# Difficulties With ECM8000 Phantom Power / Levels?



## BladeUK2001 (Jan 27, 2013)

Hi Gents,

I'm a new user of Home Theatre Shack, and have just started trying to use Room EQ Wizard 

I've purchased a Behringer ECM8000 Microphone, and have this connected to a Behringer PS400 Phantom Power Supply.

The output from this is XLR, so I have an XLR to 1/4" Stereo Jack lead, and that runs to my PC, into the 1/4" microphone input of an Asus Xonar STX Sound Card. 

Problem is, I can't get any input to register in Room EQ Wizard, when I do a Levels Check  I've gone into preferences, and have definitely selected the right input, but the microphone just doesn't seem to register any input. I have the input settings in Windows Control Panel to 100%, and mic boost enabled. Still no joy...

I've read through the FAQs here, but couldn't seem to find an answer. 

Any idea what could be going wrong here?

Many thanks in advance,
Rich


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## BladeUK2001 (Jan 27, 2013)

Continuing my research, could I need some kind of microphone Preamp?

Or is my current Behringer PS400 Phantom Power Supply OK?


http://www.behringer.com/EN/Products/PS400.aspx


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## AudiocRaver (Jun 6, 2012)

Your equipment is probably just fine. Going from a balanced microphone into a PC microphone input is a little bit tricky. It is because of the way the wiring is done for the PC microphone input. I figured it out a while back, will have to dig into my notes to remember just how it worked. It will involve either some hand wiring or an adapter of some kind. I will sketch up a diagram and post it later today (hopefully).:bigsmile:

It is not the recommended way to run REW, but it will get you started.


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## BladeUK2001 (Jan 27, 2013)

Good news! I've found a setting in the sound card app, which has made the microphone work!


However, I'm struggling now to get the microphone volume high enough.

If I turn the stereo up as loud as I dare (without damaging the speakers) and run the test sweep, Room EQ Wizard still complains that the volume is too low.

Microphone volume is at max, with boost enabled in the windows settings... Any idea how I can get more "juice"?


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## Wayne A. Pflughaupt (Apr 13, 2006)

BladeUK2001 said:


> Any idea how I can get more "juice"?


Yes indeed – you need a mic pre-amp. Most of them include phantom power, so you wasted your money on the PS400. Sorry...

Regards, 
Wayne


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## BladeUK2001 (Jan 27, 2013)

Oh dear... Moving forward, could I buy a microhone preamp to add the necessary gain?


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## AudiocRaver (Jun 6, 2012)

I think this might explain why you're not getting a good level. A standard PC mic input is wired so that it can work two different ways:

with a PC style condenser mic with a TRS connector, wired so a bias voltage is available for the buffer amplifier that is part of the condenser mic
with a PC style dynamic mic with a TS connector, wired so the bias voltage is grounded in the TS connector so it is not apply to the dynamic element
If you are using a TRS connector, one side of your balanced mic output is going to the amplifier input and the other side is going to that bias voltage point. So the balanced output is being partially unbalanced and then half of the signal is being wasted.

You need to connect your measurement mic as an unbalanced mic using a TS connector with one side of the mic output grounded, like the dynamic mic connection example. It is not ideal, but it is the only way you'll get a decent signal level. And it will not harm your microphone.

I hope this works for you.:sn:

Edit: There is no guarantee that this will completely solve your signal level problem, but it will definitely work better than what you have now.


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## Wayne A. Pflughaupt (Apr 13, 2006)

Yes, that’s the purpose of a pre-amp, to boost the low signal of the mic to something usable by downstream components or applications. :T

Regards, 
Wayne


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## BladeUK2001 (Jan 27, 2013)

AudiocRaver said:


> I think this might explain why you're not getting a good level. A standard PC mic input is wired so that it can work two different ways:
> 
> with a PC style condenser mic with a TRS connector, wired so a bias voltage is available for the buffer amplifier that is part of the condenser mic
> with a PC style dynamic mic with a TS connector, wired so the bias voltage is grounded in the TS connector so it is not apply to the dynamic element
> ...


That makes sense... Thank you for the detailed reply.

Is there an adapter I can buy to achieve this? I'm not too handy with a soldering iron


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## AudiocRaver (Jun 6, 2012)

BladeUK2001 said:


> That makes sense... Thank you for the detailed reply.
> 
> Is there an adapter I can buy to achieve this? I'm not too handy with a soldering iron


Something like this will give you the change from balanced to unbalanced, then something like this will get you into your input jack. Both parts are made by Hosa, they make good quality cables and connectors that should last. Keep the cable short since it is unbalanced (that is the shortest one I could see with a brief search), and make sure it is a shielded cable.

At some point you will end up needing a preamp, but this should get you going for now, and another $10 isn't too bad a price.


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## BladeUK2001 (Jan 27, 2013)

Hi Guys,

In the end, I bit the bullet and bought one of these:-

http://www.behringer.com/EN/Products/502.aspx

Can anyone tell me what lead I need to use to go from this into the Mic input of my sound card (1/4 stereo jack)?

Many thanks.


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## tonyvdb (Sep 5, 2007)

Just curious does the XENYX 502 have phantom power as well?


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## Wayne A. Pflughaupt (Apr 13, 2006)

BladeUK2001 said:


> Can anyone tell me what lead I need to use to go from this into the Mic input of my sound card (1/4 stereo jack)?


The mic input is a _stereo_ jack? That would be unusual. The cable you’d need would have a 1/4" connector on one end, and a plug to mate with whatever kind of jack your sound card has on the other end.




tonyvdb said:


> Just curious does the XENYX 502 have phantom power as well?


Hard to tell. The manual covers all models from 1202 down to 502, and lists phantom power as a feature. However, it also shows a switch and indicator light for phantom power, which the 502 does not have. It’s possible the 502 has “automatic” phantom power that can’t be turned off.

Regards, 
Wayne


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## AudiocRaver (Jun 6, 2012)

The description lists phantom power is a new feature, they probably updated the 502 to include it and have not updated their online photo to show one with the switch added.

Plus you had an outboard phantom power unit already correct? Sounds like you are covered there.

I forget what kind of sound card you had. If it is a laptop, it will only have a microphone input, which is Mono. For the that, you want 1/4 TS from a line output (they are mono on the 502) to 1/8 TS to the mic input, and reduce the laptop input gain way down. A regular PC soundcard will also have a stereo line input, for that you would also best go 1/4 TS from the 502 mono line output to 1/8 TS to the line input. The unused side of the stereo line input will be shorted to ground this way so it will not be noisy - no harm to the soundcard in doing it, either. If you have the option - if you have a full PC soundcard with stereo line input - I would use that over using the mic input, the signal level match will be easier to work with.

That 502 is kinda cute, I way eyeing one awhile back as a super-backpack-portable mixer/preamp. Behringer makes some great stuff.

Let us know how it works for you.


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## BladeUK2001 (Jan 27, 2013)

AudiocRaver said:


> I forget what kind of sound card you had. If it is a laptop, it will only have a microphone input, which is Mono. For the that, you want 1/4 TS from a line output (they are mono on the 502) to 1/8 TS to the mic input, and reduce the laptop input gain way down. A regular PC soundcard will also have a stereo line input, for that you would also best go 1/4 TS from the 502 mono line output to 1/8 TS to the line input. The unused side of the stereo line input will be shorted to ground this way so it will not be noisy - no harm to the soundcard in doing it, either. If you have the option - if you have a full PC soundcard with stereo line input - I would use that over using the mic input, the signal level match will be easier to work with.


My Soundcard is a Xonar Essence STX... It has a 1/4 input on the back that can be set to either be a microphone input OR a line-in...

So with that in mind, would a mono cable like this one be what I need to connect the Behringer 502 into the back of the PC?

http://www.dv247.com/cables/proel-mono-jack-to-mono-jack-cable-3-metre--77492


Many thanks for all the help guys.


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## AudiocRaver (Jun 6, 2012)

BladeUK2001 said:


> My Soundcard is a Xonar Essence STX... It has a 1/4 input on the back that can be set to either be a microphone input OR a line-in...
> 
> So with that in mind, would a mono cable like this one be what I need to connect the Behringer 502 into the back of the PC?
> 
> ...


Then you will go 1/4 TS (mono) to 1/4 TS (mono). The Xonar has a 1/4 in stereo in, set it to line level. The unused side of the input (R in) will be shorted to ground, keeping it quiet, which is OK with an input (usually not OK with an output).


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## eddiekun (Feb 2, 2013)

Hi, I'm having some difficulties with setup as well. I have the 502 (with phantom power) and a UCA 202 as a soundcard for my laptop and an ECM8000 mic. I believe I've followed the setup diagram correctly - The R Line in on the UCA 202 is connected to an RCA cable and an RCA to 1/4 Mono TS Adapater into the Line In on the 502.

When I open REW and select the UCA 202 for the Line in and then check levels, REW doesn't register any anything on the Line IN side unless I tap on the mic. I feel like I'm missing something. Anything advice would be greatly appreciated!


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## AudiocRaver (Jun 6, 2012)

eddiekun said:


> The R Line in on the UCA 202 is connected to an RCA cable and an RCA to 1/4 Mono TS Adapater into the *Line In* on the 502.


You should be connected to the *Line Out* on the 502.


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## BladeUK2001 (Jan 27, 2013)

Well, I think I'm onto something here, but still struggling a little... The 502 has arrived, and I've got it wired as follows:-

PC Xonar Essense STX Line in (but I've also tried Mic In) >>> Behringer Xenix 502 >>> Behringer PS400 Phantom Power Unit >>> ECM8000 Mic

The Xonar Sound card is connected to the Xenix via a 1/4 TS connector cable, as suggested... I'm going into the "Left Output" on the Xenix


Problem is, when I do level checks in Room EQ Wizard, I only get an input on the left channel (but I can get this channel up to the suggested level

So, when I do a measurement, it's telling me that my levels are way too low 


Have I gone wrong somewhere?


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## AudiocRaver (Jun 6, 2012)

BladeUK2001 said:


> Problem is, when I do level checks in Room EQ Wizard, I only get an input on the left channel (but I can get this channel up to the suggested level
> 
> So, when I do a measurement, it's telling me that my levels are way too low
> 
> ...


Forgive me for not understanding. Are you saying you "*can* get this channel up to the suggested level," but that level is too low? At what point do you see the suggested level? On the 502? On the Windows Recording Device meter? In REW?

If you can *not* get it up to the suggested level, do you see a good level anywhere? By the way, silly question, but just to be sure, your microphone goes to the Phantom power unit and then into the *microphone* input of the 502, correct? The phantom power unit gives you no boost, just powers the microphone, so you still need the input gain of a microphone preamp.


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