SM7DB audio hiss, I am a bit concerned & need guidance

[23GirlAudioSOS]

sooo my sm7db has hiss.

equipment:
1. UAD volt 1 EIN of -127
2. rode xlr cable
3. sm7db

i stream to obs, and need to reach about -10 db

okay so i reached about -10 db good

"oh no theres hiss" !!!!

okay i change the cable to rode

"still hiss"

okay...i try to add some filters?

"makes me sound tinny..and artifacting?"



i am willing to give out my discord name to get some 1 on 1 help but fr i have no idea what else to do..

tried gain staging...

advice i've been told by others are

stranger: "its your room causing that hiss"

me in my thoughts: "my room doesn't sound hissy?"

okay i try eq, high pass and low pass filter

"it helps alittle but..that main hiss..why!!!"

i need some advice, need to know if its normal noise please please help me!

also i am abit stupid i am not joking so a wall of text while greatly seriously greatly appreciated! hold the phone!! i cant absorb that much info in one go! i'm abit...slow

yes i am an idiot woman please i for the love of god need help

[Sam Spoons]

The SM7B is a low output dynamic mic so if you speak quietly with the mic placed at a distance you will need a lot of gain. Once you crank the gain up on your preamp/audio interface you will crank up the hiss that the input generates (they all do but some are better than others and with higher output mics and the preamp gain lower it's less intrusive anyway). The solution is to either speak louder, speak closer to the mic or add an inline preamp like a Cloudlifter or similar, or ideally a combination of the above. If the first two are impractical then the third will certainly improve matters or you could just change your SM7B for a more sensitive mic.

edit to admit :- I hadn't come across the SM7db version which, obviously means most of my advice is wrong

[Hugh Robjohns]

tried gain staging...

What exactly do you mean by that? (Just checking — different people mean different things).

The SM7dB version of the SM7 includes an internal active gain stage, providing up to 28dB of boost. In effect, it already incorporates a Cloudlifter inline preamp inside.

Sam Inglis' review below explains the differences between the standard SM7B and SM7dB, but the SM7dB is certainly the model I'd use in your situation.

https://www.soundonsound.com/reviews/shure-sm7db

That extra gain stage in the SM7dB should be enough, given your Volt has only 55dB of gain available. Just make sure you're sending phantom power to energise the gain stage, and it's switched to max gain.

To be fair, the Volt preamp is not the quietest hiss-wise, but it should be okay with max gain from the SM7dB.

stranger: "its your room causing that hiss"

me in my thoughts: "my room doesn't sound hissy?"

Our ears and brain are incredibly good at ignoring background noise, which microphones are very good at capturing! So yes, some of that hiss really could be ambient noise in your room (often computer fan noise) that you haven't noticed.

However, all SM7s are intended to be used very close (about 2 inches or less) from the mouth, so the voice-to-ambient-noise ratio should be good. If you're using the mic at a larger distance you could well have ambient noise problems.

[23GirlAudioSOS]

what exactly do you mean by that?

making sure my volume hits the required -db for live streaming as i understood it! and yes i use 48V with my sm7db and the preamplifer enabled inside the microphone!

However, the SM7 is intended to be used very close (>2inches) from the mouth, so the voice-to-ambient ratio should be good. If you're using the mic at a larger distance you could well have ambient noise problems

yes! i do use it very close! but unfortunately i am but a very soft spoken woman i do have to have my face be tracked with the new and cool wacky face tracking softwear tho! for my purposes so i do move the mic slightly to the corner of my mouth sometimes, not always!

[Hugh Robjohns]

what exactly do you mean by that?

making sure my volume hits the required -db for live streaming as i understood it!

Ah. Okay. Hitting the required peak volume is just 'setting the level'.

'Gain Staging' is the process of optimising the gain and headroom in different devices in the signal path.

For example, you might choose 18dB of mic gain and 55dB or interface gain, versus 28dB of mic gain and 45dB of interface gain. These are different gain staging options with different pros and cons in terms of headroom, noise, preamp character etc.

(I suspect you'd need both 28dB of mic gain and 55dB of interface gain, by the way!)

...and yes i use 48V with my sm7db and the preamplifer enabled inside the microphone!

Good. Not everyone does!

i do use it very close! but unfortunately i am but a very soft spoken woman

Hmmm... so the SM7dB might not be the best choice for your voice and placement needs. A high sensitivity small diaphragm capacitor mic that you can place further away might well give better results. But I would recommend trying with your interface before buying.

[23GirlAudioSOS]

Hmmm... so the SM7dB might not be the best choice for your voice and placement needs. A high sensitivity small diaphragm capacitor mic that you can place further away might well give better results. But I would recommend trying with your interface before buying.

I'm not sure what you mean by 'trying with my interface.' I have already been trying, which is why I'm seeking help and advice. I have a Rode condenser microphone, but its placement is uncomfortable. I can't set it up in a way that isn't distracting and directly in my face or monitor. using it on its side is a hassle since it requires my voice to be directly on the side instead of the top. I can't get it angled in a way that doesn't block my view of the screen, and it picks up a similar hiss.

[ef37a]

"and it picks up a similar hiss." Oh dear! Thot plickens.
I think you need to post some test recordings. One of your voice hitting -10dBFS and then 20 seconds of 'silence'. Then the same with the other mic with exactly the same setup and control settings.

That way someone here could run the clips through an analyser and maybe identify what the hiss is?

The suggestion of a small capacitor mic should be taken on board IMHO. There are now quite a few close working, low sensitivity capacitor mics on the market. Not cheap but then the 7bdB was not exactly peanuts!

Dave.

[23GirlAudioSOS]

-10dBFS

i know of db or dba but dbfs i'm not sure how to measure correctly

[ef37a]

-10dBFS

i know of db or dba but dbfs i'm not sure how to measure correctly

To save Hugh's hair I shall tell ya! "dBFS" is the level scale you see in recording software (called a "Digital Audio Workstation) To K I S Sis, have you come across Audacity?

Dave.

[Zukan]

I use an SM7B with an Audient id22 interface. I use it with the Klark Teknik CT1 and have no problems.

[Hugh Robjohns]

I'm not sure what you mean by 'trying with my interface.'

I meant try a high-output capacitor mic with your interface, as an alternative to the SM7dB, to see if it gives more satisfactory results, before buying. If your local retailer won't let you borrow a mic for evaluation, you could find a hire facility that will.

I have a Rode condenser microphone, but its placement is uncomfortable.

The mind boggles!

...and it picks up a similar hiss.

Which suggests the hiss problem is either acoustic ambient noise in the room, or the interface preamps are noisy.

Just checking, is the Vintage mode turned off on the interface (it boosts hiss!) and are you running any compression (that will also raise the background noise level).

Regarding the dB.... It was named after Alexander Graham Bell, so it has a capital B. But the Bel is too large a unit for most applications, so we use a deciBel, which is 1/10th of a Bel.

The decibel is a logarithmic ratio of two quantities — signal levels in this case. But when we are comparing an unknown signal level to a specified reference level we add a suffix to denote the reference in use. If the wanted signal level is the same as the reference, the logarithmic ratio is always 0.

In digital systems, the reference level is always the maximum that can be encoded, or Full Scale, so the maximum level is 0dBFS, and any normal signal will be somewhere below the maximum, hence -10dBFS. This is what your meters are showing you.

Other reference suffixes are available. In the analogue world we use dBu and dBV. If describing acoustic sound levels we use dB SPL.... and so on.

[23GirlAudioSOS]

To save Hugh's hair I shall tell ya! "dBFS" is the level scale you see in recording software (called a "Digital Audio Workstation) To K I S Sis, have you come across Audacity?

yep i use audiacify

[ef37a]

To save Hugh's hair I shall tell ya! "dBFS" is the level scale you see in recording software (called a "Digital Audio Workstation) To K I S Sis, have you come across Audacity?

yep i use audiacify

Is that a typo or an attempt at humour or do you not know of the "DAW" called Audacity? Google will soon find you any number of the usual droning YTs.

I am not known to be a miserable old bugger(?) but "Grokking must be before fun can be had".

(OK! I am misquoting Bob a bit.)

Dave.

[23GirlAudioSOS]

omg yeah it was a typo omgg sorry

[23GirlAudioSOS]

Just checking, is the Vintage mode turned off on the interface (it boosts hiss!) and are you running any compression (that will also raise the background noise level).

yep vintage mode is off! i do notice it boosts hiss too1

[Hugh Robjohns]

I quite like the rename.

But I have no idea what difference Audacify, or even Audacity, would make to your noise issue, or why Dave even brought it up.

I know Dave likes Audacity, though.

The mysteries of forum responses....

[Hugh Robjohns]

yep vintage mode is off! i do notice it boosts hiss too1

Hmmm.... I've not used or tested the Volt, but I'm beginning to wonder if it is a significant contributor of your noise problem.

I know the mic is good. If we take your word that there is no noise source in the room then that only leaves the interface. And I am suspicious of an interface that only offers 55dB of gain and claims an EIN of -127dBu.

Could you borrow a different interface from a friend to try to see if it makes a worthwhile difference? Or even a decent mic preamp so you could feed a line-level signal into the Volt1?

[23GirlAudioSOS]

i cant borrow but i can find out if i can rent one somewhere in sydney

[ef37a]

I quite like the rename.

But I have no idea what difference Audacify, or even Audacity, would make to your noise issue, or why Dave even brought it up.

I know Dave likes Audacity, though.

The mysteries of forum responses....

DO keep up Hugh! The lady asked about "dBFS" and I mentioned Audacity as the easiest, most available software she could look at. And yes, I quite like it but mainly because it is ubiquitous and just about anyone who has an interest in audio and recording knows it and it is useful as a starting point for newbs.

Dave.

[23GirlAudioSOS]

i can record with the sm7db if you want to hear the hiss, are links able to be sent here?

[Drew Stephenson]

Post some samples as a private link (downloadable) on soundcloud or shared file in google drive and people will have a listen.

[23GirlAudioSOS]

i'll send the voice stuffs tomorrow its 3:11 am rn ;3;

[23GirlAudioSOS]

hello heres my audio link, the hiss is more prominent on obs should i of recorded from obs instead? https://audio.com/23girlaudiosos/audio/23girlaudioso

[23GirlAudioSOS]

Post some samples as a private link (downloadable) on soundcloud or shared file in google drive and people will have a listen.

obs audio: https://audio.com/23girlaudiosos/audio/recording
audacity: https://audio.com/23girlaudiosos/audio/23girlaudioso

[James Perrett]

I don't hear any hiss. All I can hear is normal room tone on both samples. (Normal for a domestic room that is)

The only ways to get rid of it at source are to build a soundproof room (very expensive) or to work extremely close to the mic. Otherwise you would be best off using Izotope's RX Voice Denoise to remove it from the recording. Voice Denoise is available as part of RX Elements which can often be found very cheaply on special offer. Don't try to use the de-noiser built into Audacity or any other free/cheap alternative - they are very poor compared to the one in RX.