Lekholm Instruments DM48X User manual

USER MANUAL
Firmware version 1.06
© 2022 Lekholm Instruments AB
DM48
LEKHOLM INSTRUMENTS
DIGITAL CHROMATIC HARMONICA

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Contents
Important general notes .................................................................................................. 4
Introduction ........................................................................................................................... 5
Overview of the DM48X.............................................................................................................. 5
Quick start guide........................................................................................................................... 5
General configuration and operation guide ........................................................... 6
Introduction to MIDI and the DM48X................................................................................... 6
Setting up your DM48X .............................................................................................................. 8
Changing and restoring default settings........................................................................... 8
Battery and charging .................................................................................................................. 9
Firmware version and serial number check..................................................................... 9
Menu reference...................................................................................................................10
Global preset.................................................................................................................................10
Breath control submenu..........................................................................................................10
Breath sens.................................................................................................................................................10
Breath curve ..............................................................................................................................................10
Breath CC#.................................................................................................................................................11
Note trig level ...........................................................................................................................................11
Velocity sens..............................................................................................................................................11
Mono/poly ...................................................................................................................................................11
Hole sens bias...........................................................................................................................................11
Bend/modultn submenu .........................................................................................................12
Ribbon func ...............................................................................................................................................12
Ribbon sens ...............................................................................................................................................12
Ribbon center...........................................................................................................................................12
Rbn smooth...............................................................................................................................................12
Rbn mod CC#...........................................................................................................................................12
Brth bend trig...........................................................................................................................................12
Brth bend sens.........................................................................................................................................12
Brth mod trig............................................................................................................................................13
Brth mod sens..........................................................................................................................................13
Brth mod CC# ..........................................................................................................................................13
Sliders submenu..........................................................................................................................13
Slider interval............................................................................................................................................13
Slider delay.................................................................................................................................................13
2nd/3rd slider ...........................................................................................................................................13
2nd slider intv...........................................................................................................................................14
3rd slider intv............................................................................................................................................14
Sliders CC# .................................................................................................................................................14
Sliders CC value.......................................................................................................................................14
Key transp ......................................................................................................................................14
Octave transp................................................................................................................................14
Tuning ..............................................................................................................................................15
Tuning editor ................................................................................................................................15
MIDI submenu...............................................................................................................................15
MIDI channel.............................................................................................................................................15
MIDI program............................................................................................................................................16
Double notes.............................................................................................................................................16

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Display..............................................................................................................................................16
Setup examples and guidelines .................................................................................17
GarageBand or Logic .................................................................................................................17
Reason and Acoustic Electro Waves..................................................................................17
Multichannel setup with ThumbJam ................................................................................18
Multichannel setup in Reason...............................................................................................18
Yamaha VL70-m and other hardware synthesizers....................................................19
Lid removal and breathing resistance adjustment ...........................................20

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Important general notes
Please read these notes carefully before using the DM48X multichannel
MIDI wind controller.
• Note that the on-board battery only charges when the backside
connector is in the “on/charge” position (indicated by a flash symbol).
This allows charging to be switched off when connecting to low-
power devices such as iPhones or iPads. These can power DM48X itself
but do no supply enough current for charging.
• The red light on the back of the instrument will go off when charging
is finished. When charging is disabled, the red light will simply
indicate that the DM48X is connected and powered via USB.
• Bluetooth (BLE) MIDI is typically connected from within your music
app (“MIDI settings” or similar – please see relevant manual)
• The DM48X it designed to be played in the same pressure range as a
acoustic chromatic harmonica. When properly setup, it should
respond swiftly to gentle blowing force. While the pressure sensors
are rated to handle pressures beyond what can be experienced
during normal play, in no way must they be exposed to unnatural
excessive air pressure, such as pressurized air from compressors or
“canned air” containers.
• Do not expose the slider button to unnecessary force.
• Similar to a normal chromatic harmonica, the DM48X should be
handled with care and not be exposed to falls or strong forces. Store
and transport it in its protective case. Be careful not to scratch the
protective black anodized surface on mouthpiece.
• The mouthpiece can be cleaned using a damp cloth. We recommend
cleaning it before first use. Cotton swabs can be used for cleaning
inside the channels. The mouthpiece can be detached using a
screwdriver, although this is generally not needed or recommended.
When reattaching the mouthpiece, do not over-tighten the screws.
Pull it just enough to ensure it sits airtight against the chassis (test
this by blocking each hole with a finger on the back of the
instrument).
• Make sure the USB cable is properly connected: a slight “click” should
be felt when connecting the micro-USB connector. Ensure proper
orientation of the connector to avoid damage. Do not expose the USB
connector to mechanical forces. A hole in the chassis at the backside
of the instrument allows the USB cable to be secured using a cable
tie for safer live playing.

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Introduction
Overview of the DM48X
The DM48X is a MIDI controller without sound synthesis. From the point-of-
view of a music production application or synthesizer, it behaves like a MIDI
controller keyboard. However, rather than keys, it makes use of twelve
pressure sensors to present the user with a chromatic harmonica-like
control interface. Similar to a MIDI controller keyboard, knowledge of MIDI,
synthesizers, and computer-based sound synthesis/production is useful to
make good use of it.
A single USB cable supplies both communication (using the so called “class-
compliant USB MIDI” standard) and power. The supplied USB cable allows
the DM48X to be connected to a Mac or PC, and using a suitable converter
such as the Apple Lightning to USB adapter it can also be connected to
portable devices such as iPads/iPhones. When the backside switch on the
instrument is in the “on/charge” position, the USB connection will allow the
onboard battery to be charged (note that Apple devices can power the
DM48X but do not provide enough power for charging). A suitable software
or hardware synthesizer is needed for sound synthesis, and examples and
affordable suggestions are given below (see Setup examples and
guidelines ). Bluetooth Low Energy (BLE) MIDI allows wireless playing. On
iOS, this connection is typically established from within each music app
(please see relevant manual for your software).
Quick start guide
Connect your DM48X via USB to a computer (Mac or Windows) or
iPad/iPhone (either via Bluetooth or using an Apple USB Camera Adapter).
Select an instrument of choice in your music software (e.g. GarageBand or
similar) and start playing. The DM48X is usually recognized immediately,
and if not, check the MIDI settings in your software and choose DM48X as
your input device.
Upon startup, the DM48X will show the Global preset page. Press the round
button to enable toggling between presets using the arrows. Use the Wind
preset when playing wind instruments sounds such as saxophone. Use the
Keyboard preset if playing piano-type or other plucked sounds. That’s it!
The DM48X is a lot more advanced than this, but in most situations this
should get you started. Detailed information about configuration and
relevant MIDI concepts is found in the pages that follow.

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General configuration and operation guide
Introduction to MIDI and the DM48X
Even if you are familiar with MIDI – and even MIDI wind controllers – we
recommend reading the following notes, which go deeper into some
special considerations and some more advanced aspects of the MIDI data
generated by the DM48X. However, it is by no means necessary to have a
full understanding of these concepts to get a lot out of the instrument, and
many users may only need to consider the Quick start guide above.
There are two main types of MIDI messages: note on/off events and
“Controller Change” (CC) events. A MIDI controller keyboard can work well
using only the former, which is enough to trigger notes at different velocities
(depending on the force applied to the key) and stop notes when keys are
released. While MIDI wind controllers also sends note on/off messages,
sometimes with variable velocity depending on configuration, they
primarily make use of MIDI CC events to modulate the intensity/volume of
the sound. Such messages are transmitted continuously at a high rate also
after a note has been triggered. This allows the intensity of the sound to be
modulated during the full duration of the note, as the player changes the
applied air pressure. MIDI pitch bend messages are likewise transmitted
continuously during the duration of the note.
By default (the Wind global preset loaded at startup), the DM48X is set to
monophonic mode (see Mono/poly below), meaning that no more than one
note is ever triggered at a time. Velocity is set to a fixed static value (see
Velocity sens below), while breath MIDI CC data will be transmitted
continuously (see Breath sens below). Most users will find that this gives
good playability with wind instrument sounds. A second preset is provided
( Keyboard ), where velocity is dynamically determined depending on breath
force, breath MIDI CC data is turned off, and polyphonic mode is active.
These settings are suitable for piano-type sounds, where sound intensity
modulation occurs only at note triggering. It is often not desirable to
combine dynamic velocity (velocity sensing) and breath MIDI CC data, an
exception being patches/sounds specifically adapted for wind controllers,
which may sometimes accurately handle both types of information
simultaneously.
MPE (MIDI Polyphonic Expression) patches/synths is another case where
combined dynamic velocity and breath pressure data is highly beneficial.
These are sounds meant to be controlled by expressive controllers such as
ROLI Seaboard or the Linnstrument. An appealing property of these sounds
are that they are designed to be modulated by a continuous pressure signal,
much like wind controller patches, and may therefore be interesting to
explore with the DM48X. A specific preset ( Mpe ) provides settings suitable
for MPE sounds, which are further discussed below.
In polyphonic mode, when multiple notes can be triggered simultaneously,
there are some additional considerations. An important property of the MIDI

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standard is that MIDI CC and pitch bend messages affect all triggered notes
on a given MIDI channel. For a saxophone-type MIDI controller this is not a
limitation, since the instrument is monophonic. In the case of a MIDI
harmonica, this means that notes in a chord will be played at the same
breath intensity, and that bending affects all triggered notes equally. If
neighboring holes are triggered by mistake, these will be played at the same
intensity as the target note (there is also more advice in Setting up your
DM48X below). Velocity does not have this problem, as velocity values are
sent for each note individually.
The limitation described above applies when the DM48X is set to
Polyphonic mode and transmits all data on a single MIDI channel (1 by
default). The issue can be overcome by instead using multichannel mode
(see MIDI channel below). In this configuration, each hole transmits MIDI
data on a separate MIDI channel (1-12). With proper setup on the
synthesizer side, the holes can then be modulated completely
independently of each other, as on an acoustic harmonica. This is not
complicated in principle, but does require a more complex setup on the
receiving end. Some synthesizers (see Multichannel setup with ThumbJam
below) will work immediately with the DM48X in multichannel mode, while
others require a more complicated configuration, sometimes involving
multiple instances of a synthesizer on multiple tracks where each one is set
to only receives on a single MIDI channel (see Multichannel setup in Reason
below). “Reduced” multichannel configurations are also possible, such that
for example four channels are used (the twelve holes will in this case
transmit on channels 1-2-3-4-1-2-3-4-1-2-3-4 or 2-3-4-5-2-3-4-5-2-3-4-5).
This reduces the number of required synths/tracks.
One simple way of achieving true polyphonic “per hole” pressure
modulation is to use some of the above mentioned MPE synths and patches,
as these are normally designed to receive polyphonic pressure data on
multiple channels. Using an MPE sound source, proper polyphonic pressure
modulation can often be achieved simply by selecting the Mpe preset on
the DM48X. Note that MIDI over Bluetooth (BLE), which has low data
bandwidth, may lead to latency issues in combination with the MPE preset
and multichannel mode in general, in particular when using the ribbon
controller, since pitch and modulation data will be sent on all channels
simultaneously (thus generating lots of data per time unit). Reducing the
number of channels will in this case be helpful.
With C solo tuning (and many other tunings) and using polyphonic mode,
it is possible to trigger two identical notes (typically “C”) simultaneously –
something that cannot be achieved with a keyboard. Many synths will
handle this correctly and will play double notes, including standard wind
instruments in GarageBand or Logic. However, some, including most
monophonic synths, are not prepared for this. When two notes are triggered
and one of them is released, this may cause the second one to go silent, too.
By default, the DM48X is therefore set to block double triggering of the

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same note. This is controlled by Double notes parameter (see below).
However, when using a synthesizer that correctly handles double notes, or
when using a multichannel configuration, it is more appropriate to allow
double note triggering.
Setting up your DM48X
By connecting the USB cable, the DM48X should immediately become
selectable as an input MIDI device in your favorite music software without
any special drivers. Alternatively, connect via Bluetooth MIDI, which is done
within your music app (iOS) or in Audio MIDI Setup (MacOS).
The default settings on the DM48X give a good starting point and few
changes should be needed for an initial setup. Parameters will return to
default as soon as you turn it off and on again, so there is no need to be
afraid to explore different settings.
The most important parameter that may need to be changed is Breath CC# ,
which determines what MIDI CC number is used to transmit breath pressure
data to the receiving synthesizer. This parameter defaults to 11 (Expression),
which works for many standard instruments, for example in Logic or
GarageBand. However, some synths may instead expect 2 (Breath
Controller) or a specialized message called Channel pressure (also called
aftertouch), which is also supported by the DM48X and selectable on the
same menu page.
Breath sens determines the pressure sensor gain. Less force is required
during playing when this parameter is increased, but this will also make it
easier to saturate the intensity of the sound, resulting in loss of
expressiveness/dynamics. Many times it is rather the playback volume on
your amplifier that needs to be increased – try that first! Note trig level
determines the amount of pressure required to trigger a note. Lowering it
makes the DM48X more responsive, but also increases the risk of triggering
a note by mistake. Velocity sens should normally be off and set to a static
value around 100-127 but this depends on the type of sound being played,
as discussed above. Asstd poly (assisted polyphonic mode) makes it easier
to play clean solo tunes by actively suppressing triggering of neighboring
holes, while still allowing chords. This feature is accessible from the
Mono/poly menu page, as is also monophonic mode (default), which is
usually preferable if only single notes are to be played. Many sounds are
more interesting outside of the default note range – try Octave transp to
shift down an octave or two.
Changing and restoring default settings
Once you have found settings that you like, you can make these your new
defaults such that they will be loaded every time you power up the
controller. Go to the Global preset menu page and hold down the round
button for two seconds. Select one of twelve possible “slots” and press the
round button. The name of the slot will now be editable using the arrows,
slider and round button. To save without changing the name, keep pressing

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the round button several times until a confirmation message is shown.
The DM48X can be restored to factory default settings by holding down all
three menu buttons during power-up. Release when a confirmatory
message is seen on the display. Note that custom tunings will still be
maintained. A full restore, including tunings, will be achieved if the three
buttons are kept pressed even longer, until a confirmation about restored
tunings is shown.
Battery and charging
A built-in battery keeps your DM48X running wirelessly for up to 5 hours.
Charging is done via USB and takes about 2 hours from empty to full
battery. Then backside switch on the instrument has dual roles, depending
on whether there is a USB connection or not. Without USB, it serves simply
as an on/off power switch. When USB is connected, the switch decides
whether the battery should be charged (indicated by a battery and bolt
icon on the back) or not. This is to allow connection to low-power USB
devices such as iPads and iPhones, which would otherwise inactivate the
connection due to overloading of the USB port. Remember to put the
switch in charge position when charging is desired! The red backside LED
on the DM48X will turn off when charging is complete. When charging is
turned off using the backside switch, the LED will simply indicate an active
USB connection. A warning is displayed on the DM48X screen when the
battery is low. When the battery is basically empty, operation of the
instrument will stop and the user will be advised to immediately start
charging via USB.
Firmware version and serial number check
By holding down the slider during power-up, the version of the currently
installed firmware as well as the electronic serial number of your DM48X
will be shown on the screen. Keep holding the slider a little longer and the
DM48X will enter “update mode”, meaning it is ready to receive a firmware
update via USB. Further information about this is provided in the firmware
update files that are distributed through the Lekholm Instruments
homepage, where the latest version is always available for download.

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Menu reference
This section lists all parameters and features on the DM48X, all accessible
through the on-board menu system, which is organized into submenus.
Simultaneously pressing the slider and the round button will quickly take
you out of a submenu, and this shortcut can also be used to quickly reach
the Global preset and 2nd/3rd slider pages.
Global preset
The DM48X provides 18 “slots” for storing global settings. By holding down
the round button for two seconds, this page will also allow the current
settings to be saved to one of the available slots. Note that the first slot
( Wind ) is always loaded at startup. A Keyboard preset is also provided for
Keyboard-type instruments, as well as an Mpe preset for MPE (MIDI
Polyphonic Expression) synths/patches (see Introduction to MIDI and the
DM48X above). A Geoswam preset is also provided, containing settings
suitable for SWAM instruments in the GeoShred iOS app. Stored settings are
recalled immediately when selected on this menu page, and corresponding
tunings will also be loaded. Additionally, MIDI program change messages
will be sent in cases when loading a preset causes this parameter to change.
After a slot is selected, the name of this slot can be edited. The arrows are
used to change the character at the cursor, and the round and slider
buttons are used to move to the next and previous character, respectively.
Press the slider and round button simultaneously to quickly reach this page.
Breath control submenu
This submenu contains settings for adjusting the general playing response
as well as selection of the MIDI CC number used for sending breath data.
Breath sens
Controls dynamics and volume depending on how hard and soft you play.
Specifically, this is the sensitivity/gain for controller (MIDI CC) messages that
determine sound volume/intensity. Controller messages are sent at a high
rate, such that the volume/intensity can be modulated post triggering a
note based on the applied pressure. When set to a lower (less sensitive)
setting, more pressure needs to be applied to reach maximum sound
intensity. If set too high, the instrument becomes less dynamic as maximum
intensity is quickly reached. Set Breath sens to off to completely turn off
breath MIDI CC data. Note that many times it is the playback volume that
needs changing rather than Breath sens – try this first.
Breath curve
Response curve for volume/intensity MIDI CC messages. A non-linear curve
that reaches higher intensities sooner may provide a more harmonica-like
feel/response. However, it should be noted that this also depends on the
characteristics of the downstream synthesizer. Sensitivity (above) may need
to be reduced to compensate for a more aggressive response curve.