Having issues with hum in background

N

Ninzhan

New member
So, I recently bought a cheap mic and 48V phantom power supply, and whenever I record with them, I get lots of hum in the background.

I have tried changing settings on my computer, grounding the power supply, and making sure the mic is grounded.

My current setup is a line from the mic into the power supply, from the power supply into the computer, with the computer and the power supply plugged into the same outlet.
 
Is this a laptop computer?

If so have you tried it on battery-power? Hum still there?

Crucial question... you say 'cheap mic'.... what make/model?
 
Hey,
If you're running into the the computer line input, then you're going in unbalanced.
There's a good chance that's why you're pickup up, or hearing, noise.

Maybe try moving away any equipment which might be interfering, (anything with a transformer is a good start) or using shorter more direct cable runs?
Trying switching things on and off to see if there's a measurable difference. Lights, A/C, that kind of thing.

Failing that, a balanced-input audio interface wouldn't be a bad idea, whether it's the root of this problem or not.
 
Farview said:
What interface are you using?
Click to expand...

Not sure what this means. Do you mean the program like Audacity? if so, it's OBS and/or audacity.

Mike Stranks said:
Is this a laptop computer?

If so have you tried it on battery-power? Hum still there?

Crucial question... you say 'cheap mic'.... what make/model?
Click to expand...

I have tried it on a laptop, to the same result, even on battery power. I am trying to use it on a desktop.

Its a BM-700 from Tonor. Amazon link here (just because that's where i got it from.) : TONOR XRL to 3.5mm Podcasting Studio Recording Condenser... Microphone

Steenamaroo said:
Hey,
If you're running into the the computer line input, then you're going in unbalanced.
There's a good chance that's why you're pickup up, or hearing, noise.

Maybe try moving away any equipment which might be interfering, (anything with a transformer is a good start) or using shorter more direct cable runs?
Trying switching things on and off to see if there's a measurable difference. Lights, A/C, that kind of thing.

Failing that, a balanced-input audio interface wouldn't be a bad idea, whether it's the root of this problem or not.
Click to expand...

Unbalanced? If this is newbish, sorry, but what does that mean? I will try what you suggest though.
 
You must be using the internal sound card. That is never the best way to do it. For recording, you would normally get an audio interface that has the appropriate inputs and outputs for what you are trying to do. It will have mic preamps with phantom power, proper monitoring facilities, etc...
 
Farview said:
You must be using the internal sound card. That is never the best way to do it. For recording, you would normally get an audio interface that has the appropriate inputs and outputs for what you are trying to do. It will have mic preamps with phantom power, proper monitoring facilities, etc...
Click to expand...

What kind would you recommend for someone with a small budget? What does an internal soundcard not do that an interface will?
 
Ninzhan said:
Unbalanced? If this is newbish, sorry, but what does that mean? I will try what you suggest though.
Click to expand...

It might not be the reason for your problem but unbalanced audio is more susceptible to noise and interference.
The input on a computer uses three conductors - Shield, left and right.

Line inputs on interfaces use those same three conductors for left, and three more for right - Two input cables.
Without going into detail, the additional signal conductor is used to cancel or eliminate noise picked up by the cables.

Unbalanced signal cables aren't usually a problem as long as the cable runs are kept short and they aren't physically close to anything that'd cause big problems, like power supplies with transformers etc. (like the one in the back of your computer!)
 
The mic kit you bought appears to have an XLR to 1/8" (3.5mm) cable. You're probably using this between the phantom power box to the computer input. Some of these BM-700 mics seem to be able to use 'plugin power' the MIC jack on a computer provides for electret type mics and the Amazon ad hints at this. Give the mic a try without the phantom power box, just connecting the mic to the computer with the XLR to 1/8" cable. Depending on your computers soundcard and software it uses, you may need to select the input jack to be for a microphone (although it may prompt you when you plug something in as to what the device is.
There is another forum member here that has a BM-700 or did and he may be able to give some pointers if he sees this thread.
 
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arcaxis said:
The mic kit you bought appears to have an XLR to 1/8" (3.5mm) cable. You're probably using this between the phantom power box to the computer input. Some of these BM-700 mics seem to be able to use 'plugin power' the MIC jack on a computer provides for electret type mics and the Amazon ad hints at this. Give the mic a try without the phantom power box, just connecting the mic to the computer with the XLR to 1/8" cable. Depending on your computers soundcard and software it uses, you may need to select the input jack to be for a microphone (although it may prompt you when you plug something in as to what the device is.
There is another forum member here that has a BM-700 or did and he may be able to give some pointers if he sees this thread.
Click to expand...

Thanks, but this is one of the first things i tried. Doesn't work.

Who is this member>
 
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Mark, If you mean me I bought a BM-800 and sent it to son but you are right, the mic was supplied with a female XLR to 3.5mm stereo jack plug and worked very well plugged into this HP g6 i3 laptop upon which I am typing.

If the OPs' -700 has a similar cable (the plug is IDENTICAL to a headphone plug chap) it should work and surprisingly well from my experience.
If two computer OB soundcards do not work I suspect a duff mic. The QC is not likely that good for £20!

Who said/why did you buy a phantom power unit? The mic either runs as described above into a PC or, it needs to go into a device with phantom power AND a pre amp such as an Audio Interface or mixer via an XLR to XLR cable. Is there a shop such as our Maplins who might test it for you?

As an example as to WTF we mean by "interface" Google..Steinberg UR22.

Dave.
 
ecc83 said:
Mark, If you mean me I bought a BM-800 and sent it to son but you are right, the mic was supplied with a female XLR to 3.5mm stereo jack plug and worked very well plugged into this HP g6 i3 laptop upon which I am typing.

Dave.
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Oops, yeah I remembered BM-something and like you say it should be similar.

"NOTE:It cannot be used with mobile phone and tablet computer.(2)Voltage Required:5V, to obtain the best sound quality.(3) 48V Phantom Power Supply is NOT INCLUDED! "

This spec implies that 'plugin power' should work, although I don't know for sure without hunting it down if 5vdc is normally what the MIC jack would provide, think it was slightly lower. As long as the desktop and laptop have a MIC/LINE input jack it should have plugin power available when the jack is set to mic. Some laptops have combo headphone/mic jacks (TRRS) and I'm not so sure those would work with this mic.
 
Sorry to be the bearer of bad tidings, but these mics have proved to be notoriously unreliable... lots of problems reported on various forums.

To keep it simple I think your best bet would be to get a USB Mic. Plenty of good ones around for not too much money. Check out those by Samson and Blue at the cheaper end of the spectrum, but there are loads of good quality ones around at slightly more expense.

If you're not sure about which one to get come back and ask....
 
Mike Stranks said:
Sorry to be the bearer of bad tidings, but these mics have proved to be notoriously unreliable... lots of problems reported on various forums.

To keep it simple I think your best bet would be to get a USB Mic. Plenty of good ones around for not too much money. Check out those by Samson and Blue at the cheaper end of the spectrum, but there are loads of good quality ones around at slightly more expense.

If you're not sure about which one to get come back and ask....
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Did not know that Mike, seems I have been lucky. I fully intend to buy another one and notice that they have become even cheaper! £13.99 on Zon.

Yes, a USB mic of about £50 would be ok however I had one and the BM-800 beat it for sensitivity and noise.
I would urge OP to give us a breakdown of exactly what they want to do, now and in the future since USB mics are very limiting. Noobs ALWAYS forget "monitoring"!

Dave.
 
Ninzhan said:
So literally, the consensus is, get rid of the power supply in favor of an interface (Would this one work?: Behringer U PHORIA UM2), or test it again without the power supply.
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Yes, you will need an XLR-XLR cable to use an interface. Check the specc of the UM2 to ensure it HAS +48V, some of the bottom feeder gear doesn't.

Dave.
 
These mics are stupidly cheap and will either work on a laptop or not. You cannot guess. The blurb that comes with them is appalling - so the translation doesn't help. The phantom adaptor will power any 48V phantom mic, and of course, cannot be connected direct to a laptop - only something that has a proper XLR balanced mic input - either with or without an phantom power feature (and of course if it has one, you didn't really need the phantom power adaptor.

What do do? Well if you are serious about wishing to record - then you need the interface - which always seem to have at least two mic sockets in case you want to record two thing at the same time or stereo. USB mics are universally limited. If you never need two at the same time, they will do the job, but it's like recording with an arm tied behind your back. They are for podcasters who wish to talk. Most recording enthusiasts start to build mic collections because some mics work better on certain things. One mic is rarely enough.

These cheapo mics won't be a waste - they will always do decent enough duty for when you need better, and for some things, they're actually surprisingly good. I bought 5 of the things. One hummed - permanently. Soldering the lead on - that was solder free and had just been forgotten cured that one. Two will not work on my laptop, and none work on this mac. Realistically, you need to spend about a hundred quid to get up and running. Plenty of nice interface preamps in that kind of area.
 
rob aylestone said:
These mics are stupidly cheap and will either work on a laptop or not. You cannot guess. The blurb that comes with them is appalling - so the translation doesn't help. The phantom adaptor will power any 48V phantom mic, and of course, cannot be connected direct to a laptop - only something that has a proper XLR balanced mic input - either with or without an phantom power feature (and of course if it has one, you didn't really need the phantom power adaptor.

What do do? Well if you are serious about wishing to record - then you need the interface - which always seem to have at least two mic sockets in case you want to record two thing at the same time or stereo. USB mics are universally limited. If you never need two at the same time, they will do the job, but it's like recording with an arm tied behind your back. They are for podcasters who wish to talk. Most recording enthusiasts start to build mic collections because some mics work better on certain things. One mic is rarely enough.

These cheapo mics won't be a waste - they will always do decent enough duty for when you need better, and for some things, they're actually surprisingly good. I bought 5 of the things. One hummed - permanently. Soldering the lead on - that was solder free and had just been forgotten cured that one. Two will not work on my laptop, and none work on this mac. Realistically, you need to spend about a hundred quid to get up and running. Plenty of nice interface preamps in that kind of area.
Click to expand...
kk. good advice. I will probably get an interface.

In other news, it doesn't work just plugged in w/out power supply.
 
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