Shure SM57 low signal

[rob aylestone]

The irony with Thomann is they actually sell the Chinese counterfeit under their own brand at a low cost. The factories knocking out the counterfeit 57s were actually making quite a good microphone, but pretending it was a 57 to generate sales and most of these are actually not at all bad - Thomann recognised this and branded them as their own product. If you have both mics in your hand you can tell the 57 by the sound, but if you just have one, you cannot!

 

[ecc83]

The irony with Thomann is they actually sell the Chinese counterfeit under their own brand at a low cost. The factories knocking out the counterfeit 57s were actually making quite a good microphone, but pretending it was a 57 to generate sales and most of these are actually not at all bad - Thomann recognised this and branded them as their own product. If you have both mics in your hand you can tell the 57 by the sound, but if you just have one, you cannot!

Rob, is the copy of comparable sensitivity?

Dave.

 

[Blackstar2020]

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

When I plug in the XLR connector the mic led is selected automatically, if I plug in a 1/4” jack the line-in led is selected automatically. If I turn the gain knob to max I get about -20 db recording my guitar at 60-80 db. I can work with that, but 100% gain produces a bit of noise. Turning the knob back a bit gives too weak a signal, so that’s no alternative. It seems to me that the audio interface is the problem. The mic and cable are both new. I contacted IK Multimedia and their suggestion was to record at a higher level, but as I mentioned before that’s no alternative as long as I don’t want a visit from the cops. I know the SM57 normally needs no cloud lifter, but under these circumstances I wonder if that’s not the best solution after all. Btw, I tested with a Scarlett 2i2 and it’s the same problem. I’ve seen people with Scarlett 2i2 report the same problem.

 

[Blackstar2020]

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.

I’m afraid 90 dB is too loud where I live, 60-80 dB is probably my recording level. A small mixer instead of a cloud lifter?
Sobriquet? Blackstar2020? Poor imagination, I guess.

 

[ecc83]

I’m afraid 90 dB is too loud where I live, 60-80 dB is probably my recording level. A small mixer instead of a cloud lifter?
Sobriquet? Blackstar2020? Poor imagination, I guess.

That's 90 AT THE AMP. Do you own a sound level meter?

Dave.

 

[Blackstar2020]

That's 90 AT THE AMP. Do you own a sound level meter?

Dave.

Only an iPhone App. Maybe not accurate? I'm recording at more or less the some level as a loud TV. I haven't swapped the cable yet, that might be the culprit. It's new, but inexpensive (snake). I'll try to find somebody who can lend me another SM57 to exclude the possibility that the mic is faulty.

 

[ecc83]

Something silly going on here!
I whacked the gain on the KA6* to maximum and with the previous settings the meter went ape!
I had to back the amp volume down to a near whisper in the room. At 1.5mtrs the level was 67-70dB, that is not even conversational sound level! At the cab fret the level was 88-90dB.

Samplitude was still getting a healthy -20dB fs average and -12pk.
The attached recording is of that. Then I unplug the signal, amps settings stay as was, i.e. you are hearing 99% gitamp noise. Then I switch off the amp and you get room noise (hear the car?) which is mainly the desktop computer which is barely a mtr from the mic. The residual noise of the KA6 at max gain is around -75dB fs.

*As stated previously the AI does not have a lot of gain, an SM57 six inches from a picked nylon acoustic will give barely -25dB fs but still the pre amp is quieter than I can geyt my room which is actually pretty good.

Dave.

 

[CoolCat]

the sound clip

with guitar playing looked to be avg -12db as the swings from -18 to -6peaks and valleys...
the noise only was reading about -50 ~-48 db on my meters....then of course it dropped to a dead silence.

its weird I listened to the soundclip twice at least and it doesn't show any views? oh well...
noise isn't anything that a lite gate couldn't handle.

 

[Blackstar2020]

Something silly going on here!
I whacked the gain on the KA6* to maximum and with the previous settings the meter went ape!
I had to back the amp volume down to a near whisper in the room. At 1.5mtrs the level was 67-70dB, that is not even conversational sound level! At the cab fret the level was 88-90dB.

Samplitude was still getting a healthy -20dB fs average and -12pk.
The attached recording is of that. Then I unplug the signal, amps settings stay as was, i.e. you are hearing 99% gitamp noise. Then I switch off the amp and you get room noise (hear the car?) which is mainly the desktop computer which is barely a mtr from the mic. The residual noise of the KA6 at max gain is around -75dB fs.

*As stated previously the AI does not have a lot of gain, an SM57 six inches from a picked nylon acoustic will give barely -25dB fs but still the pre amp is quieter than I can geyt my room which is actually pretty good.

Dave.

Dave, I connected the mic cable to the amp’s emulated output XLR socket (the other end remained plugged into the interface) and I get a strong and healthy signal. Only 50-60% gain is needed. Nothing wrong with the cable, so it doesn’t leave much room to anything else than a faulty SM57. Think I'll send it back to Thomann.

 

[ecc83]

the sound clip

with guitar playing looked to be avg -12db as the swings from -18 to -6peaks and valleys...
the noise only was reading about -50 ~-48 db on my meters....then of course it dropped to a dead silence.

its weird I listened to the soundclip twice at least and it doesn't show any views? oh well...
noise isn't anything that a lite gate couldn't handle.

Views CC? Dunno what you mean. There would be no need for a noise gate IMHO unless one was very fussy? Just bring the amp up 6dB and back the gain off ten and there will still be a good neg 18dB signal and you would be well above the amp's residual noise.

The HT-20 is in any case a very low noise amp (mine is actually better than stock, did an OPTraff mod) and the noise you see is high because the mic gain is flat out. Mostly hum in fact, bit of 50 Hz (traff to traff) and 100Hz and harmonics.

Of course! IF you were giving the amp full chat, I reckon around 108dB SPL, you would need buggerall gain on the AI and could even back the mic off 150mm. Then amp noise would be zilch.

Dave.

 

[TalismanRich]

Blackstar, it sounds like you are trying to set the amp at conversation levels or below. That doesn't seem to be a microphone issue. You probably need to look at something like building an Isocab to limit the sound in the room while letting your amp and mic work together.

 

[ecc83]

Blackstar, it sounds like you are trying to set the amp at conversation levels or below. That doesn't seem to be a microphone issue. You probably need to look at something like building an Isocab to limit the sound in the room while letting your amp and mic work together.

That was my initial thought TR but my tests have show me that even with the amp putting less than 75dB SPL into the room you will get plenty of signal from a dynamic on the fret.

Of course, if OP want to create OD type sounds with the amp cooking a bit he might have a problem. I think he has a power soak? Maybe it is still too loud even with that to get the 'tone' he seeks?

Dave.

 

[Blackstar2020]

Blackstar, it sounds like you are trying to set the amp at conversation levels or below. That doesn't seem to be a microphone issue. You probably need to look at something like building an Isocab to limit the sound in the room while letting your amp and mic work together.

Lower than conversation level, where did you get that from, if may ask? I've said 60-80 dB. 80 dB is as loud as you normally can play during the day in an apartment or townhouse without annoying your neighbors too much. 80 dB is like an alarm clock, really loud TV or playing your hi-fi system loud. There are people using SM57 to record an acoustic guitar, which is something I couldn't even dream about with my gear. Besides, even if you have an attenuator a tube amp doesn’t sound good at minimum level. Just to make it clear, I’m not trying to achieve something which is impossible.

 

[ecc83]

"a tube amp doesn’t sound good at minimum level" Depends upon the design of the VALVE amplifier!

Even those huge rigs that threaten defenistration get a lot of their overdrive sound from the pre amp stages. It is a myth that you have to go deaf to get a good tone nor do you need to drive a speaker to its limits (not just me, Celestion say so)

Of course, if the amp does not have a master volume control you are a bit buggered but given most modern amp DO plus the use of a power soak, a good tone at 75-80dB SPL (in the room!) should be easily possible.

And no, you are not asking for the impossible. I think I have showed that? You mention however that you rig could never work with the 57 on an acoustic. Guess what I am going to do next?

Dave.

 

[TalismanRich]

Lower than conversation level, where did you get that from, if may ask? I've said 60-80 dB. 80 dB is as loud as you normally can play during the day in an apartment or townhouse without annoying your neighbors too much. 80 dB is like an alarm clock, really loud TV or playing your hi-fi system loud. There are people using SM57 to record an acoustic guitar, which is something I couldn't even dream about with my gear. Besides, even if you have an attenuator a tube amp doesn’t sound good at minimum level. Just to make it clear, I’m not trying to achieve something which is impossible.

60 dB is considered coversation level, but that's a generalization. Two people sitting at the kitchen table might be 60dB conversation level, but several people in a room will be significantly higher than that. In any case, 80dB would be plenty loud for an SM57

I've recorded my acoustic with a 57 using a Tascam 16x08 which has less gain specified than your Axe. At 24bit levels, the noise floor is plenty low. Certainly with a small guitar amp (I've got a Princeton type amp and an old National Supreme) I can get PLENTY of level at bedroom volume. I can't say that I'm getting the guitar tone I want at those levels, but I can get to an adequate recording level.

In any case, I don't think a Cloudlifter or FEThead will give you a "better sound".

 

[ecc83]

No, not really practical is it?
The mic was a bit above the guitar, pointed at the 12th fret and about 200mm away. The KA6 gain was backed off a touch from max.

Do bear in mind that this is a rubbish guitar (and a rubbish player!) small bodied, very cheap, nylon strings and a sod to keep in tune.

Rich. I said 70dB ish was 'conversational' level because the old mic specs used to be given at 70dB and that was said to be "Average speech at one foot (300mm)" These days mics are tested at one Pascal or 93dB SPL which of course improves the figures enormously!
Dave.

 

[Blackstar2020]

60 dB is considered coversation level, but that's a generalization. Two people sitting at the kitchen table might be 60dB conversation level, but several people in a room will be significantly higher than that. In any case, 80dB would be plenty loud for an SM57

I've recorded my acoustic with a 57 using a Tascam 16x08 which has less gain specified than your Axe. At 24bit levels, the noise floor is plenty low. Certainly with a small guitar amp (I've got a Princeton type amp and an old National Supreme) I can get PLENTY of level at bedroom volume. I can't say that I'm getting the guitar tone I want at those levels, but I can get to an adequate recording level.

In any case, I don't think a Cloudlifter or FEThead will give you a "better sound".

TalismanRich, thanks for your reply. I'll try the FetHead anyways and send it back if it doesn't improve anything. 100% gain causes a bit of humming (not from the amp) and I'd like to see if I can get rid of that. I'll be back after checking out the FetHead.

 

[CoolCat]

Dave, I connected the mic cable to the amp’s emulated output XLR socket (the other end remained plugged into the interface) and I get a strong and healthy signal. Only 50-60% gain is needed. Nothing wrong with the cable, so it doesn’t leave much room to anything else than a faulty SM57. Think I'll send it back to Thomann.

thats good news....at a minimum you isolated the issue...too bad you dont have another 57 laying around.
ive had a bad 57 and i screwed up and didnt get it returned to Shure...its been years.
But bad new 57 does happen. Mine was a messed up capsule I think, and the capsules cost almost as much as a new 57...anyway its in the garage still, i took the $100 hit. ouch

Emulated out XLR sounds like a hassle free way to go.

 

[ecc83]

TalismanRich, thanks for your reply. I'll try the FetHead anyways and send it back if it doesn't improve anything. 100% gain causes a bit of humming (not from the amp) and I'd like to see if I can get rid of that. I'll be back after checking out the FetHead.

TBH I would just get the cheap Berry dynamic? That will prove the Shure faulty or not and a spare mic is never out of the way, especially one so cheap you don't care overmuch if it gets nicked or trashed!

The Fetheads and their ilk are really more intended to make dynamics (and ribbons) a bit hotter AND to reduce the AI pre amp noise. As I think I have shown, more gain will just worsen the amp signal to noise ratio.

Dave.

 

[Blackstar2020]

TBH I would just get the cheap Berry dynamic? That will prove the Shure faulty or not and a spare mic is never out of the way, especially one so cheap you don't care overmuch if it gets nicked or trashed!

The Fetheads and their ilk are really more intended to make dynamics (and ribbons) a bit hotter AND to reduce the AI pre amp noise. As I think I have shown, more gain will just worsen the amp signal to noise ratio.

Dave.

I might just do that. At any rate, I've been thinking about recording with two mics, experimenting a bit. I know that the mics would have to be in phase, but that's another thread. Probably go the local music store. Maybe they lend me an SM57, if I buy something from them.