Re: [Avid-L2] OTish: Audio Level Converter? Pyle Premium Direct Injection Audio Box - 2.36" x 4.09" Passive DI Unit Hum Eliminator w/ Input Attenuator to Connect Guitar & Bass, 1/4'' Impedance Transformer Connector to Balanced & Unbalanced XLR

In the context of audio waveforms the convention of hot and cold comes from that a positive deflection of the diaphragm in a microphone should result in a positive voltage (ie the top half of the waveform). 

All pretty esoteric I agree. And yes, I agree with you - much balanced equipment appears to not be so balanced under the hood. 

T. 

Sent by magic over t'interweb

On 14 Oct 2025, at 03:10, John Moore via groups.io <bigfish=pacbell.net@groups.io> wrote:



I hear what you are saying but to nerd it up a bit.  Given the balanced outputs are generating an AC signal what does hi and low or hot and cold really mean.  I know in household AC the neutral is generally considered to be 0 volts relative to ground, although floating and iffy neutral connections can change this.  Here's a quick Google:

Standard 3-pin XLR configuration (Balanced Audio)

The standard wiring for professional balanced audio follows the AES (Audio Engineering Society) convention, often called "Pin 2 Hot". 

 

Pin	Function	Proper Term
Pin 1	Ground / Shield	Ground: Connects to the cable's braided shield to provide electrical grounding and protect against interference.
Pin 2	Positive / Hot	Hot: Carries the audio signal with positive polarity.
Pin 3	Negative / Cold	Cold: Carries a second copy of the same audio signal but with its polarity inverted.

 

Since the signal from a dynamic mic is an alternating current signal pins 2 and 3 alternate their polarity don't they?  Electrons run negative to positive so for the current to alternate that means the polarity of the pins have to reverse.  I suppose just like speakers  can be out of phase so can a microphone.  When the air pressure pushed the mic diaphragm, voice coil (in dynamic mics) or backplate (in condenser mics) forward the speaker cones should move forward as well, shouldn't they?  So the hot and cold have more to do with phase than actual polarity of the connection or am I just over thinking this?

 

I do recall at ABC I had to take an XLR TimeCode signal into the RCA TimeCode input of a Sony BVU-800.  I shorted Pins 1&3 and got nothing.  I then found the Timecode XLR Source was mis-wired switching pins 2&3.  I've seen some behavior on Behringer mixers that make me think that their "balanced" inputs are really unbalanced under the hood.  Could it be there is a global conspiracy of unbalanced inputs and outputs masquerading as balanced?  That might explain this whole thing.  ;-)