Mic / Mixer Question

[Soccer Shout]

I have a lavalier lapel mic. I bought a nice mixer (a $200 yamaha number). I have a couple of connectors to take the 1/8 in mic plug to a 1/4 in then to a XLR.

This is so I could plug it into a mic-in socket (rather than a line-in) on my mixer.

However, in order to get a decetly audible signal, I need to turn the gain and level both up to max (or nearly to max). I naturally get a good amount of hiss on the signal when do this.

I've not used a mixer before so this seems a bit unnecessary to me. Any comments?

Also, when I record on my PC via the Yamaha's USB, I get a clicking noice about five times a second. I haven't really had a chance to troubleshoot this, but if this rings any bells let me know what you think it is.

Thanks!

[BridgeHands]

Perhaps your lavalier is a condenser-type, requiring phantom 48vdc power. Have you tried turning on phantom power for that input? Otherwise, you'll probably need a pre-amp.

Good luck, Michael

I have a lavalier lapel mic. I bought a nice mixer (a $200 yamaha number). I have a couple of connectors to take the 1/8 in mic plug to a 1/4 in then to a XLR.

This is so I could plug it into a mic-in socket (rather than a line-in) on my mixer.

However, in order to get a decetly audible signal, I need to turn the gain and level both up to max (or nearly to max). I naturally get a good amount of hiss on the signal when do this.

I've not used a mixer before so this seems a bit unnecessary to me. Any comments?

Also, when I record on my PC via the Yamaha's USB, I get a clicking noice about five times a second. I haven't really had a chance to troubleshoot this, but if this rings any bells let me know what you think it is.

Thanks!

[X Pat Radio]

I have a lavalier lapel mic. I bought a nice mixer (a $200 yamaha number). I have a couple of connectors to take the 1/8 in mic plug to a 1/4 in then to a XLR.

This is so I could plug it into a mic-in socket (rather than a line-in) on my mixer.

However, in order to get a decetly audible signal, I need to turn the gain and level both up to max (or nearly to max). I naturally get a good amount of hiss on the signal when do this.

I've not used a mixer before so this seems a bit unnecessary to me. Any comments?

Also, when I record on my PC via the Yamaha's USB, I get a clicking noice about five times a second. I haven't really had a chance to troubleshoot this, but if this rings any bells let me know what you think it is.

Thanks!

I use a Mackie mixer, and have to turn the gain up and the level up. While I don't use the same mic as you do, I found adding a noise gate is a big help.

[WildeGeek]

I have a lavalier lapel mic. I bought a nice mixer (a $200 yamaha number). I have a couple of connectors to take the 1/8 in mic plug to a 1/4 in then to a XLR.
This is pretty much all I need to know to identify the problem. There are several different standards for electrical interfaces between microphones and the preamps (or the preamps built into recorders or mixers) that they connect to. It has to do with the source impedance (http://www.google.com/url?sa=X&start=2&oi=define&q=http://en.wikipedia.org/wiki/Source_impedance) of the microphone versus the load impedance (http://en.wikipedia.org/wiki/Load_impedance) of the preamp.

A professional microphone with an XLR connector is designed with a 150-ohm source impedance (except some very old ribbon mics, which are 50-ohm), optimized to drive a load impedance between 600-ohms and 2,000-ohms. Consumer microphones with various single-pin, multi-contact connectors such as your 1/8" phone connector, provide a source impedance of at least 2,000 ohms, and are optimized to drive load impedances of 10,000 to 50,000 ohms.

If your consumer microphone was designed to get power from its preamp, then it's looking for 3 volts supplied through a 10k-ohm source. A professional microphone uses the phantom power (http://en.wikipedia.org/wiki/Phantom_power) system, and expects either 12 volts delivered through a balanced 1,200-ohm source, or 48 volts delivered through a 6.81k-ohm source.

Simply put, they weren't designed to work together, and your consumer lavalier microphone really doesn't have the power to drive that professional mic input.

However, in order to get a decetly audible signal, I need to turn the gain and level both up to max (or nearly to max). I naturally get a good amount of hiss on the signal when do this.
You'll need one of two devices to fix this. I don't know how easy to find or how cheap either of them are these days. (A quick search at Radio Shack didn't turn up anything.)

But what you'll need is either a matching transformer with a female 1/4" phone jack and a male XLR. These typically adapt a 10k-ohm load to a 600-ohm source. Or you'll need a consumer-grade microphone preamp (probably even harder to find). Either of these are going to cost as much as your microphone, around $30 - $60.

Or, ideally, you need a professional lavalier microphone with an XLR connector. Shure and Audio Technica have models that sell online for around $70 each.

[Soccer Shout]

Wow...great information.

I'm glad you summed it up with: "Simply put, they weren't designed to work together, and your consumer lavalier microphone really doesn't have the power to drive that professional mic input. " :D

At some point I'll get a 'real' mic that takes phantom power and I can plug it straight in. It's just hard to justify all these costs at once.

Thanks everyone.

[etomorrow]

I have a lavalier lapel mic. I bought a nice mixer (a $200 yamaha number). I have a couple of connectors to take the 1/8 in mic plug to a 1/4 in then to a XLR.
This is pretty much all I need to know to identify the problem. There are several different standards for electrical interfaces between microphones and the preamps (or the preamps built into recorders or mixers) that they connect to. It has to do with the source impedance (http://www.google.com/url?sa=X&start=2&oi=define&q=http://en.wikipedia.org/wiki/Source_impedance) of the microphone versus the load impedance (http://en.wikipedia.org/wiki/Load_impedance) of the preamp.

A professional microphone with an XLR connector is designed with a 150-ohm source impedance (except some very old ribbon mics, which are 50-ohm), optimized to drive a load impedance between 600-ohms and 2,000-ohms. Consumer microphones with various single-pin, multi-contact connectors such as your 1/8" phone connector, provide a source impedance of at least 2,000 ohms, and are optimized to drive load impedances of 10,000 to 50,000 ohms.

If your consumer microphone was designed to get power from its preamp, then it's looking for 3 volts supplied through a 10k-ohm source. A professional microphone uses the phantom power (http://en.wikipedia.org/wiki/Phantom_power) system, and expects either 12 volts delivered through a balanced 1,200-ohm source, or 48 volts delivered through a 6.81k-ohm source.

Simply put, they weren't designed to work together, and your consumer lavalier microphone really doesn't have the power to drive that professional mic input.

However, in order to get a decetly audible signal, I need to turn the gain and level both up to max (or nearly to max). I naturally get a good amount of hiss on the signal when do this.
You'll need one of two devices to fix this. I don't know how easy to find or how cheap either of them are these days. (A quick search at Radio Shack didn't turn up anything.)

But what you'll need is either a matching transformer with a female 1/4" phone jack and a male XLR. These typically adapt a 10k-ohm load to a 600-ohm source. Or you'll need a consumer-grade microphone preamp (probably even harder to find). Either of these are going to cost as much as your microphone, around $30 - $60.

Or, ideally, you need a professional lavalier microphone with an XLR connector. Shure and Audio Technica have models that sell online for around $70 each.

the main point you missed here is:

an UNBALANCED 1/8" plug on that mic cannot require 48v power (unless the mic has a battery) which any decent LAV mic will need.

you will also get significant signal loss with every adaptor you put in line with that mic.

[barrybadmood]

have you tried talking louder? Then you could turn it down a bit.

[WildeGeek]

the main point you missed here is:

an UNBALANCED 1/8" plug on that mic cannot require 48v power...
I did provide a link to an explanation of phantom power (http://en.wikipedia.org/wiki/Phantom_power) which does mention that phantom power requires a balanced (3-wire) connection.

... (unless the mic has a battery) which any decent LAV mic will need.
Actually, I'm not aware of any lavalier microphones, even high-end professional models, that are DC polarized condensers. Every model I know of, from Sony, AKG, Sennheiser, Shure, etc. are all electret condensers, which means that they can be operated on a 12V phantom power, or often on an internal battery.

you will also get significant signal loss with every adaptor you put in line with that mic.
You will get some signal loss through every connector in the line. I'm not so certain that it will always be audible or significant. A matching transformer could indeed improve his situation. I'm just not certain it's the most cost effective approach.

[mental-escher]

Rule #1: Keep it simple.

Go 1/8 inch to 1/4 inch and plug the 1/4 inch into the mixer "instrument" input.

As for clicking, USB mics can bleed sound card HD noise (eg, your sound card is not designed for high fidelity digital audio I/O).