Test Drive: Lexicon LXP-5 and MRC

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LXP-5 and MRC Effects Processing Module & MIDI Remote Controller from Lexicon

by Jerry Vigil

Lexicon LXP-5This month's Test Drive takes a look at yet another digital effects processor, but this one is a little out of the ordinary. To begin with, the LXP-5 from Lexicon is only half the size of your basic one rack-space processor. Frankly, it's not much bigger than a college text book. The second thing that caught our eye was that there is no digital readout of any kind on the front panel. Hmmm. Then we discovered it was nominated for a TEC award for Outstanding Technical Achievement in the Signal Processing Technology category. HMMMM! Then we spotted its mate, the MRC remote control. While this remote control unit isn't necessary, it does have a display screen for the LXP-5, it offers better control over the LXP-5, and the two units together pack a MIDI punch like you've never seen.

Like many digital processors, the LXP-5 offers delays, pitch shifting, reverb, and EQ; and all of these effects can be used simultaneously, so, in effect, you get four effects at once. There are two algorithms in the unit. The first is called PITCH/DELAY. It includes the delay line, the pitch shifter, and two more effects called "ambience" and EQ. The ambience effect is simply a somewhat limited reverb effect, and the EQ is simply a lo-cut and hi-cut filter. The second algorithm is called DELAY/REVERB. This algorithm basically eliminates the pitch shifter and uses the extra processing power to provide longer delays in the delay section and longer decay times and larger "room sizes" in the reverb section. The EQ filters are also accessible in this algorithm.

The unit comes from the factory with an impressive 128 preset programs ready to use. Sixty-four of these programs are factory presets in locations that cannot be written to. The other sixty-four are stored in "user memory" and occupy half that memory, leaving space for an additional sixty-four programs of your own. The busy programmer could end up with a maximum of 192 programs in the LXP-5.

Each of these programs is accessible and programmable from the front panel controls which are reminiscent of the analog days of knobs to twist instead of buttons to push. The left half of the panel consists of an INPUT control, a MIX control for adjusting the wet/dry mix, and an OUTPUT level control. Access to these functions using knobs makes their adjustment simple and quick. The right half of the front panel is where program selection and editing are done. The knob closest to the center is used to select the various banks of factory presets and user memory banks. This control also places the LXP-5 in the EDIT mode and offers a BYPASS mode. Next to this control is the SELECT control. Once a "bank" of presets is selected, the SELECT control lets you choose one of sixteen pro-grams in the pre-selected "bank." This SELECT control is also used when editing a program. More on that later. Finally, on the far right, is the ADJUST knob. This control is attached to various parameters in each program and adjustment of such things as pitch, reverb decay time, delay times, etc. are done with this control. The only other items on the front panel are two level indicator lights in the upper left corner. One light indicates that there is input, and the other lets you know when it's too high. In the upper right corner of the panel is a LEARN light which blinks at various rates to indicate the current status of the LXP-5. Next to this LED is the LEARN button which is used to store and edit programs. It is also used to "learn" patches and select a MIDI channel when an external MIDI device is used.

Four of the preset banks accessible with the FUNCTION control are labeled PITCH, DELAY, CHORUS, and MULTI. When PITCH is selected, sixteen programs utilizing the pitch shifter become selectable by using the SELECT knob. Just about anything a pitch shifter can do is programmed for you in one of the sixteen locations.

Select the DELAY bank and sixteen programs emphasizing various types of delays are available. There are short delays, long delays, stereo delays, and a number of other delay effects.

The same goes for the CHORUS bank of programs. "But you didn't mention chorus as one of the effects," you say. Remember that chorusing and flanging are both effects created by utilizing a delay. An LFO is necessary to get the sweeping effect of a flanger or chorus and the LXP-5 has its own LFO which is adjustable.

The last of these four banks is the MULTI bank. While you might assume that this is where simultaneous effects are stored, that is somewhat misleading. Almost all of the effects in the other three banks mentioned above use more than one effect. In the case of the PITCH programs, many of them use delays and reverb. Many of the DELAY programs use reverb as well as the EQ filters. Likewise, the CHORUS programs include reverb, various delays and even the pitch shifter. The MULTI bank of programs is more a collection of odd effects using various combinations of all the effects available.


The sixty-four programs in these four banks are stored in read-only memory. An additional sixty-four different programs are stored in user RAM in four of the eight USER banks selectable from the FUNCTION knob. All 128 of these programs have parameters (as many as five) that have been "pre-attached" to the ADJUST knob which, like the SELECT knob, has sixteen positions. So, with the twist of the ADJUST knob you get sixteen variations of each of the 128 factory programs. That comes to 2,048 different effects available from the LXP-5 right out of the box. Of course, if you count the various parameter settings of other digital processors, one can say they have thousands or even an infinite number of effects; but what is special about the LXP-5 is that these 2,048 various effects can be accessed by turning only three knobs. This makes programming and editing programs in the LXP-5 practically un-necessary. Just about every conceivable and useful combination of effects and parameter settings has been done for you.

Now, if you want to edit a program, this is where the LXP-5 is a little stranger than most digital processors. You don't have a screen to display which parameter you have selected for editing. Instead, there are three EDIT positions on the FUNCTION switch. Two of these three EDIT positions (A and B) give you access to twenty-eight parameters which are selected using the SELECT knob. The third EDIT position (C) is used to create MIDI patches which we'll touch on later. The FUNCTION and SELECT knobs are used to select a parameter, and its value is changed with the ADJUST knob. When you're happy with the setting, the LEARN button will store the new program in one of the 128 user memory locations. Since there is no screen to indicate which parameter is selected, you must keep the LXP-5's very handy reference card nearby. It tells where each of the parameters are.

The EDIT C position of the FUNCTION switch is where we come to the aspect of the LXP-5 that probably is responsible for its nomination for a TEC award for Outstanding Technical Achievement. The possible MIDI applications of the LXP-5 are more extensive than any we've seen on any other digital processor. It would easily take two pages to get into even a little detail. The EDIT C position of the FUNCTION knob accesses the LXP-5's ability to write "patches" so that any of the unit's parameters can be controlled by an external MIDI controller. While external MIDI control of processor parameters is not uncommon on many other processors, other available MIDI functions include things only the most intense MIDI user would have use for. If you're a MIDI enthusiast, you won't have any limitations with the LXP-5.

Lexicon MRCBeing on the subject of MIDI brings us to the MRC remote control box, the other part of this review. This remote control doesn't connect to the LXP-5 with a special remote control cable. The connection is made with any MIDI cable, and communication is done using MIDI messages.

The MRC provides the familiar LCD display we've grown accustomed to seeing on our digital processors. With the MRC, the LXP-5 itself can be stashed in your desk drawer. All programs in the LXP-5 are numbered. Selection of a program is done by entering the number on the numerical keypad of the MRC and hitting ENTER. MIDI program change data is sent to the LXP-5 and the program is selected. An EDIT button on the MRC takes you into the parameters of the program. The screen shows you which parameters are available for adjustment and a PAGE button lets you page through the parameters in groups of four. Below the LCD screen are four sliders and four buttons which are called switches. The switches and sliders are used to make adjustments to their respective parameters, and adjustment with the sliders is very fast. This is a definite advantage over other processors where you have to hold a button down for ten seconds to go from one extreme to another.

The MRC also has its own memory for storing sixty-four user "setups" for the LXP-5. These setups are simply more programs for the LXP-5. The difference is that they are stored in the MRC. The MRC comes with thirty-two pre-programmed setups in locations one through thirty-two. The remaining locations are empty and available for storage of your own creations. The setups are accessed by pushing the SETUP button then entering the number of the desired setup with the numerical keypad, the sliders, or the switches on the MRC.


Parameter adjustment and program control of the LXP-5 with the MRC is straight forward and easy to get acquainted with, but there is much more to the MRC. In fact, the manual for the MRC is considerably thicker than the manual for the LXP-5. The MRC (Version 3.0) provides four basic modes of operation. The modes are referred to as "machines." One of these modes is for the LXP-5. Another is for Lexicon's LXP-1 processor. The third is set up to control Lexicon's PCM-70 effects processor; and the fourth is the GMIDI machine mode. The MRC is capable of controlling up to sixteen "machines," but these machines don't have to be Lexicon products. The GMIDI machine mode is a general purpose MIDI controller which can be used to hook your synthesizer(s) up to the MRC. You can hook your sampler up to it. You can hook any MIDI capable digital processor to it. Whatever the device is, if it can receive MIDI messages, the MRC can send them to it. (Cont. on page 17) The four sliders and four switches on the MRC can be assigned to any available parameters desired. We hooked the MRC up to an Ensoniq synthesizer and the Eventide H3000 and realized a person would have to live with the setup for a couple of months to really explore the possibilities. What is most impressive and applicable to radio production is the ease with which any parameters can be adjusted with the sliders on the MRC. Not only is parameter adjustment fast and easy, but you can control several parameters simultaneously.

The MRC, like the LXP-5, is designed to fully implement the power of MIDI and is capable of MIDI functions even the most MIDI-ized radio producer will probably never use.

Getting back to the LXP-5, here are some specs worth noting. There are two inputs and two outputs, but there is only one processing chain. Therefore, you don't get true stereo processing, but you do get stereo effects. This is typical of most processors in the price range of the LXP-5. Inputs and outputs are unbalanced. The sampling frequency of the unit is 31.25kHz which means the frequency response of the "wet" effects is 20Hz to 15kHz -- not a nice 20 to 20K, but easily apropos for broadcast purposes. Audio connections are all ¼-inch phone jacks. The unit is rack mountable and occupies half of a standard rack space. Two LXP-5's side by side fill one rack space. List price on the LXP-5 is $549. The ticket on the MRC is $399.

The LXP-5 is a nice box for the production room. The 128 factory presets provide ample effects without having to get into the more complex task of programming your own. The programs themselves are easy to select and the ADJUST knob, pre-assigned to various parameters, makes altering selected programs as simple as the twist of a knob, therefore eliminating the steps of entering edit modes, selecting parameters, and pressing "value" buttons to change an effect, as is the case with many other processors in this class. Add the MRC to the package and you get, not only better control over the LXP-5, but a remote control for your other MIDI capable processors as well, not to mention applications involving samplers and synths.

It's a fun box and we wish Lexicon the best in the upcoming TEC awards. The competition will be tough, however. In the category of Signal Processing Technology, the LXP-5 is up against ART's SGE Mach II, the Alesis MIDIverb III, the Bedini BASE, DigiTech's MEQ Dual14 MIDI Programmable Equalizer, and Eventide's H3000SE Ultra-Harmonizer. Whew! For more info on the LXP-5 and the MRC, contact Lexicon in Waltham, Mass. at 617-891-6790. ♦

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