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Alesis MidiVerb IV

Multi-effects Processor By Paul White
Published February 1995

Alesis' Midiverb was a big hit with cost‑conscious studio musicians when it was first launched back in the mid '80s. Now Paul White assesses whether the Midiverb 4 is still first among sequels...

With so much of Alesis' R&D effort going into ADAT, it looked as though my original Quadraverb was going to be old enough to vote before it was replaced — then the Quadraverb 2 came along. But it was immediately evident that something simpler must follow to address the more cost‑sensitive end of the market, and that's exactly what's happened with the Midiverb 4.

It isn't as easy to get excited about effects units as it was a decade or so ago, but the Midiverb 4 has an immediacy and quality about it that makes you want to sit and play with it — which is exactly what I did. On the whole, I liked what I heard.

You can see from the styling of the 1U package that it is logically set out and benefits from a large display window which, although not as fancy as that of the Quadraverb 2, handles the necessary patch and edit information very clearly. Power comes from the ubiquitous external PSU, and the audio connections are on unbalanced jacks at a nominal ‑10dBV level, but with sufficient headroom and range to handle a maximum level of +10dBV. The two inputs and two outputs can be deployed in a number of ways depending on the effects configuration selected: the usual mono‑in, stereo‑out way of working is obviously supported, but you can also work stereo‑in, stereo‑out or use the two channels to create independent mono effects. Other subtle series and parallel effects connections are possible with up to three different effects per patch, though the majority of options provide just one or two effects at a time.

Technically, the Midiverb 4 is quite sophisticated, employing oversampling, 18‑bit converters and internal 24‑bit processing to yield a dynamic range in excess of 90dB over a 20Hz to 20kHz frequency range — a far cry from the original 12‑bit Midiverb with its 10kHz bandwidth. The internal patch memory provides 127 (plus bypass) presets and 128 user memory locations, which may be called up directly from the front panel using the Value knob or via MIDI. Patches may also be incremented using an optional footswitch.

In order to provide access to both user and preset patches over MIDI, the familiar assignment table facility is provided, where you can map any 128 of the internal patches (both user and preset) to MIDI Program Change numbers. You can also control up to two effects parameters in real time over MIDI, the actual parameters depending on the Configuration (algorithm) used.

Auto Sensing

It seems as though Alesis have gone out of their way to make the Midiverb 4 as easy to use as possible; one notable example of this is Auto Level Sensing. I've been pushing this concept for over five years now, but this is the first time I've actually seen it put into practice. Instead of setting up the input level manually, you just put the system into Learn mode (in this case by pressing the Input and Output buttons at the same time), and then feed the input with the signal you wish to process. The unit 'listens' to the input for around five seconds (or longer if you use a footswitch), notes the peak level and then sets the gain structure for you automatically. Of course you can still take the craftsman approach and do it manually, and in this case, there are separate VU meters built into the display for the left and right inputs. There are no physical input and output level knobs — it's all done in software — but because the editing system is so simple (just hit the Input button and twiddle), this presents no problem at all.

Effects Hierarchy

Like the original Quadraverb, the effects and effect combinations are based on Configurations — preset algorithms which determine which effects are used in a patch and how they are connected. There are 32 different configurations in all, and the last 32 preset patches employ each of the configurations, so that they can be copied and used as the basis for new patches.

The Configurations fall into four basic types:

  • Single
  • Double
  • Dual Mono
  • Multi Chain

Single Configurations include: mono‑in, mono‑out; mono‑in, stereo out; and stereo‑in, stereo out; while Double provides a pair of mono‑in, stereo‑out effects working in parallel. Dual Mono can provide either two independent mono‑in, mono out effects or two mono effects wired in series, with the left output taking the output from effect 1, and the right output taking the output from effect 2. Multi Chain, as might be expected, is where the multiple effects reside; each effect in the chain is driven from a mono signal but contributes a stereo output to the effects mix (unless a mono effect is specified). The contribution of the individual effects to the final mix may be adjusted, as well as the effect parameters themselves.

The basic effects comprise reverb, delay and pitch, where pitch covers all the usual modulated delay treatments, as well as pitch shifting, pan and Leslie simulation. Delays come in both mono, stereo and multi‑tapped versions (up to three taps) and with a maximum delay time of 1300mS. Delay times can be entered on the fly using a tap‑tempo facility, and there's also the option to specify a delay by tempo and note length. A nice touch is the inclusion of basic delay filtering — both high and low cut — which makes it possible to emulate tape echoes.

Some of the reverbs are very processor intensive, so can only be used on their own, while others are designed to be used in multiple effect chains, but because all the effects Configurations are ready defined (as opposed to 'roll‑your‑own', as in the Q2), there's no way to get confused over what you can and can't use together.

Most of the effects should be familiar enough, though there are one or two neat twists, such as simulated 'through‑zero‑flanging'. This is achieved by delaying the normally clean part of the signal slightly to emulate tape flanging, which occurs when two tape machines carrying copies of the same tape are played slightly out of sync. The Leslie effect includes the speed change parameters of its namesake, and these may be triggered from keyboard aftertouch or any other convenient MIDI source. The speed ramps up and down to simulate the inertia of the real thing (rather than switching abruptly), which makes it quite convincing when used properly.

A footswitch socket is included on the rear of the case, and this may be set to perform one of several operations: it can be used to advance through the program numbers, to act as a bypass switch or to enter tap tempo information for setting delay times. If the pedal is pressed and held down in Tap Tempo mode, you can enter tempo information via the audio input using any percussive sound — damped guitar, bass, drum sound and so on. Furthermore, when Control Mode is selected, the footswitch may be used to change the Leslie effect speed.

The Driving Seat

Working with the Midiverb 4 is made very easy, both by the operating system and by the fact that you aren't faced with too many parameters. To create a new patch, you must first copy an existing patch that uses the Configuration you want, after which you simply dive in and change the parameters to suit your needs. As you can see from the photograph, the control panel comprises just 10 large buttons, which light up in green when operated, and a Value wheel. Hitting Edit puts you into Edit mode, whereupon you're confronted by a screen (called a page) containing up to four parameters. There's no need to mess about with cursor keys here — the A,B,C and D buttons take you directly to the parameter of your choice, whereupon the wheel is used to modify the value.

For effects that need more than one page of information, hitting the Edit key again will scroll through the various pages. To make life easier, the effects mix level is always to the left of the last page so you know exactly where to look for it. A further nice touch is that you can also do a 'dry defeat', to kill the dry component of all relevant patches — great for when you want to use the Midiverb 4 in a mixer send/return loop.

Navigating edit mode is really so simple that you probably won't need to look into the manual very often, other than to see how the Configurations actually look on paper, but just to make sure you feel thoroughly looked after, pressing any parameter button for more than a second or so will display a more detailed description of that parameter on screen — a kind of on‑line help system. To make setting delay times easier, the screen displays longer delay times as three parameters — hundreds, tens and units. These can be edited separately, which makes it very fast to set up a new time, and it's certainly more attractive than having to hold down a single button while the display scrolls from 1mS to 1300mS in 1mS steps. All the user patches can be named, and a compare feature allows you to switch back and forth between a patch and its newly‑edited version to make sure that it really is an improvement.

Listening Test

Though none of the available effects could be described as new, the overall quality offered by the Midiverb 4 is extremely high. The reverbs might not be quite as lush and dense as those provided by the Q2, but they are definitely better than on the original Quadraverb, as well as being significantly quieter. The chorus and flange effects are amongst the best I've heard from any processor, and for once, the flanging gets very close to having the depth of a good analogue flanger, which should be good news for all those who still bang on about the old Electric Mistress. Incidentally, did you know that Hhad a rival model called the Clockwork Concubine? Flanging algorithms have a nasty habit of overloading, but these also seem far less prone to breaking up than on my old Quadraverb.

In addition to the usual chorus effects, there is a Quad Chorus patch which is seriously lush — and each of the four elements has its own Pre‑delay time, which enables you to modify the rhythmic component of the effect. Inevitably, the pitch shifter doesn't overcome the problem of 'lumpiness', which afflicts all low‑cost pitch shifters, so this is best used either for detuning or for special effects. If you must use it musically, it's best to make sure it's mixed low behind other effects.


If you're the kind of user who wants access to quality 'bread‑and‑butter' effects but without having to devote large amounts of time to programming, then you probably needn't look further than the Midiverb 4. It doesn't have the fire‑power to create some of the more dramatic Quadraverb‑type effects, notably because of the lack of serious EQ, but what it does do, it does exceedingly well.

The operating system is a real joy to use and all the effects have a great sense of warmth and space. Patch switching is very fast (though on the review unit I felt the changeover could have been a little smoother), and I was particularly pleased at the low level of background noise on all the patches, flanging included. The automatic level setting feature is a very welcome addition for those who still believe that gain structure is just something that happens to other people, and the large, clearly marked buttons and generous display make the whole interface more welcoming than on many competing units. Admittedly, the Midiverb 4 may not break any new ground in the effects department, but it does provide exactly the right blend of features, quality and cost to win it a lot of friends. I already have a fairly full processor rack, but I could easily justify adding one of these.


The Midiverb 4 is equipped with a MIDI In socket and a MIDI Out/Thru, the latter of which is used to send SysEx dumps (either all 128 user patches or the patch assignment table) or program change commands. MIDI Out/Thru also passes on any information received at the MIDI In socket if MIDI Thru is enabled in the Utility edit menu. Each of the 32 configurations includes two parameters which may be mapped to MIDI controllers; the choice of controllers includes Pitch Bend, Aftertouch, Note Number, Velocity or any controller number in the range 000 to 119. The Midiverb 4 can be set up to work on any MIDI channel.


  • Concert Hall
  • Real Room
  • Ambience
  • Plate Reverb
  • Reverse Reverb
  • Mono Delay
  • Stereo Delay
  • Ping Pong Delay
  • Multi Tap Delay
  • BPM Mono Delay
  • Delay:Delay
  • Mono Chorus
  • Stereo Chorus
  • Quad Chorus
  • Chorus:Chorus
  • Stereo Flange
  • Flange:Flange
  • Lezlie>Room
  • Stereo pitch Shift
  • Pitch:Pitch
  • Auto Pan
  • Delay>Real Room
  • Chorus>Real Room
  • Flange>Real Room
  • Real Room>Flange
  • Chorus>Delay>Room
  • Flange>Delay>Room
  • Real Room + Delay
  • Real Room+Chorus
  • Real Room+Flange
  • Chorus:Delay
  • Flange:Delay
  • Pitch:Delay


  • Extremely user friendly.
  • Quiet.
  • Effects generally work well on a subjective as well as technical level.
  • Auto Level Sensing system automates setting correct gain.


  • Limited number of simultaneous effects.
  • Patch switching not as smooth as it could be if a signal is present at the input.


A competent, friendly all‑rounder that is best suited to producing a limited number of simultaneous effects to a high standard. Should appeal both to the home studio operator and to the more professional user looking for a second or general‑purpose device.