Allen & Heath Qu mixer NRPN

Every 2 or 3 years, I have need of the mighty MTP, and I start all over learning it.

I'm trying to talk to my Soundcraft Qu32 mixer, controlling bus sends from specific channels with a BCR2000. The Qu speaks sort of 14 bit NRPN, except the channel number is Parameter MSB, there's a function identifier constant in the Parameter LSB, the variable is in the Value MSB, and there's a bus identifier constant in the LSB. How do I construct that and output it? If I select NRPN as an output message, it wants a number for Parameter MSB and LSB. Not accepting a variable.


Hi, well this is a new one for me but I have an idea. I’m not sure why the MSB and LSB need to be constants.

I suggest you use raw MIDI message instead. If I remember the MSB is 99 and LSB is 98 and the value is 6.

So if I convert to hex the message would look something like this

B0 63 pp B0 62 qq B0 06 rr

B0 is controller on MIDI channel 1

63 is hex for 99

62 is hex for 98

So you would use the value of pp as your value for MSB and the value of qq for your value of MSB and rr as the value you want to send.

Let me know if this helps. In the meantime, I’ll check around to find out why NRPN MIDI requires hardcoded values instead of variable.


Independent Bome Programming Specialist

Bome Q&A moderator


1 Like

Oh, of course, I can just build it myself. That should work.

> I’ll check around to find out why NRPN MIDI requires hardcoded values instead of variable.

Thanks. I wonder if I have something set wrong somehow.

Whoops, Allen & Heath, not Soundcraft.

indeed, we never envisioned this use of NRPNs and therefore did not provide for variables in NRPN LSB or MSB. Not sure how common that is, and the workaround is fine…

I have it fully functional now, and bidirectional, but my decision tree makes it difficult to arbitrarily assign channels. If MSB and LSB were independent variables, that would be trivial. I’m trying to grab a selection of effect sends from among 32 channels and 15 sends, and assign them to my 32 knobs.

If you show me what you have, maybe I can find a better algorithm with rules to make it easier for you.
It probably just needs a little bit of “bit manipulation” rules to properly assemble the output message.

I started over with a few global variables to assign Qu channels to BCR columns, and Qu sends to BCR rows. Much more efficient.

Glad you found a solution!

Steve – tech2… I have the same need here (working an Allen & Heath iLive board into a MIDI controller). The iLive seems to be sending 7-bit NRPN, but I’m sure the same process for your solution will work. In any case, can somebody show me the process to get bidirectional access with these NRPN values?

Hi Jamey,

Please post a new question with a given NRPN message that you want to convert to some other type of MIDI message and what you would like it converted to and I can post a project file with an example for converting in both directions.

If you want me to create a complete solution for you, I’m available for hire so send me email.

Steve Caldwell
Bome Q and A Moderator and
Independent Bome Consultant/Specialist