Hiss!!!!! Ideas on how to remove it anyone?

Victorthesecond · #1 04-20-2020, 03:50 AM

Hi guys. So, during this lockdown thing, I've been asked to record some tunes for our church for them to use on their streaming services. I've got hold of my bands Behringer PMP4000 powered mixer and a couple of condenser mics, obviously set up via the usual XLR inputs on the desk. Set those up in an X/Y formation, 6 inches or so in front of my Takamine G Series. Turned the sliders right down, and pushed the gain on each channel so it clips only at the top of the green when really attacking the guitar. (To be fair, the recordings I'm trying are only really finger picking.)

The desk is connected to the mic socket on a Win 10 laptop (a couple of years old) via 3.5mm jack cable.

I'm using Audacity to do all this.

So, off I go. Apart from the usual stress of recording resulting in the odd error, the playing is acceptable! But, the background hiss I'm getting is just horrid. I've used the Noise Reduced in Audacity and that's helped, but I'd much rather have a much reduced / zero hiss on the original recording!

I've been at this for, literally, days now. Trying different mic positions, including mono recording with single mic. All to no effect, the darn hiss is still there.

In terms of the room I'm using, it's an unfurnished space, so the sound is quite hard.

I'd really welcome any suggestions or ideas! Thanks in advance, stay safe everyone.

Mike

Rille · #2 04-20-2020, 04:23 AM

Is it the same using headphones from the mixer? Then the source is there. Otherwise it could be the 3.5 mm cable if it is long and of cheap quality.
If it is the mixer check for open inputs of any kind, mic, aux, efx returns.

Peace

Bob Womack · #3 04-20-2020, 05:08 AM

Three hints:
1) To optimize gain and noise for each channel, run the fader up to the nominal position (around 2/3s of the way up and usually marked as "0" then adjust the preamp gain to meet that.
2) Powered mixers aren't typically the best choices for recording. They are often noisy. I don't know your particular model, however.

3) The preamp on most computers is quite noisy. That is why most people run their audio into an external interface (or an interface card). Even inexpensive interfaces such as the Focusrite Scarlette 2i2 Gen3 ($159.99 at Sweetwater) sound good, handle two mics, and have low noise. They plug in the USB connection of your computer and are incredibly easy to install. You can substitute that for your mixer and do well.

If you already have recordings you need to clean up, you can use a plug-in such as Waves Z-Noise ($29 with coupon, $49 without) to clean up the noise. It doesn't end up as pure sounding but can rescue a travesty.

Bob

rmp · #4 04-20-2020, 05:32 AM

As other say your, gain should be set low, faders to at "0", for starting out, control the level with our main outs..

catdaddy · #5 04-20-2020, 05:54 AM

Quote:

Originally Posted by Bob Womack

Three hints:
1) To optimize gain and noise for each channel, run the fader up to the nominal position (around 2/3s of the way up and usually marked as "0" then adjust the preamp gain to meet that.
2) Powered mixers aren't typically the best choices for recording. They are often noisy. I don't know your particular model, however.

3) The preamp on most computers is quite noisy. That is why most people run their audio into an external interface (or an interface card). Even inexpensive interfaces such as the Focusrite Scarlette 2i2 Gen3 ($159.99 at Sweetwater) sound good, handle two mics, and have low noise. They plug in the USB connection of your computer and are incredibly easy to install. You can substitute that for your mixer and do well.

If you already have recordings you need to clean up, you can use a plug-in such as Waves Z-Noise ($29 with coupon, $49 without) to clean up the noise. It doesn't end up as pure sounding but can rescue a travesty.

Bob

What Bob said. Great suggestions/advice!

Chipotle · #6 04-20-2020, 10:06 AM

Quote:

Originally Posted by Bob Womack

If you already have recordings you need to clean up, you can use a plug-in such as Waves Z-Noise ($29 with coupon, $49 without) to clean up the noise.

Audacity has some noise-reduction capability built-in, so you can try that before purchasing a plugin: https://theaudacitytopodcast.com/tap...with-audacity/

If you've used Audacity before, you probably know that effects processing like that is "destructive": it works on the signal and then replaces your original data. My recommendation for Audacity is to duplicate the track, mute one, and then run the effects on the copy, so you can go back later if you need to.

ChuckS · #7 04-20-2020, 02:07 PM

I agree with the responses on how to set up the mixer gain and channel fader levels.

Even with those corrections, I believe you're still going to have severe signal to noise issues. The mixer is designed to output line level signals, but since you're connecting the mixer output to the laptop's microphone input (which has a max input level way way lower than line level) you are going to have to set the mixer's master out faders really low. Based on this, the best advice (as provided by Bob earlier) is to get an audio interface; this will give you preamps for your mics and send the signals digitally via usb to your laptop.

Victorthesecond · #8 04-21-2020, 03:30 AM

Thanks for all the suggestions, they're all much appreciated!

I think the interface is going to be the best option. It takes less space, and is much more permanent than the mixer which we use at gigs (not very many booked at the moment for some odd reason!!!), so means less disruption overall.

Thanks again, stay safe and away from this nasty bug. I'm in the UK where we've worked hard to start seeing things improve, but we're some distance (ha!) from getting a solution. I see reports from the US of many protests but would urge that the advice to keep your distance is followed. We're seeing too many people suffering. And, my eldest son lives in Tennessee and I'd like to see him and his family safe! Goodness knows when we'll be able to get over and hug them again.

Take care

YamahaGuy · #9 04-21-2020, 04:27 AM

Is the cable you're using of decent quality? I assume you're using a dual phono/rca to 1/8" trs/stereo. At my church, we always had a bad hiss and a faulty/poorly shielded cable was to blame. Also, is the mixer plugged into the same electrical outlet as the computer? If you're going to upgrade and get an interface, why not get a USB mixer like a Yamaha MG10XU? That way you can eq. An interface has no eq adjustments at all. And if you're using two mics and going for that stereo effect, the mixer will allow you to pan. With the interface, you can always do that in post, but I've always tried to get my recordings dialed in on the front end of things first. Good luck.

Victorthesecond · #10 04-21-2020, 06:31 AM

Thanks for that. TBH, I don't really want to buy a new mixer - not sure I can justify the cost for what is likely to be a short-term project, but I do appreciate your taking the time to suggest it. I am more inclined to follow the suggestion of a USB Audio Interface but am advised that Audacity struggles with the ASIO4ALL drivers. So, I think that cuts out any Behringer inexpensive solutions!

Out of interest, and this sounds stupid, I pulled the XLR plugs out and put them in again....and a lot of the hiss has now gone! Perhaps it's that simple.....