M-48 FAQs

Since we’ve been using the M-48s for the last few weeks, I’ve gotten several questions about our set up, how we do things and how it works. In this post, I will attempt to answer those questions. Hopefully I’ll get them all, but if not, feel free to leave yours in the comments section and I’ll address them as they come up.

What is your system set up (or What is your signal flow)?

We are using a DIGiCo SD8 at front of house. We have a DigiRack on stage that is connected to MADI 1 of the SD8. The SD8 has a “Copy to MADI” feature. In our case, I’m copying MADI 1 to MADI 2. Both MADI ports have two sets of jacks; we take one output of MADI 2 and send it to an RME MADIFace for multitrack recording (and bring it back in on the input side of MADI 2), the other output feeds the S-MADI Bridge. Essentially, we’re taking the signal right after the mic pre and subsequent A/D conversion and sending it to the S-MADI Bridge. The S-MADI converts the first 40 channels of the MADI stream to REAC and sends it down a Cat5 to the S-4000D distro. The M-48’s connect to the distro on stage.

How do you handle local inputs (ie. iTunes or Video playback)?

We have two Aux mixes set up as fold-backs; one for RF-Mics (for teaching and announcements) and talkback, another for playback (iTunes, Video, CD, whatever). Rather than directing those Aux mixes to analog outputs, we send them directly to MADI 2 channels.This overwrites the copied MADI stream from MADI 1 (though we intentionally do not use those two inputs on the stage rack). In the M-48’s, we combine these two fold-backs into a single group and balance the levels of all sources at the SD8. If we needed to do any sub-mixing, this is also how I would handle it.

How do you handle inputs that need EQ, dynamics or effects?

Since the M-48’s have 3-band EQ on board, we do 99% of our EQ there. Reverb is also provided, so again, if any of the musicians want it, they can dial it up in their own mix. Compression is not currently offered in the M-48 however, so we play some tricks to make that work.

The challenge is that we record from MADI 2 as well, so we need a clean feed of any channel that may need to be compressed. In our case, our worship leader is very dynamic and requested that we come up with a way to compress his vocal to help him keep it in the mix. The direct outs are post-fade, so we can’t use them, and we still needed a way to record a clean signal (so we can apply dynamics & EQ later for training).

I figured out we can use the insert sends to solve this dilemma. I bring Mark’s vocal in on channel 25. I send it out of Insert A on MADI 2, channel 49 (I chose that because it’s one past our maximum input count right now). I record that channel in Reaper as our clean feed because Insert A is prior to EQ and Dynamics (it’s post-HPF and LPF, but I can live with that). I then send Insert B’s output to MADI 2:25. This re-writes Marks vocal, now compressed, into the MADI stream right where it should be. The trick to making this work is to not turn the inserts on, because the board then expects the signal to return.

The only downside to this is the aforementioned HPF filter and the fact that the EQ and dynamics on his vocal are the same for the house and the M-48’s. For us it’s not been a problem. We originally triple-patched his input into a house, M-48 and record channel strip and applied EQ and dynamics (or none) as appropriate for each output, but that became really cumbersome to manage. I’m trying to balance power & flexibility with ease of use and easy repeatability, and I like the current solution better.

How do you handle wireless IEMs?

We built this cool little rack that rolls out on stage. It contains the S-4000D, two wireless transmitters, a plug-in patch panel and power. A single Cat5 cable (Gepco Tactical grade w/ Ethercons) runs from our Cat5 patch panel on stage left to the rack to provide REAC. The M-48’s are cabled from the S-4000D. Since I have access to my own personal custom cable shop in the form of my fantastic ATD Isaiah, we (and by “we” I mean “he”) made up some cables with a right-angle 1/4” on one end and two XLRs on the other (we used 2-channel Mogami snake cable). The 1/4” plugs into the headphone jack on the M-48 while the XLRs go into the patch panel and thus into the transmitters.

That's a PowerCon on the right to power the rack.We chose to use the headphone jacks to take advantage of the extra output features (master bass & treble, limiter, ambient mic) available only on the headphone jacks (as opposed to the line out jacks).

In the near future, we’ll be ordering up some braided poly loom to combine the Ethercon data cables and audio cables into one neat package to tidy up the wiring.

Do you save mixes each week?

We could, but we don’t. Our band is different enough each week that it doesn’t make sense to do that. Isaiah spent a fair amount of time setting up a library of standard configurations for each instrument. Each config puts that musician’s instruments and vocals in the first few groups of their mixer for easy access, while the rest of the band is spread out on the rest, combined as needed. These baseline mixes start with all groups off except for the fold-back (so they can hear talkback). I’ve found it’s actually easier to start from scratch each week than build from a mix that has no potential relation to the band on stage this week.

In this scenario, it takes him about 10 minutes to set up the system and load the proper presets into the M-48’s each week.

How does the Engineer Monitor function work?

The engineer monitor function allows us to designate one M-48 as an Engineer monitor (it can be anyone on the network). Once one is so designated, the engineer can select any other mixer on the network and it is mirrored to the engineer monitor. For example, we have an M-48 at FOH, and when this is the engineer monitor, I can plug my ears into it, and listen to any one of the band member’s mixes. If they are having a problem, I can hear it and fix it.

Here the FOH M-48 is the Engineer Monitor, and we're mirrored to the Drum mixer.Some weeks, we’ll take a spare M-48, set it out on stage and designate it as the Engineer’s monitor. Isaiah can then plug into that and act as a virtual monitor engineer right on stage with the band during sound check and rehearsal. It makes a great troubleshooting tool (especially since we use VNC and remote access heavily). He can actually control the system from his laptop on stage.

Speaking of remote control, how does that work?

The software connects to the S-MADI via an RS-232 port. In our case, we have a Mac Mini that’s BootCamped running Win7 Pro at FOH. This “PC” runs the DIGiCo software for remote controlling the SD8, and the RSS control software for assigning and mixing the M-48’s. Soon we’ll have a second Mac Mini “PC” running just SD8 software so we don’t have dueling VNC sessions when we’re both on the floor, but that’s another post.

We found Microsoft’s Remote Desktop Connection to be too slow with screen refresh to be useful so we currently run RealVNC on the Win7 box and either Chicken of the VNC on the MacBook Pros or Desktop Connect on the iPad to remotely control the S-MADI.

Both solutions work well, though I think we’ve found the MBPs are better for controlling the M-48 software, while the iPad works great for the DIGiCo.

How does the band like it, and does it work well from a technical standpoint?

Great and Yes. The band has taken to the new system very well; in just 3 weeks of use, we now have sound check down to about 10 minutes (from a previous 30-40). The band is much happier with their mixes and really seem to enjoy playing with the new toys.

Though there was a learning curve (at only 2-3 weekends, it wasn't bad), our workload has decreased dramatically. Once we get into sound check, we set gains and go. They musicians do 95% of the rest. Occasionally, we tweak relative levels in the groups, but it’s a lot less than I expected it to be. With greatly reduced stage volume, there is a great improvement to the clarity of the mix. And as an FOH engineer, I can focus more on getting the house sounding good. We mix 2-3 vocal wedges a week from FOH, which typically takes just a few minutes to get set up and we’re done.

That’s all I can think of for now. If you have more, leave them in the comments section.


1/4" Headphone jack to dual XLR Drawing

Below is the drawing. Chad asked about this, so here you go. We built these cables to go from a stereo headphone jack to the left and right inputs of our stereo IEM transmitters (Shure PSM900 and PSM600). We used 2 channel snake cable from Mogami for this application. Typically the 900 is out every week, and the 600 occasionally. Everyone else is wired.
click to enlarge