Mixer console woes

Submitted by toord on Sun, 07/31/2011 - 10:07


I bought an Alesis MultiMix8 USB. I had my AT2020 condenser mic in channel 1, and flattened stereo (mono) output from my Yamaha keyboard/synthesizer. At first while testing it out seemed like a good setup. However after connecting the headphones or the monitors a very pronounced hiss was present on all tracks. At first I thought it could've been then USB cable, changed it to a new one, and no dice. Then thought it could've been the xlr cables, switched them and again, no change. All tracks had the same pervasive hiss. Then I decided to take the computer completely out of the equation and I could still hear a substantial hiss through the monitors and headphones even when I wasn't playing any instruments/voice. I tried Audacity's noise reduction tool (which is phenomenal, btw) and got rid of the brunt of it; however, the background hiss on all tracks was a little too much for my neurosis to stand. So, I'm returning the Alesis mixer but that leaves me 'upstream and without a paddle'. So, in the iterim I'm going to bite the bullet and get a replacement hoping the vendor will refund me the money for the Alesis mixer.

While I know that recommendations can be and are subjective in nature what would you guys recommend for a sub-$200 mixer? So far my research has directed me to look at these:

Yamaha MG82CX 8 Input Stereo Mixer with Digital Effects
Focusrite Saffire 6 USB Audio Interface Featuring Two Focusrite Pre-Amplifiers, Saffire 6 USB
Mackie 802-VLZ3 8-Ch. Compact Recording/SR Mixer

All see like really good alternatives and within my price range, but I'm open minded to any other suggestions. Your input is much appreciated.

Your only problem is not understanding proper gain staging. There's nothing wrong with your mixer. I've used those and they are perfectly fine. This is all operator error. You don't know how to set your levels. A new mixer is not going to remedy this problem. You have to learn what you're doing to remedy the problem. All electronics have hiss. Much of this comes from improper gain trim adjustment, nothing loaded into the inputs, excessive output level driving low-level inputs. You're new, so you're still learning.

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MX. Remy Ann David

Hey Remy,

Thanks for the info. While operator error is likely the cause, perhaps my expectations are also out of alignment with reality. For instance, what would be considered "normal" hiss/hum levels? Should you need to run a noise reduction utility on each channel? I tried searching for that aspect and couldn't come up with any meaningful info, so if you got a link or a detailed explanation in this regard, I would much appreciate it.

Back in the days of analog recording, the tape frequently created more noise than any of the electronics. Maybe with the exception of the console used for Roberta Flack, Killing Me Softly which was a custom-built transistorized console built by Bell Sound Studios in NYC. The mixer you currently have produces a low enough noise level so as to be quite compatible with a 16-bit, 44.1 kHz digital recorder which has a signal-to-noise ratio of 96 DB. That is nearly imperceptible. But when your gains are over cranked & you don't understand how to trim properly, you can experience too much noise coming from your console. Some of this has to do with what kind of microphone technologies you're using, how far the sound source is from the microphones or if your guitar amplifier is making excessive noise that you're mistaking for your mixer? Almost all of these basic entry-level devices all feature the same kind of general electronics and do not vary appreciably from one manufacturer to another. The difference will come in when you start spending $500 per input on your mixer. I have made perfectly quiet recordings on the world's cheapest mixers. Mixers whose microphone preamp's were a single-chip and cost less than $5. Which is true for about all of these mixers. And they're perfectly adequate when used correctly. Gain staging is the art of understanding which volume control gets turned up higher than other volume controls. On most audio mixers, we observe unity gain. Unity gain is generally around 2 o'clock on a circular round knob fader or approximately 2/3 of the way up at the 0 DB setting on a linear slide fader. This is where those faders should be placed. If the output is too low, you turn up the trim level. If the output is too high, you turn down the trim level while keeping your volume controls at the unity gain positions. If you're zero DB markings on your faders are at full up, this usually indicates an output bus. And those faders should generally be placed at the full up 0 position. Other faders indicate the 0 position, -12 DB down from full up. This will get you more into the ballpark and your mixer will appear quieter and much more professional. But if you are utilizing a low output dynamic microphone and trying to record an oboe, 30 feet away, yeah, it's going to get noisy. But if your sound source is 3 inches from the microphone and you're screaming into your microphone, you shouldn't hear any noise. Is this making more sense?

Setting levels is part of the art
Mx. Remy Ann David

Wow, man. That's a lot of awesome info. Thank you so much for taking the time to explain this to me. I will start at those levels you suggest and will fiddle with them until my ears are satisfied. Just for info my setup includes an Audio-Technica AT2020 condenser mic and a keyboard. I don't think that changes your advice at all but just as a side note. Again, thx much for your help.

I'm familiar with the 2020 and not 100% excited by it but it's adequate. As I recall, it has a rather thin diaphragm which makes it a little too bright & brittle for my tastes. This is where I think a Shure SM58 really wins hands down so much of the time. They're smooth, they're fat and they're not too crispy. And you can't easily overload them. And because that 2020 has a substantially higher output level than a 58, I can definitely overblow preamp inputs. If you don't have a smooth open sound, you might need to kick in a pad? A pad can either keep your microphone from overloading its internal electronics or it can prevent overloading preamp electronics. Some of us like a lot of transients while in other situations, we might want to reduce excessive transients. It's all 100% subjective which really makes it difficult to tell anybody how to do anything. We have a little more proficient with learning how to properly set your gain trims, you'll then start to figure out how it affects the overall color of your sound. We all cheat on our gain trims to help provide the proper coloration. When you cheat your gain trims up or down, the compromise will be more or less noise, more or less distortion, more or less sonic character. You just have to find where the right spot is for each source you're recording. It's a lot of fun.

We can't get enough of it
Mx. Remy Ann David

Good starting point...

1) Turn main mix knob to unity (wherever it is on that one). If not marked, try 1/2 way. You may need to tweak that later a bit.

2) Turn any unused channels' input trim and volume faders all the way down.

3) If not running anything through Auxilliaries, turn down their knobs (channel sends and main returns).

(Steps 2 and 3 help reduce any noise present in those paths. You're not using them, turn them down).

4) Set all EQ on channels you are using to "flat", (probably 1/2 way). Remember that later, if you start tweaking around EQ settings, you may be adding signal strength or noise. Start with it all flat, and work from there, after you've initially managed levels.
If you end up trying to boost highs much on a particular channel, you're going to add hiss, especially if you turn it past about...oh..75%. If you start boosting lows or mids, you could overload the channel because it's adding volume...so you'll need to deal with that later. Of course, the opposite happens if you start drastically cutting things. It may lower the overall volume of that channel. (I suspect you probably already know that, but...). IDEALLY, you shouldn't have to boost or cut much at all, if you have decent equipment/micing techniques to run though them. Leave them flat, to start.

5) On channels that will be used, set level knob/fader to "unity" (or try about 1/2, if not marked).

6) While singing through mic/playing through instrument inputs, bring up "Input trimpot" to see if you get a clean, robust signal. Input trim is last for a reason. The channel and main out levels have been set to optimal (supposedly). Now, the input trim is bringing the signal into the mix, at only the levels that are necessary. If you are (possibly) running through a stereo channel input that has no input trim, like with the keyboard, start with the keyboard volume down, set all the EQ and channel fader as mentioned, and then start turning the keyboard volume up until it's good. Most keyboards should send a good, strong signal. You DON'T want the keyboard output volume full-blast, and the channel fader too far down, OR the keyboard volume down and the channel fader way too high.

My Mackies channel and main faders all have a printed 'U' and the faders are center-detented to easily do an initial setup. I don't know where the Alesis "Unity" or 'optimal' setting is. If it isn't marked, and it isn't centered, and the manual doesn't specify where they are, you'll have to experiment from here. For instance, if you've done all that with everything centered, and you have to bring the input trim all the way up and still get a weak signal and too much noise, it's possible that the Alesis 'sweet spot' is around the 2/3 position...but definitely not lower than 1/2.

The input trim shouldn't have to be turned up much past 2/3, and definitely not all the way up. You'll likely get TONS of hiss and noise, if it's all the way up.

Ideally, all the channel faders should be set to the "unity" sweet spot while anything you have running through the mixer is playing, with no overloads. This gives you a little bit of tweaking room to very slightly raise a channel on the channel fader, if needed (not too much), or lower it. Additionally, while setting individual levels, if the Alesis has LED level meters, you don't want any individual peaking into overload. They should all be slightly below peaking, individually, and when all channels are passing signal at once, the entire summed signal should not cause overload peaks (they add together on the main mix bus).

So, nothing in the mixer should be set too high, or too low. The first thing to do is to set the channel and main faders to the sweet spot, and adjust the incoming signal with input trims...or the output level of outboard devices like keyboards, sound modules, etc. Find the 'sweet spots' on that mixer, and try all that.

If you STILL can't get a clean, robust signal...report back with what you've done, and what it's doing.


Yeah we noticed that brittleness as well. The mic, at least for us, works great for spoken word/voice-over work. However, for vocals even with a not-so-strong a voice it will clip even with the input gain almost all the way down. I'm going to take a look at the Shure you mention see if it makes sense for our situation and budget.

Thx Kapt.

I'm in the process of trying to baseline/clean slate our home studio. Routing cables neatly, making sure our "quiet room" is indeed quiet, making sure any of our input cables are busted, and so forth. You and Remy have provided quite a wealth of newbie advice and I intend to make good use of it.

Yeah, the 2020 while it is a reasonable condenser microphone, I don't believe they include a capsule pad switch. Their specifications are slightly misleading. It indicates the microphone can accommodate SPL up to 144 DB. However it indicates its maximum dynamic range is 124 DB. And without a pad, the membrane of the capsule won't rupture but it can't deliver the output level without crapping out. The output circuitry can only pass so much. And so a capsule pad (without being technically necessary) would keep the internal microphones amplifier from overloading. This is where the venerable SM58 can hardly be beat. There is a valid reasons for utilizing dynamic microphones even on your albums lead vocals. You have to take care of the high pass filtering either from your console/microphone preamp or, within software. All of the presents you already need is built in. If you want that edgy top end, you boost a couple of DB between 12-15 kHz and voilà. Crunch it good with your favorite dynamics processing and you'll be good to go. I'm highly selective about using condenser microphones, with all of this digital stuff we use, on lead vocalists. There is a time and a place for it. These microphones are really better suited for instrumental purposes where they can really shine. But you already know that. Frequently more lyrical vocalists along with as you noted announcers/DJs do very well with this microphone. It's just another of the many wonderful colors for your collection.

I'm still collecting after all these years
Mx. Remy Ann David