High-pitched whine with recording? / Suggestions on how to improve setup?

[supez2004]

Hi there,

I had a question about system setup, and would greatly appreciate any advice. I am pretty new to this ...

So my end goal is to be able to broadcast audio live via UStream. Currently I have an AT4033 (medium-diaphragm condenser mic) feeding into an Mbox. I have that hooked up to my laptop via USB. While my laptop lists the MBox as an audio option in the control panel, UStream does not recognize it (it only lists my onboard SigmaTel as an option for audio).

I've been fiddling with it, and the only way I've been able to get it to work is to buy a 1/4" to 1/8" cable from Radioshack, plug the 1/4" into the MBox headphone output, and the 1/8" into the microphone input on the SigmaTel.

This seems kind of dumb to me (I don't exactly understand how the systems work, but I would guess the signal gets processed via the MBox and then outputs analog, and then the SigmaTel re-processes it ... so it is ultimately my onboard audio determining what it sounds like).

Anyway -- my output this way is not very high-quality, and I would tremendously appreciate any suggestions on how to improve it.


Here are some specific questions I have:

1) I specifically have this high-pitched whine in the background that bothers the heck out of me. At first I thought it was the mic picking up my laptop fans, but the noise-level is the same regardless of where I position my laptop relative to the mic (or how far away I put it). So it makes me wonder if it has to do with something else? Does anyone have experience or advice regarding this?

2) Is it better to use the 1/4" headphone output from the Mbox, or the 1/8" to 1/8"? Does it make a difference in terms of sound quality? Are there significant variations in the quality of these cables? (i.e. should I buy a more expensive one than just the Radioshack brand)

3) Is there a difference in sound quality using the 1/4" headphone output on the Mbox to the 1/8" input on my laptop, vs. using the dual TRS outputs and some sort of Y-splitting cable?

4) Like I said, this seems like a dumb way for me to be processing my sound. Does anyone have a suggestion for a better setup to achieve what I want (either using the MBox or other type of equipment that won't cost me more than a few hundred bucks)? Do I buy a sound card that I can install directly into my laptop? Do I buy a mixer? Or is there a way to make this work better than I have, with the MBox?


I would really appreciate any thoughts -- I am very new to this, as I'm sure you can tell. Thanks in advance!

[getz76]

You just want to do live streaming? Why not just get a XLR-to-USB adapter?

[nwrstudio]

I had a high pitched whine back when I had the Digi001 and it traveled right to my Digi002 update. Come to find out it was due to me using unbalanced cables. I switched to balance cables on all ins/outs and I've never had the problem again. It might be the place to start.

[wolfie]

Is this your signal path?

Condenser Mic -> Mbox Input -> Mbox Headphone Jack -> SigmaTel Input

In which case, you're just using the Mbox to supply phantom power to your microphone? Make sure you have the Mix knob all the way to Input if this is what you're doing.

As far as the high-pitched wine goes, here are a few things I would try.

1. Replace your USB cable with a high quality one. I just did this and it took care of a noise problem I had with my Mbox. This is a good cable: http://www.amazon.com/Monster-Cable-.../dp/B00008OAJ0

Here's the link to the discussion that talked about this: http://duc.digidesign.com/showthread.php?t=151510

If your mix knob is all the way to Input, I don't think I would expect the USB noise to bleed into your signal path though....

2. You should probably have your SigmaTel configured for line-in, rather than mic because you'll have signal on the tip and ring.

3. Try line-out on your Mbox instead of your headphone jack. You'll need a y cable to go out of the two mono outputs of the Mbox into the stereo in on your SigmaTel.

4. Don't use the Mbox - plug into the mic input of your SigmaTel.

Just some thoughts.. not sure if any of it will lead to success...

BTW, I really like the idea suggested by getz76. I'd probably just go for that simple solution.

[supez2004]

Thanks for your suggestions guys. wolfie -- you are right about my setup (which is why I said that it seemed like a dumb setup to me haha).

I don't think that it's strictly the USB cable because when I recorded in PT, I did not hear the whine. I think it must be related to my output from the Mbox -> the SigmaTel.

I did not think to try setting the SigmaTel input to line-in instead of mic. I will try that when I get home tonight. I read something along the lines of line-in having higher/lower impedance and thus risking damaging equipment -- so I've just been going with mic. I'll also look for one of those Y-connectors.


Overall though -- does anyone have any advice on a better setup? Does anyone know how I can get ustream or flash media live encoder to recognize the mbox? Is it dumb to be using a decently nice condenser mic with a SigmaTel soundcard? Should I upgrade the soundcard? Or does it not really matter? Getz, if I were to just get an XLR -> USB converter, how would the sound quality be?

To nwrstudio's point: there's a $3.69 y cable on amazon from Hosa:
http://www.amazon.com/CMP-153-Y-Cabl...0&sr=8-1-fkmr1

a $9 cable from Live Wire:
http://www.amazon.com/Live-Wire-8-TR...0&sr=8-3-fkmr1

and then a $45 cable from Monster:
http://www.zzounds.com/item--MONIP400M

My impression is that the monster cable is the only one that's balanced?



Thanks again everyone!

[getz76]

Originally Posted by supez2004

Getz, if I were to just get an XLR -> USB converter, how would the sound quality be?

For streaming spoken word, it should be fine. It will beat your current solution.

If you want to get better results, think about buying a broadcast microphone, like an Electrovoice RE20.

[supez2004]

Oops sorry I didn't clarify this -- it's not for streaming spoken word, it's for singing (male vocals) and guitar. Does that make any difference?