GK MB115 questions

[jsanchey]

I've had this GK MB115 about a year. I need to understand it better. It's too complicated for me.

For example, the "Low Mid" dial states the following: "Boost and cut at 250Hz. A “Q
optimized” band pass type, effects the main body
of your sound..."
Can someone please explain this to me in simpler terms. How can something "boost and cut'' and what is 250Hz and what is Q optimized.
I'm tired of pressing buttons and twisting dials on this thing. It all sounds pretty much the same, anyways.

And, also, the horn hisses noticably loud (which the service center says is normal) Any thoughts here?:
Thanks in advance for your assistance.

[will33]

In a eq like that, having the knob centered, 12:00 if thinking of a clock face should have no effect. Boosting is to turn it up, that adds more of that frequency range. Cut is to turn it down, takes away that frequency range.

On a 4 knob tone section like the GK you can think of the bass knob as deep, low bass. The lowmid knob as the body or thickness of your sound. The highmid knob as definition/clarity or going the other way twang/clank/honk. The treble knob as high treble, air/crispness/snap.

Start with them all in the middle at moderate volume, then turn each one all the way back and forth and hear how it affects the sound. Put that one back in the middle and do the same with the next one and so on.

At high volume using a lot of bass boost can damage speakers. When playing alone, it sounds good to turn the bass up and the mids down. When playing with a band that sound usually creates mud and gets you lost in the mix. With a band it's usually best to use a little more mids and less bass, or closer to even on the knobs. It sits better with the other instruments.

[jsanchey]

Thanks Will33

I've been experimenting with the controls as you said and am closing in on my sound. I didn't realize the 12 oclock position was the "no effect" . I thought that was 50 percent effect, so your comments have been extremely helpful.
J

[Joe Louvar]

Start with all the EQ knobs set to the12 o’clock position (flat) and tweak as needed. I have two MB115’s that I drive with a preamp/compressor and I usually run my MB115s close to flat with the contour off, horns and limiters on, and use my bass guitar tone to roll off highs when needed.

[will33]

That's the way it is on lot of amps. The "fender tonestack" is a different animal but don't worry about that until you've got this one figured out or you have an amp that uses one.

Nearly all amps also have a "baked in voicing" meaning that all knobs at noon doesn't mean "flat" if you were to see it on a graph but don't worry about that now either. Just turn yours until you get a sound you like.

[scottfeldstein]

Slightly off topic, but here's another bit of novice EQ advice:

Cutting the mids back (or boosting lows and highs--same thing) may give you the sound of your dreams while you're at home practicing, listening to nothing but yourself. This kind of EQ setting is called "scooped," meaning the mids have been scooped out.

Most EQ ninjas agree, however, that a scooped setting does not work as well in a live band situation. Your instrument will tend to "disappear." This will cause you to turn the volume up higher than you normally would do--sometimes so high as to reach the limits of what your amp/speakers can accommodate. To make your instrument "reappear" at lower volumes, bring back some of the mids. In fact, may bass players run just the opposite of scooped: cut back the lows and highs, boost the mids. It helps you cut through the mix like buttah.

NOTE: the "contour" knob on your amp is essentially a scooper. The higher you twist it, the more it removes mids and boosts highs/lows. I never touch mine. I'd like to rename it the "disappear" knob, because the higher you turn it the less you'll hear yourself.

I have a GK MB500. I used to have the GK MB210 combo. These are very similar to your MB115. I run that EQ kind of like this:

highs 10 AM, low-mids 2 PM, high-mids 2 PM, lows 10 AM

Your mileage may vary.

[JonnyAngle]

Originally Posted by scottfeldstein

Slightly off topic, but here's another bit of novice EQ advice:

Cutting the mids back (or boosting lows and highs--same thing) may give you the sound of your dreams while you're at home practicing, listening to nothing but yourself. This kind of EQ setting is called "scooped," meaning the mids have been scooped out.

Most EQ ninjas agree, however, that a scooped setting does not work as well in a live band situation. Your instrument will tend to "disappear." This will cause you to turn the volume up higher than you normally would do--sometimes so high as to reach the limits of what your amp/speakers can accommodate. To make your instrument "reappear" at lower volumes, bring back some of the mids. In fact, may bass players run just the opposite of scooped: cut back the lows and highs, boost the mids. It helps you cut through the mix like buttah.

NOTE: the "contour" knob on your amp is essentially a scooper. The higher you twist it, the more it removes mids and boosts highs/lows. I never touch mine. I'd like to rename it the "disappear" knob, because the higher you turn it the less you'll hear yourself.

I have a GK MB500. I used to have the GK MB210 combo. These are very similar to your MB115. I run that EQ kind of like this:

highs 10 AM, low-mids 2 PM, high-mids 2 PM, lows 10 AM

Your mileage may vary.

This is very good advice. I, however, like to keep my amp's knobs around noon and adjust the eq on my bass. This is essentially the same thing as above, just a different way of doing it.

[scottfeldstein]

True. I could, too. In fact, my Ibanez SR300 has a mid cut/boost contour knob on it. I could easily use that while playing. I'm just too lazy to fiddle with my EQ while playing, no matter where it is. I'm a set it forget it guy.

[craig.p]

Originally Posted by jsanchey

I didn't realize the 12 oclock position was the "no effect".

It's not. Some months ago, I think it was Fdeck who published what "no effect" is on an MB200. I have no reason to believe it's significantly different on your amp:

Contour: off
Treble: 10 o'clock
Hi Mid: 2 o'clock
Lo Mid: 1 o'clock
Bass: 10 o'clock

With all your tone knobs centered, you've got about 10dB of bass boost centered at 60 Hz and about 9 dB of treble boost at about 9 KHz. Flat that sure ain't. In fact, that tone setting is way across the county line from flat.

Start with the above settings and work from there.

[scottfeldstein]

Wow, that's pretty much exactly how I run mine! Who knew that was flat? Well, apparently some folks did, but I didn't.

[craig.p]

Don't feel bad, I didn't either, until Fdeck posted that info. (I hope I'm giving credit to the right person.) But anyway, that 10/2/1/10 setting is the trick for me, too, when I use either the MB200 or the BL600 with my Avatar cabs, which go pretty deep and seem flat on the way down. With "nominal flat" (12/12/12/12, which is majorly scooped) they sound like W.C. Fields -- big, fat, slow, and tubby. First time I tried 10/2/1/10, those big cabs suddenly slotted right in. It was just what I was looking for.

[scottfeldstein]

Even with these settings, the Ampeg 810 sounds like being hit in the head with a mattress wrapped around an anvil. Big punch, kind of featureless otherwise. They sound great, kind of hi-fi even, through my GK cabs.

[Joe Louvar]

Originally Posted by scottfeldstein

I'd like to rename it the "disappear" knob

lol, +1

[Bredian]

Thanks for the advice on the contour knob.

Active P Lyte - run the tone knobs on the instrument full 10 typically, sometimes roll off and move 100% to the neck pup for the softer sound. (passive Hoffner completely opposite eq set up when I use)

Amp Eq typically 3-5 oclock treble, hi mids at 2-3, low mids 1-2, bass 10-11.

Most of the time, the 15" produces a ton of volume on my low e notes, but I like to get some balance and visibility above the 12th fret on the g string. Using the horn. My kid says the "boost" was killing off some of the highs.

[jsanchey]

Originally Posted by scottfeldstein

Slightly off topic, but here's another bit of novice EQ advice:

Cutting the mids back (or boosting lows and highs--same thing) may give you the sound of your dreams while you're at home practicing, listening to nothing but yourself. This kind of EQ setting is called "scooped," meaning the mids have been scooped out.

Most EQ ninjas agree, however, that a scooped setting does not work as well in a live band situation. Your instrument will tend to "disappear." This will cause you to turn the volume up higher than you normally would do--sometimes so high as to reach the limits of what your amp/speakers can accommodate. To make your instrument "reappear" at lower volumes, bring back some of the mids. In fact, may bass players run just the opposite of scooped: cut back the lows and highs, boost the mids. It helps you cut through the mix like buttah.

NOTE: the "contour" knob on your amp is essentially a scooper. The higher you twist it, the more it removes mids and boosts highs/lows. I never touch mine. I'd like to rename it the "disappear" knob, because the higher you turn it the less you'll hear yourself.

I have a GK MB500. I used to have the GK MB210 combo. These are very similar to your MB115. I run that EQ kind of like this:

highs 10 AM, low-mids 2 PM, high-mids 2 PM, lows 10 AM

Your mileage may vary.

Thanks very much. I've tried your settings, along with contour off (which I suspected was my problem all along) and now the amp has a decent tone. Horn still buzzes a little, though.

[Joe Louvar]

Originally Posted by jsanchey

Horn still buzzes a little, though.

Hmm, that shouldn't happen - maybe try turning the horn off and see if you like it that way better.

EDIT:
BTW, do you have a newer or older GK MB115 (the newer ones have a little fan and vent on the back - the old older ones don’t)?

[Joe Louvar]

another thing that should be taken into consideration is the room - for example, sometimes the room or something in the room is vibrating and rattling (IE windows, etc).