Low levels on new Microphone

E

ElderMelder

New member
So I just got a new microphone (t.bone EM9900) which I thought sounded really nice when I saw it in a YouTube Review and so I just hooked it up to my old setup which consists of a very cheap Phantom Power Supply (Justin Phantom 1) connecting directly to my laptops microphone Input.

Now I have the problem, that the Microphone delivers a very very quiet sound, around -36dB with the Phantom Power attached and I have to apply a really high gain (around +25dB) to even be audible which in return amplifies the before very quiet sound-floor so much that I cant use it to record.

I would like to know what is wrong with my setup if there is an easy answer. I suspect it to be the cheap Phantom Power Supply not providing the right amount of amplification to the mic and additionally adding a lot of noise to the sound floor but I am kinda new to this so Id like to know if I did anything wrong and weither I should just go ahead and buy a different preamp (it has to be kinda affordable, I dont want to spent another 100 Euros on the AMP) like for example this one: ART Tube MP

Thanks for the help!
 
Phantom power doesn't amplify the signal, it just provides DC power so the mic operates. That said, lower phantom power could mean somewhat lower output, but that's not likely to be your problem.

The core of your problem is running a pro mic into the laptop mic input. The wiring schemes are different and incompatible. It's possible to interface them, but the wiring has to be done correctly. I don't suppose you have a DMM.

The real solution is, of course, to get a proper audio interface.
 
One problem on some phantom power units is that the outputs are no isolated from the inputs so when you connect to an unbalanced device like a computer, you short pin 1 to one of the signal conductors, and this has a direct path to the two resistors that create the phantom voltage between conductors 2 and 3, reducing the ability to power the mic properly. In practice, you buy the power supply and have to try it, then perhaps return it. I second the advice to just buy a proper interface.
 
I think it's possible that an adapter from XLR to TS where pin 3 is left floating might work, but it's still going to be inferior to a decent USB audio interface.
 
Typically going from balanced XLR to an unbalanced TS mono connection plug, such as the input on a laptop/desktop, the pin 3 of the XLR is connected to the sleeve(Gnd) of the TS plug, either at the XLR or the TS plug. You do lose signal doing this (6 dB I think is the number).

r415_9_image_xlr_vers_tps_thumbnail.png

If connecting an XLR via a TRS plug to a stereo input (camcorder or similar) the pin 3 is still connected to the sleeve, but pin 2 is bridged to the tip and ring of the TRS plug. This maintains signal on both left and right channels. A Hosa cable will do this .. Microphone Cable - Hosa
XVM-100F_diagram1-600x254.jpg

I'm interested why the OP selected a hyper-cardioid shotgun style mic and what the intended purpose is. Given what he tried, I'm guessing he's a noob that could use some guidance possibly even with the type of mic for what use as well as recording software(DAW).

The connection to the laptop may be possible with a phantom box and the correct cable, but leaves alot to be desired. The other potential issue is if the laptop has a combo mic/headphone TRRS jack which could hose up a 'normal' connection of gear.
 
arcaxis said:
Typically going from balanced XLR to an unbalanced TS mono connection plug, such as the input on a laptop/desktop, the pin 3 of the XLR is connected to the sleeve(Gnd) of the TS plug, either at the XLR or the TS plug.
Click to expand...

I agree, but if rob aylestone's point about the output not being isolated is the case then connecting pin 3 to shield might short out the phantom.
 
If most manufacturers hopefully as they should follow the convention of using coupling capacitors to isolate the phantom voltage from the outputs connecting pin 3 to the shield/ground should not pose a problem. Consider a balanced transformer output with its two legs connected to pin 2(hi) and pin 3(lo). Lifting pin 3 would lose half the signal path. Connecting pin 3 to shield/ground provides a signal path to an unbalanced termination, but then loses the benefits of a balanced connection.

I did try a condenser mic through a Behring phantom power box connected via one of the cables I noted in the previous post into my desktop PC. The mic worked and I got adequate recording levels, but there was an unlying noise I think from the power suppy that got coupled through the power supplies caps. I've used an dynamic mic straight in with one of these cables and it worked OK. The onboard motherboard soundcard pretty much sucked and makes good argument for a USB interface or at the very least a USB mic.:)

I still want to know why the OP needs a shotgun mic.

Schematic of a typical phantom power supply in this Shure link
How do I build a phantom power supply?
 
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