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TC Electronic BH250 for GK MB115

Discussion in 'Amps and Cabs [BG]' started by 8liter, Jan 19, 2013.

  1. 8liter

    8liter Supporting Member

    Apr 30, 2009
    The thread title sound weird, I know. But here is my situation.

    A while back I bought a new GK MB115 combo. Shortly after a year the head died. I was so busy with school and work that I wasn't doing any gigging at all, so I let it slide when I couldn't get the repair covered.

    Fast forward! I've been using my trusty Fender Rumble for bedroom practice, but now I have gigs coming up and I need a bit more oomph.

    My plan is to use a TC Electronic BH250 on the GK cabinet with the old head removed. I dissembled the amp/cabinet today and it's pretty basic from what I was expecting.

    The wires connecting to the 15" speaker use "slip on" style quick connectors with a simple red/black wire situation, so my main question is can I use the red and black wires and connect them to a speakon plug and run it to the BH250?

    Edit: I just remembered that I have a horn/driver on the cabinet as well. I'm not sure how to go about wiring that....hmm

    My apologies if my wording is hard to understand. I am very new to wiring and all this.
  2. Low Class

    Low Class Supporting Member

    Jul 4, 2005
    Orange Park, Florida
  3. 8liter

    8liter Supporting Member

    Apr 30, 2009
    Well that was relatively painless, haha. Thanks for the answer, Low Class.

    So now the plan is to connect the speaker to a speakon plug and then run a speakon to speakon cable to connect the plug to the BH250.

    Sounds good?

    I'm still curious about what I can do with the horn....
  4. Shardik


    May 24, 2011
    Halden, Norway
    How was the horn wired inn the first place? I guess most amps have only one power section, which means the horn should have a passive high pass filter. The bass element and the input to that filter should be wired in parallel into the amp / speakon plug.
  5. 8liter

    8liter Supporting Member

    Apr 30, 2009
    The horn just has two wires coming off it into a plastic plug, same as the main speaker. That's really all I can tell you. The original head had a driver on/off switch for the horn.

    I'm sure that's not what you were asking, but I am just too unfamiliar with electronic terminology to fully understand what you are asking and how to answer correctly. (I'm a noob).
  6. Shardik


    May 24, 2011
    Halden, Norway
    That may mean that the filter was in the amp itself. Do not connect the horn without at least a highpass filter of some kind. The tweeter horn can not handle the full power from the amp.
  7. 8liter

    8liter Supporting Member

    Apr 30, 2009
    ahh, that makes sense now. Thank you for the warning.

    I will leave the horn disconnected for now and just run the BH250 to the main 15" speaker.
  8. AstroSonic

    AstroSonic Supporting Member

    Dec 10, 2009
    rural New Mexico
    Hey, this is just what I had in mind if the amp in my MB115 failed and the repair cost was close to the cost of a small class D head (like the BG250 or a MB200). This will make a really nice, light weight 1x15 cab. Fitting the new head into the cab would be great if the fit is tolerable.

    The horn is a piezo and has no crossover other than an inherent rise in impedance below around 4-5kHz (er, like a crossover). The wires from the tweeter to the amp were required for the horn on/off switch. The horn may be wired in parallel with the bass driver. It would be a good idea to add a 10w 8 ohm resistor in series with the horn (some amps misbehave with capacitive loads). If you want a tweeter but don't like this one it could be a good time to add a better horn with crossover and L-pad. I put a new (better) tweeter in mine. The treble is now much smoother and more articulate.