Features/In Use

At the heart of the MPX-1 are two separate DSP processors. The first is the “Lexichip” which is devoted solely to reverbs and ambience algorithms. The other processor is a fast-math DSP chip that handles the other effects. Reverbs are notorious for “eating” DSP power. In single DSP processors, reverb quality if often sacrificed to “make room” for the other multi-effects. Lexicon gets around this problem by using the Lexichip. As for the effects in the fast-math chip, there are 5 types including chorus, equalization, pitch shifting, modulation and delay.

Another significant feature in the MPX-1 is the ability to reconfigure the audio paths of the effects blocks. For example, a chorus can be fed into a reverb or the reverb into a chorus, etc. This reconfiguration is accomplished with the “routing map.” Within this section, a graphic display shows the routings and connections between the effects blocks. There is a ton of flexibility, however expect to spend time getting it straight. Also, not more than one type of the same effect can be used at once. For example, a chorus can not be fed into a flange. And yes, it is possible to exceed the processing limits of the MPX-1.

The first preset “MPX Blue” illustrates the power of this machine. There are 6 simultaneous effects blocks being processed, split-path routings and 5 patches to internal controllers. And any of the data from the continuous controllers can be routed to a sequencer via MIDI for future recall. By the way, “MPX Blue” is a gorgeous preset - a good show stopper for anyone auditioning the unit!

While Lexicon is not a company with a history of user-friendly interfaces, the MPX-1 is a different story. This box is designed to make editing a breeze. Unique on the front panel are 9 backlit buttons. Six of these buttons correspond to each of the effects. With the “MPX Blue” preset, all six buttons are lit. This indicates that all effects are in use. Hit a button to turn the effect on or off. While in “edit” mode, hitting one of these buttons goes into that effect’s parameters. The other three remaining buttons handle mix, controller patching and bypass. This kind of architecture makes a lot of sense.

Also on the front panel are 8 other buttons. As opposed to the backlit ones, these buttons are hard plastic with a somewhat “wobbly” feel. They initiate utilitarian chores like cursor control, parameter editing, program select, global system controls and save commands. If one of these buttons is pushed long enough, a help message appears. For the display, the MPX-1 has a two line LCD and a large numerical LED.

Another new feature on the front panel is the A/B button. This allows the user to morph between selected parameter settings in a preset. Try setting the A parameter to a slow chorus and the B parameter to a fast chorus. While in “edit” mode, select the rate of change. When the A/B button is hit, the parameters will glide between the two settings. Very, very interesting. Lastly, the MPX-1 has a button for tap tempos. This is used to tap in delay times in lieu of menu editing.

Flip the box around and there will be two foot controller inputs, MIDI connectors, a +4/-10 dB button, audio inputs and outputs. The audio connections are both 1/4 inch and XLR. The 1/4 inch connectors can handle either balanced or unbalanced signals. Also present are a pair of digital S/PDIF I/O (44.1 kHz sample rate only). I have a feeling that digital connectors will be standard fare on most “serious” processors from now on. And depending upon which effects are in use, the MPX-1 provides 16 to 32 bit processing, 18-bit A/D and 20 bit D/A conversion.

Within the six different effects types, the MPX-1 provides a total of 57 blocks. There are numerous choices available. For example, within the chorus effect, there are flanges, phasers, rotary cabinet and other esoteric stuff like aerosol, orbits and centrifuge. Pitch shifting includes fine detunings, transpositions, volume control and even a test tone. The equalization section includes high and low cut, high and low shelf, bandpass/notch, parametric, sweep filters, wah-wah, frequency crossovers and much more. Delays have echoes, looper and ducker. In the modulation blocks are several panners, tremolos, overdrive and more volume controls. Finally, there are five different types of reverbs. The choices include chamber, hall, plate, gate and ambience. Each block is totally independent with its own mix, level and bypass controls. And many of the effects are available in both mono and stereo.

The MPX-1 ships with 250 memory locations - 200 factory presets and 50 user presets. By utilizing the built-in database, the MPX-1 can sort preset categories into “acoustic,” “drums,” “guitars,” “keyboard,” “live PA,” “tempo,” “sound FX,” and “vocal.” However, user defined categories are not supported.

Sonically, the MPX-1’s forte is the reverb quality. They are thick and rich with no sense of graininess. The other 5 multi-effects are strong and will hold their own in any situation. Also, the MPX-1 has very good imagery with plenty of sonic detail.

Interesting presets include “ChrsRvbMorph.” Here the input level controls the amount of morphing between a stereo chorus and a plate reverb. “MIDI Arp1” uses the MPX-1’s arpeggiator function. By utilizing MIDI with a keyboard, the MPX-1 will arpeggiate two or more notes. And on “S/H Pitch,” the pitch shifter is controlled by the sample-and-hold generator. This creates semi-random angular melodies. Also interesting are several dual mono presets. One has a pitch shifter on one channel and a reverb on the other. Another interesting preset utilizes a dual tap delay. Each channel has a separate delay with different rhythms, feedback and damping controls.

Summary

While the MPX-1 is easy to use, there is a lot of depth for those who wish to dig-in. The menu hierarchy is quite extensive, so keep the manual’s menu-diagram handy. Speaking of which, the manual is very good. Unfortunately, there is no index.

The MPX-1 fits squarely in-between the LXP and the PCM series - a good move on Lexicon’s part. This is an excellent piece of gear for any project studio, live rig or even a pro facility. At $1299, it is priced right. And it has plenty of amenities found only on much more expensive gear. But the good news it that the MPX-1 does a lot of tricks that no other Lexicon does. You can’t beat that.

At-A-Glance

Applications: Live studio, studios
Key Features: Dual chip archetecture, flexible effects routing system, digital connectors, A/B morph button, arpeggiator, preset database
Price: $1299