lyrics having wave cancellation

NeroCaesar

NeroCaesar

Member
I would like to think I have an ok grip on audio physics but then I get bested by things I know should be Audio 101. I apologize as this may have been covered, but my search terms were poor and vague apparently.

I have a laptop connected to a 3.5mm to xlr adapter to the https://www.amazon.com/dp/B07GT48X2P/?tag=controlbooth-20
When I use this adapter the lyrics in most songs seem to get cancelled and reduced in volume by about 20db. The wave forms are not mirrored L and R but they are not set up like old records with vocals on one side etc either. Everything is panned center, I am using balanced cables and a balanced in on the Behringer and the music is normal in every other way (Multiple songs as well). If I play with the LR pan on the laptop the volume of the vocals get much louder, which leads me to believe its a weird cancellation issue. I ended up making a special adapter that works much better, but I don't understand what is fully going on and why, and more importantly what adapter get I buy so I dont have to keep making special adapters? Sorry for the simple question.
Bought Balanced>>>
51eO1-tF2uL._SL1200_.jpg
Special adapter >>
2.jpg
 
The reason I am asking as well is because when I use the special adapter and play certain things from youtube, it will come out distorted, but not with the balanced cabled. I feel like I need a pile of different 3.5mm to xlr depending on the circumstance.
 
NeroCaesar said:
I would like to think I have an ok grip on audio physics but then I get bested by things I know should be Audio 101. I apologize as this may have been covered, but my search terms were poor and vague apparently.

I have a laptop connected to a 3.5mm to xlr adapter to the https://www.amazon.com/dp/B07GT48X2P/?tag=controlbooth-20
When I use this adapter the lyrics in most songs seem to get cancelled and reduced in volume by about 20db. The wave forms are not mirrored L and R but they are not set up like old records with vocals on one side etc either. Everything is panned center, I am using balanced cables and a balanced in on the Behringer and the music is normal in every other way (Multiple songs as well). If I play with the LR pan on the laptop the volume of the vocals get much louder, which leads me to believe its a weird cancellation issue. I ended up making a special adapter that works much better, but I don't understand what is fully going on and why, and more importantly what adapter get I buy so I dont have to keep making special adapters? Sorry for the simple question.
Bought Balanced>>> View attachment 22820 Special adapter >> View attachment 22821
Click to expand...
@NeroCaesar Try looking at it this way.
When mixing engineers prep' their mixes for mastering, it's common to place vocals, kick drums, and bass guitars in mono, straight down the middle. Their rational is a solo vocal is the feature and belongs front and center. Bass benefits from more amplifier power and low frequency cone area. The voice is often mono with its effects (reverb et al) panned a little left and right to create space.

When end users take an unbalanced stereo output and connect it directly to a balanced line input, the common elements are cancelled out leaving your vocal in a hole surrounded by stereo effects.


This is largely how old school vocal eliminators achieved their magic.


A better answer?
Convert your unbalanced stereo source to two balanced sources (left and right) then connect them to two mono balanced line inputs and pan to taste.
Toodleoo!
Ron Hebbard
 
That makes a lot of sense why the L and R are so similar and why its not completely cancelled.

My understanding of the practical nature of balanced is a bit shakey. I know balanced is used to help cancel out external electrical interference, and reduce noise in the signal. But how could a laptop (3.5mm jack) be considered an unbalanced source?
 
NeroCaesar said:
I would like to think I have an ok grip on audio physics but then I get bested by things I know should be Audio 101. I apologize as this may have been covered, but my search terms were poor and vague apparently.

I have a laptop connected to a 3.5mm to xlr adapter to the https://www.amazon.com/dp/B07GT48X2P/?tag=controlbooth-20
When I use this adapter the lyrics in most songs seem to get cancelled and reduced in volume by about 20db. The wave forms are not mirrored L and R but they are not set up like old records with vocals on one side etc either. Everything is panned center, I am using balanced cables and a balanced in on the Behringer and the music is normal in every other way (Multiple songs as well). If I play with the LR pan on the laptop the volume of the vocals get much louder, which leads me to believe its a weird cancellation issue. I ended up making a special adapter that works much better, but I don't understand what is fully going on and why, and more importantly what adapter get I buy so I dont have to keep making special adapters? Sorry for the simple question.
Bought Balanced>>> View attachment 22820 Special adapter >> View attachment 22821
Click to expand...
Yep, Audio 101, the Balanced Line Class:

The tip is signal + (or hot), the ring is signal - (or cold), and sleeve is ground. The illustration reflects correct wiring to the XLR: pin 1 is ground, pin 2 is signal +/hot, pin 3 is signal -/cold. The Wikipedia article covers the "why it works" and is required reading :D

Balanced audio - Wikipedia

en.wikipedia.org en.wikipedia.org

When you plug the XLR into the mixer's mic input, the signals panned center will be mostly cancelled out (-20 is likely a low estimate). In addition to needing a whole bunch more input gain, it's usually distorted and you'll get lots of EFX (reverbs and choruses) that don't sound THAT LOUD when you listen to the music normally.

The second "Special adapter" illustration is the most common way to 'unbalance' a signal and prevent the cancellation you are experiencing but comes with a caveat: you're not dealing with a balanced signal, but 2 unbalanced signals with a common ground, so you're effectively losing the right channel.

What are your 3.5mm plugged into? Phones? Tablets? Laptops?
 
Indeed, some songs were lower than others depending on the effects it seems, or the audio engineer style.

The 3.5mm was right into a laptop

I'll pick up a 3.5mm to a split xlr and see how that does, I would just prefer to have it on one channel if possible since this is for anyone to walk up and use.

I hate asking questions that I know are super basic, but most of what I learned was self taught.
So why is it that with the same laptop, same bought balanced 3.5mm to xlr adapter into a mic channel on a sound board it works just fine?
 
NeroCaesar said:
Indeed, some songs were lower than others depending on the effects it seems, or the audio engineer style.

The 3.5mm was right into a laptop

I'll pick up a 3.5mm to a split xlr and see how that does, I would just prefer to have it on one channel if possible since this is for anyone to walk up and use.

I hate asking questions that I know are super basic, but most of what I learned was self taught.
So why is it that with the same laptop, same bought balanced 3.5mm to xlr adapter into a mic channel on a sound board it works just fine?
Click to expand...
The original recording was mixed with fewer things panned dead center, or spatial processing was used that doesn't sum to mono 100% (and hence does not cancel 100%). One of the things that has gone away from recordings is mono compatibility, hence little attention is paid to polarity or phase of individual tracks when compared to other tracks. Or if it's using the "unbalanced" connection, there is sufficient duplication of program material on both left and right that losing the right channel has little impact.

My suggestion: Radial's SB-5 Stage Bug or the similar but not as well made Rapco LTIGLBLOX. Either will transformer-sum the L/R to mono XLR, correctly.

My next suggestion, but less friendly to multiple, casual users: the Peavey USB-DI. Computers 'see' it as a class-compliant audio device and will add it to the device list automatically. 2 XLR outputs or it can sum to mono. You'll be surprised at how much better the USB audio sounds with the $70 Peavey box compared to the $0.39 headphone amp chip in the laptop driving a $70-$100 analog DI, but users need to know how to select the device in their computer.

ps: In my first post I mentioned that polarity and phase are different things. Polarity is a DC (direct current) phenomena; you hook up a battery correctly or you hook it up backwards (and nothing works, or works backwards). Phase is based on TIME, and 2 otherwise identical signals being separated in time, and summed together. A good example is "3 phase electrical service." The generator has 3 coils (or muliples of 3 but that's for another discussion), each physically occupying 1/3 of the circumference. As it spins, the "A" phase coil first passes a reference point (say, top dead center) over 120° of travel, at which point the "B" phase now passes the reference, and at 240°, the "C" phase passes the reference and the process begins again. You can turn the generator faster or slower but the TIME relationships between the signals remain the same. SUMMATION of sine waves (search hint) - the adding of identical signals separated by time - is where you will hear it, and increasing or decreasing the time difference between the signals changes the starting frequency of the resulting comb filter (another search hint).

And all of this does not stop the frequent mis-use of "phase" to mean polarity. Console manufacturers use the Greek letter Θ (theta). which represents phase, to mark the POLARITY button on channel inputs. Bah and Humbug!
 
TimMc said:
One of the things that has gone away from recordings is mono compatibility, hence little attention is paid to polarity or phase of individual tracks when compared to other tracks.
Click to expand...
Which I find amazing because in observations, I see most listening these days done in mono -via phone speaker or bluetooth battery speaker. (yes the popular ones from the "no-highs/no lows" people are indeed mono)
Even if the playback device is "stereo" with 2 speakers, when they are only a foot or so apart and being listened to from across the room it is essentially blended mono acoustically. Parties, Tailgating, TV-set speakers, restaurant/bar BGM all benefit from a mix that translates well to mono. and yes, even off-axis to the perfectly balanced stereo PA in your auditorium or theater! (an argument I have all the time with certain sound designers)
 
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