Blown combo help/advice

Psycho Bass Guy · October 05, 2011, 06:17:53 AM

Quote from: ack1961 on October 05, 2011, 04:34:32 AMit's strange that I don't even hear a hiss from the bass amp speaker - not sure how a speaker goes completely dead.

It's quite likely that the amp simply overpowered the speaker and destroyed it. According the specs you posted, the amp puts out 180 watts into a 4 ohm load, and your blown 4 ohm speaker was only rated for 120 watts. When a speaker is damaged by too much power, its voice coil is literally cooked and melted and the speaker is completely useless. In simple terms, the amp doesn't get as loud as its ratings imply and it has been used at and above its limitations and that blew out the speaker. Behringer's aluminum speakers are especially prone to damage, and odds are that it's power handling figures are inflated anyway, since most of Behringer's ratings are fudged anyway. The good news is that the amplifier itself it probably fine.

QuoteNow I need to scour the Internet for a compatible speaker and I should be all set.

Here are some decent 8 ohm speakers:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-118

http://www.speakerrepair.com/mm5/merchant.mvc?Screen=PROD&Store_Code=genem&Product_Code=01-804&Category_Code=B-Alpha-100W-200W

and here is a 4 ohm model:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-332

Don't worry about tuning or any of that garbage; you're just replacing a cheap crappy speaker with a better cheap speaker.

dadagoboi · October 05, 2011, 06:22:54 AM

PBG, might it be better to use an 8 ohm speaker to avoid exceeding the rated power handling capacity of the 4 ohm or wouldn't the amp like that?

Psycho Bass Guy · October 05, 2011, 06:35:05 AM

Quote from: dadagoboi on October 05, 2011, 06:12:48 AMMy 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.

...exactly

QuoteHave your son tear the cone off the Bugera, you'll probably see where it failed.

The coil will be under the dust cover in the center and most likely the damage won't be visible.

Psycho Bass Guy · October 05, 2011, 06:40:19 AM

Quote from: dadagoboi on October 05, 2011, 06:22:54 AM
PBG, might it be better to use an 8 ohm speaker to avoid exceeding the rated power handling capacity of the 4 ohm or wouldn't the amp like that?

It's a toss-up. It doesn't matter to the amp, and its power rating is inflated anyway. To get rated power out of them, Behringer takes power measurements with its output transistors under looser regulation (biasing) than their max linear operation calls for. Their THD figures are atrocious.

ack1961 · October 05, 2011, 06:50:01 AM

Thanks for all the great information and links.
I'll get a replacement speaker and get it going again.

ack1961 · October 07, 2011, 03:13:59 PM

Thanks again for all the help and links.
I ended up getting the 4 Ohm woofer from Parts-Express (thanks, Psycho).
It took a little cabinet mod to get it in (it's just a pinch wider than the cutout), but it has solder-less connectors and it sounds great!
So, for like $60, I now have a great little monitor/practice station for the drum kit.

Chris P. · October 09, 2011, 12:42:39 PM

Nice!!

Pilgrim · October 09, 2011, 12:49:07 PM

Yup, IMO it's worth putting $60 into that little combo.

Freuds_Cat · October 17, 2011, 02:30:33 AM

Win

ack1961 · October 17, 2011, 06:54:25 AM

Quote from: Freuds_Cat on October 17, 2011, 02:30:33 AM
Win

Thanks guys - It has cool multi-functionality now, and I'm glad I didn't toss it out or set it ablaze. It's small footprint and tilt-back capabilities allowed me to put it behind his hi-hats and snare in our crowded little jam room.

@ Pilgrim
Last night, I bi-amped out the Crossover of my rig over to this combo - my kid drummer and I were just jamming a bit (trying out my new chinese 6-string). It actually sounds OK with this no-name speaker in there. Way better than stock.

I don't know what Behringer pays for the Bugera Alumi-cone POS, but they'd probably save themselves a lot of tech support calls and hate mail if they switched to something other than Alumi-anything. I realize that Behringer is the Yugo of the amp world, but they do make some nice entry level products (I like their Xenyx mixers).

Thanks again - this forum truly rocks.

Psycho Bass Guy · October 17, 2011, 02:55:18 PM

Quote from: ack1961 on October 17, 2011, 06:54:25 AMI don't know what Behringer pays for the Bugera Alumi-cone POS

"Bugera" is a fake brand name Behringer came up with for some of their musical instrument speakers and amps to try and sound like some kind of boutique. They are Bugera.

ack1961 · October 17, 2011, 03:10:17 PM

Quote from: Psycho Bass Guy on October 17, 2011, 02:55:18 PM
"Bugera" is a fake brand name Behringer came up with for some of their musical instrument speakers and amps to try and sound like some kind of boutique. They are Bugera.

(sigh) I'm always the last to know...