# Ohmforce — Bohm Multimodal Kick Drum Voice - [Manual PDF](../../manuals/Bohm_Eurorack_Manual_Compiled.pdf) --- [Manual PDF / Source](https://bohm-eurorack-manual.readthedocs.io/en/latest/index.html) # Using Bohm for dense, hyper-complex percussion Bohm is especially good for this because it is not just a single static kick voice: it is a **stereo dual-voice kick system** with **multiple models**, plus optional **Groove** and **Performer** expanders. That means you can treat it less like “just a kick” and more like a **central low-end percussion engine** for layered rhythmic architecture. ## What the module gives you musically From the manual, the key strengths for complex rhythm design are: - **Multiple kick models** with different architectures - **Stereo dual-voice behavior** - Controls for: - **HIT** - **VELOCITY** - **LENGTH** - **SUSTAIN** - **ATTACK** - **PITCH** - **CURVE** - **TRS DECAY** - **COLOR** - **FX** - **TRS TONE** - **Groove expander** for a **secondary kick voice** suited to rumbles and layered percussion - **Performer expander** for **DJ-style effects, ducking, and stereo processing** - **Running modes**: - Studio Mode - Live Song Mode - Jam Mode This makes Bohm ideal for building **nested rhythmic relationships** rather than a simple 4-on-the-floor kick. --- # Core strategy: think of Bohm as 3 percussion roles Use Bohm in three layers: 1. **Primary pulse** - The main downbeat anchor - Shorter, punchy, more defined 2. **Secondary low percussion** - Off-beat thumps, ghost kicks, tom-like low hits - Can come from alternate models or Groove voice 3. **Spatial/rumbled rhythmic tail** - Longer decays, stereo motion, FX, ducking - Creates density between primary hits If you patch and sequence those layers independently, you can create the impression of a whole percussion section from one kick-centered ecosystem. --- # Patch ideas for polyrhythms and complex time signatures ## 1. Polyrhythmic kick lattice Use separate trigger streams to create interlocking cycles. Example concept: - Main Bohm voice: trigger every **5 steps** - Groove voice: trigger every **7 steps** - Accent CV or velocity modulation: cycle every **3 steps** - Performer FX changes: cycle every **8 or 9 steps** This creates a composite pattern that takes many bars to fully repeat. ### How to shape it - Keep the **main voice** short: - lower **LENGTH** - moderate **ATTACK** - controlled **SUSTAIN** - Set the **secondary/Groove voice** longer: - more **TRS DECAY** - more **COLOR** - subtle **FX** - Modulate **PITCH** on only selected hits for pseudo-tom phrases This works especially well for **5:7**, **4:5**, or **3:4:7** relationships. --- ## 2. Complex-meter kick phrasing Instead of sequencing in 4/4, build phrases in meters like: - **7/8** - **9/8** - **11/8** - alternating **5/4 + 7/8** - **3+3+2** - **2+2+3** - **4+4+3** ### Practical use on Bohm Program your triggers so the strongest accents are not always on beat 1. For example in **7/8**: - Hit pattern accent structure: **3 + 2 + 2** - Strong hit on step 1 - medium on step 4 - lighter on step 6 Then use: - **VELOCITY** variation for accent hierarchy - **ATTACK** for sharper accented hits - **CURVE** to make some kicks snap and others bloom - **PITCH** slightly lower on the first group to reinforce phrase boundaries This gives the listener a strong internal pulse while still sounding asymmetrical. --- ## 3. Euclidean low-end percussion If your trigger sequencer supports Euclidean rhythms, Bohm can become the anchor for very dense structures. Try: - Main kick voice: **5 hits over 13 steps** - Groove layer: **7 hits over 16** - Accent modulation: **3 over 8** - FX bursts: **2 over 5** ### Why this works Because Bohm has enough tone-shaping controls to differentiate each layer: - shorter Euclidean streams become **dry punches** - longer sparse streams become **sub punctuation** - denser streams can be made **clickier and more percussive** with shorter sustain and more attack You are not just varying timing; you are varying **spectral role**. --- # Making the voice unique, punchy, and percussive Even though Bohm is a kick module, you can push it into a broader percussion vocabulary. ## 1. Turn kicks into a family of tuned percussion The manual notes that **PITCH** ranges roughly from **C1 to C2**, with adjustable pitch curves inspired by 808/909 behavior. Use that musically: - lower pitch = classic body/sub kick - mid pitch = tom-like percussion - high end of range = clicky attack drum or synth blip ### Technique Sequence pitch changes across a phrase: - Beat 1: low root kick - Beat 3: slightly higher “tom” - Beat 5: even higher accent hit - Ghost notes: very short, higher-pitched taps Then vary **CURVE**: - steeper curve = more classic electronic punch - softer curve = rounded low percussion This gives you **melodic percussion**, which is excellent in odd meters. --- ## 2. Use ATTACK and LENGTH as rhythmic articulation controls These are not just tone controls; they are groove controls. ### For punch - Increase **ATTACK** - Reduce **LENGTH** - Keep **SUSTAIN** controlled - Use shorter **TRS DECAY** This makes hits feel more like precision drum machine transients. ### For dense rhythm beds - Use alternating short and long hits - Short hits act like punctuation - Longer hits fill space between accents Example: - downbeats: short, sharp - offbeats: longer, smeared, colored - phrase-ending hit: long decay with FX That contrast is what creates “hyper-complex” feel without total mud. --- ## 3. Use VELOCITY as a structural sequencer lane If you can send variable accent or CV into velocity-related behavior, think of it as a compositional layer. Use 4 velocity tiers: - **high** = structural accents - **medium** = groove support - **low** = ghost hits - **very low** = almost-clicks Then map parameter response by model: - some models may react with more attack - some may react with more body - some may change timbre strongly This means a single trigger stream can become a **multi-level percussion line**. --- ## 4. Exploit model differences as “kit pieces” Because Bohm includes multiple kick “models,” assign different models to different compositional purposes. For example: - Model A: tight, dry punch for meter definition - Model B: boomy low-end support - Model C: distorted or colored industrial accent - Model D: click-forward transient percussion In **Studio Mode**, explore immediate parameter changes to find: - one model for anchor pulse - one for syncopated secondary hits - one for special fills Then save programs if your workflow allows, since the module stores **up to 32 programs**. --- # Using Groove for layered and rumble-heavy complexity The manual says Groove adds a **secondary kick voice for techno rumbles and layered percussion**. This is extremely useful for dense rhythm. ## 1. Separate transient from tail Use: - **Main Bohm voice** = transient and impact - **Groove voice** = longer low-end tail or off-beat rumble This gives you cleaner control over rhythmic density. ### Patch idea - Main voice on the grid - Groove voice delayed or sequenced in between grid points - Main voice: low sustain, sharp attack - Groove: more decay, more color, more FX Result: - the main voice defines meter - the Groove layer creates rolling momentum --- ## 2. Create call-and-response between voices In odd meter, alternate the voices as if they were two drummers. In **11/8**, for example: - Main voice accents: steps 1, 4, 7 - Groove voice answers: steps 3, 6, 9, 11 Then tune them slightly apart with **PITCH** and vary **COLOR** so they occupy different low-frequency identities. This becomes more like **interlocking hand drums or taiko logic**, but in electronic kick form. --- ## 3. Build pseudo-ratchets with layered short hits If your sequencer can create fast repeated triggers: - send the first trigger to main Bohm - subsequent flams/repeats to Groove - shorten both voices This makes percussive bursts that feel like: - machine-gun kicks - low tom rolls - granular impact clusters Especially effective before bar transitions or phrase resets in complex meters. --- # Using Performer for rhythmic motion and stereo complexity The manual says Performer adds **DJ-style effects, ducking, and stereo processing**. ## 1. Turn ducking into groove architecture Ducking is not just for mix cleanup. In dense percussion, it can become a rhythmic sculptor. Use ducking to: - carve space after major accents - make long Groove tails pulse around the main kick - exaggerate asymmetrical meter For example: - every strong hit ducks the stereo tail - weaker hits do less ducking - this creates macro-accent structure across a 7/8 or 13-step phrase --- ## 2. Use stereo processing to separate polyrhythms Put different rhythmic functions in different stereo behaviors: - centered = main structural pulse - widened/processed = secondary or off-grid material This helps dense patterns remain intelligible. A practical idea: - main kick dry and center - Groove/performance-processed tails wider - FX emphasized only on every 5th or 7th event This creates the sensation of multiple percussion layers moving at different rates. --- ## 3. Use FX as phrase punctuation, not always-on decoration With complicated rhythms, constant effects can blur the structure. Instead: - dry for most of the bar - apply **FX** only at: - phrase ends - metric pivots - fill moments - polyrhythm intersections That makes complexity feel intentional rather than messy. --- # Best running modes for this goal ## Studio Mode Use this first. Because parameter changes happen immediately, it is ideal for: - dialing in contrasting kick personalities - finding the exact attack/sustain balance - testing model behavior under rapid modulation - building a library of saved rhythmic voices Best for: - designing kits for odd-meter percussion - tuning layered rumble vs punch - discovering how models respond to accents ## Live Song Mode Use this when you want: - preplanned kick changes - different sections with different meter emphasis - reliable transitions between pattern families Good for arrangements like: - intro in 5/4 - main section in 7/8 - breakdown with sparse 3-against-4 pulse - climax with layered polymeter ## Jam Mode Best when you want performable instability. Use it for: - mutating pattern emphasis live - improvising fills - switching which voice dominates - riding FX and color for tension For hyper-complex percussion, Jam Mode is likely best when the sequencing is external and Bohm becomes the expressive sound-shaping center. --- # Patch recipes ## Recipe 1: Odd-meter industrial kick ensemble Goal: sharp, asymmetrical percussion in 7/8 - Sequence main voice in **3+2+2** - Set: - short **LENGTH** - medium/high **ATTACK** - low/moderate **SUSTAIN** - controlled **COLOR** - Add Groove on offbeats with: - longer **TRS DECAY** - lower pitch - subtle **FX** - Use Performer ducking on strong accents only Result: - articulated phrase divisions - heavy but readable low-end - aggressive machine-percussion feel --- ## Recipe 2: Polymetric techno rumble engine Goal: long-cycle interaction - Main voice: 4-step regular pulse - Groove voice: 5-step cycle - Accent/velocity: 7-step cycle - FX modulation: 9-step cycle Sound design: - Main voice = clean punch - Groove = longer rumble tail - Every 7th accent = extra pitch drop or color shift - Every 9th event = FX splash or stereo widening Result: - evolving phase relationships over many bars - still club-functional, but much more intricate than straight techno --- ## Recipe 3: Low tom + kick hybrid system Goal: make Bohm act like multiple drum instruments - Use one model as a classic kick - Use another setting or voice as a higher-pitched low tom - Sequence alternating pitches within one phrase - Shorten sustain on higher notes - Increase attack on accented tom-like hits - Use color variation to separate the “drums” Pattern example in 11 steps: - 1 = low kick - 3 = high tom hit - 5 = low kick - 7 = ghost tap - 8 = high tom accent - 11 = long tail phrase ending Result: - one module behaves like a mini percussion battery --- ## Recipe 4: Hyper-dense ghost-note engine Goal: lots of activity without losing punch - Main accents: high velocity, short decay - Ghost hits: low velocity, shorter length, slightly higher pitch - Keep ghost hits quieter and thinner - Use Groove only for selected reinforcement hits - Add Performer stereo or ducking to prevent overlap mud The trick is **spectral hierarchy**: - loud hits = low and full - ghost hits = smaller, brighter, shorter That makes density possible. --- # Composition tips specifically for complex rhythm music ## Use contrast, not maximum density everywhere If every hit is huge, complex rhythm turns to mush. Instead: - accents big - inner notes small - fills bright and short - rumbles reserved for transitions or support ## Let timbre mark the meter In odd signatures, listeners need cues. Use: - lower pitch on the first beat of a cycle - sharper attack on group boundaries - more color on phrase endings - extra FX only at long-cycle resets ## Build long-form repetition cycles For true hyper-complex feel: - trigger cycle length - velocity cycle length - pitch cycle length - FX cycle length Make each a different number of steps so the full phrase evolves slowly. ## Keep one stable reference layer Even with heavy polymeter, keep one voice acting as the listener’s anchor. Usually: - shortest - driest - most centered - least processed Then let everything else mutate around it. --- # Practical sound design checklist When dialing in Bohm for punchy complex percussion: - **Need more impact?** - raise **ATTACK** - shorten **LENGTH** - reduce excessive **SUSTAIN** - **Need more definition in dense patterns?** - shorten decays - separate main and secondary roles - use stereo/ducking to create space - **Need more variation?** - change **model** - modulate **PITCH** - vary **CURVE** - use **VELOCITY** in tiers - **Need more rumble without losing clarity?** - let Groove handle tails - keep main voice dry and punchy - use Performer ducking to shape overlap - **Need more “percussion” than “kick”?** - tune some hits higher - shorten them - use attack-heavy settings - alternate tonal roles across the phrase --- # Final approach If your goal is **densely rhythmic, hyper-complex percussion**, use Bohm as: - a **kick anchor** - a **layered low percussion pair** - a **stereo rhythmic texture generator** The real power is in separating functions: - **main pulse** - **secondary counter-rhythm** - **tail/rumble/space** - **accent/effect punctuation** With external sequencing, odd meters, and differing trigger cycle lengths, Bohm can become the low-frequency heart of a very advanced rhythmic patch. The module’s controls let you move beyond straight kick duty into **tuned low percussion, ghost-note structures, industrial impacts, rumble counterpoint, and evolving polymetric low-end architecture**. [Generated With Eurorack Processor](https://github.com/nstarke/eurorack-processor)