Strange waveforms in Audacity

I am recording our bagpipe band for a CD. We are practicing now

We are using a Zoom R16 to record 8 tracks.
We are mixing using Audacity. Free Sample:
Any suggestions or comments are appreciated…

I am seeing strange wave forms on different mics.

Normal view:
Zoomed in View:

Top mic Shure Prologue 8L Dynamic Mic. Wave form has sine wave in it. Assume pipers are not fully tuned.
Middle Shure SM58 Wave form has sine wave in it. Assume pipers are not fully tuned.
Bottom New Pyle PDKM7-C Single piper, Pipe Major - Waveform clipped on bottom, what gives? Not a shrilly as the others.

Any help or comments are appreciated…

It’s not unusual for instruments and voices to be non-symmetrical. I can identify one local announcer almost without fail because their blue waves are off-center. So the bottoms may not be clipped. They may just not be there.

Have you pointed all three microphones at one performer and then compared the waveforms? That would be instructive.

It’s certainly possible to have a broken MicPre inside the mixer/recorder do that. Swap microphones around and see if the odd damage follows the microphone.

None of these microphones take phantom power. Do you have it turned off? The instructions seem to obliquely suggest phantom power is only available on a limited number of connections. Is that true?

Any reason you’re using a very clearly marked drum microphone set on non-drums? I get suspicious when a maker designates a microphone for one particular purpose. Most makers want their products to have a wide an audience as possible. True, impact sounds/tympani/percussion are particularly difficult to reproduce, but there’s no way of knowing what shortcuts and customizations the maker took to get there.


The resolution of the pics is a bit low, but I don’t think that waveform is normal. It’s not asymmetrical, it’s not DC.

There seems to be some kind of low frequency AM on the gain.

You wouldn’t happen to have one of the onboard effects of the R16 enabled by accident, would you?

Any huge transformers in the vicinity when you recorded? Army base or airfield?

@Koz: Yes, the R16 only has phantom power on 2 inputs. The R24 on 4 inputs. Both have 8 channels. That’s not the only oddity. You can also switch phantom power from 48 to 24 and even 12V to save batteries. And some R16’s “sing” with certain phantom powered mics that consume more than the allowed 8 milli amps. I have an AKG C451/CK8 that likes to motorboat for a minute or so before becoming stable. And I have a phantom to T12 adapter that makes the preamps whine, whatever mic is attached.

I’ll be running right out to get one.

This explains why “Eight Recording Channels!!!” is right at the top of the ad dialog.


Here’s sentence I’d never thought I’d write : the bagpipes aren’t loud-enough …

i.e. on the mp3 there’s more than 6dB headroom , 1dB is usually sufficient on the final mix.

Stereo mostly lives above 6kHz , your recording benefits from boosting that frequency range IMO …
Bagpipes frequency-analysis , before-after equalization#.gif
If you’re on a Windows computer, real-time adjustments to equalization is now possible if you add a free plugin ,
see …

[ Audacity’s limiter (on “soft”) comes in handy to cut-back any overly-loud snare hits , which would otherwise restrict the maximum volume of the track ].

Mic Input and Phantom Power
The Condensor mic was plugged into port 5 which has phantom power. It was turned on.
I noticed all my dynamic mic inputs had to be turned up while the condenser was not has high to get the same record level.

Try to re-record many on one
I was thinking the same thing. I will record my pipes with several flavors of mike. Ports 5 and 6 are the phantom power ports.
I will use both condensor mics to see if there is a difference.

As far as the waveform that Trebor was commenting on. Was that taken from the beginning of the tune?

This set is called The Bells Of Dunblane. This a slow march started by 1 piper. Then 2 more join in and finally the other 10 pipers and drums.
After this we go into a few marches. Before we record we adjust the input values to what it will be when all the pipes and drums are in. So when the first piper starts he is low, and the others joining builds the volume. The pipes have only 9 notes, no sharps or flats and you cannot adjust the volume. So this is how we make some dramatic affect.

In addition I ran this through the Large Volume Room Reverb. Here is the cut without reverb, same idea no reverb…
I do some high end EQ reduction on the pipes so they are not so shrilly.

What did any of you think of the mix and arrangement? Be brutal… :smiley:
Thank you all for your feedback…

I could not figure out where you were getting phantom powered microphones from. Microphones 6 and 7 in the drum kit are phantom-powered, condenser microphones.

Condenser microphones have a booster between the super delicate condenser sound pickup and the cable. That’s what the phantom power is doing.

The sound goes down from the microphone to the mixer, but the 48 volt power is going up from the mixer to run the microphone electronics and by some phantom method they don’t interfere with each other.

Correct me, but haven’t we just figured out where the distortion is coming from? The mixer/recorder is sailing so close to the wind that it can’t always supply 48 volts to a microphone and you have to rub its feet to warm it up for some tasks. I think we can go home now.

I’ve never seem a dynamic (moving coil) microhone that wasn’t functionally bulletproof and the computer can’t generate that kind of distortion. That leaves… [gaze wanders slowly over to the R16].


IMO it lacks treble , as-if there was a wall between the mic and the band , but that may just be my hearing&headphones combo . An objective-test, (not influenced by an individual’s hearing / headphones/ speakers), is to compare the frequency-analysis graphs of your recordings versus shop-bought popular pipe-band recordings , to see if there is enough treble on yours.

Why invest in producing batches of CDs when you can create a digital-download , delivered via t’internet , ( no up-front investment ).

Because some of us “oldies” like to have the physical shiny disc and the accompanying “sleeve notes” to store on our shelves :slight_smile:

And note that even the youngsters are turning to the novelty of analog vinyl to play with …


But if all the CDs don’t sell the band can loose money, [ and all the band members get a lifetime’s-supply of shiny coasters ]. Stick it on the internet first, with no up-front cost. [ Then maybe invest the proceeds in CDs , if there is a demand for that format ] .

A friend’s band, who also tours countries like Poland and Belarus besides Germany and Holland, is selling lots of cassette tapes these days… Kids luv’em.

Interesting release in 2010 - on wax cylinder :open_mouth: :

If we had a Like button I’d the previous two posts :slight_smile: