Как сохранить миди в fl studio, чтобы звучали ударные.

для ударных нужно выбирать 10-й MIDI канал

зачем вам миди, вы хотите слушать миди-музыку? FL не поддерживает полноценную работу с миди, У вас всё играет пианино, значит всё играет на первом миди-канале.
https://ru.wikipedia.org/wiki/General_MIDI
В стандартных MIDI-файлах GM канал 10 зарезервирован только для перкуссионных инструментов. Ноты, записанные на канале 10, всегда производят звук перкуссии при передаче на клавиатуру или синтезаторный модуль, использующий стандарт GM. Каждый отдельный номер ноты указывает на уникальный ударный инструмент, а не на высоту звука.
Миди-инструменты:
Piano
1 Acoustic Grand Piano
2 Bright Acoustic Piano
3 Electric Grand Piano
4 Honky-tonk Piano
5 Electric Piano 1 (usually a Rhodes Piano)
6 Electric Piano 2 (usually an FM piano patch)
7 Harpsichord
8 Clavinet
Chromatic Percussion
9 Celesta
10 Glockenspiel
11 Music Box
12 Vibraphone
13 Marimba
14 Xylophone
15 Tubular Bells
16 Dulcimer
Organ
17 Drawbar Organ
18 Percussive Organ
19 Rock Organ
20 Church Organ
21 Reed Organ
22 Accordion
23 Harmonica
24 Tango Accordion
Guitar
25 Acoustic Guitar (nylon)
26 Acoustic Guitar (steel)
27 Electric Guitar (jazz)
28 Electric Guitar (clean)
29 Electric Guitar (muted)
30 Electric Guitar (overdriven)
31 Electric Guitar (distortion)
32 Electric Guitar (harmonics)
Bass
33 Acoustic Bass
34 Electric Bass (finger)
35 Electric Bass (picked)
36 Fretless Bass
37 Slap Bass 1
38 Slap Bass 2
39 Synth Bass 1
40 Synth Bass 2
Strings
41 Violin
42 Viola
43 Cello
44 Contrabass
45 Tremolo Strings
46 Pizzicato Strings
47 Orchestral Harp
48 Timpani
Ensemble
49 String Ensemble 1
50 String Ensemble 2
51 Synth Strings 1
52 Synth Strings 2
53 Choir Aahs
54 Voice Oohs (or Doos)
55 Synth Voice or Solo Vox
56 Orchestra Hit
Brass
57 Trumpet
58 Trombone
59 Tuba
60 Muted Trumpet
61 French Horn
62 Brass Section
63 Synth Brass 1
64 Synth Brass 2
Reed
65 Soprano Sax
66 Alto Sax
67 Tenor Sax
68 Baritone Sax
69 Oboe
70 English Horn
71 Bassoon
72 Clarinet
Pipe
73 Piccolo
74 Flute
75 Recorder
76 Pan Flute
77 Blown bottle
78 Shakuhachi
79 Whistle
80 Ocarina
Synth Lead
81 Lead 1 (square)
82 Lead 2 (sawtooth)
83 Lead 3 (calliope)
84 Lead 4 (chiff)
85 Lead 5 (charang, a guitar-like lead)
86 Lead 6 (space voice)
87 Lead 7 (fifths)
88 Lead 8 (bass and lead)
Synth Pad
89 Pad 1 (new age or fantasia, a warm pad stacked with a bell)
90 Pad 2 (warm)
91 Pad 3 (polysynth or poly)
92 Pad 4 (choir)
93 Pad 5 (bowed glass or bowed)
94 Pad 6 (metallic)
95 Pad 7 (halo)
96 Pad 8 (sweep)
Synth Effects
97 FX 1 (rain)
98 FX 2 (soundtrack, a bright perfect fifth pad)
99 FX 3 (crystal)
100 FX 4 (atmosphere, usually a nylon-like sound)
101 FX 5 (brightness)
102 FX 6 (goblins)
103 FX 7 (echoes or echo drops)
104 FX 8 (sci-fi or star theme)
Ethnic
105 Sitar
106 Banjo
107 Shamisen
108 Koto
109 Kalimba
110 Bag pipe
111 Fiddle
112 Shanai
Percussive
113 Tinkle Bell
114 Agogô
115 Steel Drums
116 Woodblock
117 Taiko Drum
118 Melodic Tom or 808 Toms
119 Synth Drum
120 Reverse Cymbal
Sound Effects
121 Guitar Fret Noise
122 Breath Noise
123 Seashore
124 Bird Tweet
125 Telephone Ring
126 Helicopter
127 Applause
128 Gunshot