1. Music & Audio
  2. Audio Production

How to Create Post Production SFX Using Propellerhead Reason


When working in post production for film and television, gaming and other types of media, sound effects are half the picture. There are many sound effect libraries available on the market these days and although the sounds can be of high quality, getting into the routine of dragging and dropping sounds from libraries can take all the creativity out of the production process.

Even with great microphones to capture original recordings, finding the time and the means to record many types of sounds can be difficult, especially when deadlines are tight in post production. By using synthesis and sampling, a wide array of sounds can be designed without having to leave the studio. The challenge of designing sounds through synthesis keeps the creativity flowing and having a unique sound layer in your productions can be very rewarding work.

Step 1: The Initial Patch

For this tutorial I will be creating the basis of an underwater atmosphere using the 'Thor' synthesizer and the 'NN-XT' sampler in 'Reason'. It is recommended that you have a basic understanding of synthesis and sampling before reading on.

When you first create a 'Thor' synthesizer, initialize the patch so that the 'Analog Osc' is in oscillator 1. The patch will also contain default envelopes and a 'Low Pass Ladder Filter' inserted at 'Filter 1'. Change the first oscillator to 'Noise' and bypass 'Filter 1'. Noise oscillators can be used to create a vast amount of textures and they're great to start with when first designing sound effects.

The basic patch using a noise oscillator

By drawing a note in the piano roll editor and playing back the sequencer we can hear the basic sound of the initial patch

Step 2: Shaping the Sound

Notice the envelope of the sound. There is a very fast attack, quite a long decay, a low sustain level and a very fast release. To create our ocean atmosphere, we want the sound to build up gradually to full amplitude and then decay slowly once the key is released.

The Amp Env settings

The type of noise being used at the moment is 'White', which contains a greater amount of energy in the higher range of the frequency spectrum. By changing the type of noise to 'Band', we can adjust the range or band of frequencies that are audible using the 'Noise Mod'. At the lowest setting, a near pure tone is produced and at the highest setting, full on noise again.

The Noise Osc settings

Step 3: Adding Low End

Now that we have the basic shape and tone of our sound in place, the next step is to insert an additional noise oscillator into 'Osc 2'. Setting up this oscillator an octave below the first and fine tuning the oscillators in relation to each other will add more body and low end to the sound.

Setting up an additional noise oscillator

Step 4: Filtering

Once the oscillators are setup, creating the basis of our underwater atmosphere, filtering the sound is the next process to be used. Routing these oscillators through filters gives us greater control over the sound and will help enhance the underwater effect.

Setup a 'Low Pass Ladder Filter' in 'Filter 1' and reduce the 'Env' amount to its lowest setting. The 'Filter Env' is connected directly to the 'Env' amount on the first two filters. By increasing the 'Env' amount, we control how much the filter is affected by the 'Filter Env'. For this tutorial, we do not want this envelope to have any affect over the filter.

Route both of the noise oscillators to the first filter by clicking the numbered 'Osc to Filter' buttons and making sure they are lit red. Using the default '24 type II' mode, we filter the sound extremely, removing quite a large amount of higher frequencies. By turning up the resonance, we increase the amplitude of frequencies at the cut-off point and a greater effect of the inserted filter is achieved.

The last step in filtering the noise is using a high pass filter. Click the left arrow directly after the 'Shaper' output to route the sound to 'Filter 2'. Insert a 'State Variable Filter' and click the subsequent arrow to connect 'Filter 2' to the 'Amplifier' section.

Select 'HP 12' mode on the 'State Variable Filter' and again, reduce the 'Env' amount to its lowest setting so that the 'Filter Env' has no affect over the filter. Notice how the frequency knob is at its lowest position. Because we added an additional noise oscillator an octave lower, using a high pass filter with these settings will remove excess sub bass only.

Using filters to remove unwanted frequencies

Step 5: Creating Movement

Filtering noise in this way achieves a great underwater sound but we need to add movement and variation to create a realistic effect. It is important to have a clear idea of how the sound should move before experimenting and in this case, I want the listener to hear the effect of repeated 'ocean waves'. By using a LFO and the modulation matrix we can create this effect.

Setup 'LFO 1' to generate an Inverted Sawtooth waveform. This will create a ramped cycle in the 'Destination' selected through the modulation matrix. If we routed the LFO to the 'Gain' in the 'Amplifier' section for example, the sound would begin at a low amplitude, gradually increase in volume and then instantly return to a low amplitude once the cycle has completed.

The LFO's 'Rate' and 'Delay' settings are also important for shaping the sounds movement. The 'Rate' controls the speed of the LFO modulation or the amount of cycles that occur in one second. In this case, the LFO 'Rate' will resemble the speed of the 'ocean waves' so we use quite a low setting or slow 'Rate'. By using the 'Delay', we can also specify the amount of time it takes before the LFO waveform starts and repeats. Increasing the 'Delay' amount creates the effect of gaps between each 'ocean wave'.

Configuring the LFO

Now that 'LFO 1' is configured, it must be routed to a destination within the synthesizer before any modulation can take place. To create the effect of moving 'ocean waves', we send the LFO to the pitch of oscillator 1 using a modulation bus in the matrix. By selecting 'LFO 1' from the 'Source' drop-down menu and 'Osc 1 Pitch' from the 'Destination' drop-down menu, we can control how much the LFO will affect the first oscillator's pitch using the 'Amount' parameter.

In this case a full 'Amount' setting has been used; the gradual rise in pitch resembles the sound of 'ocean waves' approaching from a distance. By routing the LFO to the frequency cut-off point in 'Filter 1' using another modulation bus, this approaching effect is enhanced, with a greater amount of higher frequencies becoming audible as the waveform cycle progresses.

Using the modulation matrix

Notice how 'Osc 2' has no modulation from the LFO. In essence we have created two layers in our underwater atmosphere. The first and higher oscillator contains the movement and dynamics of the sound while the second and lower oscillator acts as a backdrop to this or a background ambience. If the pitch of oscillator 2 was also modulated the effect would become too extreme, and subtlety is the key.

Lengthen the note in the piano roll editor so that the effects of the LFO can be heard over time

Step 6: Blending Sounds

When creating sound effects in post production, the end result is often a combination of two sound sources: synthesized and sampled. We use synthesis to create unique sounds and that's all well and good but to achieve realistic effects, we must blend these with recorded or sampled sounds.

For this tutorial, I've used the 'NN-XT' sampler to playback an audio file. The audio itself is a stereo recording of the ocean that I sourced from a sound effects library. However, I had to edit this in a DAW to create a seamless loop.

By creating a new zone in the 'NN-XT's Remote Editor' and loading the sample, the next step is to match the 'Amp Envelope' to the synthesized sound. Click on the zone that contains the sample within the 'Remote Editor' to highlight it. Highlighting a zone allows the various parameters of the sampler to be adjusted, controlling the sounds within the selected zones only.

Adjust the 'Amp Envelope' settings so that they're identical or similar to the synthesizer's envelope to achieve a uniform shape in our sound. Also change the 'Play Mode' to 'Forward Loop' so that the sound will loop continuously until the note is released.

Matching the amplitude envelopes and changing the Play Mode

Step 7: Using the Sampler

By adjusting only a few parameters on the sampler, the recorded sound is already very usable in its own right. However, because we want to blend it with our synthesized sound we have to start thinking about the frequency relationships between both sources and how they should mix together.

For this underwater atmosphere, the synthesized sound will mainly occupy the low end of the mix with the first oscillators pitch gradually sweeping upwards. The sampled sound will be designed to sit above this, occupying the midrange. With the zone still highlighted, change the filter mode to 'Band Pass' and reduce the frequency position until there are only mid frequencies audible.

We use a 'Band Pass' filter for three reasons. Firstly, the effect we're creating is underwater and setting the 'Band Pass' to a mid frequency will cause higher frequencies to be reduced, achieving a realistic underwater effect. Secondly, the 'Band Pass' will also reduce the low bass frequencies, creating space in the mix for our synthesized sound. Finally, using a 'Band Pass' filter will allow the sample to cut through at the midrange and be heard clearly.

sing the samplers Band Pass filter

To further adjust the recorded sound and make it more unique, experiment with the samplers LFO. The 'Rate' or 'Waveform' of this LFO does not have to match the synthesizers but I find a slow 'Rate' definitely works best. In this case, the LFO is configured to affect the pitch, filter and level of the sample. This again adds more movement and variation to the sound.

The LFO settings

Step 8: Routing Audio Signals

Now that our sampled sound has been adjusted to taste, it's nearly time to blend it with our synthesized sound. At the moment, the synthesizer and sampler are connected to two separate channels on the mixer and this is fine but to create cohesion between the two sources they must be processed together. This can be done several ways but for this tutorial, I will route the audio from the sampler directly to the synthesizer's 'Filter 3' input. Any further processing after this point on the synthesizer will affect the sound of both the oscillators and the sample.

Temporarily disable the synthesizer's oscillators audibility by clicking on the numbered 'Osc to Filter' buttons again. Press the tab key to flip the rack around so that we can see the various cables and connections. Disconnect the sampler from the mixer and reroute the cables to the 'Audio Input' section on the synthesizer. Even though this connection is made, the audio from the sampler will not be heard until it is routed through the synthesizer's modulation matrix.

Changing audio cable connections

Press the tab key again so we can focus on the matrix section of the synthesizer. Because the sample being used is stereo, we will need to use two modulation buses; left and right. For the first bus, select 'Audio Input 1' from the 'Source' drop-down menu and 'Filter 3 Left Input' from the 'Destination' drop-down menu. The second bus will use 'Audio Input 2' and 'Filter 3 Right Input' from the 'Source' and 'Destination' menus respectively. The 'Amount' setting is used to balance the sampled sound with the level of the oscillators.

Routing audio signals using the modulation matrix

Finally, insert a 'Low Pass Ladder Filter' into 'Filter 3' and reduce the frequency cut-off point to remove any of the higher frequencies that the 'Band Pass' filter did not affect. Only a small amount of filtering is taking place here and the difference is subtle. However, this filter will become more important towards the end of the process and will be revisited in the final step.

Configuring the last filter

Step 9: Routing CV Signals

Before the sampled and synthesized sounds can be mixed and processed together, they should first have identical movements over time. To achieve this, we need to use the LFO from the synthesizer to affect the pitch of the audio in the sampler. Using another modulation bus, select 'LFO 1' from the 'Source' drop-down menu and 'CV Output 1' from the 'Destination' drop-down menu. A full 'Amount' setting is being used here.

Routing CV signals using the modulation matrix

Flip the rack to the back view and use a CV cable to connect 'CV1' from the synthesizer's 'Modulation Output' to 'Osc Pitch' on the sampler's 'Modulation Input'. Reduce the amount on the 'Osc Pitch' input so that the effect isn't too extreme. Playback the sequencer; the movement of the samples pitch is now identical to the movement of the oscillators pitch over time.

Connecting CV cables

Step 10: Further Processing

The final step in creating the basis of our underwater atmosphere is to process both sound sources as a whole. Cohesion is achieved by using both dynamic and spatial effects to mix the synthesized and sampled sounds together. Firstly, reroute the two oscillators to 'Filter 1' by clicking the numbered 'Osc to Filter' buttons again so that both sound sources are audible. The combined signals are heard at the output of 'Filter 3', which is where the first step of processing takes place.

Compressors are often used when dynamically processing two separate signals together for cohesion. For this tutorial however, we will use the 'Drive' parameter on the 'Low Pass Ladder Filter' we inserted at 'Filter 3'. Raising this amount will increase the input gain to the filter and because both sound sources are connected at this point, they will be processed together. Driving the filter in this way will have similar dynamic effects of a compressor but will add more character to the signal.

Finally, the last step in the entire process is to apply spatial effects for more depth and movement in the sound. We do this by using the 'Delay' and 'Chorus' devices built into the synthesizer. Because the effects section is after 'Filter 3' in the signal flow, this again will affect both the synthesized and sampled sounds. Experiment with various settings in the effects section to create more or less depth and movement in the final sound.

Driving the filter and using effects

In Context

Listen to the finished sound in a complete underwater atmosphere. Only one other sample was used in the production process with everything else being synthesized.

Experiment with the parameters on the synthesizer and sampler to create your own unique sound. Try using different oscillators and filters or the various LFO waveforms available. Find other audio recordings or even record your own, the possibilities and results are endless.

Download the Play Pack for this tutorial (7.2 MB)


  • Reason Source File
  • WAV Source File
Looking for something to help kick start your next project?
Envato Market has a range of items for sale to help get you started.