HELP! Need to Avoid BLOWING a Speaker

Hekbass · #1 10-29-2011, 08:45 AM

Can please someone explain to me, like I'm 5 years old (preferably with some examples as opposed to just rattling off dry facts), how to be sure I won't blow any speakers when I hook up an external bass cab to a combo amp or head?

Here's what I got: I have a GK MB210 combo.
Welcome to Gallien-Krueger: Power to Groove

And I'm buying a TC Electronic RS210 cab to hook up to the combo above.
TC Electronic RS210 Bass Cabinet at zZounds

The GK combo specifies clearly that it pumps out about 350W by itself, but goes up to its max of 500W when you hook up an external cab.

Will this match work? I've just never understood that whole ohms thing.

THANKS!

RickenBoogie · #2 10-29-2011, 08:49 AM

Use your ears, really. If it sounds bad, turn down the low eq and/or volume. That's it.

Hekbass · #3 10-29-2011, 08:55 AM

Ok, thanks. I was just wondering about the whole "ohm load" concept thing as well. What I've read so far is like a physics class. One day I hope someone can go, "When you hook up two 8ohms cabs to an 8ohm head..." and kinda break it down in very simple terms.

I do appreciate your feedback. Thanks again.

Hekbass · #4 10-29-2011, 08:56 AM

P.S. Let me rephrase it: Is it possible to have such a mismatch between the cab and the head (ohms and watts-wise), that the moment I turn on the power and hit the first note I'll blow a speaker? I'M SCARED, and I don't know if I'm just being stupid, paranoid, or both.

modulusman · #5 10-29-2011, 08:57 AM

it will work since the TC electronic is an 8 ohm cab. Just wondering why you don't want a GK MBX cab instead. It would look better and is made to stack with the GK combo.

JonnyAngle · #6 10-29-2011, 08:59 AM

Two 8 ohm cabs will produce a 4 ohm load.

Hekbass · #7 10-29-2011, 09:02 AM

Thanks! Well, you can't always have what you want. I found the TC electronic RS210 for $175 - yes, less than $200 on craigslist. That's way less than half the usual price I found online.
The guy just said he's got several amps and cabs, all of them 12" or 15" - then tried the 10" and never liked it. I LOVE 10's.

So, the offer is just WAY too good to pass up. I'm poor, so I can't just buy anything I'd want. Ebay's got very little right now in terms of 2 X 10's. Oh, well. I think it should be fine. I don't mind looks. I'm sure I can just sit the cab atop the combo and it will be fine (maybe put some black foam in between to prevent rattling?).

THANKS FOR YOUR FEEDBACK, GUYS!

Hekbass · #8 10-29-2011, 09:06 AM

Quote:

Originally Posted by JonnyAngle

Two 8 ohm cabs will produce a 4 ohm load.

Ok, but what does that mean?!?!? LOL! I'm sorry, I'm just DUMB when it comes to techie stuff. Modesty aside, I can play. That's been my focus since 1992. After almost 19 years of busting my fingers, I think I got the playing part well-covered: I can read bass and treble clef, I'm good at theory, etc.

But the gear/technical stuff has never been my thing. I'm just dense when it comes to the theory of HOW the gear works.

Sad, eh? LOL!

modulusman · #9 10-29-2011, 09:08 AM

[quote=Hekbass;11681976]Thanks! Well, you can't always have what you want. I found the TC electronic RS210 for $175 - yes, less than $200 on craigslist. That's way less than half the usual price I found online.
The guy just said he's got several amps and cabs, all of them 12" or 15" - then tried the 10" and never liked it. I LOVE 10's.

So, the offer is just WAY too good to pass up. I'm poor, so I can't just buy anything I'd want. Ebay's got very little right now in terms of 2 X 10's. Oh, well. I think it should be fine. I don't mind looks. I'm sure I can just sit the cab atop the combo and it will be fine (maybe put some black foam in between to prevent rattling?).

If you put it on top of your combo then you will cover up all your controls for the amp.
]

Hekbass · #10 10-29-2011, 09:14 AM

[/b]
If you put it on top of your combo then you will cover up all your controls for the amp.
][/quote]

Point taken. But, wouldn't that be the same with the GK 210 MBX cab? So, I take it the GK's dimensions are tailored to fit atop the combo without blocking the control, while the TC is bigger?

Dimensions for the TC: 14" W x 26-1/10" H x 14" D

The GK: 18.5 x 23.5 x 16.5 inches

Is the last measurement the one that runs fron to back (the one that probably matters most when it comes to the controls thing)? I'm not sure, but if it is, then the TC actually leaves more space.

If not, I'll find a way!!! The TC is pretty thin, so I can probably just put it on the floor vertically next to my amp. In fact, it's meant to be able to be stacked vertically or horizontally.

Thanks...

Oh, gear. Why art thou so complicated?

modulusman · #11 10-29-2011, 09:20 AM

You would put your combo on top of the GK extension cab. The corners are designed to fit together to keep the top cab from falling off.

modulusman · #12 10-29-2011, 09:25 AM

Musicians friend is selling the 210 MBX cab for $299.00. The other day I could have bought one from them at 15% off. That would have been around $255.00. So for another $80.00 you could get the cab that is designed to work with your combo.

sanderic · #13 10-29-2011, 09:47 AM

If you use too low an ohm rating, say you run a 2 ohm load from a 4 ohm minimum amp. YOUR AMP WILL NOT BLOW UP ON THE FIRST NOTE!!!!!.

HOWEVER: your amplifier will run hot, same as if you run your car without any coolant, and you will eventualy overheat and burn up your amp.
Amp manufacturers usualy know at what load there amplifiers are prone to failure, that is how they rate their amps.

Hekbass · #14 10-29-2011, 09:55 AM

Sadly, I'm pushing it financially as it is, so an extra $80 is not doable. Yes, I'm not greatly knowledgeable about tech stuff, but I have seen quite a few top notch pros that mix and match heads and cabs from different manufacturers (reading every article of Bass Player magazine since 1992 has helped. Yes, EVERY article, barring about a 1 year gap in 2007).
So, I really don't think it's that big a deal. Of course, it's going to LOOK and stack up better, as they're designed by the same company to match. But, in terms of the power and volume I'll gain, I don't think there'll be any noticeable difference.

*shrug*

AwkwardLoudness · #15 10-29-2011, 10:08 AM

Begin at a low volume when you first turn on an amp. If you blast the speakers at full volume on the first note, then thermal shock can possibly damage speakers particularly the voice coil.

If you bring your amp and speakers indoors from a vehicle in cold whether, let the equipment warm to room temperature before turning anything on.

Wattage ratings on speaker cabs are often too optimistic and unrealistic. Speaker displacement is what matters. Lower frequencies and/or hgher volume causes more displacement. Speakers will make non-musical sounds if they reach maximum displacement. Turn down the volume or low end frequencies if you hear unwanted 'pop' or 'farty' sounds.

For the record, I have blown a couple speakers in a '1600W' rated speaker 8x10 cab using a 100W RMS tube amp. I could hear the strain of the speakers, and this was an experiment that I did on purpose to prove a point to someone. I replaced those speakers and later sold the cab.

For anyone using tweeters, do not employ distortion in your tone when tweeters are on.

Regarding impedance, measured in ohms (Ω), in solid state amps (or hybrids with SS power section), do not use cab(s) totalling less than the rated minimum impedance. This could hurt the amp...not on the first note...but the output transistors can get fried. I wouldn't go too far above the minimum impedance either because then the amp's power output lowers.

billfitzmaurice · #16 10-29-2011, 10:31 AM

Quote:

Originally Posted by RickenBoogie

Use your ears, really. If it sounds bad, turn down the low eq and/or volume. That's it.

+1.

Joe Louvar · #17 10-29-2011, 12:03 PM

Quote:

Originally Posted by Hekbass

Ok, thanks. I was just wondering about the whole "ohm load" concept thing as well. What I've read so far is like a physics class. One day I hope someone can go, "When you hook up two 8ohms cabs to an 8ohm head..." and kinda break it down in very simple terms.

I do appreciate your feedback. Thanks again.

Hopefully a picture will help picture it ~
Wiring Diagrams | Eminence Speaker

MontanaBassDude · #18 10-31-2011, 10:02 PM

Hekbass -You're trying to understand, and people here aren't helping your sitch.

Get your mind around the concept that 2 ohms is a bigger strain on an amp than 8 ohms. (I'm over simplifying this, and people are gonna jump in my ****, too, but here goes.)

You need to know for certain three things: 1) Your amp's ohm ratings. 4 Ohms is the lowest your GK210 will handle. Period. Never go 3 ohms or 2 ohms. OK?
2) Know for certain your cab's ohms. The speakers in your combo are 8 ohms. Great. Your amp is happy and cool.
3) Add on another cab (like that 8 ohm TC RS210). Your 8 ohm combo PLUS another 8 ohm cab equals 4 Ohms. Great. Your amp is happy, you're within its specs.
4) Add on a third 8 ohm cab - 8+8+8 adds to 2.66 Ohms, and now you're courting trouble. Your 4 ohm maximum amp is sweating. Overheatting, thermal shutdown.
5) Know that 8 ohms plus a 4 ohm cab adds up to a 2.66 ohm load. A LOT of 2x10 cabs are 4 Ohms. IF your TC Electronic 210 is a 4 ohm cab, that (along with your GK 8 ohm combo speakers) add up to 2.66 ohms, and you'll have trouble. Before you drop the dime on that TC210 cab, make sure it's an 8 ohm cab.
Just keep studying, it'll come around.