TC Electronic BH250 for GK MB115

8liter · #1 01-18-2013, 11:58 PM

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.

Low Class · #2 01-19-2013, 12:00 AM

Quote:

Originally Posted by 8liter

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

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?

Yes

8liter · #3 01-19-2013, 12:15 AM

Quote:

Originally Posted by Low Class

Yes

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....

Shardik · #4 01-19-2013, 12:25 AM

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.

8liter · #5 01-19-2013, 12:36 AM

Quote:

Originally Posted by Shardik

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.

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).

Shardik · #6 01-19-2013, 12:58 AM

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.

8liter · #7 01-19-2013, 09:14 AM

Quote:

Originally Posted by Shardik

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.

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.

AstroSonic · #8 01-19-2013, 05:49 PM

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.