tmux, systemd and jack capture

Hey!

I have a hard time setting up a tmux session started with systemd on 
raspbian (patchbox OS, realtime kernel) to behaves like as if I started 
my script manually.


This is my Jack Capture service:

[Unit]
Description=Jack Capture autostart daemon
Wants=jack.service
After=multi-user.target

[Service]
Type=forking
EnvironmentFile=/etc/environment
User=patch
Group=realtime
ExecStart=/home/patch/jack-capture-tmux.sh

[Install]
WantedBy=jack.service


and this my script to start tmux with jack capture:


#!/bin/bash
. /etc/environment
/usr/bin/jack_wait -w
tmux new-session -d -s jackd
tmux new-window -t jackd -n Jack Capture -d
sleep 1
tmux send-keys -t jackd:0 'cd ~/' C-m
tmux send-keys -t jackd:0 'clear' C-m
tmux send-keys -t jackd:0 'jack_capture -c 2 -mb -tm -f wav 
--filename-prefix ABC-TEST- --hook-close ./hookstop.sh --hook-timing 
./hookstart.sh' C-m

everything a bloated from all my tries to make this work...

Now it starts properly but if I look into that tmux session I get 
warnings/errors:

  jack_capture -c 2 -mb -tm -f wav --filename-prefix ABC-TEST- 
--hook-close ./hookstop.sh --hook-timing ./hookstart.sh
Cannot lock down 82287136 byte memory area (Cannot allocate memory)
>>> Warning. Could not set higher priority for a SCHED_OTHER process 
>>> using setpriority().
Cannot use real-time scheduling (RR/70)(1: Operation not permitted)
JackClient::AcquireSelfRealTime error
>>> Waiting to start recording of "ABC-TEST-10.wav"
>>> Press <Ctrl-C> to stop recording and quit.

I had this solved when starting the script manually by adding * - nice 
-20 into /etc/security/limits.conf - but this obviously is not working 
when starting the script within systemd (although same user).

Any ideas?

Cheers
Jan