Diatonic Shifter 2 User Manual
Contents
1. Hamming Hann Hann and Sine Transposition group Key Sets the root note of the scale you are playing in C l C CE Since the Diatonic Shifter 2 scale transposition pattern is entered relative to the scale s root note unison you can easily change the modality you are playing in by setting the key parameter while maintaining the relative scale transposition pattern For consistency always create your scale transposition pattern with the key parameter set to the root note of the equivalent major scale Do not set the key parameter to A when working in A minor in stead set it to C because of the equivalent C major scale Master transposer Controls all individual scale note pitch shift parameters at once Use the master transposer to easily raise or lower the pitch shift for every individual note Page 20 of 28 Diatonic Shifter 2 Audio Unit User Manual Note that the lower and upper boundaries of the individual note pitch shift parameters will always be maintained you can not raise a note s pitch to a value above 2400 cents or lower than 2400 cents using the master transposer If setting the master transposer to a new value would cause an individual note pitch shift parameter to exceed its boundaries the value will be clipped to fit within the boundaries As long as Diatonic Shifter 2 is active the master transposer can be used to undo this clipping Scale group Unison Major seventh Controls the target inte2. folder to the Audiowish presets folder on your local disk 6 The Diatonic Shifter 2 Audio Unit uses the industry standard Cocoa and Carbon interface views for Audio Units load ing and saving presets will generally not vary between Audio Unit host applications However some third party host applications are known for offering custom user interfaces See the Known Issues section for more information Page 6 of 28 Diatonic Shifter 2 Audio Unit User Manual Using Diatonic Shifter 2 Diatonic pitch shifting basics Before going into the details of the Diatonic Shifter 2 interface we will take a short look at the mu sical concept of diatonic pitch shifting A solid understanding of the theory behind Diatonic Shifter 2 will help you maximize its usefulness The main purpose of the Diatonic Shifter 2 Audio Unit is to shift the pitch of an incoming audio signal dependent on the note that was played Diatonic Shifter 2 tracks the incoming notes and out puts notes based on a user defined musical scale This diagram visualizes the flow of sound through Diatonic Shifter 2 beste AB beter Original melody C D E F Set to transpose Transposed melody A B C D C major major 6th Diatonic Shifter 2 transposing a melody in C major A melody in the key of C major is played on an instrument and this audio signal is sent to Diatonic Shifter 2 which transposes each of the incoming notes to its major sixth in the C ma
3. in host software If you did not follow the installation instructions in this manual please read and follow the Instal lation section first Diatonic Shifter 2 not showing up in your Audio Unit compatible host software can have multiple causes Please follow the following steps to make sure your computer is set up correctly e Verify that your host software supports version 2 Audio Units e Make sure that DiatonicShifter component is installed correctly by double clicking the In stall CALL users link in the disk image and checking if it is listed there as e Use Apple s auval tool to verify the Audio Unit is working correctly open up the Terminal application and copy and paste the following command auval v aufx dtsf Awsh Press the Enter key to execute this command Please send the output of this command to frank audiowish com for further troubleshooting the problem Audible pops and clicks Pops and clicks are usually the results of one of three causes e Verify that the original incoming audio signal does not contain pops or clicks Diatonic Shifter 2 will only shift the pitch of the incoming signal and won t correct imperfections e Using Activity Monitor verify your computer s CPU usage for spikes or constant high load if the Audio Unit host application cannot process its audio signals within a short amount of time it will generate a pop or click e Check the parameters in the Q
4. rn 2400 0 Cents major third E 2400 rn 2400 300 Cents fourth F 2400 r 2400 400 Cents aug fourth F 2400 fir 2400 0 Cents fifth G 2400 ete 2400 400 Cents minor sixth G 2400 m 2400 0 Cents major sixth A 2400 m 2400 300 Cents minor seventh A 2400 m p 2400 0 Cents major seventh B 2400 m 2400 300 Cents Diatonic Shifter 2 showing the transposition pattern Now would be a good time to play a melody in C major and listen to the effect Diatonic Shifter 2 has on the melody Pay close attention to the pitch monitor group while playing the melody to see the incoming notes being detected in real time 10 For the semitones to cents conversion see Wikipedia on cents http en wikipedia org wiki Cent_ 28music 29 Page 10 of 28 Diatonic Shifter 2 Audio Unit User Manual Feel free to revisit the key and master transposer for instance try setting the key to D and playing a melody in D major The same transposition as before will be applied to the melody but now in the key of D major instead of C major Try setting the master transposer to 1200 cents and playing a melody again Notice how the trans posed melody now sounds a full octave higher than before Lowering the master transposer to 1200 or even 2400 cents will achieve the opposite effect lowering the transposed melody Experiment with different scale transposition patterns scales and the key and master transposer un til you feel com
5. 19 TET scale For instance the F note in the original scale is 600 cents higher than the root note C The target note for F is the 19 TET E which is 379 cents higher than the root note To give the original F the same relative frequency as the target 19 TET E note its pitch must be lowered by 221 cents Implementation By entering the difference values into the Diatonic Shifter 2 scale transposition pattern and then playing a C chromatic scale you will hear the first twelve notes of the 19 TET C chromatic scale being produced by Diatonic Shifter 2 The actual scale transposition pattern in Diatonic Shifter 2 would look like this 16 The table lists both the 12 TET and 19 TET interval first followed by the note name for better legibility Page 18 of 28 Diatonic Shifter 2 Audio Unit User Manual Scale unison C minor second C major second D minor third D major third E fourth F aug fourth F fifth G minor sixth G major sixth A minor seventh A major seventh B 2400 Cr pn 2400 2400 Ce Bp 2400 2400 pn 2400 2400 em the 2400 2400 rr Bp 2400 2400 ets 2400 2400 eB 2400 2400 em tes 2400 2400 rr 2400 2400 rr pn 2400 2400 Hen Op 2400 2400 rp 2400 0 Cents 37 Cents 74 Cents 111 Cents 147 Cents 184 Cents 221 Cents 258 Cents 295 Cents 332 Cents 368 Cents 405 Cents 19 TET C chromatic microtuning im
6. Diatonic Shifter 2 Audio Unit User Manual Copyright 2006 2012 Audiowish Diatonic Shifter 2 Audio Unit User Manual Table of Contents Preface About this manual About Audiowish Diatonic Shifter 2 Audio Unit Introduction System requirements Installation Preset pack installation Trial version limitations Using Diatonic Shifter 2 Diatonic pitch shifting basics Harmonizing basics Interface overview Basic usage Getting started Transposition group Scale group Pitch Monitor group Pitch Tracking group Congratulations Usage Examples Introduction Harmonizing Intervals Chords Recursive Delayed arpeggios Intervals Chords Microtuning Introduction Theory and math Putting everything together Implementation Concluding words Audio Unit Parameters Overview oo ON NN D OO OO A Aa KR HK A lt ua 25 ua O D N O i a a 1 Ww CO Ww i in ot OMAN OO OO OO AA O1 KR WwW k 4 k L L L D N O O Page 2 of 28 Diatonic Shifter 2 Audio Unit User Manual Transposition group Key Master transposer Scale group Unison Major seventh Pitch monitor group Current note Accuracy Pitch tracking group A4 frequency Accuracy threshold Jitter threshold Quality group Processing Rendering Windowing Oversampling Troubleshooting Diatonic Shifter 2 does not show up in host software Audible pops and clicks Pitch tracking is incorrect or unstable Known Issues Parameter groups not shown in Carbon inter
7. Unit User Manual Basic usage Getting started The first time seeing the Diatonic Shifter 2 Audio Unit might feel a bit overwhelming but don t be intimidated by the sheer number of parameters and settings You will feel at home in no time by fol lowing this brief tutorial So take a deep breath and relax as we take a look at each of the parameter groups in the interface Transposition group At the top of the interface is the transposition group which allows you to set both the key of the mu sical piece you are playing and a master pitch shift value for every note in the scale Try changing each parameter and observe the changes in the interface visualized below Audio Unit Diatonic Shifter 2 Manufacturer Audiowish Audio Unit Diatonic Shifter 2 Manufacturer Audiowish Transposition Transposition key ker master transposer 2400 m 2400 0 Ce master transposer 2400 m 2400 0 Cents Scale unison C 2400 O 2400 0 Cents unison C 2400 eff 2400 0 Cents minor second C 2400 rr 2400 0 Cents 2400 Or 2400 0 Cents major second D 2400 ef 2400 0 Cents 2400 m e 2400 0 Cents minor third D 2400 m e 2400 0 Cents 2400 COCO 2400 0 Cents major third E 2400 nr 2400 0 Cents major third 400 pn 2400 0 Cents fourth F 2400 O 2400 0 Cents fourth F 22400 enfin 2400 0 Cents aug fourth F 2400 ef 2400 0 Cents aug fourth F 2400 ef 2400 0 Cents fifth G 2400
8. cale to 12 TET The effects chain set up is very simple as shown in this diagram Input Output Transpose 19 TET subscale Effects chain for microtuning using Diatonic Shifter 2 The real magic is in the 19 TET subscale transposition pattern which is based on the fact that notes are 100 cents apart in the 12 TET scale while they are approximately 63 cents apart in the 19 TET scale gt Theory and math To illustrate the microtuning possibilities of the Diatonic Shifter 2 Audio Unit we will walk through a simple C chromatic scale example which will introduce you to the theory and mathematics behind microtuning The following table lists notes and their interval in cents compared to C for both the 12 TET and 19 TET scales Interval 12 TET Interval 19 TET 14 Theory behind alternate scales is described on Wikipedia see http en wikipedia org wiki 19 equal temperament 15 19 TET means 19 notes in one octave An octave is 1200 cents so each note equals 1200 19 63 16 cents Page 16 of 28 Diatonic Shifter 2 Audio Unit User Manual Interval 12 TET Interval 19 TET 568 Comparing note intervals in the 12 TET and 19 TET scales If you are used to playing in the 12 TET scale you will immediately notice that the 19 TET scale contains seven additional notes like D b and B which are not part of 12 TET We can use the above table of 12 TET and 19 TET intervals to create a mapping from the full 12 TET scale to t
9. ch monitor accuracy as the note changes Note the lowest ac curacy you see when playing different notes Use this lowest accuracy minus twenty five percent as a starting point for tweaking the accuracy threshold You will want to find a value that is comfortably low enough for each note to be recog nized while preventing small imperfections from accidently triggering a note change Jitter threshold Stabilizes the pitch tracker s note recognition The jitter threshold allows you to guard yourself against short bursts of odd harmonics and noise by setting a minimal threshold on the duration of a note forming a useful safety net Stray harmonics and noise typically last only a few milliseconds which you can filter out by in creasing the jitter threshold The jitter threshold depends on the sample rate for time measurement so you will usually want to increase this parameter as the sample rate increases Experiment with the jitter threshold to find the lowest value which does not cause the transposed melody to jitter while playing a melody If you are able to comfortably set the accuracy threshold to a value of twenty five percent or higher without the pitch tracker skipping notes you can typically set the jitter threshold to a very low value of zero or one The default settings are set up this way Quality group Processing Choose between Diatonic Shifter 2 s low latency or high precision processing modes The low la tency mo
10. de uses less than half of the processing load of the high precision mode enabling you to explore very low latency responses during live performances or studio monitoring For post processing tracks in a studio recording where latency is not an issue select the high preci sion mode for high fidelity results 18 Note that the jitter threshold is applied after the accuracy threshold The Diatonic Shifter 2 pitch tracker will only take sufficiently accurate samples into account when considering the jitter threshold 19 Low latency processing in Diatonic Shifter 2 can be combined with the Audio Unit host application settings to de crease overall latency even more Refer to your host application s manual to explore this option Page 22 of 28 Diatonic Shifter 2 Audio Unit User Manual Rendering Controls the resolution of Diatonic Shifter 2 s advanced audio analysis and synthesis steps Choose one of the predefined quality settings ranging from Minimum to Maximum to find a balance between sound quality and processing load Lower rendering qualities will decrease processing load and thus latency but will also degrade the sound quality of the output signal The Medium rendering quality offers a solid balance and it is advised not to change this parameter unless absolutely necessary Technical note the rendering quality parameter maps to the internal logarithmic size of the Fourier trans formation The quality to sample count mapping
11. e http www lilypond org for more information and downloads Page 27 of 28 Diatonic Shifter 2 Audio Unit User Manual Revision History May 10 2007 Slight overall rewordings added preset replacement warnings May 8 2007 Minor revisions updated Acknowledgments section May 6 2007 Added screenshot drop shadows added Trial version limitations section May 5 2007 Initial draft for internal use Disclaimer First of all thank you for your interest in the Diatonic Shifter 2 Audio Unit We hope you will enjoy the continued use of this software product The Diatonic Shifter 2 Audio Unit has been designed programmed and extensively tested for use in a great diversity of operating conditions Even though a lot of care and testing went into the user interface and algorithms in this product we can not guarantee flawless operation under every condi tion imaginable Under no circumstances including negligence shall the author be liable for any incidental special or conse quential damages that result from the use or inability to use the Diatonic Shifter 2 Audio Unit even if the author has been advised of the possibility of such damages You may not redistribute versions of the Diatonic Shifter 2 Audio Unit other than the Trial version without the author s prior written consent All quoted products and trademarks are the property of their respective owners Page 28 of 28
12. ed interval arpeggio idea try combining three or more voices in a cascaded delay effects set up This diagram visualizes a three voice delayed chord arpeggio Delay gt Set to 333ms Transpose major sixth Output Delay gt Set to 667ms Original melody Transpose perfect fifth Effects chain for a three voice delayed chord arpeggio using Diatonic Shifter 2 and Octave Shifter 2 You will want to use mono channels during processing to maximize the number of real time voices and merge them into a stereo field after processing Combining multiple delay times transposition patterns and panning can give both very lush as well as eerie effects Try to not limit voices within a one octave boundary make sure some of them transpose the origi nal notes by more than 1200 cents or less than 1200 cents for a very dynamic feel Page 15 of 28 Diatonic Shifter 2 Audio Unit User Manual Microtuning Introduction This somewhat unexpected application of the Diatonic Shifter 2 Audio Unit was introduced to us by Philippe Gruchet see Acknowledgments His idea is very simple conceptually but the results are quite amazing Instead of using whole semitone pitch shifts relative to a twelve tone scale you can use the twelve tone scale 12 TET to simulate a nineteen tone 19 TET or even thirty one tone 31 TET scale by using fractional pitch shifts mapping twelve notes from the 19 TET s
13. et 2400 0 Cents fifth G 2400 Qn 2400 0 Cents minor sixth G 2400 2400 0 Cents minor sixth G 2400 ent 2400 0 Cents major sixth A 2400 fr 2400 o Cents major sixth A 2400 _ e 400 0 Cents minor seventh A 2400 mjm 2400 0 Cents minor seventh A 2400 Oo 2400 0 Cents major seventh B 2400 O 2400 0 Cents major seventh B 2400 m 2400 0 Cents Pitch Monitor Pitch Monitor current note Pitch tracker off current note Pitch tracker off accuracy 0 0 SSS 11000 accuracy 00 EE 100 0 Pitch Tracking _ Pitch Tracking A4 frequency 400 0 ef 480 0 440 0 Hz A4 frequency 400 0 oO 480 0 440 0 Hz accuracy threshold 0 0 fe 100 0 25 0 accuracy threshold 0 0 fe 100 0 25 0 jitter threshold 0 00 16 00 1 00 Samps Jitter threshold 0 00 16 00 1 00 Samps Quality Quality processing Low Latency processing Low Latency rendering Medium B rendering Medium windowing Hann windowing Hann a oversampling 1 00 p 32 00 8 00 oversampling 1 00 eme 32 00 8 00 Influence of the Diatonic Shifter 2 key in red and master transposer in blue parameters As you can see the key parameter sets the scale root note unison but retains the scale transposition pattern which allows you to use a scale transposition pattern in different keys The master transposer adjusts each of the individual note tra
14. face Third party graphical interface imperfections General Absolute note names are not updated Master transposer does not update scale interactively Pitch monitor is not shown Pitch monitor displays Trial muted message Trial label still showing after installing full version Version History Acknowledgments Stephan M Bernsee Philippe Gruchet The Apple CoreAudio Team Lilypond Revision History Disclaimer 20 20 20 21 21 24 24 21 24 22 22 22 22 23 23 23 24 24 24 24 25 25 25 25 25 25 25 25 26 27 27 27 27 27 27 28 28 Page 3 of 28 Diatonic Shifter 2 Audio Unit User Manual Preface About this manual You are reading the Diatonic Shifter 2 Audio Unit user manual which covers installation and usage of the Diatonic Shifter 2 software effect After reading this manual you will be able to use the soft ware in a variety of Audio Unit hosts and know the purpose of each of the Audio Unit s processing parameters To obtain the latest revision of the Diatonic Shifter 2 user manual please visit the Audiowish web site at http www audiowish com You will find an up to date version of the manual in PDF format ready for download The manual you are reading now was last modified on June 20 2012 For a brief overview of revi sions consult the Revision History section of this manual About Audiowish Audiowish is a young software company dedicated to developing high quality Audi
15. figuration e Apple Macintosh computer with an Intel or PowerPC G4 or GS processor e Mac OS X Snow Leopard 10 6 or higher for the optimized Intel 32 64 bit version e Mac OS X Tiger 10 4 or higher for the legacy PowerPC compatible version e 5 Mb of free disk space e Audio Unit version 2 host software All existing Apple Intel and recent PowerPC computers will conform to these requirements and should have no problems running the Diatonic Shifter 2 Audio Unit 1 In this manual real time refers to internal processing latencies lower than 2 milliseconds 2 SSE will only be used on Intel based computers Altivec will only be used on PowerPC based computers 3 Diatonic Shifter 2 is packaged as a Universal Binary it performs equally well on Intel and PowerPC based computers 4 Disk space requirement is estimated actual required disk space may vary Page 5 of 28 Diatonic Shifter 2 Audio Unit User Manual Installation To install the optimized Intel 32 64 bit version of Diatonic Shifter 2 Audio Unit on your computer drag the DiatonicShifter component file from the disk image to the Install ALL users folder link in the disk image To install the legacy PowerPC compatible version open the Legacy version folder in the disk image and drag the DiatonicShifter component file to the Install ALL users folder link Please note that Diatonic Shifter 2 will replace any previous versions of the Diatonic Shifter A
16. fortable with them You re already past the hard part now Pitch Monitor group Diatonic Shifter 2 features a real time pitch tracker which analyzes the incoming audio signal and determines which note is being played The pitch monitor group lets you inspect the pitch tracker so you can more easily adjust the threshold parameters in the pitch tracker parameter group The current note parameter tells you which note is currently being picked up in the incoming signal and the accuracy meter indicates the confidence of the real time pitch tracker Sample pitch monitor values are displayed in these screenshots Pitch Monitor current note E accuracy 0 0 100 0 Diatonic Shifter 2 detects the note E being played with 98 confidence Pitch Monitor current note A accuracy 0 0 SS 100 0 Diatonic Shifter 2 detects the note A being played with 30 confidence Of course the higher the score within the accuracy meter the better the pitch tracker follows your melody Accuracy values of 25 or higher are sufficient for successful pitch tracking Besides indicating which note is being played along with the accuracy the pitch monitor can indi cate that the pitch tracker is off as in this screenshot Pitch Monitor current note Pitch tracker off accuracy 0 0 Sei 1000 Diatonic Shifter 2 indicates the pitch tracker is turned off The two main reasons for this indication are either that all notes within
17. fter 2 Manufacturer Audiowish Transposition key C master transposer 2400 ee 2400 0 Cents Scale unison C 2400 oir 2400 0 Cents minor second C 2400 fi 2400 0 Cents major second D 2400 Qn 2400 0 Cents minor third D 2400 Or 2400 0 Cents major third E 2400 gt 2400 0 Cents fourth F 2400 mO 2400 0 Cents aug fourth F 2400 Op 2400 0 Cents fifth G 2400 ef 2400 0 Cents minor sixth G 2400 2400 0 Cents major sixth A 2400 m 2400 0 Cents minor seventh A 2400 m 2400 0 Cents major seventh B 2400 2400 0 Cents Pitch Monitor current note Pitch tracker off accuracy 0e 100 0 Pitch Tracking A4 frequency 400 0 mO 480 0 440 0 Hz accuracy threshold 0 0 100 0 25 0 jitter threshold 0 00 O 16 00 1 00 Samps Quality processing Low Latency rs rendering Medium is windowing Hann oversampling 1 00 aef 32 00 8 00 Diatonic Shifter 2 generic Cocoa view in AU Lab Like other Audio Units you can adjust Diatonic Shifter 2 s processing settings by manipulating the on screen parameters using your mouse or keyboard 8 Popular Audio Unit host applications are Logic Pro Garageband and AU Lab You can find more Audio Unit host software on Apple s Mac OS X Downloads page at http www apple com downloads macosx Page 8 of 28 Diatonic Shifter 2 Audio
18. he first twelve notes of the 19 TET scale This diagram visualizes the concept dei Original 12 TET C chromatic scale C C Db D D Eb E E F F Gb G Transpose to 19 TET C chromatic scale 19 TET C chromatic subscale from C to G twelve notes Mapping the 12 TET C chromatic scale to a 19 TET C chromatic subscale In short this means that you are be able to simulate the first twelve notes of the 19 TET C chromatic scale by actually playing a 12 TET C chromatic scale Putting everything together To build a 19 TET C chromatic subscale transposition pattern you must decide which original notes in the 12 TET scale will map to which target notes in the 19 TET scale In this walkthrough we will map all 12 TET notes to the first 19 TET C chromatic notes Page 17 of 28 Diatonic Shifter 2 Audio Unit User Manual The following table lists the 12 TET source note along with its 12 TET C chromatic interval 6 the target note in the 19 TET scale along with its 19 TET C chromatic interval and the difference in cents between the note s 19 TET and 12 TET intervals 12 TET source interval and note Difference e A je ee D CO Cc DE D CS sf Comparing the original 12 TET note intervals to their 19 TET target intervals The difference column is calculated by subtracting the 12 TET interval from the 19 TET interval This value represents the exact interval change from the note in the 12 TET scale to the
19. hresholds to their optimal values Known Issues Parameter groups not shown in Carbon interface The generic Carbon Audio Unit interface provided by Apple does not support parameter groups for Audio Units There is currently no known workaround but Diatonic Shifter 2 will perform nor mally despite the minor graphical differences compared to the Cocoa interface Note that the generic Carbon Audio Unit interface inserts small horizontal separators between pa rameter groups to visually distinguish them Third party graphical interface imperfections General Third party Audio Unit host applications are known to provide custom but not fully compliant graphical interfaces for Audio Unit effects While the graphical interface might show minor imper fections audio processing is unaffected Known issues and workaround for third party graphical interfaces are listed below Absolute note names are not updated Apparently the Audio Unit host application does not support live changes of parameter information when the key parameter changes Either use the relative note names as a guide for setting up the scale transposition pattern or try closing and reopening the Diatonic Shifter 2 view or the host ap plication itself after changing the key Master transposer does not update scale interactively This problem is caused by the Audio Unit host application not reacting on interactive changes of the master transposer parameter Instead of just dragg
20. ing the parameter slider try releasing it fre quently the scale parameters will be updated accordingly as you release the slider Pitch monitor is not shown The Audio Unit host application does not support read only parameters like the current note and accuracy meters Use a different host application like Garageband or Logic to determine correct values for your instrument and apply these as a guideline in the third party host application Pitch monitor displays Trial muted message The trial version of Diatonic Shifter 2 will mute its output for a short period of time every few min utes See the Trial version limitations section for more information Page 25 of 28 Diatonic Shifter 2 Audio Unit User Manual Trial label still showing after installing full version After installing the full version of Diatonic Shifter 2 some host applications will continue to list the Audio Unit as Diatonic Shifter 2 Trial To resolve the issue go to Library Caches where represents your user folder and remove the com apple audiounits cache file This will cause the host application to rescan all Audio Units 2 This issue has been mostly reported by users of Apple s Logic line of software Page 26 of 28 Diatonic Shifter 2 Audio Unit User Manual Version History Date June 20 2012 Adding Intel 32 64 bit optimized version tuning processing code for improved audio quality October 2 2007 Migrated to Audi
21. is Minimum 512 Low 1024 Medium 2048 High 4096 and Maximum 8192 samples Windowing Controls the sound character of the pitch shifted sound Diatonic Shifter 2 offers five different windowing functions each of which is suited for a variety of input signals The default Hann win dowing function is a solid choice for almost all input signals and offers a noise free and serene out put Use the Blackman windowing function to emphasize frequency peaks in the input signal Both the Cosine and Sine functions offer a louder body in the sound with a bit of a cold touch The Hamming windowing function tends to emphasize higher frequencies The choice of a windowing function does not influence the processing load Oversampling Controls the overall quality of Diatonic Shifter 2 s processing by smoothing out the synthesis step Raising the oversampling will audibly boost the quality of the output signal at a significant increase of the processing load Use the oversampling parameter with caution as excessively high values might result in pops and clicks in the output signal due to high processing load Values between 8 and 16 offer a good trade off between sound quality and processing load 20 An analysis of windowing functions is available on Wikipedia at http en wikipedia org wiki Window_ Function Page 23 of 28 Diatonic Shifter 2 Audio Unit User Manual Troubleshooting Diatonic Shifter 2 does not show up
22. ixth which in turn will be transposed to its major sixth all around the scale you are playing in Make sure you build and test this effects set up with the volume turned down or muted as the recur sive feedback can make the output sound very loud and high pitched if the low pass filter and feed back amount are not set up correctly 3 Note that you can up mix and pan the mono channels to a stereo field after processing for unique effects Page 14 of 28 Diatonic Shifter 2 Audio Unit User Manual A variation on this effects chain is to not use recursive feedback but to add a few serial delays and Diatonic Shifter 2 instances yourself This way you have better control over the resulting harmonies and volume Delayed arpeggios Intervals Combining the real time interval harmonizing effect with a medium delay you can create a unique delayed interval arpeggio sound with the following set up Delay gt Set to 500ms Transpose major sixth Output Original melody Effects chain for a delayed interval arpeggio sound using Diatonic Shifter 2 The example uses major sixths to fill in the notes played coming from the delay but again feel free to experiment with any scale transposition pattern you like By combining pitch shifts well beyond and below one octave in one scale transposition pattern you can achieve an astonishing sound that can puzzle listeners trying to figure out how it was created Chords Expanding on the delay
23. jor scale The resulting transposed melody sounds like it was played in the key of A minor Harmonizing basics Diatonic Shifter 2 can also function as a real time diatonic harmonizer by adding its output signal to the input signal The following diagram visualizes the flow of sound in this scenario bate Original melody C D E F Set to transpose Harmonized melody C major major 6th A el Diatonic Shifter 2 harmonizing an input pattern in C major A melody is layered with a transposed version of itself creating major sixth intervals in the C major scale For example a single C note in the original melody is harmonized to a CM6 interval See the Usage Examples section for more creative ideas and the corresponding settings for Dia tonic Shifter 2 7 An in depth look at diatonic concepts is available on Wikipedia see http en wikipedia org wiki Diatonic Page 7 of 28 Diatonic Shifter 2 Audio Unit User Manual Interface overview Diatonic Shifter 2 is an Audio Unit effect not a stand alone application You will need an Audio Unit version 2 compliant host application to be able to use Diatonic Shifter 2 in your effects chain Please refer to your host software s manual on how to add Audio Unit effects to your projects In this manual we will look at Diatonic Shifter 2 in Apple s AU Lab host application using the ge neric Cocoa interface or view Audio Unit Diatonic Shi
24. l clearly carries a key note Low accu racy values are an indication of a noisy or strongly polyphonic input signal Refer to the Pitch tracking is incorrect or unstable section for applications of both the current note and accuracy parameters Pitch tracking group A4 frequency Sets the base frequency of the middle A note in Hertz Change the A4 frequency parameter if your musical instrument is known to be tuned to a different frequency Most instruments and musical performances are based around the A4 note having a frequency of 440 Hertz 17 See the Wikipedia entry on cents for detailed information at http en wikipedia org wiki Cent_ 28music 29 Page 21 of 28 Diatonic Shifter 2 Audio Unit User Manual Accuracy threshold Controls the minimally required pitch tracking accuracy for recognizing a note As the name implies the Diatonic Shifter 2 pitch tracker will only pick up new notes if the confi dence of the tracker is above the accuracy threshold This threshold will prevent stray harmonics and noise from influencing the note recognition The default accuracy threshold suits most instruments like guitars keyboards flutes and even vo cals If you find that the pitch tracking isn t working properly for you read the Pitch tracking is incorrect or unstable section first Determine an optimal value for the accuracy threshold by playing notes all along the full range of the instrument and checking the Pit
25. nsposition sliders by the same amount This allows you for example to raise the transposed signal by a full octave using only a single pa rameter Scale group The scale group contains the pitch shift parameter for each one of the twelve notes in the twelve tone equal temperament scale The parameter name of each note consists of the relative interval to the root note and the absolute note name as based on the key 9 See the Wikipedia article on equal temperament http en wikipedia org wiki Equal temperament Page 9 of 28 Diatonic Shifter 2 Audio Unit User Manual As an example we will set up a transposition pattern for a melody in C major which will be trans posed diatonically up two notes The following table shows the transposition pattern Interval Unison Major second Major third Fourth Fifth Major sixth Major seventh Building a transposition pattern for use in Diatonic Shifter 2 Set the key parameter in Diatonic Shifter 2 to C because we are working in C major and set the master transposer to zero Fill in the pitch shift for each original note or interval using a value of hundred times the difference in semitones Transposition key D master transposer 2400 rn 2400 0 Cents Scale unison C 2400 Ser 2400 400 Cents minor second C 2400 rn 2400 0 Cents major second D 2400 fi 2400 300 Cents minor third D 2400
26. o Unit sound effects Thanks to our enthusiasm and continued interest in providing robust tools for musicians producers and sound engineers we re able to offer exciting products at very low prices Audiowish started in 2006 under the Forever For Now umbrella and became a dedicated effort in the third quarter of 2007 For the latest news and software updates visit the Audiowish website at http www audiowish com Page 4 of 28 Diatonic Shifter 2 Audio Unit User Manual Diatonic Shifter 2 Audio Unit Introduction Diatonic Shifter 2 is a real time diatonic pitch shifting and harmonizing Audio Unit effect By leveraging existing technologies like CoreAudio SSE and Altivec Diatonic Shifter 2 offers a unique audio experience Key features of the Audio Unit include e real time low latency processing for live performances e high precision post processing for studio quality results e truly diatonic in scale pitch shifting harmonizing and microtuning e robust real time pitch tracker with integrated visual pitch monitor e four full octaves of pitch adjustment Additionally Diatonic Shifter 2 makes use of the industry standard generic Cocoa and Carbon graphical interface views for Audio Units offering a seamless integration into host applications like Logic Express and Pro Garageband Final Cut Express and Pro and Soundtrack System requirements To use the Diatonic Shifter 2 Audio Unit you will need at least the following con
27. owish May 15 2007 Initial release of the Diatonic Shifter 2 Audio Unit Acknowledgments Stephan M Bernsee The Diatonic Shifter 2 Audio Unit builds on the work and tutorials written by Stephan M Bernsee posted on his website called DSP Dimension Thanks to Stephan for answering questions and ex plaining audio concepts Philippe Gruchet Philippe Gruchet author of Open Tuning has offered a lot of suggestions ideas and testing on the PowerPC platform Thanks to Philippe for all communications and efforts which have helped make Diatonic Shifter 2 what it is today Philippe also contributed the Sine windowing function implementation a large portion of the pre sets contained in the bundled preset pack and introduced the concept of microtuning using Diatonic Shifter 2 The Apple CoreAudio Team The Apple CoreAudio Team has been very supportive and helpful while developing the Diatonic Shifter 2 Audio Unit and related products Special thanks to Michael Hopkins and William Stewart for answering a multitude of questions and helping debug code Lilypond The examples in musical notation in this manual were typeset using the open source Lilypond soft ware Thanks to the Lilypond team for providing this software application 25 See http www dspdimension com for Stephan M Bernsee s tutorials and examples 26 See http www open tuning com for more information on Philippe Gruchet s Open Tuning software 27 Se
28. plementation in Diatonic Shifter 2 You can easily switch to 19 TET D chromatic or any other 19 TET chromatic scale by setting the key parameter Concluding words The concept of producing a 19 TET G note by actually striking a 12 TET B note on your musical instrument might seem odd but it allows you to explore new musical scales and temperaments without having to acquire specialized musical instruments In this walkthrough we looked at simulating the first twelve notes of a 19 TET C chromatic scale but there is actually no limit as to which target scale and combination of notes you want to play Microtuning is possible because Diatonic Shifter 2 allows you to change the intervals between notes in the original 12 TET scale with great accuracy all the while preserving the sound characteristics of your original instrument Page 19 of 28 Diatonic Shifter 2 Audio Unit User Manual Audio Unit Parameters Overview Diatonic Shifter 2 offers numerous parameters for controlling the audio processing The following table lists individual parameters their group range default value and unit of measurement An elaborate description of each parameter is included below the table Master transposer 2400 2400 Scale Unison Major 2400 2400 seventh Accuracy threshold Jitter threshold Quality Low Latency or High Precision Low Latency Rendering Minimum Low Medium High and Medium Maximum Windowing Blackman Cosine
29. rval of the pitch shift relative to the original note Diatonic Shifter 2 labels each individual note with its interval relative to the root note like major second or perfect fifth as well as the absolute note name based on the key like D or G The pitch shift for each note is defined in cents a logarithmic measure for musical intervals 7 For regular musical performances in the 12 TET scale semitones are 100 cents apart adding up to 1200 for a full octave interval Diatonic Shifter 2 supports pitch shifts of minus two octaves 2400 cents to plus two octaves 2400 cents and everything in between For example if you wish to pitch shift a note up five semitones use a value of 500 cents Because Diatonic Shifter 2 is a diatonic pitch shifting effect the actually applied pitch shift at any given point in time is dependent on the note being played in the incoming audio signal Pitch monitor group Current note Shows the note that the pitch tracker currently detects in the input signal Although the current note parameter can not be manipulated it provides useful information for tweaking and troubleshooting the pitch tracker which is built into the Diatonic Shifter 2 Audio Unit Accuracy Displays the current confidence of the pitch tracker on a scale of zero to one hundred percent The accuracy meter is your main instrument for tuning the pitch tracker if results are flaky High accuracy values indicate that the incoming audio signa
30. the scale have been assigned the same pitch shift value or that the Diatonic Shifter 2 Audio Unit is being bypassed or muted from within the Audio Unit host application Page 11 of 28 Diatonic Shifter 2 Audio Unit User Manual Pitch Tracking group The A4 frequency parameter sets the frequency of the A4 note in Hertz In almost all cases the de fault value of 440 Hertz is correct Only set this parameter to a different value if you are playing in a non standard tuning or if your instrument is known to be slightly de tuned The pitch tracking threshold parameters and the quality group parameters fall outside of the scope of this basic usage tutorial See the Parameter Overview section for a technical explanation of these advanced parameters Congratulations If you have made it this far pat yourself on the back as you now know how to apply Diatonic Shifter 2 for basic diatonic pitch shifting and harmonizing Explore the rest of this manual for addi tional creative ideas and technical details 11 See the A440 entry on Wikipedia for a historical overview of this frequency http en wikipedia org wiki A440 Page 12 of 28 Diatonic Shifter 2 Audio Unit User Manual Usage Examples Introduction Diatonic Shifter 2 can be used for more than simple diatonic pitch shifting of an incoming audio signal This chapter provides examples in which Diatonic Shifter 2 is integrated into an audio ef fects chain Be creative and e
31. uality Group of Diatonic Shifter 2 and try to lower the Over sampling and Rendering parameters to reduce processing load Pitch tracking is incorrect or unstable If the pitch monitor built into Diatonic Shifter 2 consistently reports incorrect or inaccurate notes please check the following conditions e Make sure that the Diatonic Shifter 2 Audio Unit receives a monophonic instrument signal with proper volume and try raising or lowering the volume 21 Consult your application s manual documentation or contact the manufacturer of the software 22 If your system does not have the auval utility installed indicated by a command not found message you can get it as part of the Xcode suite Consult Apple s developer website http developer apple com on how to obtain Xcode 23 On multi processor or multi core systems check for spikes or high load on single processors or cores Page 24 of 28 Diatonic Shifter 2 Audio Unit User Manual e Check if the A4 frequency parameter corresponds with the current tuning of the instrument you are playing and check the tuning of your instrument retuning it if necessary e Set the Rendering and Oversampling parameter to a higher value to increase the implicit ac curacy of the pitch tracker If these actions do not solve the issue follow the instructions listed under the Pitch tracking group in the parameter overview to set the accuracy and jitter t
32. udio Unit Make sure to back up previous versions of the Audio Unit and document your user presets be fore replacing the old version If you want to make sure you performed the installation correctly refer to the Diatonic Shifter 2 does not show up in host software section in the troubleshooting chapter Preset pack installation Diatonic Shifter 2 comes bundled with a preset pack containing lots of predefined scales You can install these presets by dragging the Audiowish folder from the disk image to the Install Pre sets ALL users folder link in the disk image The presets are stored in thematic folders for convenient access Refer to your Audio Unit host software s manual on how to load and save presetst Trial version limitations The Diatonic Shifter 2 Audio Unit trial version is fully functional and will continue to function in definitely but every few minutes the output will be muted for a short period of time The trial ver sion of Diatonic Shifter 2 may not be used for commercial purposes To obtain a fully functional version of the Diatonic Shifter 2 Audio Unit visit its product page on the Internet http www audiowish com audio units diatonic shifter html 5 Be careful not to overwrite any existing presets for Audiowish Audio Unit effects by confirming the replacement of any existing folders If you already have Audiowish Audio Unit presets installed drag the Diatonic Shifter 2 sub
33. ve Shifter 2 is a free ware Audio Unit developed by Audiowish optimized for pitch shifting an audio signal by a fixed amount See http www audiowish com audio units octave shifter html for details and downloads Page 13 of 28 Diatonic Shifter 2 Audio Unit User Manual The following diagram shows a sample effects chain with three voices the original signal a dia tonically shifted major third voice and a perfect fifth voice using Octave Shifter 2 Original melody Transpose perfect fifth Output Transpose major third Effects chain for harmonizing chords using Diatonic Shifter 2 and Octave Shifter 2 It is entirely possible to have six or more simultaneous voices playing full chords like a six string guitar To maximize the amount of voices your computer can process use the low latency process ing mode combined with mono input channels Recursive If you are really in an experimental mood this effect might satisfy your quest for new sounds On a bus parallel to the input signal add a medium delay and Diatonic Shifter 2 Mix the output signal with the original melody and also feed it back around 25 with a low pass filter to the delay This diagram visualizes the effects chain 25 feedback Low pass Output Set to 333ms Transpose major sixth Original melody Effects chain for recursively harmonizing using Diatonic Shifter 2 In short what will happen is that each note you play will be transposed to its major s
34. xplore the possibilities Harmonizing Intervals Diatonic Shifter 2 can be used to add an extra diatonically transposed layer to a solo or lick by add ing it to a bus parallel to the input signal This diagram shows how to set up your effects chain Transpose major third Original melody Effects chain for harmonizing intervals with Diatonic Shifter 2 Set up the Diatonic Shifter 2 scale transposition pattern to transpose each note to its major third Adjust the mix of both the unmodified and transposed signal to find a sound you like Of course you can experiment with the scale transposition pattern as much as you like For in stance try shifting each individual note to a different target note or alternating major thirds and ma jor sixths Another things to pay attention to is using the master transposer to shift the transposed signal up or down one or multiple octaves If you play the guitar try adding a distortion effect at the end of your effects chain to achieve a solo guitar sound reminiscent of Queen s guitar player Brian May Given the right set up you can also come close to playing overdubbed solos in the metal genre on a single instrument Chords Why stop at harmonizing intervals when you can add a large number of parallel buses being shifted by Diatonic Shifter 2 in combination with Octave Shifter 212 You are only limited in the number of voices by the amount of processing power your computer provides 12 Octa
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