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Table of Contents Introduction!..................................................................................3 User Interface Front!.....................................................................4 User Interface Back!.....................................................................5 Using Bitspeek with Stereo Signals!.............................................7 Bitspeek Versus Vocoders!...........................................................8 Example Combinators!..........................
Introduction INTRODUCTION Bitspeek is a real-time pitch-excited linear prediction codec effect. Right now you are probably thinking, "oh, another one of those"? Or perhaps not. Chances are that you have never heard about "linear prediction", although most of us use it daily when we talk on our cell phones. Linear prediction coding is a voice compression technology that appeared in commercial products in the seventies and was implemented in some well-known speaking toys of the early eighties.
User Interface Front RATE (kHz) Bitspeek performs its calculations at a designated fixed sample-rate, regardless of the sample-rate your project is running at. The possible settings are 8 kHz, 11 kHz, 22 kHz and 44 -> 48 kHz (the last mode will actually adjust to the project samplerate and select a rate between 44 and 48 kHz). Notice that Bitspeek is still compatible with any sample-rate by performing automatic sample-rate conversion.
PITCH You can transpose the generated audio by -36 to +36 semitones (-3 to +3 octaves). FINE Fine pitch adjustment from -100 to +100 cent. TRACKING Determines the amount by which the synthesized audio follows the pitch of the source signal, from 0% to 200%. At 0%, the pitch will stay fixed and produce a robotic vocoder-like quality. At 100%, the processed audio will follow the pitch intonation of the original audio as closely as possible.
EXT IN, the internal synthesizer in Bitspeek will be disabled and the external signal will be processed by the formant filter instead. There is a built-in pre-emphasis stage that boosts higher frequencies to prevent the result from becoming too "muddy". AUDIO OUT The output signal. If you have connected both input channels (or external input channels) you would normally want to connect both outputs as well. Bitspeek will not automatically mix or split signals from stereo to mono or vice versa.
PITCH OUT Unlike NOTE OUT, PITCH OUT is bipolar and not quantized to semitones. It provides an alternative to connecting NOTE OUT if you need more exact pitch tracking. However, it requires a slightly more complicated setup, depending on implementation details of the synth you are connecting. E.g. Thor uses a different range for CV pitch modulation than SubTractor and Malström. When PITCH OUT is connected, the NOTE OUT signal will be fixed at middle C.
Bitspeek Versus Vocoders Vocoder is short for "voice encoder" and technically that means any device that is capable of breaking down a voice signal into a set of parameters from which you can reconstruct the voice intelligibly. With this terminology, Bitspeek may be called an "LPC vocoder". (LPC is short for "linear prediction coding".) However, in musical contexts, the vocoder we all know is a device consisting of a filter bank that is controlled from a modulation source (e.g. speech).
FMTalk This wacky lo-fi patch is similar to SubSpeek but it does not connect PITCH CV OUT. Instead it relies on NOTE CV only (which is "quantized" to semitones). The SubTractor patch is set to "Legato" and has a little "Portamento" to make pitch changes smoother. "Amp Level" is scaled less than 100% which produces a slightly compressed result. ChoruSpeek Another Bitspeek SubTractor Combinator, this time with two SubTractors and a little chorusing before returning the audio to Bitspeek.
MalSpeek This Combinator uses Malström instead of SubTractor. Malström's "level" CV input uses a logarithmic curve instead of the linear one found on SubTractor. Luckily we have a logarithmic volume output on Bitspeek too and it is called GATE. A Spider does the job of feeding the GATE both to "gate" and "level" on Malström. BitFreeze With the default Combinator settings, Bitspeek is using SYNC mode with a pretty low FRAME RATE and it is set to full NOISE.
TalkingDrums This time we are feeding drums into EXT IN to filter them with the formants of the audio that is entering AUDIO IN. With the default Combinator settings, the FRAME RATE is set to SYNC on 16th notes, producing a sample-andhold like quality. Subtle reverb and compression is applied before feeding the signal to Bitspeek. NoiseWash Here is an interesting concept.
Credits and Contacts Sonic Charge Bitspeek RE v1.0.0 (2012) Created by: Magnus Lidström Graphical design and additional development: Fredrik Lidström Sonic Charge website: http://soniccharge.com Copyrights And Trademarks The Sonic Charge Bitspeek software and documentation is owned and copyright by Sonic Charge 2012, all rights reserved. Bitspeek software and documentation is protected by Swedish copyright laws and international treaty provisions.
