What exactly happens when..

If you are new here check this forum first, your question may have been answered.
Post Reply New Topic
RELATED
PRODUCTS

Post


What exactly happens when.. an impedance matching transformer XLR plug is used to plug in a low impedance microphone into a low impedance input ? Anything ?
:hihi:

Post

Pretty sure that would trigger a world wide explosion.
my music: http://www.alexcooperusa.com
"It's hard to be humble, when you're as great as I am." Muhammad Ali

Post

I suspect you may have caused COVID by accident... :evil:

Post

kritikon wrote: Sat Sep 19, 2020 12:19 am I suspect you may have caused COVID by accident... :evil:
Honestly, I've often thought about whether or not certain humans could be responsible in that way, but of course, that would only be a theory. Slightly off topic..

Anyways, I'm guessing using a simple matching impedance transformer plug on a low impedance input would just be like NULL or something. I was thinking I'd get some weird scientific formula when I asked the question here because that's what usually happens, but oh how wrong was I !

*Gracefully accepts the sarcasm*

Post

Maybe if you had not changed the font, gave a bit more specifics and did not end with a laugh, it would not be interpreted as :troll: and you'd get a decent answer.

Do you have specs on the XLR transformer / adapter? Which end is low impedance? What do you plug into it at either end? How low do you call low for a microphone?
We are the KVR collective. Resistance is futile. You will be assimilated. Image
My MusicCalc is served over https!!

Post

The question was clear. The op wants to know why you‘d have to match impedances.
If they don‘t match, the levels will be lower, thus give you more noise, and if they don‘t match its like a bad filter it will sound different, mostly much worse...
The sound of a guitar needs a matching input to sound as intended by the luthier...

Post

Tj Shredder wrote: Sat Sep 26, 2020 7:25 am The question was clear. The op wants to know why you‘d have to match impedances.
If they don‘t match, the levels will be lower, thus give you more noise, and if they don‘t match its like a bad filter it will sound different, mostly much worse...
The sound of a guitar needs a matching input to sound as intended by the luthier...
Simple question, simple answer. :tu:

A matching impedance transformer plug obviously allows using a low impedance microphone to be used when plugging into a high impedance input. So given the explanation, plugging a low impedance transformer into a low impedance input would only create more noise. :clap:

This place is such a wealth of knowledge ! It only took 2 weeks to clear that up. More than I can say for Gearslutz though. This would have just turned into a 10 page argument, with exception of the algebraic formulas because I'm pretty sure nobody knows basic math on that site.

Post

BertKoor wrote: Thu Sep 24, 2020 7:38 am Do you have specs on the XLR transformer / adapter? Which end is low impedance? What do you plug into it at either end? How low do you call low for a microphone?
It was a small Archer XLR impedance matching transformer plug going into an old Rocktron processor (low impedance to low impedance). The plug actually made the signal quieter, but the mic is still louder than hell and I'm not sure why (with or without the plug). The mic is just some weird dynamic Korean model.. I think made for karaoke, which is extremely loud for some bizarre reason. There isn't even a transformer inside of the mic, but it's like 3x louder than any microphone I ever owned. Maybe someone can explain that..

Post

To answer the last question first: this most likely has to do with the efficiency. How much juice does it spit out given the same moving air.

If you want to pad it, you need two resistors to form a static potmeter. A transformer won't do that.

I could give a more thourough explanation, but I don't see how without it turning into a full passive electronics lecture. Would you want that?
We are the KVR collective. Resistance is futile. You will be assimilated. Image
My MusicCalc is served over https!!

Post

Don't expect a worldwide explosion, but it could blow a medium city off the map.

Post

BertKoor wrote: Wed Sep 30, 2020 6:35 pm I could give a more thourough explanation, but I don't see how without it turning into a full passive electronics lecture. Would you want that?
Just the basics is cool. I may be pretty handy with a soldering iron, but I can't really do all the deep math. I think I consider myself more of an experimentalist than anything else (with emphasis on the mental).
If you want to pad it, you need two resistors to form a static potmeter. A transformer won't do that.
How ironic! I almost never do things like this, but yesterday I actually made a strange little menagerie with a potentiometer, an output jack and a few too many capacitors. It's basically like a strange LPF I'm using with an old electret mic, so I can roll off the top end.

There's a lot more to the signal before getting into the DAW, but when I lay down a vocal track with the mic in this manner, I essentially end up with a few screechy squeaks and knocks on certain notes, like 'E' or "Ah" type syllables. It's not feedback and it's not horrible, it just needs.. something.. else to.. like.. mangle it into listenable form. Or something. An external chorus works really good, but it starts to sound too wishy-washy or phasy. :scared:

Post

Part 1 - Resistance

If you want to understand something about impedance (mainly a phenomena in alternating current circuits) you first need to understand resistance; it's brother in decent current.

Take this most basic circuit: on the left something that supplies an electrical current (in the ideal world a steady voltage) and on the right a resistor that consumes it (converts it into heat)

Image

So here we know the voltage and the resistance. Using Ohm's Law the current (in Ampere) and power (in Watt) can be computed. The formulas are basic, but I made a calculator for that to make it easy:
http://www.bertkoor.nl/VawoCalc/
Just fill in the two things you know, and the other two are calculated. It resembles a calculator, not a web page. Click on a button on the left to fill in the variable next to it.

For example for a light bulb labelled "110 Volt, 50 Watt" it computes the current is 0.4545 Ampere and a resistance of 242 Ohm.
If you have a headphone amp that can feed 250mW into a 16 Ohm load, that's about the same as saying it produces 2V / 125mA.

You could go mental with all sorts of computations, but it's easy to get bogus answers from the calculator. Figures that do compute but do not make any sense. You have to know which of the four "variants" are not likely to change in your circuit, and thus are fixed. That's usually the supplied voltage and the resistance hooked up to that.

For instance the power socket in your wall. No matter how much appliances you hook up, it will always supply 110 or 230 Volts (depending on where you are.) It can supply far more current than your household or street or city demands. The limit is in the used cable. Copper has a bit of resistance and will get warm from the current flowing through. Longer cables have more resistance than short ones, and thicker cables have less resistance. You can look up what diameter is fit up to which current - the Amperes! Voltage does not matter here. Say that 1.0mm diameter cable is good up to 10 Ampere, it does not matter whether that's 12V (and thus 120 Watt) of a car battery or 230V (and thus 2.3kW) mains power.
We are the KVR collective. Resistance is futile. You will be assimilated. Image
My MusicCalc is served over https!!

Post

BertKoor wrote: Thu Oct 01, 2020 12:37 pm Part 1 - Resistance
Nice calculator. Works pretty good.

I believe what you may be getting at is the difference between Output Impedance and Load Impedance or how a lot of people (including myself) can get confused between consumer vs. professional - because when you look at the general specifications of a microphone (e.g.; in a manual), it's never specific about load impedance, if at all.

For example, one could easily mistake 1.1k Ohm output impedance specification for 1k load impedance or the 1.1k Ohm output impedance is actually high impedance, while the 1k load impedance microphone is actually only 50 Ohms or low impedance ! Tricky stuff..

I think what I really may need again though (definitely not my first rodeo) is an extremely surgical hardware EQ because the problem with software EQ is, like certain microphones, it can also have a tendency to create those evil 'whistling' type resonances, knocks or squeaks.. and that's why I'm always trying to move away from VST.. again. I've always found myself gravitating back to the original source, since there's obviously a key difference between hardware or trying to manipulate things with software, after the fact.

So much for room acoustics.. :hihi: :roll:

Post Reply

Return to “Getting Started (AKA What is the best...?)”