Tag Archives: Roland Micro Cube GX

Roland Micro Cube GX speaker size

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A quick project while booting Windows…

The speaker in the Roland Micro Cube GX is just OK and I think I can do better. Roland specs claim 5 inches (12cm), but folks have tried 5 inch replacement speakers and have found the speaker hole to be too small.

Remove four screws and the grill. Watch out for the sharp edges on the back of the metal grill! The speaker itself is attached by four additional screws. The diagonal distance from screw to screw is about 4 7/8″ inches (12.5cm), give or take. The screw to screw distance along the “square” sides is about 3 3/8″ (8.5cm). The cone diameter is 4 1/4″ (11cm).

I think Roland are being optimistic here. Turns out, there’s nothing in the way of a speaker size standard. Some vendors measure the diagonal distance between screws; some measure the outer frame diameter. Yikes, you get the picture.

The most important measurement here is the cutout diameter, AKA, the speaker hole.

Remove four more screws and gently pull the speaker out. The speaker wires are relatively short, so don’t get too aggressive. The speaker lugs use spade connectors: the red wire needs a 1/4″ lug and the black wire needs a 1/8″ lug. Keep this in mind when going to the hardware store.

The cutout diameter is 4″ (10.4cm). If you bought a 5″ speaker, I can see why it didn’t fit the cutout hole. Argh! Don’t worry about mounting depth in this case — there’s plenty of room. I think I’ll buy a speaker to fit the 4″ cutout and drill new speaker mounting holes, if necessary. Increasing the size of the cutout sounds like a bear.

BTW, the Roland part number is W120FP70-00C. The speaker impedance is 4 ohms.

Taking a quick look through Parts Express, here are some candidates:

I’m looking for cutout size, decent frequency response, and reasonable cost. Why put a $100 speaker in a $120 combo amp? I favor woven fiberglass over paper and suggested use in PA line arrays. Hole alignment doesn’t matter that much. I can always drill new pilot holes.

Just in case you need to know, all of the electronics are on a single printed circuit board just below the top panel. The controls are mounted directly on the PCB (low cost). There are leads from the PCB to the speaker and the battery compartment. Lead length is trimmed quite short and there isn’t much play during disassembly.

Copyright © 2022 Paul J. Drongowski

Review: Roland Micro Cube GX for keyboard

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You’ll find plenty of rave on-line reviews for the Roland Micro Cube GX — the go-to battery-powered practice amp for guitar.You won’t find a review covering the Micro Cube GX as a portable keyboard practice amp — until now.

Here’s a quick rundown (from the Roland site):

  • Compact guitar amp with a 5 inch (12cm) custom-designed speaker
  • 3 Watt rated output power
  • Eight COSM amp tones, including the ultra-heavy EXTREME amp
  • Eight DSP effects, including HEAVY OCTAVE and dedicated DELAY/REVERB with spring emulation
  • MEMORY function for saving favorite amp and effects settings
  • i-CUBE LINK jack provides audio interfacing with Apple’s iPhone, iPad, and iPod touch
  • Free CUBE JAM app for iOS
  • Chromatic tuner built in
  • Runs on battery power (6xAA) or supplied AC adapter; carrying strap included
  • 6 pounds (2.7kg)

I haven’t tried the Roland CUBE JAM application yet, so I’ll be concentrating on the amplifier itself. The included 3.5mm cable is the usual 4 conductor affair although it’s rather short. Roland also includes the AC adapter.

I’ve been searching for a good portable, battery-powered keyboard rig for quite some time. On the keyboard side, the line-up includes Yamaha Reface YC, Yamaha SHS-500 Sonogenic and Korg MicroKorg XL+. Although the YC and Sonogenic have built-in speakers, their sound quality is decidedly inadequate and poor quality. The MicroKorg XL+ doesn’t have built-in speakers. All three keyboards have mini-keys and are battery-powered.

To this point, I’ve been using a JBL Charge 2 Bluetooth speaker.The JBL has solid bass, but its output volume is easily overwhelmed during living room jams. It’s been a good side-kick, but I found myself wanting.

Roland Micro Cube GX and Yamaha SHS-500 Sonogenic

So, the latest addition is the Roland Micro Cube GX. Without comments from fellow keyboard players, buying the GX was a risk. Guitar amps are notoriously voiced for electric (or acoustic) guitar tone. Like the GX, you’ll typically find amp and cabinet simulators that help a guitar player chase their “tone.” The GX, however, includes a “MIC” amp type in addition to the usual 3.5mm stereo AUX input. Fortunately, my intuition was correct and the “MIC” setting does not add too much coloration.

Of course, there is some compromise in sound quality. The amp puts out 3W max through a 5 inch speaker (no coaxial or separate tweeter). Needless to say, you don’t hear much high frequency “air.” The GX cabinet does have a forward-facing bass port, producing acceptable bass even with B-3 organ. No, you will not go full Keith Emerson or Jon Lord with this set-up. 🙂 I first tested the GX with Yamaha MODX and found the B-3 to be acceptable.

Volume-wise, yes, you can get loud — too loud for your bedroom or ear-health. Bass heavy sounds can get buzzy. For clean acoustic instruments, I recommend the “MIC” amp setting. The reverb is pleasant enough and adds depth to my normally dry live patches. The delay is a nice alternative to the reverb ranging from reverb-like echo to explicit (non-tempo synch’ed) repeats.

I find the Sonogenic/Micro Cube GX combination to be the most fun. The SHS-500 has DSP effects, but they are rather tentative, as if Yamaha is afraid to offend anyone. That’s where the GX makes a good companion for the Sonogenic. Feel free to dial in the Jazz Chorus amp with the jazz guitar patch or a British stack with electric guitar. Or, try any of the modulation effects on the Sonogenic’s electric piano. Working with the GX is a far more intuitive and rewarding experience than the built-in Sonogenic DSP effects. You can cover Steely Dan EP to Clapton with this rig!

I have to call out the Heavy Octave and Spring reverb effects. You’ll find them at the right-most position of the modulation (EFX) and delay/reverb knobs, respectively. You can think of them as “going up to eleven.” The spring reverb is decent and you can throw the Heavy Octave onto just about anything to thicken up the sound.

Overall build quality is good. The Micro Cube GX feels solid. A metal grill protects the speaker. The knobs have a pleasant resistance and don’t feel cheap. The only not-so-robust feature is the battery compartment and its cover. As long as you avoid heavy abuse, you should be OK.

For the money, $160USD, it’s a decent sounding, inexpensive package. Given the physical cabinet, output power and speaker size, one should adjust expectations. However, if you’re a keyboardist and need a light, portable, battery-powered amp, the Roland Micro Cube GX is worth a try.

Copyright © 2020 Paul J. Drongowski