Rode NT1-A Malfunction?

longeagle

longeagle

New member
I just got a Rode NT1-A condenser microphone from Sweetwater. I am running through a Focusrite Scarlett 18i8 into my Macintosh via USB. I have a LOT of noise coming through which I think is the mic malfunctioning, but Sweetwater Tech Support is not convinced. I'd like your opinion.

Here is a video of a test I did with the Rode side-by-side with an SM58. The video is impromptu, so its a little long, but stick with it to the end for an interesting data plot.

Dropbox - File Deleted - Simplify your life

www.dropbox.com www.dropbox.com

A second video with the same setup uses a tone generator to demonstrate that audio presented to the Rode is buried in the noise.

Dropbox - File Deleted - Simplify your life

www.dropbox.com www.dropbox.com

I should note for you that the noise occurs when any cable is used, when any channel in the interface is used, when I monitor directly in the interface (without computer), and when the Rode is connected to a Yamaha analog mixer (no digital at all).

What do you think?

EDIT: Corrected link to first video
 
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The two videos are the same. Can you edit and insert the first video?

Typically the Rode mics are among the quietest mics around. The way your mic's meter is bouncing around looks much more like it is picking up ambient noise. If a mic is noisy, it will generally be constant and will show up as something like hiss or hum. Can you do a recording of JUST the room, no talking except for maybe a comment at the beginning, no moving around. Stand as still as possible. Give use something like 20 seconds or so of silence. That way we can listen closely and see if it is electrical noise or ambient room noise.

Also, since you're using Dropbox, you might make it a 24bit wave file, so it has plenty of S/N .

Condenser mics are notoriously sensitive, and with an extended response compared to the SM58, might be picking up sound that the Shure can't.
 
Something else, Your file is basically in mono. Even converting the M4V to audio and splitting the channels, the noise level is the same for both sides. Make sure you pan the channels fully left and right so they can be compared.
 
I can't really tell what I'm listening to. Are both mikes open? Just do one at a time, or separate them so we can get an A B comparison.

All I am able to discern is a fair bit of movement on the level indicators. I can hear mouth noises between words, but I can't hear noise that suggests malfunction.

The Rode has very low self noise, but it is more sensitve than the SM58. It also has a wider frequency response than the SM58, so it will pick up more low end rumble.
 
TalismanRich said:
Something else, Your file is basically in mono. Even converting the M4V to audio and splitting the channels, the noise level is the same for both sides. Make sure you pan the channels fully left and right so they can be compared.
Click to expand...
Tha audio on the video is just from the phone mic, not from the test mics. I did not record the audio from the actual test, but I could redo the tests and record.

Even though the Rode is "more sensitive" than the SM58, the monitor meters show about a 60dB difference when there is no voice. It doesn't seem like that could be normal.
 
gecko zzed said:
I can't really tell what I'm listening to. Are both mikes open? Just do one at a time, or separate them so we can get an A B comparison.

All I am able to discern is a fair bit of movement on the level indicators. I can hear mouth noises between words, but I can't hear noise that suggests malfunction.

The Rode has very low self noise, but it is more sensitve than the SM58. It also has a wider frequency response than the SM58, so it will pick up more low end rumble.
Click to expand...
There is not point in listening to the audio on the videos since that is just what the phone mic picked up. Watch the meters on Audacity. The "left" channel (top meter) is the Rode, the "right" channel is the Shure. This would have been clearer if the idiot OP (me) hadn't omitted the first video.
 
I think you have an excellent warranty with that mic so you should have no worries.

I can hear no noise but from the meter which is dancing around as if it was as background noise.........but there isnt any.

I have noticed once that plugging one lead into a socket was noisier than another on the meter........never found out why. Have you tried swapping where you plug the mics into the Scarlett?
 
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Orson said:
I think you have an excellent warranty with that mic so you should have no worries.

I can hear no noise but from the meter which is dancing around as if it was as Gecko says 'ambient' noise.........but there isnt any.

I have noticed once that plugging one lead into a socket was noisier than another on the meter........never found out why. Have you tried swapping where you plug the mics into the Scarlett?
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Yes, I have run each mic into all four Scarlett inputs. Same results. I have tried three different cables Including then shipped with the Rode) with the same results. Thanks.
 
longeagle said:
Yes, I have run each mic into all four Scarlett inputs. Same results. I have tried three different cables Including then shipped with the Rode) with the same results. Thanks.
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So where is the noise it is showing dancing all over the meters? Can you turn up the playback volume of a recording with the mic and post a video and not talk over it?
 
If there is a noise problem with the mike, then that's what we need to hear. Meters dancing around is not necessarily an indication of a problem. The meters dance around when I have a Rode connected with the gain up (usually to between 2 and 3 o'clock), which I did to just have a look at the activity without recording anything.

I did have a problem with a Rode (it started generating a heap of white noise) , and their service is excellent. If you do have a problem, then contact Rode.

Also, I have registered all my Rode mikes with them, which comes in handy if repairs are needed.
 
The only experience I've had with a noisy Rode mic has been a bad phantom supply, usually by having a cheap lead or dirty connections.

Alan
 
Thank you all for your suggestions as to how to collect and present the evidence.

Here is a .WAV of a new test: 20 seconds with the Rode at 50% on the interface and the Shure turned down to 0), then 20 seconds of the Shure at 90% and the Rode turned down to 0. https://www.dropbox.com/s/mvggrt1hmv3ko5m/rode test 3.wav?dl=0

In Audacity, the waveforms look like this:
Rode test waveform.png

The spectrum plot for the 20-eecond Rode clip is:
Rode spectrum.png

The Spectrum plot for the Shure clip is:
Shure Spectrum.png

What do you make of this?

Thanks for your help and your patience. ( If you like, the Audacity project is here: https://www.dropbox.com/s/73hp3tql72m83l8/rode test 3.aup3?dl=0 )

-- Joshua
 
Is it a fan blowing air?

I think before you go any further, if it were me I would try different leads. Cheapest and simplest options first.
 
Taking your wav file, the first part sounds like ambient noise... either an AC or refrigerator motor, or a fan running. Something of that nature. So I took the file, split it when you switch to the SM, and then boosted that portion of the signal to equal the Rode. It's the same noise. Definitely not microphone noise.

Listen to the comparison with the two mics equalized:
View attachment Rode vs Shure Noise content.mp3
I think what is throwing you is that the Rode is almost 15x more sensitive than the Shure. For a pressure of 1 pascal, the Shure puts out 1.6 mV. The Rode puts out 25 mV. That's huge.
 
What I would like to hear now is the Rode set to a recording level, with a few seconds of silence, then a few seconds of talking. And then do the same for the Shure.
 
TalismanRich said:
Taking your wav file, the first part sounds like ambient noise... either an AC or refrigerator motor, or a fan running. Something of that nature. So I took the file, split it when you switch to the SM, and then boosted that portion of the signal to equal the Rode. It's the same noise. Definitely not microphone noise.

Listen to the comparison with the two mics equalized:
View attachment 109604
I think what is throwing you is that the Rode is almost 15x more sensitive than the Shure. For a pressure of 1 pascal, the Shure puts out 1.6 mV. The Rode puts out 25 mV. That's huge.
Click to expand...
On listening, I see what you mean. They do sound the same. There are lots of fans and fridges all over our house. I had turned off the loudest one (the furnace/AC), but the others are not readily turned off.

I was unaware that the sensitivities of the mics were SO different, so thanks for that. Still, a difference of 15x is about 25dB, and Audacity tells me the Rode (RMS) is -23.63dB, while the Shure is -79.11dB, even though the interface record level is set at 50% for the Rode and 90% for the Shure.

A difference of 55dB seems like too much. Also, I wonder -- in the tone generator test (second video above, or see link below), the beeps were barely audible in the Rode, but ran the Shure up to 0dB. So Rode vs. Shure, for the same inputs, the Rode's noise level was higher, but its signal level was lower... can that be right?

Do remember that the audio in the video is NOT recorded through the test mics, but only through the phone mic that was shooting the video. I (foolishly) didn't record the audio of the test, relying on monitoring meters to make the point.

rode test 2 480.m4v
 
I think if the Rode was turned up as high as on the meter it would be off the scale with that bleeping.

The meter is dancing all over the place and there is no sound to match except earlier some quite fan/air sound. It is weird but I cant see how it can be the mic otherwise you would clearly hear the sound.

Could you download the free version of Reaper and get your hands on another interface for 5 minutes to test again?
 
Thanks for taking time to help.

I did run the Rode through a Yamaha analog interface and heard the noise, but it was in a music store and I only had a minute (and of course, didn't record it). I'm still looking for somebody out here the wilds of Idaho who has a source of phantom power I can test with at home. Is there any reason for suspicion that the Focusrite is passing dirty phantom power to the Rode? Even passing electrical noise from the house current? I have tested with multiple cables with the same result, and I checked the voltage at the end of the cable (47.7 v) (and yes, the Rode is the P48 model).

And what would I do with Reaper that I can't do with Audacity?

-- Joshua
 
Thinking twice about it, I'm not sure how the RMS difference and the voltage difference should be compared. I apologize for an ill-considered remark. If anyone really knows how this comparison should be done, I'd like to know.
 
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