Podcast Audio Quality Feedback

Hello Everyone,

I’ve been involved in the podcast world for about 1 year now and it seems like I’m learning new things everyday. It’s interesting that every time I record a podcast episode, I feel the audio is slightly better than previously. Whether or not this is placebo I don’t know, but it is comforting to know it’s not getting worse. :wink:

I’m looking for some feedback on my setup regarding the audio quality and perhaps anything I am missing that could make the audio quality even better. Originally, when I began recording, I went for a very bassy AM radio sound. However now, I’m starting to enjoy a more natural sound… I think this is a good thing.

Here is my setup:

  • Mackie 1202 VLZ4 Mixer
  • ATR 2100 Microphone
  • Multicom Pro-XL MDX 4600 Compressor, Limiter, Gate (Both Skype and myself are processed through this prior to being recorded)
  • 2 Windows 8.1 Laptops (One is used strictly for Skype, other for recording)
  • Audacity Version 2.1.0
  • Both Laptops are processing the sound through 2 UCA202 USB sound cards. (One for each laptop)

I have not added ANY effects from Audacity onto this test audio, however I do have a hair of the “High” EQ being adjusted at about 1300. The gain is at about 40-45% and the volume is at 75%. I’ll go ahead and add another post to this thread with some pictures of my setup, including a picture showing the settings that I have the MDX 4600 at.

There is a “white noise” sound when I’m not talking and I do believe I hear a little buzz when I do talk. The buzz makes slight sense because the noise gate will only allow external sounds through when I talk, however I’m not sure where it’s coming from. The buzz was very bad, but I took my entire setup apart and rebuilt it so that I could hopefully remove the buzz. I believe I was fairly successful, and I am not sure if it is still there or if I am hearing anything.

I would like advice on the sound quality in general. By the way, forgive my poor reading on the news article that I picked. It was fairly technical, and my first read, so I stumbled a few times. :smiley:

Thanks.

Alright here are some pictures:
MDX 4600.jpg
Mackie Mixer.jpg
Entire Setup.jpg

I feel the audio is slightly better than previously.

It probably is. This just kills people performing their first audiobook. They get to the last chapter after weeks of work and go: You know, Chapter One really sucks.

I’m starting to enjoy a more natural sound… I think this is a good thing.

I agree. It prevents surprises later. “How come you don’t sound like your podcast?”
But that is assuming “natural sound” doesn’t include “recording in the kitchen” echoes and reverb. It is my unshakable opinion that a couple of furniture moving pads on the wall to kill echoes works head and shoulders better than all the gates, processing and software patching in the world.

  • 2 Windows 8.1 Laptops (One is used strictly for Skype, other for recording)

That’s pretty much how I did it.

My variation was to bring the Skype computer connections into the mixer instead of recording them separately. This is the Pando Podcast…

…where they have to do it that way because they go straight to streaming server.

There is a “white noise” sound when I’m not talking and I do believe I hear a little buzz when I do talk.

Entirely possible. if you have noisy microphone channels it can make adjusting compressors and gates a nightmare. How far do you get without the processor? You should identify the shortcomings of your studio first, and then take steps to fix them. Not throw everything into a bucket and then try to figure out why it sounds funny later.

I recently found a bad powered bass cabinet in my “studio” by setting up for a recording in monitor mode (Right-click on the Audacity sound meters > Start Monitoring). The system wakes up and starts working…but doesn’t make a recording. I put my headphones on and started waving the microphone around. It went nuts when I got close to the bass cabinet. Turns out it’s in serious electrical trouble. It was turned off, by the way.

You should go to monitor mode without the processor. If you can’t make a plain, clean recording like that, then it’s time well spent to find out why not. For example, I have one machine with a power cable that causes hum. Apparently, that’s normal. Running the microphone cable next to that power cable is begging for troubles. Other power cables don’t do that.

After I cleaned everything up, I announced a simple test recording which passes ACX AudioBook standards with just a slight volume change. No processors, no filters, no effects, no patching. Straight recording. Rock-band microphone into a small mixer and into the computer.

I can’t listen right now. I have to wait until I get inside to the grownup computer.

Koz

Overprocessing.

“Currently, I’m running a MultiCom Pro…”

That’s what you said. In the sound file, however…

“…urrently, I’m running a Multicom Pro…”

The gate is whacking off the first letter of several words.

Oh, and it’s low, but that’s easily fixable. You should peak the Audacity sound meters at roughly -6 like this.

Which loops us back to:

Do a test recording without the processor. Just plug the microphone directly into the mixer, set it up and record a test.

Attached is the one I shot, cut for length. There is one odd sound problem at 8-1/2 seconds and we’re tracking that down. It’s a raw clip and it’s slightly too loud for audiobook standards.

ACX had the good form to publish their audiobook sound standards and they’re not insane. They’re about the same sound standards as broadcast. They’re a good, rational goal and we have semi-automated tests for them.

Koz

I noticed what was said about the noise gate, so I went ahead and recorded 2 more short recordings. One with the noise gate adjusted (and me speaking a little louder), and one with just the mixer. I do notice a very subtle buzz noise, and now I’m kinda wondering if it’s from a power strip I have on the ground that some of the wires are over. I’m not sure how to alleviate that as everything has to be plugged in.

As far as the volume is concerned, I’m not sure what to do. I don’t want to turn the gain up anymore because that “ocean” sound is just going to get louder. Same thing goes for turning the volume up on the mixer or the processor. Is there a way for audacity to do it automatically? I know I could just use “Amplify” post processing, but I hate doing that because I feel like it’ll cause problems somewhere in an hour long recording.

Other than the volume and the noise gate, no other real issues?

Thank you.

I wonder if you have a monitor problem.

I increased the volume and applied Steve’s voice “rumble” filter. I just did that to do it. It meets standards without it, but it sounds a little better. See INFO panel, attached, last sentence.

You could read for audiobooks with that setup. It would probably pass the human quality control, too, but I suspect they wouldn’t like you gently popping your P sounds probably because you’re just a little too close to the microphone. I’m going after the clip with tweezers now that the larger problems are gone.

obviously there’s been a bit of a volume drop.

The point of the processor is to slide itself in the middle of a perfect working microphone chain with no effect at all until it’s needed.

Pump up the mixer until the Audacity sound meters peak/bounce around -6.

Your mixer has about the same controls in about the same locations that mine does.

Gain or Trim about 3 O’Clock
Level around 3 O’Clock
Master around 3 O’Clock (at zero on my mixer slider)

Where are the bouncing Mackie sound meters when you talk?
Where are the bouncing Audacity sound meters when you talk?

If the unbalances are terrific, Audacity overloads and the Mackie is very low, take the Tape Out of the Mackie instead of the Main Out.

That’s how I do it.



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The point of the three places to set volume:

Gain or Trim. This is where you set the volume to make the basic mixer strip happy. All the knobs in one vertical stripe. If it’s too low, you can get hiss. If it’s too high you may get the red overload light near the bottom…ummmmm …you don’t have overload lights on this mixer, do you? Attached, this is where mine are.

Level. This is where you balance the microphones against each other. This is where you bring up Guest Number Three a little.

Master. Overall volume. This is where you fade the show out at the end.

All the adjustments are intended to run about 3/4 up. If you find yourself with any controls near either extreme, you have a problem.

Koz
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Popping.

You can get rid of P popping with a blast filter. That’s the black tennis racket looking thing just in front of the microphone. Highly recommended.

So that’s it. Once you get all the levels balanced, you can start cranking out shows. You can probably leave the processor in the garage.

You might slide the processor back in to help even out volume changes, say when someone decides to get really loud or fade into the sunset in the middle of a sentence. Or not.

Do Not use the gate.

You do that after you get a show to work without it.

Koz

Sorry for the late response, something came up that I had to take care of.

I wonder if you have a monitor problem.

I’m an idiot but I figured out the buzzing problem(s):

  • I had a cord that was used for sound effects plugged in but not being used. I had the volume at zero (apparently that doesn’t matter), but once I pulled it out, the buzz got much more faint.
  • I noticed that the buzz becomes more apparent when I use Skype, which is frustrating because I don’t see how that can be helped.

I increased the volume and applied Steve’s voice “rumble” filter. I just did that to do it. It meets standards without it, but it sounds a little better.

Wow that sounds much better!

My only concern is that if I record a show like that, I can’t have all that gain hiss/oceanic sound in the background. I realize I can get rid of it easily with Noise Reduction, but that’s going to lower the sound level of everything and sometimes I feel like it diminishes the richness of the voice. However, I’ve listened to a few of your recordings on the forums and they always sound excellent so perhaps I’m missing something.

I know you said to get the volume level FIRST with the mixer, and then only throw the processor in the mix once everything is perfect without it. However, my logic was to set the mixer up with the minimum gain and volume settings required to get a signal. Then boost the signal with the processor so I can avoid the gain sound altogether, or as much as possible.

You could read for audiobooks with that setup. It would probably pass the human quality control, too, but I suspect they wouldn’t like you gently popping your P sounds probably because you’re just a little too close to the microphone. I’m going after the clip with tweezers now that the larger problems are gone.

Thanks. :slight_smile:

The plosives or P sounds, now that you point it out, stands out always to me. It is driving me nuts. Crazy thing is, I have a pop filter on my mic, and I’m talking into it at an angle instead of directly into it… And I still get the plosives. I’ve also purchased a blast filter in the past and dug that thing out. Tried it, in addition with the one I already have, and I still heard the plosives. The only thing that seems to work is if I talk into the mic at just the right angle, and the right distance… Which is quite the chore.

Gain or Trim about 3 O’Clock
Level around 3 O’Clock
Master around 3 O’Clock (at zero on my mixer slider)

Where are the bouncing Mackie sound meters when you talk?
Where are the bouncing Audacity sound meters when you talk?

I did this and made slight adjustments until I am in the golden zone, but man is that gain noise LOUD.

my logic was to set the mixer up with the minimum gain and volume settings required to get a signal.

That will give you the most noise. The electronic noise (That’s FFFFFFFF, not the room noise) is more or less fixed. The object is to keep making the voice louder and stop just before anything overloads. That’s our rule about regular peaks in the recording sound meter reaching around -6. Note the fuzzy words. Nobody will come out with a stick if you don’t achieve this exactly, but you should get close.

You do still have to allow for theatrical expression, so that’s why the number isn’t any louder. Overload is death. You can create some very serious damage by announcing too loud and letting the sound meters go all the way up (to the right).

I noticed that the buzz becomes more apparent when I use Skype,

Run that computer on batteries just to see if it helps. I had a computer who cared which direction the power was plugged in, and the connector would go either way.

Is everybody plugged into the same power strip and is it one of those fancy-pants power spike capture things? Common power—everybody plugged into the same system—should help eliminate buzz between computers. I’m not a fan of fancy power strips. I’ve only had an unprotected computer fail once, but I’ve had several strips go into the trash.

I talk into the mic at just the right angle, and the right distance…

Plosives go mostly down. Mount the microphone so the sensitive part is about nose or eye level and point the whole mic down slightly toward your mouth. I don’t have a good picture of this. Most people don’t have this problem. I also don’t remember if you had a mic stand and boom, but it’s more or less required.

That’s how I shot this show.




I can’t have all that gain hiss/oceanic sound in the background.

Are you cranking the speaker volume all the way up to “look for” noise between words? You’re supposed to adjust the speakers so your voice is normal volume and let it tail off to the noise segment and not touch anything. -63dB is not completely silent, but it’s darn close. Unless you have one of the irritating USB Microphone whine noises, the gentle rain in the trees hiss should fade into the background.

We had another poster who didn’t like that. He ended up using aggressive noise reduction and noise gates (as I recall), to get the work he wanted. That’s very difficult to do and still maintain good quality speech. Another poster bought hardware microphone processing and his gate was cutting off the first letter of the first word of each sentence. You almost couldn’t hear it until the third pass or so. It is coincidentally a common feature of cellphone conversations, so a lot of people’s ears automatically tune it out.

I realize I can get rid of it easily with Noise Reduction, but that’s going to lower the sound level of everything and sometimes I feel like it diminishes the richness of the voice

Then you’re doing it wrong. If you use a gentle, graceful noise reduction, it’s undetectable and even better, ACX Quality Control can’t find it.

Drag-select a portion of the show that is noise-only. This might mean you need to sit there and hold your breath for a couple of seconds. We can hear you breathing and your shirt moving. Effect > Noise Reduction: Profile.

Then select the whole clip by clicking just above MUTE and Effect > Noise Reduction: 6, 6, 6 (the noise reduction of the beast). This is in Audacity 2.1.0 or 2.1.1.

Edit > UNDO and try noise reduction again with 12, 6, 6. By the time you get to 18, 6, 6, the process is starting to screw up words. Many people get by just fine with 6. 6. 6.


All of these adjustments, filters, effects and techniques assume you have blue waves whose peaks are around the 50% mark either up or down. From memory, the last clip I got from you was less than half that.

Koz

There is one other possibility. Are you sure all the Windows programs and services are turned off? I got a new computer from the IT people and I could not make it pass sound quality control. Turns out they left Cathedral Effects running in the playback system. So everything sounded like Notre Dame.

!@#$%

Koz

but man is that gain noise LOUD.

And that sentence right there means Something Is Wrong. Are you readjusting your speaker volume down as you crank the volume up inside the mixer? Is the speaker system going through that processor?

It’s not recommended, but it’s possible to do a show and assuming you’re not the performer, not hear a thing. Just using the tools and instruments on your mixer and computer is enough to make a show work. It’s a common error to assume if you can’t hear the show, the world will end. No. Probably not.

There is a flight instruction class where you’re forced to run the airplane, properly, without looking out the window. Just from the instruments. And then the instructor flips the plane over. “OK. You fly it.”

There is always going to be some shortcoming if the sound meters don’t look right, and bad monitoring can drive you nuts for a long time.

Tell you what. Leave the processor in the garage. Cut a ten second sound test making the top (recording) sound meters in Audacity peak up around -6. Use the mixer adjustments I posted, final tune for the Audacity meters. It does bother me the mixer doesn’t have clipping lights. That just makes things a little harder when something goes wrong.

Leave the speaker/headphone system off.

Use this formula. Again, this is for audiobooks, but it’s a good basic formula. I have a joke it doesn’t matter what you read. Read the side of the milk carton. “Have you seen this child? Please call Missing Persons at (800)…”

http://www.kozco.com/tech/audacity/TestClip/Record_A_Clip.html

Koz

Alright, I wanted to thoroughly invest time into working everything with this setup, prior to posting again. The location of my setup is a handicap, as of right now, I can only record near my kitchen and the damn fridge likes to go on a buzzing fit every 30 minutes when the freezer decides to cool down. I’m tempted to mess with it, but I live in an apartment… So it’s not my fridge, and I’d like my deposit back. :smiley:

Luckily, with the mic presented in the opposite direction, if the fridge goes on one of it’s fits… The damage is minimal and I guess acceptable, as I record with a co-host on Skype and I can’t have him just sitting there waiting on my fridge.

Run that computer on batteries just to see if it helps. I had a computer who cared which direction the power was plugged in, and the connector would go either way.

I forgot you suggested this, so I have yet to try it. However, on my last test with Skype, the buzzing was gone, strange. However, I think I’m going to start running everything off batteries and just keep an eye on the power level while recording to be safe. We tend to take 5 or 10 minute breaks, every now and again, so I’ll just plug them back in then to keep it charged up.

Mount the microphone so the sensitive part is about nose or eye level and point the whole mic down slightly toward your mouth.

Alright, I have to admit that this was a game changer. In my opinion, this slight change improved the audio quality immensely as it no longer sounds like I’m assaulting the microphone. In addition, my voice sounds more natural, vice fake sounding which is good.

Are you cranking the speaker volume all the way up to “look for” noise between words?

I’m just recording as usual. I think the FFFF noise is probably more noticeable to me, because I’m used to recording with the processor that has the noise gate that removes all that excess hiss. I did get curious and tried re-working the settings a bit on the processor, and more notably turned the noise gate settings down much lower… Which allowed me to talk without cutting off the first letter of every word. I am going to have to incorporate the processor in the mix because I record with a co-host via Skype, and it makes things much easier to edit.

However, I did take your advice and set my Mackie up to where I’m hitting roughly -6 without the processor, with the gain, channel volume and master volume at very similar levels. I do agree, I believe it does sound better.

Then select the whole clip by clicking just above MUTE and Effect > Noise Reduction: 6, 6, 6

Alright, this was awesome. Previously, I believe I had it set at 10, 30, 9 for whatever reason, and it definitely removed excess noise but it also would cut my audio levels in half. I was skeptical but I tried 6, 6, 6 and it was like butter.

Are you sure all the Windows programs and services are turned off?

That is a good question that I never considered, but I do not know how to verify this. Both of my laptops were purchased new off Amazon with the factory settings so I would assume it should be fine. However, on my recording computer I do have an internet browser open, and Itunes (to convert to MP3s), perhaps I’ll try closing these. I hate closing Itunes though, it takes forever to open back up.

And that sentence right there means Something Is Wrong. Are you readjusting your speaker volume down as you crank the volume up inside the mixer?

Nope. All of the volume knobs are left the same, this excess FFFF sound is heard both while recording, and later in the recording. As you mentioned, I feel it is inevitable to have, however I feel like I’m going to have to use the noise gate when talking with a co-host on Skype as that sound will just be annoying.

Cut a ten second sound test making the top (recording) sound meters in Audacity peak up around -6.

Alright that’s what I did. Strange. When I recorded this, the FFFF sound was completely gone and was replaced with a buzz, have no idea why. I unplugged both laptops, the only thing I have plugged into the mixer is the one mic, and the USB acu202.

And yes, we do know that complex troubleshooting across time zones is a lot like steering a large truck by pulling rubber bands on the steering wheel.

Haven’t listened yet.

Hiss is normal in any analog system and is a problem when the show isn’t loud enough. All microphone amplifiers hiss and the good ones have ratings for how loud the hiss is.

The buzz is not normal. Given nothing is broken, that’s usually a connection problem. Running on batteries is not a permanent solution (unless it is. I was once forced to do a voice recording on batteries). Once you find out you can solve buzz that way, you can sometimes take steps to solve the problem without the batteries. Like I think I said, I have a laptop that plugs in either direction and one is noisier than the other.

Broken shields will buzz.

http://kozco.com/tech/audacity/clips/OpenShieldHum.mp3

Touch two pieces of equipment while you’re listening in monitor mode. If the hum suddenly changes, then you could have a grounding or cable problem, or the power strip you’re plugged into may be bad.

Are you sure your house is wired OK? I’m living in the second house that featured some of the outlets wired backwards. You can get a simple, three-light socket wiring tester.

http://www.walmart.com/ip/GE-3-Prong-Receptacle-Tester/16561511?action=product_interest&action_type=title&item_id=16561511&placement_id=irs-106-t1&strategy=PWVAV&visitor_id&category=&client_guid=38f1cda4-50f5-446d-98f8-86b5fdfa4836&customer_id_enc&config_id=106&parent_item_id=17117740&parent_anchor_item_id=17117740&guid=19552c8e-92d9-441e-87f3-92be027c6a56&bucket_id=irsbucketdefault&beacon_version=1.0.1&findingMethod=p13n

And use the processor after you get a stable, quiet system.

Koz

I’ve made slight progress on that buzz, as it was driving me nuts that yesterday it was not present but today it is. Essentially, I still have no idea what is causing the buzz, BUT I noticed depending on where my microphone is pointed the buzz disappears.

For example, when my mic is pointed near a corner of the room, the buzz is gone and ironically, if I point it in the exact opposite direction which happens to be towards my laptop, the buzz is gone also. So this led me to moving my microphone as both directions were not ideal for me to speak normally into the microphone without positioning my body in an abnormal fashion.

However, here is a new recording, without the buzz, with the mic in a much quieter spot.

This is where I tell you about my buzz adventure. I had exactly the same problem. The microphone worked while I was standing on my left foot, bent forward at the waist, while facing North-Northwest. On Thursday. Everywhere not home worked fine, too.

I put a long cable on the microphone, and walked and pointed it around the room (the room isn’t that big) while I listened on headphones to the buzz coming and going. Turns out my keyboard bass cabinet produces both electrical interference and audible buzz…even when turned off. It wasn’t the Giant Hummy Monster in the Attic after all. I also have a mixer custom power cable that radiates, but not very much.

Highly recommended. The technique, not the Hummy Monster.

Koz

Your clip.

I sheared off “All right.” It’s too loud and it overloads. But I reduced what’s left slightly with the Normalize effect and it passes. Attached, last sentence. You can do this analysis yourself. This is a freely available tool.

It’s too good. Attached 2. See those comb-like holes in the blue waves? That’s processing and if you know how, you can hear it. It has a gritty sound. Once you pass the automated ACX AudioBook Robot, an actual QC human listens to it and that’s where all the people who beat up their sound to make standard die. They have a failure called “overprocessing.”

I need to peel off for a while. Overall, that’s much better. As Poirot would say, “We progress.”

Koz
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Do you smoke? That could account for the slight voice roughness. It’s not unpleasant and you’re probably good to go as is. It’s good enough now I’m having to dig to find anything wrong. This clip is after processing, right? The noise level is suspiciously low.

Audacity has two different sound meters. Right click > Preferences to switch. I would switch the Recording meters (usually on top) to Gradient and they will change to angry colors when you get close to maximum and then peak damage. Change the Play meters to RMS which is simple dual color. The lighter color on the left is loudness or “RMS.”: The darker color on the right is peak. Keep the peaks out of “0” (maximum) when you play the show and when you play the silent portions, the RMS meter should be below (to the left) of -60.

Any luck finding that buzz?

Koz

Do you smoke? That could account for the slight voice roughness. It’s not unpleasant and you’re probably good to go as is. It’s good enough now I’m having to dig to find anything wrong. This clip is after processing, right? The noise level is suspiciously low.

I smoked for about 10 years prior to quitting this year. As far as processing, I didn’t do any processing on it, not even noise reduction.

Any luck finding that buzz?

Still not sure where it’s coming from but I’m okay with just keeping my mic in this one spot. I moved my stand so that the mic is in a more natural position but outside the buzz zone.

Thanks.

I think we’re good to go. Whatever you’re doing right now is clear, natural, about the right volume and has very little background noise. So this is baseline. Whatever you do from here has to maintain this quality and still do what you want. You don’t hear any background hiss, do you? Most people can’t hear -68dB and that’s where the noise volume is on your clip.

I don’t know that the audiobook testing tool will do you any good, but knowing the Contrast trick might be handy.

Drag-select the quiet portion of the clip (attached), and Analyze > Contrast > Foreground > Measure Selection. That’s the noise level. AudioBook standard is -60. Yours is -68 which is quieter (attach-2). You have to press Measure Selection each time you use it. It’s not automatic.

Since you’re going through a mixer, are you sure you need processing for Skype? I did this badly produced clip with just the mixer.

http://kozco.com/tech/audacity/clips/DeniseFirstPass-Edited.mp3

It’s a Really Big Deal that everybody is on headphones so Skype doesn’t have to go through echo cancellation and other processing tricks. She sounds like she’s relaxing on a sofa behind me, doesn’t she? She’s four time zones away. I messed up the Skype microphone setting, so that’s the music problem. I’m going to redo that one of these days.

Same setup you have. I got the music player in the Audacity computer to play music to the mixer and the mixer “show” went to Audacity. My computer has stereo connections for record and play and will cheerfully do both at the same time. So that’s where the Glenn Miller came from.

The other computer was strictly Skype. And yes, it didn’t escape me that the only problem I had during that test was with Skype. !@$%^

Koz
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