noise issue

mrskye · 11-06-2010, 10:02 PM

Hi
I'm trying to learn the ropes for recording and I'm liking Reaper.
I have a question though.
How can i get rid of this noise: [video of flutter]
[i will soon post an audio example]
http://www.swfcabin.com/open/1289102537
Its doesn't seem to be external, as i get it when i record with the mic 8feet away from the laptop. I have a feeling its either the mbox1's preamp or noise from my laptop (internal). I have tried increasing buffer size from 256 to 512 ASIO and increasing sampling rate from 44.1 to 48khz. both didn't help with the flutter.
recording at 24bits.
the mic is relatively new and supposedly good quality.
the mbox1 is old/secondhand.
my laptop itself makes audible fan & hard rive noise and has its graphics card overheating issues sometimes but that is trivial. but that noise is external - that is, im not hearing that on the mic - im hearing internal poppy/scratchy bits background to my recording.
and i also use a pop shield - as i said, it appears to be internal
any advice appreciated

gwok · 11-06-2010, 10:12 PM

i notice it says line 2, just to be sure, that's the channel the mic is plugged into - im not saying your stupid, just covering the bases and the 2nd input made me suspicious

test out different inputs, see if you can isolate it, try an alternative for each link in the signal chain(new chord, new input etc)

mrskye · 11-07-2010, 12:00 AM

I retried Line 1 just then. same problem. nothing else in other line.
here are examples of the noise for line 2 & line 1 respectively (small files):
http://www.webfilehost.com/?mode=viewupload&id=1313356
http://www.webfilehost.com/?mode=viewupload&id=4973486
Its the crackle/spit noise im talking about.

I also tried disabling internet & laptop power supply while recording, without success.
So im suspecting its the mbox - i read somewhere the preamp in these arent so good...
But this is the first DI/preamp i have used, i bought it off ebay about 3 years ago for $500aus, so i probably got ripped off.

If it is probably the mbox preamp or noise from my lappy, how can i use equib or a sound gate to remove it if possible? im still n00b at editing.
Any recommended entry but quality DI replacements?

Im gonna try to fixup an old computer and test the mbox on it - but this lappy is more powerful, more storage & probably quieter still, albeit noisy.

gwok · 11-07-2010, 12:17 AM

lappy's are notorious for ground hum\dc offset, are you using a pci express card

dunno if a ground hum is what your getting, though it could be

mrskye · 11-07-2010, 01:05 AM

im using the stock standard inspiron 1520 soundcard, which is probably onboard sound if thats what ur asking - so it is probably a crap soundcard - which i guess could be the root of the problem too - the old computer im gona test on as soon as i workout how to setup the slave drives uses a better soundcard - so maybe it will fix the problem, its also not a laptop. i guess if that doesnt fix it, then i will be looking at replacing the mbox1. any suggestions?
Also, i read a tutorial somewhere on using reafir in subtract mode to isolate the noise profile - but it wasnt stepbystep enough for me to follow and im not sure if it will help with this varying spit/crackle.

dcuny · 11-07-2010, 02:53 AM

The noise reduction in ReaFir won't help with decrackling. But to set up noise reduction:

Add the ReaFir effect.
Change the Mode to Subtract.
Select Automatically build noise profile.
Select a portion of audio with noise, and play it. A noise profile will be created.
Deselect Automatically build noise profile.

That's it. You can adjust the noise profile using the Ctrl+MouseDrag. If you screwed up, press Reset and try again. It might be simpler if you set up the area with noise as a loop. Use MouseDrag in the Ruler at the top of the screen to set the loop, and press R to toggle Repeat on.

Zephyrus · 11-07-2010, 03:23 AM

Record a short track without any cable or mic connected on your mbox, if its still there, the problem might be the interface. At least thats for the hum, the crackle can also be from laptop internal devices such as wlan cards or something (latency issues) try to search on the forum to get rid of that problem...

-zeph

mrskye · 11-07-2010, 04:39 AM

i just tried taking out inputs and recording, no noise no nothing.
i also notice that the noise flutter occurs on both inputs, no matter what the input is, whether it is my mic, my semiacoustic or guitar effects pedal.
it is present at both small & high gain.
will spdif inputs help? i dont even know what they are. ive only used xlr and midi elsewhere.
i think if the other computer doesnt help i will open up the mbox, take a look and then look for a replacement. i will also try the reafir again - but as you confirmed i dont think it will help with the crackling.
i might as well ask again, as you guys are experienced, but what might be a good/reliable replacement DI with phantom power & at least everything the mbox1 has under $500 US? thank parity.

Zephyrus · 11-07-2010, 08:46 AM

You say, when you record just the inputs without anything connected to it is quiet, no noisefloor or crackle?
But with any connected to it there's hum and crackle?
Hmm, try another cable...or the mbox has a defect.
Opening it does not help,SMD parts are difficult to replace.
SPDIF does not help, it a digital connector, eg for effect boards or other equipment...
There are quite a few interfaces for under 500$. I don't know what the m-audio fastrack ultra costs in Australia, but this interface i use mainly and it offers all you need for record with your equipment and works perfect with Reaper.

-ph

EDIT: !!! Ähm I just read that you use your standard dell soundcard...??? Wherefor? Please say your signal path is mic->xlr-cable->mbox->USB->Laptop and NOT mic->xlr-cable->mbox->audio-cable->soundcard of Laptop! just that we are talking about the right probs...

mrskye · 11-07-2010, 05:33 PM

Quote:

Originally Posted by Zephyrus

You say, when you record just the inputs without anything connected to it is quiet, no noisefloor or crackle?
But with any connected to it there's hum and crackle?
Hmm, try another cable...or the mbox has a defect.
Opening it does not help,SMD parts are difficult to replace.
SPDIF does not help, it a digital connector, eg for effect boards or other equipment...
There are quite a few interfaces for under 500$. I don't know what the m-audio fastrack ultra costs in Australia, but this interface i use mainly and it offers all you need for record with your equipment and works perfect with Reaper.

-ph

EDIT: !!! Ähm I just read that you use your standard dell soundcard...??? Wherefor? Please say your signal path is mic->xlr-cable->mbox->USB->Laptop and NOT mic->xlr-cable->mbox->audio-cable->soundcard of Laptop! just that we are talking about the right probs...

I use a different cable for my mic and guitar inputs, and they are relatively new still, so i think it must be the mbox or something internal in the laptop allowing noise through the usb or affecting the buffering process.
Signal path is indeed the former mic->xlr-cable->mbox->USB->Laptop
But i assumed that the mbox still utilised my soundcard.. by the sound of your surprise, i guess it doesnt?
I actually sometimes output through my soundcard>speakers via the mbox earphone jack but not while i'm recording. sometimes i just use headphones.
but this is trivial again.

I will post back on what happens when i get the other computer running, but might take a few days cos im lost with the multiple drive slave master thing - need my bros help.
If it doesnt work ill look into that interface you mentioned.
Thanks for the help everyone

grapeape · 11-01-2011, 01:59 AM

Sounds as if you had the same problem I am having. How did you fix it?