Blown combo help/advice

ack1961 · October 03, 2011, 09:32:23 PM

Ok, let's get the embarrassing stuff out of the way: A few years ago, I bought a Behringer BXL 1800A (180W) combo amp for my son.
I knew it was a mistake the minute I did it. I acted quickly & foolishly. I actually do love my son very much.

It didn't get all that much use, and I should have sold it when it was working.
Anyway, as you can all probably guess, the eventual rattling ensued, followed by the ceremonial speaker blow out.
This thing is no longer under any warranty, and Behringer tech support is not a viable option (the last thing I want to do is spend another $120 bucks to get the same piece of crap back).

Now, here's my question: Is there anything I can do with this thing? I'm no electronics wizard, but I should be able to put a decent speaker in there, correct?
The original is a 4 Ohm Bugera 12" aluminum cone. I was thinking that I could make it a decent keyboard amp or monitor, since it's wedge/tilt shaped.
I hate to throw away a ridiculously expensive (for what it is) amp without first asking you folks. If someone can tell me a decent match for a speaker, I'll give it a shot. I've included some specs below:

Instrument input ¼" TS
Input impedance 250 kOhm
CD input RCA
Input impedance 40 kOhm
FX INSERT RETURN ¼" TS
Input impedance 50 kOhm

Phones Out ¼" TRS stereo
Direct Out XLR
Output impedance 500 Ohm
Line Out ¼" TS
Output impedance 100 Ohm
FX INSERT SEND ¼" TS
Output impedance 2.2 kOhm

Power amp output 180 W @ 4 Ohm
Type 12" aluminum-cone
Impedance BUGERA™ Hard Attack Series
Model 4 Ohm
Power handling 120 W

Thanks,
Steve

Psycho Bass Guy · October 03, 2011, 09:38:44 PM

Find yourself a cheap 12" bass or fullrange speaker. You might want to opt for 8 ohms if you suspect the amp is bad too. I wouldn't spend more than $50 for the speaker and would think twice about that.

Pilgrim · October 03, 2011, 10:00:13 PM

The traditional response is "download WinISD and run the cabinet dimensions to see what you get."

Unfortunately I've tried to understand WinISD and it might as well be Sanskrit for all it tells me.

Freuds_Cat · October 03, 2011, 10:03:36 PM

A few years back I bought a Behringer BX 1200 bass amp for teaching and practicing with.
Like this:

It sounded terrible and was generally a bad amp. My son aged 4 at the time plugged a guitar lead into the output jack and plugged the other end into the input before turning the amp on. Short story, amp dead.

I decided that the best thing I could do is see the good side in that I no longer had to put up with such a useless piece of kit and move up to something real. I didnt even bother getting any one to check it out.

Chris P. · October 04, 2011, 05:43:28 AM

I'm no Behringer fan, but it can't be that bad... I do hate aluminium conus speakers. I would go for PBGs option. Buy a normal 12" speaker, as cheap as possible, and maybe you've got a nice practice amp or monitor indeed.

ack1961 · October 04, 2011, 05:55:25 AM

Yeah, I think it'll be a waste to at least try out another speaker in there. Maybe make it something usable (like a monitor for the drums) without spending a lot.
I believe the amp section works fine, so I'll just look for a 4 Ohm 12" bass speaker somewhere.

Psycho's reply about using an 8 Ohm speaker kinda baffles me (which isn't hard) - I was under the impression that since the Power Amp Output was 180W @ 4Ohms, that I had to match that with a 4 Ohm speaker.
Thanks,
Steve

lowend1 · October 04, 2011, 06:40:10 AM

Quote from: ack1961 on October 04, 2011, 05:55:25 AM
Psycho's reply about using an 8 Ohm speaker kinda baffles me (which isn't hard) - I was under the impression that since the Power Amp Output was 180W @ 4Ohms, that I had to match that with a 4 Ohm speaker.
Thanks,
Steve

>>You might want to opt for 8 ohms if you suspect the amp is bad too.<<
Meaning if you wuz gonna use the combo box as a cabinet ONLY, an 8 ohm speaker is more compatible with more amplifiers. Generally speaking, a little more common as well.

Psycho Bass Guy · October 04, 2011, 07:16:24 AM

If you think the amp might have something wrong with it, using an 8 ohm speaker will cause the amp to put out less power and give it a little easier time. If you don't want to take the time and effort to look for a speaker, a better route might be to just cut it down to a head.

dadagoboi · October 04, 2011, 07:41:39 AM

Quote from: Psycho Bass Guy on October 04, 2011, 07:16:24 AM
If you think the amp might have something wrong with it, using an 8 ohm speaker will cause the amp to put out less power and give it a little easier time. If you don't want to take the time and effort to look for a speaker, a better route might be to just cut it down to a head.

Or just pull an 8 ohm 12 out of another cab and see what it sounds like in the Behringer. Then you'd have a better idea of what it would sound like with very little time spent and zero dollar outlay.

ack1961 · October 04, 2011, 12:52:53 PM

well, I do think it's just the speaker, as the amp works fine through the headphone out or the XLR DI out.

dadagoboi · October 04, 2011, 01:07:34 PM

Quote from: ack1961 on October 04, 2011, 12:52:53 PM
well, I do think it's just the speaker, as the amp works fine through the headphone out or the XLR DI out.

neither of those goes through the power amp

Pilgrim · October 04, 2011, 03:18:47 PM

If you want to test the amp, pull the speaker and connect the + and - wire to another speaker. You can even use a speaker cable; plug one end into another cab and just touch the speaker wires to the contacts on the other end of the cable.

ack1961 · October 04, 2011, 06:15:07 PM

Quote from: dadagoboi on October 04, 2011, 01:07:34 PM
neither of those goes through the power amp

Thanks...
Curious thing is that you would think if the speaker was blown or even "dead", I'd hear something/anything when powering on.
As one final test, I'm going to try house speaker leads to an old speaker as Pilgrim suggested below.
If I get nada, then it's not the speaker.

ack1961 · October 05, 2011, 04:34:32 AM

Quote from: Pilgrim on October 04, 2011, 03:18:47 PM
If you want to test the amp, pull the speaker and connect the + and - wire to another speaker. You can even use a speaker cable; plug one end into another cab and just touch the speaker wires to the contacts on the other end of the cable.

The Bass amp speaker connections are soldered, so I pulled the speaker out of the cabinet, plugged in a bass and touched a pair of household speaker leads to the speaker terminals (on the solder joint). I can hear the bass over the house speakers, so I'm assuming that the Power Amp section works and the Bugera bass amp speaker is shot. To me, not knowing much about electronics, it's strange that I don't even hear a hiss from the bass amp speaker - not sure how a speaker goes completely dead.

Anyway, I think that's kind of good news. Since the combo amp has a few features, that I'm going to find a compatible speaker, and set the combo up next to my youngest son's drum kit. He can use the stereo RCA input for an iPod & metronome for practice and we'll be able to come in from the mixer and use the combo amp as another guitar/bass/vocals monitor as well.

Now I need to scour the Internet for a compatible speaker and I should be all set.
Thanks to all for the help.
Steve

dadagoboi · October 05, 2011, 06:12:48 AM

My understanding is a speaker is sort of a pickup in reverse. The two leads go to the voice coil which moves the cone back and forth making sound. Coil overheats, coil wire fuses or breaks and you don't have a circuit. That means the voice coil doesn't move and no noise. Similar to when a light bulb filament breaks or burns out. There's still a vacuum in the envelope but no circuit.

Glad you've got it sorted out. Have your son tear the cone off the Bugera, you'll probably see where it failed.