Understanding Latency Using The X32 Rack – Two S16s – One Alesis SR16 Drum Machine and Reaper Oh My!

Reaper will be set up to receive the first 8 inputs of the S16. Using this setup, the X32 Rack user manual states I will have 1.1ms of latency between inputs 1 & 2 and the main outputs 15 & 16. I can assign any channel strip processing to any channel or bus with the exception of “Inserts” in FX Racks 1 through 8 or using an External Insert, without it affecting the established latency of 1.1ms via the X32 Rack User Manual.

Inputs 1 & 2 will be direct inputs from my Alesis SR16 Drum Machine. Channel 1 will always be the baseline for these latency tests. This will allow me to measure the latency between internal or external FX inserts, sends and returns, mix buses, matrices and mains. As an example I could send channel 1 to bus 1 with FX applied using sends and returns, then apply an insert to bus 1 and send that to matrix 1. Then I can apply an insert to matrix 1 and then measure the latency between the input of channel 1 and the output of matrix 1. Due to the amount of variables, these tests could run into the thousands due to the different configurations available.

Any signal processing you use as an internal or external insert that has a “Hold or Release” setting such as a gate, compressor or delay will always affect your latency and to what degree is impossible to say. Some people don’t seem to have an issue with latency until it gets around 10ms. 5ms if you are using In Ear Monitors.

According to current medical information concerning custom fitted ear buds, your latency should never be slower than 5ms due to comb filtering that can happen inside your brain. (Who Knows Right). You really need to choose wisely when it comes to adding inserts into your IEM system through External FX Racks or Loop Machines. When everything you do is correct and it still “just doesn’t feel right”, check your latency. It can throw your timing off on vocals, guitars, drums, keys and anything in between that requires you to hear what is going on at any given time during your performance.

What can not be noticed in wedge monitors due to stage noise, will take center stage when sent to In Ear Monitors. Just visualize the signal paths below to see where the latency happens and what it sounds like in the video below.

Baseline Test. FX 3 & 4 Sent To Ch 2 Using Sends & Returns.

 

Alesis SR16 L output into Ch 1 input 1st S16.                                                             Baseline

Alesis SR16 R output into channel 2 of the 1st S16.                                                        0ms

Bus 1 XLR output into channel 3 input.                                                                     1.125ms

166sx Outboard Compressor. (Not Used for this measurement)

Latency from FX 3 Returns to channel 2.                                                                  0.375ms

Latency from FX 4 Returns to channel 2.                                                                  0.375ms

Latency from channel 2 to Matrix 1.                                                                           0.375ms

Latency from channel 2 to Bus 1.                                                                                 1.125ms

Latency from channel 2 to Main L.                                                                             0.375ms

Latency from Matrix 1 to Main L.                                                                                    0.0ms

 

I now know that any channel added to a mix bus will have 1.125ms of latency and any mix bus added to a matrix will have 0.375ms added. Unless you add an insert to your matrix, the latency between your matrix outputs and your main outputs is too small to measure using samples or is so small it simply can’t be detected by human hearing.

 

Inserting FX 7, (M/S Fair Compressor) into channel 2 and sending channel 2 to Bus 1, Matrix 1 & Main L.

 

Alesis SR16 L output into Ch 1 input 1st S16.                                                          Baseline

Alesis SR16 R output into channel 2 of the 1st S16 inserted into FX 7.                     0ms

Bus 1 XLR output into channel 3 input showing FX 7.                                           1.125ms

166sx Outboard Compressor. (Not Used for this measurement)

FX 3 Returns.  (Not Used for this measurement)

FX 4 Returns. ( (Not Used for this measurement)

Matrix 1.                                                                                                                           1.020ms

Main L.                                                                                                                             1.020ms

Matrix 1 to Main L.                                                                                                        0.083ms

 

Inserting Outboard Compressor On Aux 5 into channel 2 and sending channel 2 to Bus 1, Matrix 1 and Main L with no additional processing or inserts.

 

Alesis SR16 L output into Ch 1 input 1st S16.                                                         Baseline

Alesis SR16 R output into channel 2 of the 1st S16 inserted into FX 7.                   0ms

Bus 1 XLR output into channel 3 input showing FX 7.                                        1.125ms

166sx Outboard Compressor.                                                                                   1.270ms

FX 3 Returns.  (Not Used for this measurement)

FX 4 Returns. ( (Not Used for this measurement)

Latency from Input 2 to Matrix 1.                                                                          0.375ms

Latency from Input 2 to Main L.                                                                            0.375ms

Latency from Matrix 1 to Main L.                                                                          0.375ms

Latency from 166sx to Mix Bus 1.                                                                          0.145ms

 

Inserting Outboard Compressor On Aux 5 into channel 2. Sending channel 2 to Bus 1. Adding FX6L Insert into Bus 1. Bus 1 sent to Matrix 1 and Main L with no additional processing or inserts.

 

Alesis L output into Ch 1 input 1st S16.                                                               Baseline

Alesis R output into channel 2 of the 1st S16 inserted into FX 7.                         0ms

Bus 1 XLR output into channel 3 input showing FX 7.                                     1.125ms

166sx Outboard Compressor.                                                                                 1.270ms

FX 3 Returns.  (Not Used for this measurement)

FX 4 Returns. ( (Not Used for this measurement)

Latency from Input 2 to Matrix 1.                                                                         0.375ms

Latency from Input 2 to Main L.                                                                           0.375ms

Latency from Matrix 1 to Main L.                                                                         0.375ms

Latency from 166sx to Mix Bus 1.                                                                         0.145ms

 

* Inserting Hall Reverb on Ch 1 & Outboard Compressor On Aux 5 into channel 2. Sending channel 1 & 2 to Bus 1. Adding FX6L Insert into Bus 1. Sending Bus 1 to Matrix 1 with FX 6L Inserted and Main L Inserted with FX 5L Stereo Imager.

 

Alesis SR16 L output into Ch 1 input 1st S16.                                                        Baseline

Channel 2 of the 1st S16 inserted into Aux 5.                                                                0ms

Ch 2 to the 166sx Outboard Compressor.                                                              1.270ms

FX 3 Returns.  (Not Used for this measurement)

FX 4 Returns. ( (Not Used for this measurement)

Latency from Ch 1 to Matrix 1.                                                                             3.541ms

Latency from Ch 2 to Main L.                                                                                   4.229ms

Latency from Matrix 1 to Main L.                                                                          0.685ms

Latency from Ch 2 Insert dbx 166sx to Mix Bus 1.                                               1.270ms

 

In conclusion, these results simply confirm what Behringer states concerning latency in their manuals and the X/M 32 Mixers. The X32 Console Manual DOES NOT have the astrix (*) next to the latency specs like the X32 Rack and S16 manuals do. They state that the latency within the mixer without using any stage boxes is 0.8ms and if you plug into a stage box and run your mains from your stage box, then the latency increases to 1.1ms. They also claim that using External FX Inserts & Effect will create 10 to 15 times more latency then using the built in FX & Inserts. I can show they are correct with their statements.

FX 1 – 4 are recommended to be used with the “Sends & Returns” method due to the lesser amount of latency they create. That’s why you should never use them as Inserts and if you do, make sure you apply 100% of the insert to your mix. FX 5 – 8 are known for adding latency and should be used as sparingly as possible. Don’t ruin your mix by over processing it. You will be amazed at what talent, a little reverb, solid EQ’ing and compression will produce at the end of a well laid out properly setup X/M32 Digital Mixer.

As long as you apply proper judgment when you start laying out your individual signal paths and their final destinations, you should never experience enough latency to cause any issues. *As the data shows above, it’s only when you start stacking inserts into channels, buses and matrices that you will start to compound your latency issues. Since we can see this latency in the data above, logic would seem to dictate that these latency figures must also be calculated when you use matrices for front and side fills, as well as your M/C Bus for subs. This is extremely important when you are delaying outputs for foyers and balconies.

What is the latency difference between the X/M32 Digital Mixer 16 bus Console and the Audient ASP8024-HE-72 Heritage 24 bus Console that retails for $104,000, who knows and I don’t care. But I promise you this, we have many of the same features this amazing mixer has for a 100th of the price and setting up channels, buses, matrices & inserts, is the same process for both mixers and when done improperly, will yield the best results either mixer can produce!

Any latency added by effect loops or guitar pedals must be taken into account when sending these signals to IEMs. If your guitar pedal adds 10ms of latency from the time you pick the string until the time it hits the mixer input, then you may want to re-think your signal path. If you plan on processing that signal further, then you will also need to add in that latency as well.

FYI, all of this was done because Charles, one of the Members in our FB group, did his own research concerning Latency & the X32 Mixer using Smaart software. He posted his results in our community along with an MP3 audio file generated by the mixer itself. His data was impressive and I could understand the point he was trying to make by reading his written words. Since I have no knowledge of using Smaart, I really didn’t know what I was looking at while I was playing the audio file and trying to match it to the graphs. There is no doubt in my mind that he can instantly see the same results using Smaart, that I can see using Reaper.

It’s funny how one thing will stick out like a sore thumb to some people and spark a line of thinking that will force you to use someone else’s data, and convert it into a way that makes sense to you. Like I said Brother, your post was going to make my head hurt & it did. You educated me & I owe ya one!

The video below will explain how I did this process using Reaper, a Alesis SR16 Drum Machine, a dbx 166sx External Compressor, Auxiliary Inserts, one XLR Patch Cable, the X32 Rack & 2 S16s. Not only will you be able to see the latency in the waveforms, but you will also be able to listen to what it sounds like as well when it is timed aligned, aka, all latency has been removed from all the inputs, and hit the master outputs at the very same moment in time. You may not believe your ears. Humbly, Dana Tucker.

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