GK Neo 112 with MB Fusion/Rb700?

[JonnnyC]

Hi all,

I'm looking at swapping my GK mb212 combo as it's developed a fault, no better excuse to upgrade right?!

I'm looking for as small as possible rig ideally and love the sound of the GK combo so am looking at either a MB Fusion 500 or a GK RB 700.

The plans to use a single 12 where I can and a second 112 for gigs etc.

Question is, will a single 112 cope with either of these amps? I see people seem to do this, but both amps look around 350w at 8ohm and the 112 is 300w at 8ohm.

For reference, my GK mb 212 is 500ws through its own on board speakers, half volume and gain is the top end I push the amp.

 

[Al Kraft]

I can tell you that my MB500 and my friend's 700RB sound just fine through the NEO 112 II. Both heads sound even better with two of those cabs and the difference is more impressive than you would expect over just the one cab. Only one caution...have reasonable expectations for deep bass and big volume out of any single 112 cab, even good ones like the Neo 112 II.

 

[Wasnex]

The plans to use a single 12 where I can and a second 112 for gigs etc.

IMHO this is a pretty reasonable strategy. I have a series I GK 700RB/112 combo. I find it's barely loud enough when I play in cover band with a loud drummer. No one complains, but the speaker gets really compressed and jumps around like crazy. Turning the amp up doesn't seem to make any difference; so it is not very satisfying for me as a player. I started bringing an extension speaker for the loud gigs and always have plenty of head room. The series I amps make a bit less power, 225W at 8 ohms and 350W at 4 ohms. Series II is rated at 320W at 8 ohms and 480 at 4 ohms.

As @Al Kraft mentioned, I would exert some degree of caution with how much low end you push if you plan to max out the amp with a single 112. The latest 112 Neo is rated for 400W RMS but its fairly common for cabs to be excursion limited well below their RMS rating for frequencies under 100hz. There is only so much you can expect from a single 12" driver.

A series II 700RB and a pair of 112 Neo would be plenty for me as I don't play large venues without PA support. But there or some people who would need much more SPL. If your good with an MB212, I think a pair of 112 NEOs with either amp will be fine for your needs.

 

[JonnnyC]

If your good with an MB212, I think a pair of 112 NEOs with either amp

I want the sound to be 'full' still, but in rehearsals (mainly due to room conditions) my bass and amp are typically EQd with the bass reduced anyway.

The drummer I mainly play with uses hot rod wooden brushed for rehearsals, so a 112 may cope?

But it sounds like a 112 alone wouldn't get by on most uses then, would it be better just to get the 212 cab instead? I'm interested if the 2 112s with two tweeters would make a difference to the 212 with presumably one tweeter?

 

[Al Kraft]

I want the sound to be 'full' still, but in rehearsals (mainly due to room conditions) my bass and amp are typically EQd with the bass reduced anyway.

The drummer I mainly play with uses hot rod wooden brushed for rehearsals, so a 112 may cope?

But it sounds like a 112 alone wouldn't get by on most uses then, would it be better just to get the 212 cab instead? I'm interested if the 2 112s with two tweeters would make a difference to the 212 with presumably one tweeter?

IME the Neo 112 II cab is satisfyingly full down low and well-balanced across all frequencies. In keeping with Wasnex's advice though don't assume that feeding a single 12 more power and more bass EQ will eventually get it to the kind of low end fullness or volume you would have with a Neo 410. I have always been impressed with what two Neo 112 II's can do and suspect you'll be pleased as well.

 

[Wasnex]

I want the sound to be 'full' still, but in rehearsals (mainly due to room conditions) my bass and amp are typically EQd with the bass reduced anyway.

The drummer I mainly play with uses hot rod wooden brushed for rehearsals, so a 112 may cope?

But it sounds like a 112 alone wouldn't get by on most uses then, would it be better just to get the 212 cab instead? I'm interested if the 2 112s with two tweeters would make a difference to the 212 with presumably one tweeter?

I think there is a good chance that a single 12 will be enough if the drummer uses hot rods. The basher drummer I played with used sticks.

The 212 cab is 8 ohms, so you give up some power and flexibility versus buying a pair of 112s.

Per the spec sheet
Neo 212
Sensitivity 101dB
Impedance 8 ohms

Neo 112
Sensitivity 98dB
Impedance 8 ohms
If I understand the relationships, the sensitivity of a pair of Neo 112s would 101dB at 4 ohms...so the sensitivity evens out, but the amp develops more power because of the lower impedance.

Series II 700RB
320W at 8 ohms
480 at 4 ohms.

dB difference from 1 to 320W is 25dB. The calculated max SPL of the 212 Neo would be 126dB
dB difference from 1 to 480W is 26.8. The calculated max SPL of the pair of 112 Neos would be 127.8dB

So the 1.8dB difference doesn't really appear to be enough to be significant.

One other tidbit from the spec sheet. F3 for the 212 is 53hz and F3 for the 112 is 51hz. I would expect the 212 to sound a bit fatter although the 112 plays a bit deeper. Keep in mind this is a guess.

In the event a 212 is not enough, you could add a second 212 for a heavier lows and a bit more headroom. The 212 and 412 Neo use the same driver, and the Sensitivity of the 412 is listed as 102dB. So, I believe a pair of the 212s would give you 128.8dB calculated with 480W. That's 2.8dB over a pair of 112s, so you might notice more head room, and I think you would definitely think the low end is fuller.

So cost, convenience, flexibility, tone, and max SPL are your considerations.

Theoretically I believe a single tweeter would be considered superior, but YMMV.

 

[JonnnyC]

I think there is a good chance that a single 12 will be enough if the drummer uses hot rods. The basher drummer I played with used sticks.

The 212 cab is 8 ohms, so you give up some power and flexibility versus buying a pair of 112s.

Per the spec sheet
Neo 212
Sensitivity 101dB
Impedance 8 ohms

Neo 112
Sensitivity 98dB
Impedance 8 ohms
If I understand the relationships, the sensitivity of a pair of Neo 112s would 101dB at 4 ohms...so the sensitivity evens out, but the amp develops more power because of the lower impedance.

Series II 700RB
320W at 8 ohms
480 at 4 ohms.

dB difference from 1 to 320W is 25dB. The calculated max SPL of the 212 Neo would be 126dB
dB difference from 1 to 480W is 26.8. The calculated max SPL of the pair of 112 Neos would be 127.8dB

So the 1.8dB difference doesn't really appear to be enough to be significant.

One other tidbit from the spec sheet. F3 for the 212 is 53hz and F3 for the 112 is 51hz. I would expect the 212 to sound a bit fatter although the 112 plays a bit deeper. Keep in mind this is a guess.

In the event a 212 is not enough, you could add a second 212 for a heavier lows and a bit more headroom. The 212 and 412 Neo use the same driver, and the Sensitivity of the 412 is listed as 102dB. So, I believe a pair of the 212s would give you 128.8dB calculated with 480W. That's 2.8dB over a pair of 112s, so you might notice more head room, and I think you would definitely think the low end is fuller.

So cost, convenience, flexibility, tone, and max SPL are your considerations.

Theoretically I believe a single tweeter would be considered superior, but YMMV.

Ah, figures and the math are what I like to see!

Good to hear that even an RB 700 wouldn't cause speaker damage through a single 112 though.

Two 112s seems the way after reading your posts! I'd rather spend the bit more for the ability not to have to carry the bigger cabs every time.
Plus the fact that I can find my mb212 to be too bassy at times and I avoid 410s for the same reason after using a few previously.

Assuming that a roughly 500w amp at 4ohms would be around the same volume as my current amp, I shouldn't really need anymore than the 2 112s for what I do.

Now, just to decide on the RB or the MB Fusion.

 

[Wasnex]

Good to hear that even an RB 700 wouldn't cause speaker damage through a single 112 though.

Sorry if I miscommunicated. Judgement and restraint are advisable when running a single 112 IMHO.

Also, If you need max SPL, I would suggest using an HPF to limit frequencies that are below the cabs intended pass band.

The way a ported cabinet works is the port is tuned to start resonating as the driver starts to cut off. In a sealed cab the driver's excursion increases as the frequencies goes down. In a ported cab, the resonance of the port works against driver excursion, so the driver's excursion decreases as you approach Fb (the resonance frequency of the port). Below the port frequency, the driver's excursion increase quickly, while the output of the cab drops quickly. So sending tones below the port frequency is more likely to damage the driver and there is little benefit because the cab cannot efficiently produce sound in this range. This is where the HPF comes in.

I have attached a cab design document for you to review, so you can get an idea of how design and driver characteristics interact. Take a look at the cone displacement graphs for each design and also review the notes for each design that describe the power limits and HPF requirements. Keep in mind the Xmax (max linear excursion) for this driver is 6.2mm.

 

[Downunderwonder]

The worst that can happen is you find 112 isn't enough by itself the hard way by blowing one up.

Do you rate yourself to hear when you are blowing up a cab? Would any situation become too tragic if you had to ask them to keep it down until you bring both cabs next time?

If in doubt take both to all your future rehearsals but only plug one in. See how that goes until confident the one is enough.

You already know 212 does the job.

 

[Al Kraft]

If in doubt take both to all your future rehearsals but only plug one in. See how that goes until confident the one is enough.

You already know 212 does the job.

Excellent advice IME. I can't tell you how many times I've had a second cab spend the night in the back of car because I didn't need it. However, what I can tell you is that number is less than the number of times I brought that second cab in and was glad I had it.

No gig was ever ruined because I had too much equipment available to cover contingencies. Although I have had some rough gigs when I miscalculated and didn't have a plan B sitting in the car. If it's too hot or cold to leave your cab in the car, using two cabs and adjusting your volume control always works too.

 

[JonnnyC]

Cheers all, I'll plan to go down and try a variety of each cab - probably at Andertons when I'm able to!

 

[Clemouze]

Hi

I play with a GK MB-500 ans a Neo 112 cab and my drummer hits like a train.
Works very fine !

I also use Neo 410 which is way more deep but also midscooped.
At reaharsal standard volume the Neo 112 is easier for having nice tone. When playing stages which need big amp, no bass PA, the 410 is fine. For small bar I use neo 112, also to play at home

I use my cab with a amp stand , so closer to my ears, and also high pass filter to reduce boom !