Shure Sm7b low signal with interface

[liberty610]

Hi guys,

I am currently on the fence of re-purchasing a Shure SM7B mic, and I am hoping someone could help me out here. I had one a a few years ago, but decided to sell it because I did not have a pre-amp to run it through, and my audio interface had a low signal volume with this mic.

I am using a Line 6 UX8 interface. The 8 XLR input channels all have a +60db on them. A few years ago when i had the SM7b, I recorded a metal band's vocalist with it. The project didn't turn out to bad, and I thought the vocals where pretty good. I ended up selling the mic, and I think it might have been a mistake to do so. But I was hoping for some feedback first.

Knowing a bit more about recording now then I did then, I decided to pull out the tracks I recorded for that metal band a few years ago. If I remember correctly, the UX8 input knob for that mic was cranked to close to max. Looking at a couple clips of the audio tracks inside Sony Sound Forge, I am seeing that the max level they get to during growls and screams is -16db on the higher screams, and -24 on the lower ones. The tracks sound clear, with little to no room noise on them.

Now, I was told on other forums that you should never 'normalize' a track, but in this case I gave it a shot. I used Sound Forge's 'normalize' feature set to 'peak volume' and boosted it about 50% to a peak of -5.00db. When I played the track back, it sounded a lot louder of course, and still had a clear tone to it without a lot of room noise being present in it.

I have posted a couple pictures that shows a difference in the signal. The beginning of the track the vocalist is silent, and you can see where he starts screaming towards the end. Is this a way I should/could go about getting a higher signal with this mic? What are your guys thoughts?

 

[Farview]

The suggestion about the fethead and cloud lifter are good ones. They are just what you need to get the signal up enough to not have to crank the input on your interface. A lot of interfaces get noise when turned up that high, this avoids that.

As far as normalizing goes, all it does is turn up the volume so the highest peak ends up where you tell it. It' s usually unnecessary.

The reason people advise against it is because a lot of people will normalize everything to 0dbfs and then try to mix. This causes all sorts of gain staging issues and is just bad practice.

If you simply record all the tracks so that the average signal level (not peak level) is somewhere in the -18dbfs range, with peaks no more that -4dbfs, you should be just fine.

 

[pikingrin]

I have an SM7b and bought a FetHead to give the mic a +20db boost of clean gain before it hits the interface. Works very well. I also use it with a low output ribbon mic and an RE-20. It does need phantom power. There is also a Cloudlifter which does the same.

In regards to normalizing, I have been doing it and I don't think I've ever seen anywhere that you shouldn't, but perhaps someone else can give an opinion on this.

+1 for the fethead/cloudlifter - you will definitely need one of those to go along with an SM7b.

 

[Steenamaroo]

If noise isn't an issue and the recording sounds good then you don't have to worry about making it louder.
It sounds like you're getting a good enough level for mixing and if your vocals do end up needing a bit more in the mix you can use make-up gain on a compressor or whatever.

If, however, you do need to boost the volume without boosting the noise, the fathead or cloud lifter a good way to go.

 

[jimmys69]

What I find funny about the SM7b, is that depending on the source, it does not really require that much preamp gain.

Now whether your preamp actually produces the recommended (by many internet posts and blah blah) gain necessary to get a good signal depends on the preamp/interface itself. If your sound source is in need of 60dB of gain and your preamp is maxed out there, you may be looking at a bunch of noise as Fairview stated.

Things like the Cloud Lifter may be needed then. I have had no issue myself with this and the interfaces I have used.

But, I have never used a UX8.


As to the normalizing question, you are just adding gain to a set peak threshold. The noise floor also comes up with that. Not really what you want or need to do.

Steeno has given the correct advice here.