Noise reduction for hiss - is there a solution?

[RuthieG]

Windows XP Pro
Creative Audigy SB 4 sound card
Samson Q1U USB mic (plugged into front USB port, not adjacent to any other USB device), not using SoftPre
Plantronics headset (mic muted on headset and in Windows Volume Control) plugged into sound card
Audacity 1.3.4-beta (Unicode)

I record talking books for Librivox, so am keen to get the best quality audio I can. I record in Audacity with the Samson mic and get considerable background hiss on all my recordings. Moving the microphone 6 ft away from the computer makes no difference to the hiss.

I attempt Noise Reduction in Audacity (current settings 24 dB, 150 Hz, 0.15 secs) and this removes all hiss from between the words. So far, so good! However, it leaves the hiss, or something similar, during the words, which is actually more distracting than leaving the hiss there altogether, I think. I have tried adjusting the Noise Reduction settings in just about every way, but it makes no difference.

In my various experiments, I have exported .wav files from Audacity and done noise reduction in Wave Pad. This actually removes all the hiss, but as it introduces a tinny, twittery artifact instead, it isn't a lot of use (though I can eliminate most of the twitter by re-importing into Audacity, normalizing, amplifying and then using Noise Reduction. It is still audible at maximum volume, though).

If the hiss is a problem with my USB mic (which I assume it is) I would happily buy another if I knew it would eliminate the problem, but of course, I won't know until I have bought it.

Any ideas on what I can further do to improve things?

Many thanks

RuthieG

[steve]

I record in Audacity with the Samson mic and get considerable background hiss on all my recordings.

That shouldn't happen, and is the root of the problem. The Noise removal effect can cope well with low level hiss, but high level background noise will always leave some sort of unpleasantness.

How loud are you talking, and how far away is the microphone from your face. Typically, a distance of around 20 cm, with a pop shield between you and the microphone is good for a normal "conversational" voice.

[RuthieG]

Thank you for replying so soon.

How loud are you talking, and how far away is the microphone from your face.

I speak from about my outstretched hand's length away from the mic (must be about 18-20 cm), and at more or less normal conversational volume. I don't use a pop shield as I have never had any problem with plosives. But the hiss is there from the moment I press 'Record' - before I start speaking. It doesn't seem to be related to me at all.

Ruth

[kozikowski]

In all the Audacitys, you can set everything up and just before recording a performance, click once inside the red record meters. This will activate them for testing and they will meter the incoming audio without going into record.

What's the level? Stuff the microphone under several layers of pillows in a quiet room and the "doing nothing" noise should be in the -60 or so range. We'll assume it's a number much higher than that--say in the -30s. That's much worse than the 40 year old audio equipment I occasionally use.

You can consider messing about inside the Windows control panels. Windows will cheerfully record everything in its arsenal at the same time and even several pathways that it shouldn't, creating feedback, thumping, and other noises. In a fit of experimentation, I once got my Windows 2000 machine to play the incoming radio, the CD playback, and the microphone at the same time. Goodness knows what was being recorded. It took me hours to get it back to the job I actually wanted.

Windows Control Panel
http://audacityteam.org/wiki/index.php? ... trol_Panel

Can you run the microphone, however briefly, on another machine?

Koz

[kozikowski]

Is there a brief sample of noisy performance on-line somewhere (you can't put it here). Something with a second or so of no voice noise only and a ten second performance. Try not to compress the pants off it in MP3 format. Uncompressed WAV is good for testing.

Koz

[YFLeo]

I have a similar problem on my new Samson CO1U mic. Laptop is running Vista, 2GB RAM, 1.6mhz chip, running the latest fully stable Audacity. I want to record very quiet voice, and there's way too much hiss. If I put the mic under a pillow in a quiet room and run the Audacity input meter, it's jumping around in the -40 range.

I'll try using the mic on different computers, though even if it works on those it won't be much help because I need the portability of the laptop. I tried unplugging the laptop from the wall and letting it run on batteries, with no change. Any other ideas?

[kozikowski]

<<<it won't be much help because I need the portability of the laptop. >>>

I understand, but it might give us an idea what's broken.

If the microphone does this on many different computers, maybe it's just a noisy microphone.

Just a note that this microphone is a very cheap knockoff of a much more expensive microphone, preamplifier and analog to digital converter.

http://www.sweetwater.com/store/detail/SolutionDM

What did you pay, $100 US? I wouldn't be shocked to learn that the preamplifier isn't perfectly quiet. Microphone grade amplifiers with low noise floor are expensive to design and build.

Do you have a USB hub or can you borrow one? This microphone gets its power from the computer. This is one of the things you were experimenting with when you ran on batteries. That's quieter. It's possible the power from the computer is noisy and you can get around this with a wall-powered (not self powered) USB Hub.

Koz

[YFLeo]

The laptop was showing baseline noise at -40. Computer #2 running Audacity 1.2.6 on Win XP shows baseline noise at -40. Computer #3 running Audacity 1.2.6 on Win Vista is a little better at -43. All measurements are across the room and under a towel.

Am I asking too much, or did I just happen to get a lousy mike and I should send it back and try again?

[orgelquaeler]

When recording live lectures, I always got the best results using a Presonus Tube Pre-amp, even with the cheap cheap microphones I was given. I'm talking no noise floor to speak of. Might want to try something like that.

[YFLeo]

When recording live lectures, I always got the best results using a Presonus Tube Pre-amp, even with the cheap cheap microphones I was given. I'm talking no noise floor to speak of. Might want to try something like that.

OK, I'm new to this. Please be patient. If the mike is generating noise on its own, how would a preamp prevent that, or somehow take that noise out? I could understand that with a passive mike, but not a condenser mike. And that won't work with my Samson C01U because the connectors just aren't there, right?