People will often think that the noise floor is generated by the mixer preamps. That is a myth and is 100% incorrect. “Your noise floor is the amount of noise generated by the device itself with no signal present, it is measured in decibels. All electronic devices will generate a certain amount of noise, even a piece of wire! Minimizing the noise floor leads to expanded dynamic range, and cleaner recordings or sound production”, as per Sweetwater.
Every electronic device produces noise. This includes your microphones, cables, and audio interface.
Noise floor refers to the amount of noise a piece of equipment naturally creates. You must also be aware of “background noise”. So what is background noise?
Simply put, background noise is anything that can make its way into an open mic that is not generated by the audio equipment, directly connected to each other. Lawn mowers, electrical hums, florescent lights, road traffic, ANY NOISE, that can be amplified via any open mics.
As I am getting my notes together to write this article, the same old debate came up again in our community. M32 Midas preamps, verses Behringer X32 Midas designed preamps. It reminds me of the ever lasting debate of recording or live mixing at 44.1kHz, 48kHz or 96kHz.
To make it even worse, some people claim they can hear the difference. However, while they claim they can hear the difference, they just can’t seem to pinpoint one file playing at one kHz, from the other. They simply say it sounds different to them, and maybe it does.
Two things I do know.
- It is important to note that humans cannot hear the difference between 44.1 kHz and 48 kHz audio. While some people claim that they notice a slight improvement in audio quality when selecting the higher audio rate, research indicates that 20 kHz is the limit to human hearing. So I will not even get into 96kHz and above. Keep in mind we are talking about “hearing”, not what is a straw dog argument on paper. “If 48kHz is better the 44.1khz then 96kHz and above must be the best”.
- CDs are made using 44.1kHz and if you are old enough, you can remember the difference in sound quality from the old 8 track tape players you had in your first car, and how the “cassette” changed the audio world in both sound quality as well as the space they took up. Then along comes the CD and everything went the way of the DODO. This technological leap concerning sound quality from cassettes to CDs, has not happened when it comes to listening in 48kHz or 96kHz.
As per Pro Tools Production, “Older conversion software would produce distortion or a loss of quality when converting integers. These same issues do not apply when converting 88.2 kHz to 44.1 kHz or 96 kHz to 48 kHz. However, when converting from 48 kHz to 44.1 kHz, your mix may not sound as good. Basically, if you are planning to burn your music to CD, 44.1 kHz remains your best option”.
This is why I always recommend setting the X32 at 44.1kHz if you will be recording! In till they come up with a new technology that is excepted in the audio industry for the masses, I doubt I will ever change my view. 4K video is awesome, but only if you have a device to play it on!
Now back to the M32 Midas preamps, verses Behringer X32 Midas designed preamps and their respective noise floors. This question comes up quite often and to be honest, it will always be debated. It always starts with the “preamp”. Are they different, absolutely. So are the preamps for my Alesis 8 channel analog mixer as well as my Tascam 16 x 8 USA audio interface and Zoom H6 digital recorder. They all three also have spectacular noise floors when it comes to their preamps.
Is the difference so drastic that one can be considered the “Best”? In my 47+ years in audio, I don’t think so. However, I can give you a list of mixers and AIs that are not worth owning, due to the high noise output from their preamps.
So lets look at the stats from both user manuals. The Midas M32R states that on page 52 of the user manual: “Equivalent Input Noise -125 dBu 22 Hz-22 kHz, @ +45 dB gain (150 Ω source) unweighted”. So with the channel set at +45dBs of gain, that particular channel output is producing a -125dBu. Just so you know, that is extremely low or in other words, very quite. On page 58 of the X32 Rack user manual it states: “Mic Input Characteristics – Equivalent input noise level, XLR (input shorted) -128 dBu and CMRR, XLR, @ 40 dB gain > 80 dB”.
On the surface, it looks like the Midas M32 may be superior to the X32. But in reality, they are no better then the preamps on my Alesis, Zoom or Tascam mentioned above. This has nothing to do with the fact that I chose the X32 Rack over Midas, it is because I know what a noise floor is and how to properly choose my input gains.
It is the “CMRR” mentioned above in the Behringer and Midas manuals that tell the real story. Manufactures have been misleading consumers for decades. Audio manufactures are no different. Why should the desired CMRR dB be typically greater than 80 dB? A CMRR of 10,000 (80dB) means that if the amplitudes of the differential input signal and the common-mode noise are equal, the desired signal will appear on the output 10,000 times greater in amplitude than the noise. With very high CMRR, noise or interference will be essentially eliminated.
So as you can see, the higher the CMMR is, the quieter your noise floor is going to be. I would be lying to anyone reading this if I said I understand this process 100%. I don’t! But I do know that I have run so many test for finding the noise floor in the audio gear I use, that it is now a simply process and anyone can do it! I did a video back in November 20th, 2020 about how you can check your X32 Rack preamps. It has 1,889 view, 7 comments and 22 thumbs up.
So one of our members asked a very simple but complex question that has sparked this debate back into existence. He asked,
“I’ve keep hearing how the Midas preamps are so much better than Behringer pres. I’d like to hear from people who use the X32 rack with a Midas DL16 stage box. Is it that much better? I’ve been considering it but haven’t pulled the trigger yet. Also, is there a difference using the X32 rack to control it instead of a Midas M32C?”.
The first thing is that the X32s and M32s are pretty much interchangeable to a degree. I have heard that Midas customers are a little upset because the same PSUs used in Behringer X32 mixers, are now being installed in Midas M32 mixers. Technically they use the same firmware, scenes and things of this nature. The Behringer Power Supply Units, aka, PSU, are famous for burning out unexpectedly.
So my response to the question above was,
“If you find anyone that tells you they can hear the difference at 100dBFS, I would disregard anything else they told you as well. While looking at technical specs as mentioned above with a very well known live mixing engineer is great information, it makes little difference when putting into practical use. It’s no different then taking a Shure SM58 and removing the transformer and a Shure 7b. One cost $99 and one cost $399 + $150 for a cloud lifter. You just can’t tell the difference between the two”.
I made my response and used the mics as a comparison, due to my experience as well as the much higher cost of one product verses the other, with absolutely no benefit at all! On paper, yes. In practical application, absolutely not!
The ONLY TIME a high noise floor will ever be an issue, is if the audio you are producing, ever falls under the volume of your noise floor! That is why it is so important to have the proper input gain to start with. That is the first step that you can physically do, to control your noise floor.
If you have a improper low input gain set, then that input signal is closer to your existing noise floor. So every time you raise that signal regardless of what it is amplifying, you are raising the noise floor right along with it. Since you started with a lower input level, you must raise the volume throughout the entire signal path to bring it to the proper levels and every-time you do, you are adding noise into your system. This is true for any mixer!
This is your signal to noise ratio. By having the proper input gain set, you have now INCREASED the distance between your input signal and your noise floor and just as before, this is also your signal to noise ratio. Since you now have the proper input level to begin with, you will only need to make minor adjustment to keep the proper signal level throughout your signal path.
In terms of definition, SNR or signal-to-noise ratio is the ratio between the desired information or the power of a signal and the undesired signal or the power of the background noise. If you wondered why I mentioned the background noise earlier, it’s because you must also take this into consideration for producing clean audio, regardless if it is for sound reinforcement or recording.
I have a very extensive background working with the ACX. I have often upset many people in the audio industry because I am a firm believer that while you may be able to run a mixer and produce a quality live event, you would more then likely fail trying to produce a audio book using your same gear. Don’t take it personal, it all has to do with your, wait for it, wait for it, YOUR NOISE FLOOR!
Everything up to this point has been dealing with the NSR and doing live events. The simply fact is that you can get away with having a higher noise floor then you can recording a audio book. The requirement for the ACX is a -60dB noise floor. Anything louder then that and your audio WILL BE rejected. When you are recording narration, you will often pause for affect and you are left wide open with just your voice, your recording environment, your AI and your mic.
When you are mixing a live event, you will always have something going on in the background coming through your system. So now when your lead singer pauses or takes a breath, you still have instruments playing that will override your noise floor so it will NEVER be heard.
So when you have dead silence, your noise floor can not exceed a -60dBs. I challenge anyone reading this to tell me when have they ever done any live event, with maybe the exception of a Wake or Funeral, where you could hear a pin drop during a song, in-between songs, sets or breaks. If you have a lot of static/noise coming out of your mains during these situations, then you have your system setup/tuned improperly.
Now on to the next myth about preamps.
“I can listen to a digital recording and tell you what preamp was used”.
Hogwash! I will setup three preamps with three mics and switch them twice while live recording both audio and video of you sitting in a chair blindfolded, with headphones on. If you can tell me what combination I am using, I will eat my words and give you a public apology! I have done this little experiment dozens of times and no one has ever been successful.
Now on to the last myth or semi-truth,
“I can hear the difference at 6800kHz between the Midas and Behringer preamps”.
This one to be honest, is more believable then the other two. There are mixing engineers who have spent a great deal of time and money defining their “ear”, but very often they will also say that it also has to do with the quality of the speakers they are listening to. So now we have to decide at what point do we stop lining up all the parameters that will produce the results when someone tells you they can hear a difference between Midas and Behringer preamps.
Here are some questions you may want to ask yourself before you make your decision.
- Will I be using $1,000 speakers or $60,000 line arrays?
- Will I be playing at small to medium indoor/outdoor events, or running sound for 30,000 people in sold out stadiums?
So now that you have answered the two questions above, one of the biggest factors you now need to consider is your own mixing experience. You can have the best mixer known to mankind in 2022, and if it is operated improperly by inexperienced mixing techs, then you will get subpar audio results. The opposite can be said by putting a experienced mixing engineer on a lesser grade mixer, and get fantastic results.
Once you have all your information gathered, done your own research and read hundreds of reviews, you need to consider the price point you are will to invest in, for what you plan on doing with either mixer. The Midas M32 LIVE 40-channel Digital Mixer sells for $3,699. The Behringer X32 40-channel Digital Mixer sells for $2,499. That’s a price difference of $1,200 for something in my opinion, when it comes to the preamps is simply over rated!
In closing, as I mentioned above, I have done many tests concerning the noise floor on the mixers I have sitting in front of me. I do this so I don’t have to rely on anyone’s opinion, as I can literately see it for myself. This is a quick test method and means ABSOLUTELY NOTHING when it comes to live mixing, or even recording. It just makes me feel better. As per Sound Devices, a very well respected company in the audio industry,
A question we often hear in Technical Support goes something like this, “I’ve cranked up the gain of my [pick a Sound Devices product] microphone input and it sounds noisy. What gives?” The short answer is, “that is a meaningless ‘measurement’”. The long answer is far more interesting for those who want a better understanding of microphone preamplifiers. Performing a valid, meaningful measurement of microphone preamplifier input noise requires more than “cranking open” an input and listening in headphones.
One last thing. If you answered that you will be using $60,000 arrays and mixing for sold out stadiums, then you have no business looking at either mixer. They simply will not be up to the task and it has nothing to do with their preamps. You can check at the Allen & Heath Avantis 64-channel Digital Mixer, for a mere $12,498.
Now you have my attention!