Mackie EM91-C USB mic

E

ecc83

Well-known member
Does anyone here have one please? My son has recently gone back to France with one I bought recently and set it up recording some gentle classical guitar (will post a clip later) He was disappointed to clearly hear noise on the recording.

He also has the same Mackie mic in XLR form and running that through an A&H ZED10 and into a MOTU M4 (3&4 rear) gives much lower noise recordings.

He has Citronics ccu3 USB LDC as well and he has used that many times for 'scratch' guitar recordings and never been conscious of a noise problem.

Love to know if this is just a bad sample?

Dave.
 
Here is a clip as promised. The 'silent' part starts at around 1:45. Called "louder" because I have boosted the signal by about 10dB. "Why record so low" you might say? Well, son finds that if he gets the mic closer the sound gets 'harder' and a bit 'spiky'. He records with XLR mics at a similar distance without the noise problem.

"So" again you say, "why use a USB mic!" I made a balls up. Thought I was ordering another EM91-C XLR mic and the USB version turned up, as he had had decent results with the Citronics we thought we would give it a go.

We now have a 'logistics' problem because he and the mic are back in Le Havre but I bought the mic from Amazon. If Zon want him to ship it back to me for me to process it is not going to be worth the additional expense for a £29.00 microphone!

BTW, if anyone knows the name of the piece please let me know? Son did tell me last night but this old fool has forgotten!

Dave.
 

Attachments

  • EM 91 C USB louder.mp3
    4.7 MB
Wow, if that's the self noise, then that's a problem! I have no experience with USB mics, so I really can't comment as to whether that's common or not. Looking at his two mics, the sensitivity is within 2dB but the S/N is better on the Citronics by 8dB. Both claim 16dB self noise. I was listening to some reviews of the Gen 5 Rode NT1, and there seems to be no appreciable noise in USB mode. They were always quiet mics in the XLR versions.

That said, it's an incredibly low recording level. I threw it in Reaper and looking at the level, the peak was -10dB and the LUFS was -26dB. If you already boosted it by 10dB, then he's peaking at -20. That's low. I would probably suggest at least a slight bit closer setup.

The first thing I would do would be to check to make sure that his Windows USB settings are good. It's possible this mic has less output than the Citronics. Maybe he can boost the record signal in the Windows sound settings.
 
Thanks Rich. Very difficult running tests so far apart! Since we both have a Citronics USB mic I have tried to record a 'baseline' noise level. I wrapped the mic in a cloth and put it in a padded guitar back in a small, quiet bedroom (I have a long USB cable through the wall for my printer) I found the Windows setting for the mic was at 95% so set that to 100% so that son could run the same test.
Attached is my result. When originally done as a 16bit .wav the noise was a bit above -90dBFS, about right for 16 bits. Converted to 320k MP3 might have changed that a bit. My next task is to get son to repeat the exercise his end with his Citronics and then the Mackie. Once I have some hard data that the mic is noisier than it should be we can tackle Amazon.
Don't know if you have kids Rich but it is sometimes hard to get them to do things your way!

Dave.
 

Attachments

  • citronics in bag.mp3
    901.3 KB
I put the Citronics file into Audacity and heard .... nothing! So I highlighted the file and hit Amplify. It suggested 50dB with a resulting peak of -50dB, so that's 100dB boost to get to a peak. I thought that strange, so I put it in Reaper and clicked Properties. Under that tab, it has a "normalize" button which said 103dB, so yeah, it's incredibly quiet.

Once I bumped that level, what you hear are beeps and boops, not hiss. I'm not sure where they come from but it makes me think the noise level was being recorded below -98dB, the lower limit for 16bit, and/or the 320kbp MP3 conversion. I don't know that I've ever encountered a mic that was below 100dB.


Reaoer Citronics.jpg

Audacity Citronics.jpg Citronics +100dB.jpg


And yeah, I have two kids. One lives 6 hours away in Alabama, and a daughter that lives 1 mile away. I understand!
 
I am obliged Rich. Yes, the recordings throw up some anomalies for me as well. I have played them in Samplitude Pro x3 and SE8 and the noise APPEARS to be below -90dBFS. Not likely? One very odd result is that the MP3 version gives a poor result of around -75dBFS in Audacity.
I am going to repeat the tests but with the mic 'open' in my living room, make a noise then STFUp for 20!

As expected, son has not yet complied!

Dave.
 
rob aylestone said:
Dave - I'm intrigued by the tempo? Why did he slow it down so much? It changes it into something quite different?
Click to expand...
OK Rob, a bit banjaxed here! First off, the piece you mentioned does not seem the same as my son's but I need to get hold of him to ask.

Tempo: He learns pieces from transcriptions and he starts slowly and builds the speed as he gets better at it. The clips were done as a mic test and really just for dad! I guess therefore that he was combining
his practice with a mic test?

Going to try him on Whappy...

Dave.
 
It's quite famous - but he's playing it really, really slow. It's old - francisco tarrega. I fiddled and at 3 times the playing speed it is about right (whatever normal is, of course) At his current tempo, the melody is lost as it only plays every few notes.
 
rob aylestone said:
It's quite famous - but he's playing it really, really slow. It's old - francisco tarrega. I fiddled and at 3 times the playing speed it is about right (whatever normal is, of course) At his current tempo, the melody is lost as it only plays every few notes.
Click to expand...
Yup, had an email from him confirming the piece and yes, he has just started to learn it.

Dave.
 
rob aylestone said:
It's a killer - while the melody is fairly peaceful, those other fingers are crazily twanging!
Click to expand...
Indeed, it is the treble he is working on now. He is 52 and started guitar at about 12. He has smashed all the Quo,AC DC, Beatles etc stuff and learned a lot of theory. He bought a classical guitar from a luthier in France a few years ago but only got really serious with it during lock downs, practicing 8 hours a day. He has made good strides with JSBach (bwv1001) but is now trying to get up to speed on other music.

Dave.
 
My band supported Quo years back and I was talking to Rick Parfit's guitar tec - I asked if I could play the white tele. He laughed and said I could try to play it. Impossible! I didn't have Mole Grip left hand muscles and an A barr chord was just about possible, but no way would my little finger press the string down!! High action, VERY heavy strings. I think the man deserved respect for playing it for one song, let alone a full set!
 
rob aylestone said:
My band supported Quo years back and I was talking to Rick Parfit's guitar tec - I asked if I could play the white tele. He laughed and said I could try to play it. Impossible! I didn't have Mole Grip left hand muscles and an A barr chord was just about possible, but no way would my little finger press the string down!! High action, VERY heavy strings. I think the man deserved respect for playing it for one song, let alone a full set!
Click to expand...
Ha-ha! I have heard about that guitar before. Son Steve has played so much and for so long that 'actions' cease to bother him. I have a really crap 'cheese grater' acoustic here that I only use for tests and he plays it just fine. I think he told me that his left hand is now bigger than his right even though he is strongly right handed.

Dave.
 
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