I just found this review of the Zoom B2 Four written by a customer on that big store that sends stuff to your home. Perhaps it is of help to someone.
I’ve been getting acquainted with the new B2 Four. Even though I have a couple higher-end multi-fx with modeling, I sometimes need a simpler and inexpensive device for some gigs. Also, there is something intriguing to me about these relatively inexpensive units that punch well above their weight.
Because there is so little review info available for the B2 Four, I wanted to provide some impressions, info, and clarifications. Strap in, though, it’s a long one. I hope new & future owners find this helpful.
HARDWARE
The design and build-quality strike a good balance of durability, simplicity, and functionality. The 1/4" jacks are metal, mounted on the plastic chassis. The 3.5mm headphone & aux in jacks are not metal and not chassis-mounted. A dc power supply is included. The recessed 9V power jack is clever, but might not fit some other power cords.
The Buttons feel very solid. However, those cursor buttons are not intuitive and are difficult to use with the foot. When pressing right-most buttons, the foot blocks the display. A diamond configuration (top, bottom, left, and right) would have been much more intuitive. Also, if the buttons had carefully-designed raised shapes it would help with foot control. The functions of the 3 foot-switches depend on the current mode. In “Memory” mode, we can select from 3 consecutively numbered patches. In “Effect” mode we can enable/bypass any of three modules that are currently on-screen. There is no customization of button functions.
The expression pedal input is only for the pedal modules (i.e., no realtime control of other parameters). Though Zoom doesn’t publish this, the expression jack is designed to “see” the pot’s center lug (wiper) on the ring of the TRS plug-- as opposed to the tip. This is not standard, so you might choose an expression pedal with a switchable option (“Standard” and “Other”).
The display is bright enough, and easy to read for calling up patches (Memory mode) and Menu functions. For editing, we need to bring it up off the floor, and/or use the GL for B2 Four app.
Turning off with the power button, the display shows “Please wait… Saving Settings.” So is powering off by unplugging or power strip switch a bad idea?
ROUTING
With only 5-slots, a serial-only path, and no send-return loop; routing options are limited. Fortunately, we can place any FX in any order (within CPU constraints). The DI/XLR out and 1/4" outs are both fixed as post-FX. So both can be wet, or both can be dry, but we can’t have dry DI and wet 1/4" outs, which would have been useful. The mono input can be run through stereo reverbs and mod FX. However, if we place any mono module after a stereo module, the signal becomes mono (unless the mono modules are bypassed) This also applies to the DI model. Even if those mono modules have wet/dry mix, the dry output is always mono. So if we want to hear stereo FX, they must be placed AFTER any mono FX modules, and the DI model must be OFF.
LEVELS
The global EQ with 3 fixed bands (low/mid/high) and a master volume are helpful. However, the lack of a patch-volume setting is disappointing. This requires us to control levels using whatever level/volume controls are present in preamps, amps and fx in ways that won’t affect tone. This just means more steps. As long as we do an occasional A/B comparison of dry bass level (bypass all) with the level of the patch, we can probably stay within a reasonable range.
EQ/TONE CONTROL
Because of the multi-layer convolution, the amp/cab combos are hardwired (the IR for each amp is fixed and no user IR’s). With all the available EQ options, we have extensive tone & character shaping capabilities. The EQ modules include: a low shelf/HPF, a single-band sweepable peak/notch, and a high shelf/LPF, graphic EQs, a splitter (dual shelf), and an exciter. The parametric EQ’s are one-band-per-module, so we use up three slots to get a 3-band parametric. Some of the preamps and amps have EQs, with either fixed frequencies or just a few selections.
GENERAL SOUND
Dynamic range refers to how well a unit reproduces every level of playing from very soft to very loud-- without compressing or limiting the very loudest notes. I think the B2 Four does well with dynamics, a few preamps & amps have some sag/squish/limiting. Most of the amps and factory patches “celebrate” cabinet resonances from around 40 Hz to maybe 160Hz. It’s a hump in the low or low-mid range. Fortunately, we can reduce this hump either with preamp EQ, amp EQ, or an EQ module.
I didn’t notice any latency; except with some pitch fx.
Depending on what is in the chain, there can be varying amounts of noise. The Zoom Noise Reduction does a good job of gating it. I was playing with a env filter, and noticed the output was clipping; so I put a compressor after the filter, and it cleaned up. This implies that there is plenty of headroom within the module path, but you have to make sure to get it down to a reasonable level by the time it reaches the output stage.
THE FX
DYNAMICS:
The compressors sound good. Most are snappy enough for slap. Good range of adjustments and nice variety of options. They have much better quality and response than those on the B1 Four.
The only gate is Zoom’s Noise Reduction, but it is a very good one. To be clear, it’s a noise gate, not actual noise reduction. ZNR can be placed anywhere in the path, and set it to either detect signal from the EFXIN (whatever signal is preset at that point in the chain) or GTRIN (which is like side-chaining the dry input signal). I usually choose GTRIN. Some super high gain FX show that the input generates some noise even with no bass connected.
The Slow Attack module is disappointing. I was hoping to use this for an “arco” (bowed) effect; but because all notes have to start from zero and ramp up, it sounds unnatural. If there was a dry level then a dry attack and decay could be enhanced by a natural swell.
FILTER:
Many of the envelope followers are too sensitive, even with the sensitivity all the way down. I often don’t want the filter open all the way even when I play loud. Auto Filter is a welcome exception. The Envelope Generator filter has several modes. It snaps from Freq1 to Freq2 when the foot switch is pressed, then immediately begins gliding back to 1st frequency at the set “speed” (regardless of holding the switch).
The selections of EQ modules is good, and they are quite flexible.
DRIVE:
There’s a good selection of drive modules for different types of drive. All the drives have either a dry-level, or balance to blend in clean-- except for the TS+Boost Drive.
PREAMP:
Zoom provides a smart selection of high-end preamps with useful EQ and drive options.
MODULATION:
I love all the modulation modules; EXCEPT for Tremolo which is very limited. The triangle waveform is ok. Both the TUBE and SQUARE are clicky, and none of them sound like a proper tremolo. I’ve heard much better tremolos, even from Zoom.
Most of the pitch-shifters are barely useable. The bass polyphonic is ok for octaves. Harmony, Bass Mono Pitch Shift, and Pitch Shift are cartoonishly unusable. The other octavers seem ok, but fall apart on lower notes.
The Super Low Preamp has a lower octave, but sounds like a sine wave, where the other octavers are more square.
SYNTH:
The Bass Talk Synth is too bright/edgy, and the tone knob doesn’t begin to tame it, so it needs some filter/EG after. The Z Synth and Bass Synth are both great.
DELAYS:
The selection of delays is good. However, the only delay that has an LPF (high-damping) is the Hold Delay.
REVERBS:
The reverbs are pretty good. Ironically, Bright Hall and Bright Room are the only reverbs with a TONE control (LPF). So the two “bright” reverbs are the only ones with darkening capability.
The Air module is actually quite a nice stereo-izer when the values are cranked. When summed to mono, it sounds like a small room (but still good).
SFX:
The fretless simulator is a subtle filter effect. I wish it had a wet/dry balance. Combined a short, dark room reverb and a kind of thumpy amp, we might get fairly close to an upright pizz character.
I wish the Bomber had three modes: fart, plop, and explosion. I’d use the first two more. This was the first module I removed with the app.
PEDAL:
The pedal effects are the ONLY way to make use of the expression input.
OUTPUT VOLUME PEDAL has no settings. Toe-down, it’s whatever level is set by your master level. Heel down it’s silent. Any patches with this pedal in the chain will be immediately affected by whatever level the pedal is at. For example, if the pedal is heel down, all patches with this pedal in the chain will be silent as they load.
NOTE: All the other Pedal FX have a P before the first knob (see the FX List doc). This P knob value is the initial “pedal” value that is set when the patch is loaded. This is useful if we might not always have a pedal connected. Moving the pedal will immediately override the stored (knob) setting. Likewise, in “effect” (edit) mode, turning this first knob will temporarily override the current pedal position until the pedal is moved again.
PEDAL VOLUME has min/mix and curve A/B options-- funny how similar the letter A & B look in that display font. “A” curve increases more at the toe end (exponential), and “B” increases more at the heel end (convex).
The Bass Pedal Pitch is officially polyphonic, but it sounds pretty terrible. The Bass Pedal Mono Pitch is ok for changing the pitch of a sustaining note, especially with “Down” which just drops the pitch down to zero.
AMPS:
The selection and quality of the amp/cab combos is excellent. When they are called up, their default settings tend to be quite woofy and humpy in the lows. I did find that even with just the amp knobs, they can all be brought into a more sane spectrum. Additional fine-tuning can be done with an EQ module or two.
PATCHES
The patches don’t show off versatility, rather focusing on usable tones. There are varying degrees of drive, lots of clean tones with hyped lows or low mids. The env filters are all too wide open. Makes me wonder if they were made with/for low output basses? Fortunately any and all factory patches can be tweaked and over-written in their same ID number. If we ever want the original factory patch back, they are easily restored.
USEABILITY
FUN FACT: when we are in the FX Library (choosing a module with arrows), we are auditioning each module by itself, in isolation from what is in the rest our chain; and we can adjust knobs while in the library, so we can adjust before choosing.
In the editor, when we turn a knob the values appear, then vanish after 3 seconds. I understand why it is this way, but it is very frustrating in use. Often, I go to press the right arrow to switch pages between knobs, but I’m too slow and I end up selecting the next column of modules.
It would be a little better if Zoom added a preference setting for
Knob Display Dwell Time:
3 seconds
5 seconds
10 seconds
BUTTON EXIT (pressing the center button exits the knob-value display)
But better yet, Zoom should just use the screen real-estate differently Put the patch #/name and slot dots on top of the screen, same size, and rework the module graphics. This way knobs could just be always visible for the currently selected module.
APP
I installed the app before I bought the unit, to see if I could learn stuff just from the app, but it has no “off-line” mode, so no dice. Once my unit arrived, connecting the unit was easy enough. BTW, I have no qualms about buying the app for $1.
There are three sections:
The Effect Pool shows a full list of available FX modules (FX, amps). I don’t know if Zoom will put new FX there as they become available, but for now it is a list of all of the built-in modules with descriptions. From here we can remove some FX from our unit, or put them back. This could reduce unwanted clutter in the FX Library on the unit.
The Patch Pool is empty until we load some patches into it. As far as I can tell, we cannot remove patches from the Patch Pool. We have to uninstall and reinstall the app to clear them.
In the News Feed, there is an option to download the factory patches which puts them in our Patch Pool.
The Editor is nice because it doesn’t do the disappearing knobs trick. To change/add an FX module, choose “Change”. Then tap a slot or module. It helps to think of “blank” as a pass-thru module. Enable/bypass via the square above each module. Re-order by tapping/holding on a module then drag.
SUMMARY
I have no regrets about this purchase. I knew I’d be getting good basic FX and a versatile signal path. Gives lots of opportunities to change character, texture, tone, and response of bass. It will definitely serve the purpose I intended.
Pros: Versatile, flexible, uncomplicated. Many good and useable FX modules. 300 patch-memory locations.
Cons: No patch level setting. Knob display awkward. Some modules lack editing depth (i.e., some important parameters are missing). The Slow Attack module lacks a dry level control. The env filters have poor sensitivity range. The Tremolo is very weak, needs to be reworked. Most pitch shifters weak. Cursor buttons awkward for foot. Routing limitations. DI models prevent stereo operation, no custom button or expression assignments.
Thanks for posting it here anyway I guess 
