Bobby Nathan's

Keyboard Magazine "In The Studio"

Article # 21

Making Synthesizers Stereo

by Bobby Nathan


One of the most popular ways to stereo-ize and widen your synthesizer sound is to use a delay unit. Long before digital delays there were tape delays and it was a matter of taste as to which of these units you may prefer. With either tape or digital delay unit the technique is the same. Usually the dry synthesizer sound can be panned left and the return of the synthesizer unit through the delay can be panned right or vice versa. Most delay units (tape or delay) have a mixed control that will balance wet (delay only) and dry (no delay). If you had panned the direct synth to the left you can pan the return of the delay unit right and adjust the mix control to add the desired amount of dry synth with the delayed synth on the right.

Using the feed back control is another important function of the delay unit. By adding some feedback you will make the delay side linger longer and give more of a feeling of movement from left to right. With certain delay time settings higher feedback settings will produce reverb-like qualities.

Setting the delay time to be in time with the programmed material is very important. For instance, if you set the delay to be a 1/4 note delay and the tempo of the song is slower than the speed of the delay unit this will cause a very anxious type of feeling. A delay slower than the tempo of the song will produce a sluggigh effect of the echo. Once again this is why it is important to have the delay be in time. Using the formula 60,000 divided by bpm of song equals the number of milliseconds delay time for a 1/4 note delay. Meaning, if the tempos of your song is 120 divide 60,000 by 120 you will get 500 milliseconds. If you set your delay to 500 milliseconds you will have a perfect 1/4 note delay in time with the tempo of your tune. Obviously to get the time of an 1/8th note divide the 500 milliseconds by half (250 milliseconds equals an 1/8th note) and for a 1/16th note divide by 4 (125 milliseconds equals a 1/16th note).

Another interesting effect is called the ping pong echo. To produce this effect you need the aid of a console with two echo sends and two delay units. Return your synthesizer to channel one for instance . Pan channel one up the middle (center). Patch echo send one to delay unit one and patch echo send two to delay unit two. Return delay unit one to channel two and pan channel two left. Return delay unit two to channel three and pan channel three right. Decide on whether you want a 1/4 note, an 1/8th note or 1/16th note delay and set both delay one and two to the same amount of milliseconds delay. Use echo send one of channel one (the synthesizer's return) to send the desired amount of delay to delay one. Adjust echo send two on channel two (delay one's return) to the desired level of delay two (in the right speaker). Next, adjust echo send one on channel three (delay two's return) for the desired level of the echo of delay one. If this sounds confusing that's because a ping pong echo is most confusing. The sound bounces back and forth from left to right. You don't need any feedback on either delay one or delay two and be careful because to high of an echo send on channels two or three of the mixer will can make ear splitting feedback. Serious feedback can damage your speakers as well as your hearing.

What also works interesting with this effect is setting delay one for a 1/4 note and delay two for a 1/16th note or vice versa.


A very popular stereo effect is to pan your synthesizer dry to the left and add a harmonizer set to either 1.01 or .99 panned to the right. Again if the harmonizer has a mix control between wet and dry set this for taste. Another popular widening effect is to pan the dry synthesizer in the middle and have two harmonizers one set to .99 and panned to the left and the other set to 1.01 and panned to the right. But it's not three part harmony but it works to fatten certain sounds. Many times a harmonizer can also be used to make a piano sound honky tonk. Settings above 1.01 or lower than .99 will definitely produce a most out of tune honky tonk piano.


The use of flanging /phasing/chorus is again as with delay and harmonizing the same technique. Dry synth on the left and the phased or flanged or chorused return on the right or vice versa. The widest effects are produced by having the mix control of the effect unit fully in the wet position.


When using reverb it is customary to pan the direct synthesizer sound up the middle and hard panning the returns of the reverb to left and right respectively. If you have a separate reverb unit to dedicate to a particular synthesizer try this effect instead. Pan the dry synthesizer left and pan both the left and right returns of the reverb to the right ( or just use the right reverb return). This effect gives movement to your synthesizer and in a busy mix can give more clarity to that particular instrument.

Using a pre-delay before the input of the reverb unit is also most effective in making the synthesizer travel further. Most digital reverb units today have pre-delay built in. Again as with the setting of a delay unit try to set the pre-delay for a 1/4 note, 1/8th note, 1/16th note slap that is in time with the tempo of the song.


The effect of auto panning was very near and dear to all of us Fender rhodes suitcase players. It was called vibrato, tremelo and very much much stereo. The Rhodes sound ping ponged between the front and back of the suitcase speakers. This same effect can be achieved with an auto panner. For this technique patch the output of the synthesizer directly into the input of the auto- panner and return the left and right outputs of the auto- panner panned left and right respectively.

Most auto-panners have an LFO that try as you like you can never match the tempo of your tune. Instead , use the auto trigger function on your auto-panner. You can send a 1/4 note click from your drum machine (or 1/8th note, 1/16th note etc. even triplets) and patch it into your auto-panners input. You can even feed the kick drum of a live drummer to pull this off live. Then, your auto-panner will pan whenever a new trigger is introduced perfectly in time with your tune. Some auto panners even have a count function that will count every 4 triggers and then pan either left or right.


Using an equalizer to widen mono sounds into sounding stereo has been around for quite a while. A lot of early monaural (Mono) records were converted to stereo using a comb filter technique. This was especially true on some of the Beatles early albums that were recorded in Mono. You can make your own comb filter with the aid of a Ten band or greater Equalizer. For example, using a Fifteen band Equalizer with center frequencies at 25, 40, 63, 100, 160, 250, 400, 630Hz, 1.6kz, 2.5kz, 4kz, 6.3kz, 10kz, and 16kz, you would boost each slider to the maximum amount of gain for each of the following frequencies: 25, 63, 160, 400, 1k, 2.5k, 6.3k, 16k and you would cut to the maximum amount each of the following frequencies: 40, 100, 250, 630, 1.6k, 4k, 10k on the left channel. On the right channel you would set the equalizer completely opposite. You would cut to the maximum amount the following frequencies: 25, 63, 160, 400, 1k, 2.5k, 6.3k, 16k and you would boost to the maximum amount the following frequencies: 40, 100, 250, 630, 1.6k, 4k, 10k. Next, using a "Y" chord, mult the output of your synthesizer into both the input of the left channel and the input of the right channel of your stereo 15 band equalizer. Patch the left output of your stereo 15 band equalizer into your mixer and pan it left and patch the right output into your mixer and pan it right. If you don't have a 15 band stereo equalizer you can use a 10 band equalizer. Just cut and boost the opposite frequencies in each channel as explained above. For comb filtering obviously a 27 band third octave equalizer will yield the best results but is out of range because of its cost.

You can also experiment with parametric equalizers even though they will not give the comb filtering you can get interesting frequency splits. For example if you boost the low frequencies on the left channel and the high frequencies on the right channel as you play up the keyboard your synthesizer will move from left to right. MIDI-ENVELOPE SETTINGS

Setting the envelope differently on any two synthesizers and panning them left and right will produce most interesting stereo effects. If you happen to have two of the same synthesizer put the same patch in both synthesizers pan each left and right and set the envelop of the right synthesizer to have a little longer release time maybe even a slower attach time.

With midi my favorite stereo combos are percussive sounds teamed with sounds with slow attacks and longer release times such as rhodes and strings, acoustic guitar and voices, clavinet and brass. The combinations are endless. Sampled sounds with synth sounds, digital with analog and etc and etc. The possibilities are endless.


As with any stereo effect , if you are recording to tape check how this effect sound in mono. In the studio stereo effects are always checked in mono. This is done by pushing the mono button on the console and preferably listening through a single Auratone speaker (the TV sound). This will tell you if what sounded so great in stereo still sounds great in mono. If the effect sounds too much in mono what you might try is panning your left and right channels on the returns of the effect to 9 o'clock and three o'clock or 11 o'clock and 2 o'clock respectively for left and right.

Well I hope you've enjoyed my tips on widening your sound. Stay loose and keep it stereo whenever you can.

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