Topic: phasing?

[nihilistic0]

So is this phasing?

It sounds fine, indoor venue, no AC or anything that I could tell

[cleantone]

I assume your talking about the compression being seemingly bigger than the rarefactions in this pic? That is not "phasing". What is the instrumentation of this recording? What was the lineage?

http://en.wikipedia.org/wiki/Phase_shifting

[nihilistic0]

digital xfer straight off the master

AT853 at the shoulders (either side of neck) pointed straight ahead, FOB position


I remember someone posting something like this before, I just cant remember what the hell it turned out to be. 

[cleantone]

What is the instrumentation of this recording?

Where there horns?

[nihilistic0]

Oh sorry,

no, no horns.  Mogwai with lots of loud guitars

[RebelRebel]

So is this phasing?

It sounds fine, indoor venue, no AC or anything that I could tell

DC Offset.

[Karl]

Actually looks more like minor brickwalling.  One side of the signal will be a little more prone to it than the other.  The At 853's will overload real easily if your just running battery box power.

[Javier Cinakowski]

It does not look like DC offset becasue the wave is centered in quiet sections.  I posted a wav file like this before.  It turned out that my preamp had a 5% variation on parts.  Thus the + wav cycle was louder than the - wav cycle. 

[SparkE!]

I used to see stuff like that when I was running mics directly into the line input of my Sony PCM-M1.  I do not have the same issues when running into the line input of a NJB3 or the mic or line inputs of a UA-5.

I've been told that you can also get this effect on very loud sources when the coupling caps on your mic's battery box are of some polarized variety or when the battery starts to die on your battery box.  In fact, I think that is what causes the problem on my Sony PCM-M1 because if I remember correctly, their line input coupling caps are polarized.  (I could be wrong on the M1 coupling caps.  It's been quite awhile since I was looking at this issue and I don't remember if I convinced myself for sure that the input caps were polarized.)  The issue with polarized caps is that their instantaneous capacitance changes with the instantaneous voltage of the AC waveform that is applied, so you get more bass cuttoff on one polarity of the signal swing than on the other.  On single tone sources, this causes what appears to be even harmonic distortion in signals that are near the lower cutoff frequency of the signal path.

[nihilistic0]

It is def not DC offset, that was the 1st thing I checked, and its fine

I guess it could *maybe* be minor brickwalling.  When listening on headphones, I can almost hear what may be very very minor brickwalling on the bass, but its so slight that I cant quite be sure.  Completely unnoticeable when listening to it on speakers

I dont think the battery is goin dead, either.  Its not brand new, but last time I checked (very recently) it was putting out ~8.5V

Hell, here's an mp3 of from it : right click, save as

[momule]

It is def not DC offset, that was the 1st thing I checked, and its fine

I guess it could *maybe* be minor brickwalling.  When listening on headphones, I can almost hear what may be very very minor brickwalling on the bass, but its so slight that I cant quite be sure.  Completely unnoticeable when listening to it on speakers

I dont think the battery is goin dead, either.  Its not brand new, but last time I checked (very recently) it was putting out ~8.5V

Hell, here's an mp3 of from it : right click, save as

I dont think the DC offset is your real prob but according to wavelab there is some DC offset. Although very minor.

After hearing a small piece of the sample there is a bit of Phasing aswell I think more from being Stealth/body worn than anything.
I see the left channell is about 2.5 db lower than the Right.

[Church-Audio]

Should have purchased a Church Audio preamp lol 1% parts



Chris Church

It does not look like DC offset becasue the wave is centered in quiet sections.  I posted a wav file like this before.  It turned out that my preamp had a 5% variation on parts.  Thus the + wav cycle was louder than the - wav cycle. 

[nihilistic0]

Someday.... dont have the cash for unnecessary toys right now

Considering how loud the show was, and the fact that there is no distortion or anything, I can pry live w/o a preamp for a little while


Still on my list of things to buy tho, along with an a/d converter

[Javier Cinakowski]

I bought one of your preamps to replace the 5% shit-box.  The shit-box was a horrible piece of shit.  

Should have purchased a Church Audio preamp lol 1% parts



Chris Church

I might just give those Sonic Studios DSM mics you recomended a chance.  SS could use a new website, not that marketing matters when it comes to sound, BUT........  

I could whip up a page in 10 minutes nicer that...... Maybe they would trade me a pair of mics.......  

[SparkE!]

I checked on the line input to the Sony PCM-M1 and it has a 20% 10 uF tantalum chip capacitor in series with the signal path and a 47k input impedance, so it's got about a .3 Hz bass cutoff frequency on the input.  So, my suspicions about being related to signals near the cutoff frequency are probably not well founded.  However, it's still a coupling cap whose instantaneous capacitance is affected by the instantaneous input voltage and that is going to modulate the gain of the front end slightly, though not to the degree you're showing in your picture.

When I first looked at the picture of your waveform, I did not realize that the vertical scale was in dB.  I'm only showing maybe 1 dB or 1 1/2 dB of difference in level between positive-going and negative-going signal peaks on my old PCM-M1 recordings and your recording is showing more like 4 or 5 dB, so you've got something more drastic going on.

My first ever recording was with a borrowed rig (AT-853 mics and SP battery box into a Sony MZR-37 miniDISC recorder) and it had distortion that looks (and sounds) very similar to the recording you've posted.  My battery was brand new that night and I checked the voltage later and found that it was just over 9 V.