500 watt Hartke kickback combos. KB12 VS. KB15?

Stay with the KB15 or go with the KB12


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Jul 2, 2000
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Anybody have the chance to A/B these combos. I just ordered the KB15 but since they are back ordered I can change my order to the KB12 IF I want.

I currently have the older Kickback 12 with the aluminum speaker and 120 watts. I love the tone but need a bit more volume from time to time especially on outdoor gigs.

Are the 500 watt versions with the Hi Drive speakers comparable in volume 12 vs 15. How about tone wise? Still nice punchy attack on notes which to me is the coveted Hartke sound?

I know volume will no longer be a problem because I bought a radial big shot ABY box so I can stack the two combos IF I need to. Hoping I don't need to under most circumstances. I usually play medium sized clubs and outdoor festival type gigs.

Any input is appreciated.
 
I would opt for the 15". I have an older KB15.... Blew out the aluminum speaker and replaced it with a paper cone. Use it from time to time at rehearsals.... Still pretty loud at 120 watts. I would bet the new 500 watt with a HyDrive would be a little beast.
 
Ok, 15 seconds after unboxing (KB15) it and plugging in "I'm in love"!!!
Nothing better than being able to set all the tone controls on an amp to 12 o'clock and having it sound FANTASTIC!
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Just went to a show last night with Bela Fleck and Victor Wooten. Just the two of them doing very cool renditions of some flecktone tunes and other jams.

Victor had some rack units, a few pedals, once of which has a patch of synths that seem to have an on board control installed on one of his Monarchs.

He was playing through the KB15 as his stage monitor! Didnt recognize the amp so I looked it up this morning. Obviously with just the two of them on stage, he doesnt need a big rig, but very cool to see him rocking a $500 combo amp with $10K+ basses!!
 
Just an updated review after 8 months of use. The new kickback 15 is handling everything I throw at it. Club Gigs, outdoor gigs, No problem Volume at 1 o'clock max. Sounds great too! One handed carry from vehicle to stage. Perfect for this old geezer.
 
Just an updated review after 8 months of use. The new kickback 15 is handling everything I throw at it. Club Gigs, outdoor gigs, No problem Volume at 1 o'clock max. Sounds great too! One handed carry from vehicle to stage. Perfect for this old geezer.

Ever run an octaver pedal thru it in a live setting?
 
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It's 500 watts @ 4 ohms. Since the 15" driver is 8 ohms...the amp is running at 250 watts.

Okay, I found the info on their site. What I don't understand is that everything I've read says to connect a 4 ohm cabinet as per this quote, "If you do wish to connect an external speaker, use only appropriately rated 4 ohm speaker cabinets that are specifically designed for bass instruments" from the owner's manual. Huh? Wouldn't it be necessary to run an 8 ohm cabinet to get down to 4 ohms?
 
Okay, I found the info on their site. What I don't understand is that everything I've read says to connect a 4 ohm cabinet as per this quote, "If you do wish to connect an external speaker, use only appropriately rated 4 ohm speaker cabinets that are specifically designed for bass instruments" from the owner's manual. Huh? Wouldn't it be necessary to run an 8 ohm cabinet to get down to 4 ohms?
Correct.... But, not sure if the newer KB15 has a external cab output jack. I believe there is only one.... In which, you would unplug the combo speaker and use either a 8 ohm cab, 2-8 ohm cabs daisy chained (makes 4 ohm) or a single 4 ohm cab.
If I am incorrect and there are parallel speaker outputs, then you can use the combo speaker with an external 8 ohm cab.
 
I have the KB12 it's not really 500 watts. If you read the fine print it's really 250 RMS.
^This.
I was wondering about this but could never find the fine print to be certain. Is the 15 really 500watts?
Answer's "yes, but". From the manual, page 11 of 12:
Rated Output Power 500 watts Peak / 250 watts RMS
In continuous power terms it's a 250W amp exactly as HMZ said. (This is true of both the KB12 and KB15, same "head" on the two.)
It's 500 watts @ 4 ohms. Since the 15" driver is 8 ohms...the amp is running at 250 watts.
Nope, see below.
Okay, I found the info on their site. What I don't understand is that everything I've read says to connect a 4 ohm cabinet as per this quote, "If you do wish to connect an external speaker, use only appropriately rated 4 ohm speaker cabinets that are specifically designed for bass instruments" from the owner's manual. Huh? Wouldn't it be necessary to run an 8 ohm cabinet to get down to 4 ohms?
Complete quote is as follows (underscore mine):
"Speaker Output Jack - The internal speaker is normally connected to this standard unbalanced ¼” jack.
Note: Because of the high power levels and low frequency content of the signal generated by the Kickback amplifier, we recommend the use of the provided internal speaker only. If you do wish to connect an external speaker, use only
appropriately rated 4 ohm speaker cabinets that are specifically designed for bass instruments.
"
Correct.... But, not sure if the newer KB15 has a external cab output jack. I believe there is only one.... In which, you would unplug the combo speaker and use either a 8 ohm cab, 2-8 ohm cabs daisy chained (makes 4 ohm) or a single 4 ohm cab.
Exactly. The amp has only one output period, and it's an external jack. As in, the powered signal does not reach the on-board woofer from inside the combo, but instead the head and cab sections are connected through the aforementioned jack, with a cable accessible from the outside. Should one need to use external speakers (for a combined minimum acceptable load of 4 ohms as stated in the quote above), the internal driver can, and has to, be unplugged, and that same socket be used in one of the three configurations you described.
 
Where are you folks seeing that the internal speaker is 8 ohms?
Nowhere, because it isn't, in all likelihood. It would be foolish if it were.

What we know for sure:
- power figures, i.e. "Rated Output Power 500 watts Peak / 250 watts RMS";
- the fact that the amp can go down to 4 ohms, since they say as much - "If you do wish to connect an external speaker, use only appropriately rated 4 ohm speaker cabinets";
- the fact that the internal speaker has to be disconnected, from the one existing output jack, for another cab to be hooked to the head - "Speaker Output Jack - The internal speaker is normally connected to this standard unbalanced ¼” jack."

If the internal speaker were 8 ohms it would mean that the combo as is couldn't put out the rated max power (not uncommon, but clearly stated every time it is the case): it would have to be connected to an external 4-ohm cab or stack, with the internal woofer necessarily disconnected and turned into dead weight/space (which would be odd and inconvenient*); alternatively, the head would have to be hooked up to an external 8-ohm cab, then daisy-chained back into the combo speaker (which, again, we are assuming for the sake of argument to be 8-ohm as well). Why not arrange for an extension speaker output, as is the case with every combo out there that has a 4-ohm min head and an internal 8-ohm speaker?

Nah. Everything points to the driver being 4 ohms.
[EDIT - Maybe not everything after all: see this post making a convincing case for the driver being a 6-ohm one.]

*EDIT: to clarify, it would be odd and inconvenient to get the head section to put out its full power with the internal speaker not contributing in any way (except negatively, as ballast).
 
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Oh, ok some of the previous posts threw me off.
So the internal speaker is 4 ohms. The amp is 500 peak 250 RMS.
That makes more sense to me.
The obvious question is, Why the heck would you ant to run a different speaker cab.
I guess you could run 2 external 8 ohm cabs w/internal speaker disconnected and get more volume? That would also depend on what speakers/cabs you were using.... Why am I even asking about this. I like the KB15 just like it is!
 
Oh, ok some of the previous posts threw me off.
So the internal speaker is 4 ohms. The amp is 500 peak 250 RMS.
That makes more sense to me.
The obvious question is, Why the heck would you ant to run a different speaker cab.
I guess you could run 2 external 8 ohm cabs w/internal speaker disconnected and get more volume?
I suppose in the odd case you had a loud outdoor gig with no PA support for bass, an 810 or two 410s at your disposal but no separate head to run the full stack.

The thing is, it's damned if they do, damned if they don't with combos: if you (the designer) make them expandable by putting in an internal speaker of double nominal impedance than the minimum one the amp is rated at, people complain they don't put out their full power on their own; if you instead choose the driver so that its impedance is the head's minimum, people complain they're not expandable; if you do the latter but add an extension out jack wired in series it means the user will get less power if (s)he hooks up a cab to it, which would only make sense if said cab is very sensitive.
Hartke's solution is no more ideal than the others, but it has its elegance: because of the KB having a single speaker out and you having to unplug the internal woofer whenever you have to expand it, you don't risk accidentally going below the amp section's minimum impedance - unless you then hook it to two 4-ohm cabs, but then you've really asked for it! The downside, as said, is you have to carry the internal driver at all times (which is inherent in having a combo), even though it's necessarily not in use when external cabs are involved (which is instead very peculiar*). At least it's light!


*There are combos with the internal driver defeatable through a switch (the GK MB150 comes to mind), in order to give the user the option to use the head section if the internal driver doesn't cut it and the only external cabinet available is not 8-ohm but 4-ohm; this is the first time I read of a combo whose internal driver must be unplugged as a necessary condition for "expansion".
 
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