This article was published in the June 1988 edition of Transoniq Hacker, the independent user's newsletter for Ensoniq products. Transoniq Hacker, 1402 SW Upland Drive, Portland, OR 97221 USA Editor Jane Talisman, (503) 227-6848 Subscriptions $14 in US.

A NEW CHOIR

Programming techniques for the Ensoniq Mirage Digital Sampling Keyboard/Module

I use a lot of voice sound in my music, often as a wash of sound that fades up and down like strings. One of my favorite Mirage sounds are the choirs which are found on factory disk #7. I've made a few adjustments to the samples which I'll describe step by step.

I've made several changes to the Mirage choirs. I've put Choir #3 on the lower half of the keyboard and Choir 1/Choir 2 on the top half. I've copied program variation #2, with its longer release time, onto program variation #1, so that it will be the way the sound appears when it is loaded. I've increased the overall amplitude and filter touch sensitivities to enhance accents, create the effective illusion of distant soft voices at low velocity values, and to bring out voice leading in contrapuntal passages.

The necessary ingredients are Ensoniq Sound Disk #7, a copy of MASOS, and a blank formatted "work" diskette. Boot up with MASOS and load the Choir samples.

If you don't have any of these ingredients, (and today such long discontinued items may be hard to find) skip to the end section, "PROGRAM MODIFICATIONS", and try the techniques on some of your own sounds to make them more responsive to your touch. You can also order the "NEW CHOIR" Mirage Disk (with two other modified factory sounds) for $12.50 postpaid from: Electronic Artist, 981 Shepard Avenue, North Brunswick, NJ 08902-2252.

MOVING THE SOUNDS AROUND

First let's move the Choirs around so that the basses and tenors join Choir #3 and the altos and sopranos shift over to Choirs #1 and #2. Men to the left, Ladies to the right. Persuading them to do so in the Mirage involves swapping the contents of the two 64K Ram memory banks that make up the Mirage's Upper and Lower keyboard halves.

On page 26 of the Ensoniq Advanced Sampler's Guide is a description of MASOS Parameters 17 and 18 which are used to move sounds between the upper and lower keyboard halves. This is complicated by the necessity of discovering which wavesample or wavesamples out of a possible 8 per keyboard half (16 total) is producing the sound we wish to change or move. Many full-featured Visual Editing Systems make this very easy. The Mirage alone without a friendly external translating computer is often quite a bit more inscrutable. For help here we use Parameter 67, which changes the wavesample's pitch by octaves, as a very obvious audible change that can be used as a test of where we are in the Mirage's memory.

MOVING THE LOWER CHORUS TO THE UPPER KEYBOARD

Select the Lower keyboard half program variation one (display reads L1). Select Parameter 67 and press the adjacent Value button (display reads 0.4). While holding down a key in the lower keyboard half, change the value of Parameter 67. Nothing happens! This means what we are not altering the wavesample that is producing the sound we are playing. Go to Wavesample Select Parameter 26. Its value should be 0.1, telling us that we are working with wavesample #1 on the lower keyboard half. Advance this parameter to value 0.2, go back to Parameter 67, and see if changing its value effects the sound. Still no effect. Fortunately, there are only eight possibilities on each keyboard half. Advance Parameter 26 to 0.3, and you will find Parameter 67 suddenly becomes very powerful, changing the pitch of the entire lower half by octaves. We have now determined through this test that the sound of the lower keyboard half is being produced entirely by lower wavesample #3.

Now that Parameter 26 is set to 0.3, the correct place in the Mirage's memory, we can now move that sound to the upper half of the keyboard. Select Parameter 18, Copy Current Wavesample to Upper. The display will read UC with the C flashing. Press button 1, and then press Enter. We have moved lower wavesample #3 to upper wavesample #1, so that the sound of the lower keyboard half will now be repeated on the upper half. Take the blank formatted diskette and insert in into the Mirage's drive. Use Parameter 12 to save the upper keyboard half to the blank "work" diskette. Check the work diskette to make sure the save was successful.

MOVING THE UPPER CHORUS TO THE LOWER KEYBOARD

Reload the Choruses back from Factory Disk #7. Now we are going to move Chorus #3 that occupies the top half of the keyboard down to the bottom half. First we need to find which wavesample is doing the singing. Select Upper program variation #1. Changing the value of Parameter 67 does effect the entire upper keyboard, so we are already in the right place, Upper Wavesample #1. Let's use MASOS Parameter 17 to move Upper Wavesample #1 to Lower Wavesample #4. Select Parameter 17, then press 4 and then Enter. The Upper Keyboard sound is now copied to the lower half.

The pitch has shifted up a major third in the move, so let's now correct that. Select the Lower Half program variation #1. Change Parameter 26 to value 0.3, so we are at Lower Wavesample #3, and you will find by testing Parameter 67 that we are now in the right place in memory to make changes to the lower keyboard sound. Change the value of Parameter 67 from 0.4 to 0.3, dropping the pitch one octave. Select Parameter 68, Fine Tune, and change the value from 0.4 to 0.6, raising the pitch a minor 6th. Now the bottom keyboard half is in proper tune. Use Parameter 11 to save the bottom keyboard half to the same work diskette.

Load Upper and Lower halves from the work disk. All of this button pushing we've done so far has managed to switch the sounds from the factory diskette so that Choir #3 is on the bottom and Choirs #1 & #2 are on top. I find that the sample is already much more usable, but we aren't finished yet.

SWAPPING PROGRAM VARIATIONS

Since I find program variation #2 to be the most realistic and usable sound, let's copy that program over program variation #1 so that it will be preset when the sound is loaded. This procedure is shown on page 17 of the Mirage Musician's Manual. Select Upper program #2, and then Parameter 16/Copy Program To Upper. The display will read UC. Press 1 (U1 displayed) and then Enter (.16 displayed). Select Lower program #2, and then Parameter 15/Copy Program To Lower. The display will read LC. Press 1, (L1 displayed) and then Enter (.15 displayed). Select Upper and Lower programs #1, and check to see that they both have the longer release times copied from program variation #2. Use Parameter 13 to save this change to the work diskette.

PROGRAM MODIFICATIONS

Now it is time to modify the program to taste. On the upper program, I reduced amplitude Parameters 51 and 53 from 0.8 to 0.0, and increased amplitude Parameters 56 and 58 from 1.4 to 2.1. Parameter 36, the filter cutoff frequency, I reduced from 2.5 to 0. 0, and I also reduced the wavesample relative filter cutoff Parameter 70 from 2.9 to 0.0. Filter Parameters 46 and 48 I increased from 0.2 to 1.2. All of these changes make this sound far more touch responsive, changing from a soft, very muted choir to a loud, bright fortissimo at a finger's touch.

I made similar changes on the lower half. First I used Parameter 67 to make sure Parameter 26 was set to the correct wavesample so that changes that are made would have some effect. I made the same amplitude changes, and I also brought filter Parameters #36 and #70 both down to zero. This makes the lower half too muted. I then set Parameters 41 and 43 to 0.8 to set a filter setting for the softest touch, and Parameters 46 and 48 to 9,8 to give a good touch sensitive brightness. I found myself liking the top notes of the lower half, so I extended the range of the lower half up a minor third by raising Parameter 72, Top Key, from 29 to 32.

All of these refinements make up a single program variation. With 4 variations per half there is a lot of room for experimentation. The touch sensitivity adjustments I've described may be too extreme for ensemble work. It all is a matter of taste. Learning how to alter and customize Mirage sound will greatly increase your enjoyment of the instrument.