It is possible to get muted brass from the stuff included with Dorico.
I’d like to encourage people to open HALion and simply play around with it. Read the user manual for it. Dorico comes with a decent pallet of sounds that were designed to be ‘shaped and molded’ by the user from day one. A sound that might not be working at its default settings, often has a lot of controls and options in HALion that can be used to shape things up so they fit your mix.
In fact, if one has updated to the latest version of HALion Sonic SE 3, one can even run it as a stand alone instrument to access the content that came with Dorico and get some ideas on how useful and expressive the HALion engine can be. Just launch it, and play it with your MIDI keyboard, wind jammer, whatever…
I’ll begin with a simple example that isn’t going to be a true muted trumpet sound, but it might be a good enough start to get the idea across. You’ll definitely be able to force enough of a timber change to get the point across that the brass is ‘now muted’.
The default Halion Symphonic Brass instruments do have a pair of controls called “Body” (CC 77) and “Air” (CC78). Bringing these to lower levels can produce a more muted sound. Altering the ambient controls can help as well. There is also a ‘width’ control (No CC by default, you can have HALion ‘learn’ one for you if needed) that can lead to a more muted trumpet sound.
It’s very possible to create expression maps that will bounce these controls around in response to mute and unmute techniques. If one is using Dorico 2 Pro, such automation can also be placed directly on Controller Lanes in the Play Tab.
Dorico ships with other brass sounds besides HSO too. Examples are [GM 060] Muted Trumpet, Soulful Muted Trumpet NoteExp, and more. Each of these instruments have a variety of controls that can be tweaked to shape the sound more to need, and users can store presets of their favorite tweaks. It’s also possible to set HALion up in a way that is responsive to ‘program changes’, so the instrument/program in a slot can be changed on the fly.
Anything you see in the HALion Quick Control knobs can be automated from Dorcio expression maps, or controller lanes. One can find the corresponding CC messages here. Controls in the “Edit” macro of an instrument can be assigned to any CC you like.
For sounds that have resonance and cutoff filter controls (see the edit tab in HALion for various brass sounds), those are a great way to shape a typical brass sample into one that sounds ‘muted’. In fact, many fine brass sample libraries do just that to get convincing wah-wah and plunger effects. They simply drive the filters…
With imagination, one can also layer up sounds to emulate the overtones prevalent from various types of mutes. I.E. One might mix a standard trombone sound, with a muted trumpet at a much lower volume to get a more ‘tinny’ effect one would expect from a harmon mute vibrating. It’s quite possible to set multiple slots in a HALion instance to receive from the same channel, thus ‘layering’ sounds.
HALion SE also has 4 Effect Sends built in, where one can assign quite an array of included effects and bring them in and out of the mix, again using CC (91-94) events. These effects include notch filters, tone boosters, compressors, equalizers, reverbs, and more. All sorts of tools are there that can be used to shape an existing brass sample into a very convincing ‘muted’ brass sound.
Finally, there are also quite a few VST plugins included with Dorico that can be placed in the Dorico Mixer inserts that can help create a very convincing muted brass sound. The catch with this approach, is that you’ll probably need to keep your muted instruments on staves of their own (at least for playback purposes).