Shure SM57 low signal

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Blackstar2020

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I'm using a Shure SM57 to record my guitar. I know that the SM57 has a weak signal and is built to record on high volume. However, I have neighbors who arn't very appreciative of my music, so I need to record on low volume. The amp has a built-in attenuator, so it still sounds good. Do you think that an TritonAudio FetHead could be the solution? Btw, the interface I'm using is a AXE I/O.

Thanks
 
In reverse order, any phantom-powered inline mic booster like the FetHead, et al, should give you plenty of signal gain.

I honestly can't quite puzzle out the specs in the AXE I/O manual
Input level, min gain: 0 dBFS is obtained with a +12 dBu signal at the XLR input
Input level, max gain: 0 dBFS is obtained with a -37 dBu signal at the XLR input​

I read (at Shure) the SM57 sensitivity is -54.5 (dBV/Pa at 94 dB SPL), which an online converter says is about -52 dBV, so I'm guess that means you're probably seeing pretty low peaks on your recording. What, -20dB or something? Is it too low to simply do a clip gain afterwards?
 
Thanks for your reply. Yes, the problem is that I get very low peaks. I’m using the DAW to normalize the gain, but since I’m recording very clean guitar sound, I don’t think it’s ideal. I also have to turn the gain on the interface to max and that produces a humming noise. If I turn the knob back just a little bit, the humming disappears but the signal get too weak to be usable. I guess I’ll go for the FetHead.
 
You do NOT need a cloud lifter with a 57. They have plenty of output. Just checking - you have plugged it in with and XLR connector, not a jack? They're never an issue with preamps that I've ever discovered, from the 70s kit to current - they are fine, gain wise.

There are a few possibilities - if you are turning the gain to max, something is wrong. Dodgy mic, dodgy cable or dodgy interface - that's assuming the combo socket is being used with an XLR connector. The jack part of the connector is of course, NOT for mics.
 
OP did say he’s recording an amp at a low )”bedroom” type) level and I’m not sure of the gain in that interface. It might help to see an actual recorded track.
 
rob aylestone said:
You do NOT need a cloud lifter with a 57. They have plenty of output. Just checking - you have plugged it in with and XLR connector, not a jack? They're never an issue with preamps that I've ever discovered, from the 70s kit to current - they are fine, gain wise.

There are a few possibilities - if you are turning the gain to max, something is wrong. Dodgy mic, dodgy cable or dodgy interface - that's assuming the combo socket is being used with an XLR connector. The jack part of the connector is of course, NOT for mics.
Click to expand...

I’m using XLR cabels and connectors. The equipment is fairly new, about 6 months, and of pretty good quality. I’m recording on low volume, don’t you think that’s causing the problem? Unfortunately I can't crank the amp because of my neighbors :(
 
If you can hear the amp across the room, and the mic is on or near the grill, that should be perfectly loud enough. Can you record yourself speaking into the mic, in a normal voice from about 150mm/6" from your mouth. How does that work?
 
rob aylestone said:
If you can hear the amp across the room, and the mic is on or near the grill, that should be perfectly loud enough. Can you record yourself speaking into the mic, in a normal voice from about 150mm/6" from your mouth. How does that work?
Click to expand...
In order to record my voice I have to put the mic very close to my mouth and turn the gain to max. More or less the same thing. I think there are some other threads about the same problem with SM57 and what I've learned is that these cheaper audio interfaces need a minimum of 60db gain. Seems to be no way around a cloudlift?
 
No that's just not true. This magic gain figure often quoted is meaningless without the amount of noise detailed too. 55dB of gain with good signal to noise, is better than 60dB with poor s/n. What you need to do is be systematic. Swapping the mic for anything else would be useful. Can you stick a clip of ten 15 seconds of recording on soundcloud or similar? A bit of guitar or voice with the problem, but then a few seconds of silence perhaps by just pulling the mic plug out. This lets us hear the mic, but then the system noise. This may give us a clue.
 
I'm wondering if you might have an SM57 fake. Some of what you describe is common with fakes. Where did you get it? Trust me....from experience.......it's VERY difficult to tell a real SM57 from a fake........and there's LOTS of fakes out there. No way should you have to be so close to the mic and max out the gain.
 
Try different cable. Try different mike. If you don't have a different cable, buy one. They are not wasted investments. If you don't have a different mike, borrow one.
 
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I agree with Rob on this one. I've got an SM57 and when I run into my Tascam with "only" 56db gain, I get a perfectly usable signal level with acoustic guitar or voice. Putting in front of an amp at any level above a whisper would be enough to record with the gain knob at about 75 to 80%.

I've never looked at the AXE I/O, but it would have to be a really weak interface not to get ample signal for recording.
 
Mickster said:
I'm wondering if you might have an SM57 fake. Some of what you describe is common with fakes. Where did you get it? Trust me....from experience.......it's VERY difficult to tell a real SM57 from a fake........and there's LOTS of fakes out there. No way should you have to be so close to the mic and max out the gain.
Click to expand...


I found a web page about counterfeit Shure SM57 mics (Spotting a counterfeit Shure SM57 | Martin Pinnau Photography). I compared the packaging, the connector pins, etc. and my SM57 is most definitely not a fake. Besides, I bought it at Thomann, paying the regular price. Thanks for the tip, though.
 
rob aylestone said:
No that's just not true. This magic gain figure often quoted is meaningless without the amount of noise detailed too. 55dB of gain with good signal to noise, is better than 60dB with poor s/n. What you need to do is be systematic. Swapping the mic for anything else would be useful. Can you stick a clip of ten 15 seconds of recording on soundcloud or similar? A bit of guitar or voice with the problem, but then a few seconds of silence perhaps by just pulling the mic plug out. This lets us hear the mic, but then the system noise. This may give us a clue.
Click to expand...

I’m gonna test with another audio interface, swapping the mic and the cable and also contact IK Multimedia. I’ll come back with the result.
 
rob aylestone said:
Fingers crossed then.
Click to expand...

I sense some conflicting opinions here. There is no doubt in my mind that the 57/58 does give some people level issues in certain circumstances. One thing I found out recording amp with my son is that you DO need the amp fairly loud even with the mic on the fret and a figure of 90dBC SPL comes to mind and that I am sure would be too loud for the OP.

I shall set some gear up in a while and try to give you all some numbers.

Dave.
 
O....Kay! I was a bit, er..Wrong! You don't need a lot of level from an amp with a dynamic on the grill.

In the attached clip the mic was a Prodipe TT1, I no longer have a '57 but the TT1 is less than 3dB more sensitive than the Shure so, in the ball park?

The mic was touching the fret of a cab containing a Greenback 12" 55Hz model and driven from a Blackstar HT-20 on clean channel.
If the track seems a bit...'rough' please bear in mind it was MP3 then converted to .wav (which of course improved it not at all!) then, re amped from a laptop. Reproduced from a guitar speaker, recorded as .wav then turn back to MP3 for attachment!

You can see I hope the level in Samplitude? The mic fed my NI KA6 and gain was advanced to 3 o'clock, i.e. a fair bit in hand. The KA6 does not have the gainest preamps but they are very quiet.

In the room the sound level, some 1.5mtrs from the speaker was around 75-80dB C. That is a loudish TV but would not I would have thought cause any problems a wall away.
WERE this a problem there is clean gain left in the KA6 and the amp's level could be dropped accordingly. Or one could try a capacitor mic such as one of my AKG P150s which are about 10dB hotter than the dymo.

If OP wants to try another microphone I can recommend the Behringer XM8500. Silly bloody money (~$20) but a remarkable good, knockabout vocal mic.

Anything else I can rig/measure/'eff about with...shout.

Should have said:Track is one of son's from a few years back because I cannot play JACK anymore.

Dave.
 

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Blackstar, when you plug the XLR connector into the Axe I/O, does it automatically select the MIC LED on the front panel of the unit or is the MIC or LINE input selection done somewhere in the interface controller software. I didn't readily see a way this gets set either in the manual or from the image I found of the interface controller software, thus I'm thinking it senses an XLR and assumes a mic is plugged in(?) I'm assuming the MIC LED is illuminated for you and not the LINE which would likely result in much less gain(?)

The -37dBu signal to attain 0 dBFS seems like it wouldn't be adequate for the SM57 unless the amp was cranked and the mic was right at the amp. A typical condenser mic likely would have the needed output to drive the Axe input OK I believe.

The SM57 has a sensitivity of 1.6mv/PA or -56dBv/PA. The dBu equivalent is about -54dBu. I think the Axe would need about 17 dB more of gain to get to 0 dBFS in the interface. I'm thinking that trying another interface may prove this out and not a problem with the mic or cable. Guessing whatever interface you may try will be in the ballpark of 54 to 56 dB of gain.
FetHead would work if you find you do need a gain boost.

dB dBu dBFS dBV to volts audio conversion digital - calculator volt to dBu and dBV dB mW SPL dB decibels 0 dBFS - convert dB volt normal decibels relatioship relation explanation analog audio absolute level true rms convertor converter decibel to dbf
 

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Mark, OP does not need to get his signal anywhere near 0dB fs.
My screen shot shows a level of around -25dB fs. Sods law, where it was when I hit the tit! In fact is was around -20 and peaking to -15dB.

I have not so far looked at the AXE manual. Will do so shortly.

If it turns out more gain is needed I am going to make a rather risky suggestion? A small mixer.

The inline pre amps are rather expensive and are really designed for peeps that need a bit of REALLY CLEAN gain, e.g. speech into a 7b. Any of the common mixer makers produce devices around $50 that have really quite good pre amps (had two cheapos and an A&H and the latter was only slightly better)

A mixer is vastly more versatile than a 'slug' pre amp and can give true zero latency monitoring. OP might even pickup a decent one from Cash Converters for $20?

Dave.
 
Hmm? Had a varder at the AXE I/O and TBH I was expecting a rather flaky, guitar oriented bit of kit with mic operation tacked on as a bit of an afterthought. Not a bit of it, seems quite 'professional' and has the best written specification I have seen in a long time.

With mic gain at max a signal of -37dBu is required for 0dB fs. That implies a signal at -57dBu will produce -20dB fs and VERY roughly that will need a sound level at the mic of 90dB SPL. Close to the cloth that should easily be achieved with only a modest level in the room.

Something very weird going on if OP* cannot get a decent level. I have a bit to do today but will get some SPL readings at the Greenback later.

*Did you HAVE to chose that sobriquet? Causes this old git no end of confusion! Heh!

Dave.
 
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