Why are my bass tones getting a high distortion?

[HarpNinjaMike]

http://mikefugazzi.com/files/HeyJoeDistorted.mp3

This is me trying to learn Hey Joe as a solo piece...everything is done in realtime. When recording, I get no distortion on my monitor (Sennheiser HD380 headphones), I the bass tones get a really weird high-end buzz on playback.

It only happens on really low notes.

That lends me to believe it is not the mic, cable, or pedals. Here is my entire rig for this...
SM 57 (could it be rattling? I tired other mics)
POG2
Line 6 M13
Tech 21 Sansamp Blonde
Mackie Onyx Blackbird Interface
Laptop
Audacity

Everything is connected via 1/4" cables except the USB chord connecting the interface to the laptop.

According to the Mackie's preamp, I am NOT clipping the preamp while recording. I guess I don't know if I am clipping in Audacity or not.

I did ZERO mixing/mastering/editing to the clip, so it isn't from adding reverb or anything...I am stumped. The noise is a huge buzz kill.

[DVDdoug]

I can't listen to your file right now 'cause I'm at work. Looking at the waveform, it's not badly clipped. The waveform is clipped (the wave is squared-off) around the 2:13 mark. It doesn't hit 0dB, so it looks like the analog signal was clipped before hitting the analog-to-digital converter, which I assume is in the Mackie. It could be your guitar amp clipping, which is OK... A lot of guitar players like the "overdriven sound".

You've got a lot of "processing" equipment. You probably need to simplify your effects chain, adding or removing one box at a time to find-out what's causing the problem.

Is all of that stuff between the mic & computer, or is it between the guitar & amp? Are you monitoring the output of all that stuff? ...i.e. Where are your headphones connected?

SM 57 (could it be rattling? I tired other mics)

Unlikely. How loud is your amp? The SM57 can take very high levels. But, if you think that could be the problem, you can move the mic back a bit or turn down the amp... Depending on the preamp, it's sometimes possible to clip a preamp's input (especially with the mic directly in front of a drum head or guitar amp) but with the preamp's gain control turned-down to the point where it doesn't show clipping on the output. (It doesn't look like that's your problem.)

...except the USB chord connecting the interface to the laptop.

Once the signal is digitized it doesn't "accidently" get altered unless something goes horribly wrong. With a USB interface to the computer, Audacity (or other recording software) has no effect on sound quality. You are just "capturing" the digital data coming from your interface over the USB bus, routing the data to your hard drive, and saving it in an audio format. (Of course, when you compress to MP3 you can potentially degrade the sound quality.)

[kozikowski]

The SM57 is a moving-coil "dynamic" microphone and unlikely to overload short of the recordists experiencing pain from the volume. The electronics are far more vulnerable. Do you get any red lights on the mixer? The waveforms on the timeline should never hit 0 during recording or production.

This is normal.

http://kozco.com/tech/audacity/Audacity1_playback.jpg

Does it sound normal if you select the whole show and Effect > Amplify it -6dB (reduce it).

I need to download the test in a bit.
Koz

[kozikowski]

Never mind the tests. Your work has an insanely high sound peak at 62Hz -- very low bass. It's way higher than all the other musical tones in your work , meaning it might be a defective effects box or generator. I can understand how you would miss it because 60Hz is barely audible on a normal sound system, but at that size, it may cause significant problems.

We noted that your voice and the harmonica seem to be perfectly clear, but whatever you're using as bass or bass processing is in deep trouble.

Also, your waveforms are perfectly OK and normal, so the problem is happening in one of your processors -- upstream from the USB adapter. The adapter would certainly have given you red lights on this music if it was overloading.

Koz

[kozikowski]

One of the ways of troubleshooting is to make a very, very simple system from what you have and see if that's OK. Take equipment out of the chain and play guitar and sing into the microphone for example. If that's OK, put some of the other pieces in and try that.

Microphone > Mixer > Digitizer > Computer. Turn all the effects, filters, and equalizer controls off.

It would take us hours to go through the specifications and failure possibilities of all that equipment, and remembering, we're all volunteers and do other jobs.

The noise is a huge buzz kill.

Actually, the buzz seems to be in perfect working order.

Koz

[DVDdoug]

I think we need some more details about how everything is connected... I assume the mic is not being used for the instrument? I assume the instrument is a guitar and you are recording direct (no amp)? You asked about overloading the mic, but I'm not sure if you are even using the mic on the guitar.

If you are plugging the instrument (or pedal) into the Mackie, it needs to go to one of the Hi-Z capable inputs, and the input needs to be set to Hi-Z. You should be able to get a clean recording with a guitar plugged directly into the Mackie (no pedals to start with). Let's start-out simple... Figure-out how to make a good-simple guitar recording and a good vocal recording. Then, you can make a two-track recording with guitar on one track and vocals on the other. Then, you can experiment with adding effects pedals, etc.

I get no distortion on my monitor...

There is a switch on the Mackie to select between monitoring what you are recording or a separate "local" monitor-mix.

I did ZERO mixing/mastering/editing to the clip..

Unless you are recording acoustically (recording everything thru the mic) there is some mixing of the vocals & guitar happening somewhere. I wonder if something's set-up wrong between the Mackie driver/utility and Windows. Are you using the Mackie software? You should have some mixer software showing all 16 inputs. The Mackie should be multitrack (or at least 2-track) recording, but somehow you've got a single track (mono) file with mixed vocals & instrument... I assume you've the mic plugged into one Mackie channel, and the instrument into the other. You should see 16 inputs on the Windows Mixer or with the Mackie supplied software. I assume you need to select the channels/tracks you want to use.

Everything is connected via 1/4" cables...

The vocals sound OK, but the mic should have an XLR or TRS connector (3 conductor).

except the USB chord connecting the interface to the laptop...

When I look-up the Mackie unit, I see a Firewire connection, but no USB...

[HarpNinjaMike]

Thanks for all the great info! I have some testing to do. I know very little about this stuff and the information you gave me makes sense and has increased my capacity. MUCH appreciated! If I find a solution, I'll share it.

[HarpNinjaMike]

FWIW...

Both my M13 and POG2 have an octave effect. I tried each in isolation going straight to the mixer and going to my Sansamp (analog amp emulator). Both pedals caused the ring no matter how I set them. That would mean that either both are "defective", or it is something else....the mic or preamp. I couldn't find any evidence online of anyone else having this same problem.

Is it possible I am setting the bass effect incorrectly? I otherwords, what would cause the spike you mentioned? Is that spike the ringing? Is the sound too low, etc? Is it related to sample rate or something?

I tried holding the mic differently with no luck. Not sure what else to try...

[kozikowski]

That's kind of why we wanted to know how you have all this stuff connected together. If you have bass boost or processing in two effects boxes one after the other, you could get an additive effect and the bass signals would be nuclear by the time you got to the end. Or it may not even get that far.

Nobody's asked yet how are you listening. Most speakers will not reproduce the tones you're talking about overloading. That buzzing in your show is the distortion caused by the excessive bass notes. Those aren't the actual notes.

Headphones? What kind of speakers? You talked about setting the bass effect correctly. We're saying you can't hear what the bass effect is actually doing and you're causing serious damage. Turn all that stuff off and see if you can make a clean recording as a simple performance with no effects.

Koz

[HarpNinjaMike]

Try to follow me on this...I will go through the setup. I also noticed I could get the rattle/buzz beatboxing when I hit the "bass drum" hard last night. No guitar is being used - it is all vocals and harmonica only. The best way to "see" what I am doing are through these two videos:


http://www.youtube.com/watch?v=vJTHZYYkQjE
http://www.youtube.com/results?search_query=son+of+dave

My rig:

Mackie Onyx Blackjack with two stereo channels...

Channel one
Vocals go right into channel one (I guess I mixed to mono for the mp3, sorry I didn't include that)

Channel two
SM57 with a 1/4" transformer>
POG2>
Line 6 M13>
Tech 21 Sansamp (amp emulator set to a Blackface tone that is pretty clean)

On channel two, I play harmonica, beatbox, and sing bass lines all into the SM57. My lead vocals go through channel one. I use this rig (sans looping) with a full band straight to the PA all the time. For home recording, I do not have anything going into a mixer before hitting the Blackjack.

On the Blackjack, I have the "Monitor" knob pretty much wide open and then control the monitor volume with the headphone controls. On channel one, I have an XLR plugged in with the gain up to the point where I still don't clip (LED turns red) on my loudest vocals. I have never NOT had the vocals come out clean...so good news there.

On the second channel, the Tech 21 has a level control that I keep fairly low...so the signal hitting the Blackjack is attenuated, and, again, I set it not to clip on my loudest levels - which are the beatboxing. Again, the Blackjack never shows clipping. In fact, the signal from both channels going to the USB are low compared to CDs/mp3's on my computer. I usually have to "amplify" them in Audacity so they are closer to CD volumes.

At first, I thought the rattle wasn't in the monitor, but it might be there. At any rate, it isn't as obvious as when listening on playback. It might be all in my head, but the rattle/clipping might be there live? I listen to everything through Sennheiser HD380 headphones.

Other than the "bass" parts, which are me signing through the POG2, I've been able to get clean beatboxing/harmonica tracks. No matter how I set the POG2 it happens. I took it out of the chain entirely and used the bass octaver on the M13 and had the same issue regardless of settings. I then tried removing the Tech 21, which made the signal hitting the Blackjack much hotter (so I turned down the gain to eliminate clipping), and got the same thing. So it isn't the POG2 or the Tech 21. I don't think it is the M13 either, as I am pretty sure I tried just the POG2 straight to mixer last night. It could be the mic, I guess, but a different SM57, PG48, and SM57 did the same thing.

I've used the Hi-Z buttons on the Mackie correctly, I believe.

To reiterate, the rattle happens on really low notes sung through a POG2 or played on a really low tuned harmonica played straight to the Blackjack. I can get the same rattle when beatboxing a bass drum. I tried changing my mic technique and all gain settings with the same negative results. I can get clean tracks doing other instrumentation, and I can get clean audio listening to other music files through the headphones or monitor out on the Blackjack.