, but only with gain cranked to like 95%. the sound is crunchy and weak sounding.

    stanidbass: i have not opened up my bass cavity, because i dont even know what a trim pot is.

    calveresgrande: i tried using the di box. i used it in between my guitar and amp. fed a xlr directly into mixer, same result. weak signal with a crappy sound.

    thanks guys for your time.
  13. BogeyBass

    BogeyBass

    Joined:
    Sep 14, 2010
    Yah i know what i said is a ridiculous statement, and could offend certain people. I just thought i would throw it in their just in case.
    Since everyone would automatically assume he was running a power amp. and for whatever he was not then it was covered.

    Otherwise its obvious its a small portable mixer. Its not going to have massive amounts of gain or voltage overhead. Any small mackie, behringer,etc mixer with a bass plugged straight in is going to need the gain turned almost all the way up. Same with passive ceramic microphones like a shure 58 or 57 or any other simple ceramic mic. That is somewhat normal for a low power portable mixer.

    The bass is active, so the impedance mismatch would not be as much of a issue. The average gain needed would be about the same. Active pickups can have a slightly hotter signal, depends on the bass. just to be safe as mentioned i would change the battery just to weed that out.

    The 2 band EQ on the channel is not designed well for bass. Its a basic generic shelving EQ. Its going to be centered around 1000 hz and the low shelf is going to boost around 80hz. Which will work for bass. But the high shelf is going to be way up at 12k so its way out of range of the bass and will not control the tone well. Plus the curve being centered around 1000hz is not good for bass it should sit lower around 400 to 600hz like on a standard bass amp tone stack.

    Point is when you say it sounds like "krap" its hard to judge if their is a problem or your just not happy with the sound of a basic mixer and channel EQ.

    To get more gain and a better EQ, using the Direct out from the bass amp should have worked. And would solve the impedance mismatch. The gain from the bass amp direct out could be turned up. So less gain from the mixer would be required. Getting more gain into the unit might make it sound better, than pushing the overhead to the max of a single channel.

    Is this a new mixer or a used mixer?
  14. tbirddad

    tbirddad

    Joined:
    Feb 22, 2006
    I have used that same board with a DI with no problems - sorry I don't have anything otherwise useful for you.
  15. seanm

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

    Joined:
    Feb 19, 2004
    Location:
    Ottawa, Canada
    I have a small Mackie mixer. Even with the gain set correctly (mine does have a PFL feature), the bass by itself barely lights the LEDs. Are you only checking the LEDs or do you have the power amp running?

    Try plugging in headphones and listening.
  16. dbogart

    dbogart

    Joined:
    Sep 16, 2008
    seanm: i have the crown amp for the mains up and running and i am watching for LED to light up. i will try the headphones tip.

    bogey: this is a mixer we bought years (over 7 years ago) new. i also do not have a knob level set on the direct out on my bass amp. i do have a knob for an effects send and return. the crunchy kind of "overdrive" sound my bass is producing through the PA is bad enough, but i can barely hear it.
  17. Calaverasgrande

    Calaverasgrande

    Joined:
    Apr 22, 2006
    Location:
    East Oakland, California
    What DI box do you have? Some are passive. They require a bit of gain though. Rarely much more than a shure sm58 might need. There are also active DI boxes which require a battery or phantom power to be turned on. Also, some DI have pads that attenuate the signal a lot.
  18. dbogart

    dbogart

    Joined:
    Sep 16, 2008
  19. Calaverasgrande

    Calaverasgrande

    Joined:
    Apr 22, 2006
    Location:
    East Oakland, California
    I would go back to plugging your bass into the direct box "IN" jack. Then an XLR cable from the DI box to the mixers mic pre input. Make sure the pad on the DI is set to 0. On the mixer bring up the mic channel to 0 on the fader and about 30-40 db gain on the input. All other eq etc set to noon or odb cut or boost. From there you should be gettgin decent signal, maybe needing to season to taste by adjusting gain up or down 10db or so.
    To be sure, I would try another signal source like a guitar, bass or even an ipod set low.
  20. uhdinator

    uhdinator

    Joined:
    Apr 20, 2010
    Location:
    Maine
    Bad mixer channel?
    Bad XLR cable?
    Battery in bass dying?
    Bad instrument cable?
    Pad switch on DI cutting signal?
  21. fokof

    fokof Gold Supporting Member

    Joined:
    Mar 16, 2007
    Is a Microphone working OK ?
    For vocal , you have plenty of power ?

    Have you tried to plug your bass directly in the "Line in" with a short 1/4 cable you're 100% it works flawlessly ?

    Start with that as a trouble shouting stage.

    If everything is OK with the bass directly in the board , then using the same channel on the board , try your DI>switch XLR >switch DI

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