Help needed - slight ghosting on finished product


I’m using OS X El Capitan, recording on the most recent Audacity, with a plug-in USB Mic (Snowball). I think the problem is probably the mic - I know I need to upgrade and USB is not ideal. However, after mastering I’m getting some ghosting / echoey sounds on the ends of words, just wondering if anyone could give me some advice? I’ve attached an MP3 of recent closing credits.

FYI, this is the chain I’ve used:

1 - LPF (Hz 16000 / Rolloff 48dB)
2 - HPF (Hz 92.5 / Rolloff 48 dB)
3 - Normalize (max amp 3.2 dB / have not ticked ‘remove DC offset’ / have ticked to normalize channels independently)
4 - Limiter (Soft limit / Input gain Mono/left - 3.00 dB / input gain right - 3.00 dB/ limit to -3.02dB / hold 10.00ms / NO to apply make-up gain)
5 - Repeat the Limiter
6 - Noise Cancellation (noise reduction - 24dB / sensitivity 14 / frequency smoothing 0)
7 - Sometimes I repeat the limiter at this point to bring the RMS down.

This gets me a peak level of -3.0, RMS around -19.5 - -20.5 and noisefloor of approx -100

I appreciate any help anyone can give me to get a crisper sound. Happy to be told I’m doing everything wrong - getting this far is the result of reading about a gazillion posts!

Ta :slight_smile:

Happy to be told I’m doing everything wrong

I don’t know there is a “wrong.” It’s not unusual to “get there” with different tools and techniques. The real magic is finding the technique that retains the most vocal quality with the least corrections.

I’m getting some ghosting / echoey sounds on the ends of words
give me to get a crisper sound.

Those are different.

Rather than beat up your finished work, post that same passage raw. Use WAV (Microsoft) which is the Audacity default WAV format. Straight out of the microphone. No corrections, filters, effects or adjustments. You do keep the raw performances, right?

There should be no reason for a reshoot if you accidentally damage any processing or mastering, or as in this case, the mastering didn’t produce a desirable result. We can’t take processing out of a performance (that’s the bumper sticker version. There are one of two we can take out, but that’s it)

The first words from our lips might be: “go back to the original performance and re-process it this way.” So there has to be a raw performance to go back to.

In my opinion you have overprocessed your performance. Your two complaints are typical of performers who get to ACX compliance by beating their performance repeatedly with a stick rather than gently and gracefully processing it.

There is no -100dB noise floor. You may be able to get that inside Audacity because of the wacky internal formatting it uses, but WAV (Microsoft) sound files run out of steam at -96dB and nobody gets that without very serious, stiff processing. ACX hates that.

The forum posting service runs out of steam somewhere just above 20 seconds for mono WAV. If it refuses you because the clip is too big, cut off some of the silent at the end.

NOTE: Cut it off at 23 seconds and then cut off a half-second from the front.


I think what you are hearing are processing-artifacts caused by noise-reduction, they are particularly noticeable in “s”, sounds e.g “Crisis”.

Noise reduction at 10dB is about as much as you can get away with without it causing conspicuous artifacts.
( Typically I use less than 10dB Noise reduction, say 6 ).
A hint of hiss is preferable to the computery artifacts inevitably created by noise-reduction.

The damage caused by noise-reduction is irreversible. Hopefully you still have a previous version before noise reduction was applied.

There are two free plug-ins for Audacity here : DeClicking & DeEssing , worth having if you do narration.

worth having if you do narration.

Perfectly true. Delightful tools, but we won’t know if you actually need them until we hear the work not smothered by tons of processing and corrections.

Noise reduction at 10dB is about as much as you can get away with without it causing conspicuous artifacts.

I cut it off at 12dB. If you manage to need more than that, it’s worth a trip back to the studio to see where original work can be improved.

There are several of us who managed to read ACX compliant short works with no processing past volume adjustment. It’s worth noting that’s the goal, not ‘let’s see how long we can make the processing list.’

I admit that’s not easy and I would not like to read a book like that, but just being able to produce a short, perfect clip at all means my studio is basically OK and tiny audio corrections will not be obvious.

We live in terror of the posting that starts: “Help me clean up…”


The need for De-Clicking the plosives, [“C/K” & “T” etc ], survives noise-reduction and equalization …

Cool. What settings did you use and which tool?



Thank you so much for all the responses :slight_smile:

I’ve attached the rough version in WAV 16-bit (cut out loads of spaces to make it short enough for upload).


I keep all versions at every stage! Completely neurotic because (whisper it) I’m not entirely sure what I should be doing…

I think I definitely need those plug-ins - I’m guessing it will really cut down on editing as well - and the difference was so much better in the sample you uploaded.

Thanks :slight_smile:


I keep all versions at every stage! Completely neurotic because (whisper it) I’m not entirely sure what I should be doing…

I’m very pleased. You can always throw out work you don’t need, but desperately needing to go back to work you don’t have is way too common. Being professionally obsessive I still have original shoots from years ago.

“Hey, Koz. Do you remember that shoot you did for the radio broadcast?”
“Of course, would you like a copy.”

People who can do that tend to get hired again.

I can’t listen to the work right this second. I’m working from the field and it’s a little noisy.


Love it! It can be tough, working in the ‘field’… :wink:

I am now past the coffee portion of my day and onto the red wine. Probably best not to be trying out any new mastering approaches until tomorrow, anyway!

Although suddenly I do want a white chocolate cookie…hmmm… :astonished:

Paul-L’s DeClicker on default settings, which reduces excessive K & T sounds.
I also equalized to reduce the deep valleys in the frequency-analysis.

I’m in 25-step ToffeeDoodle Anonymous.

“My name is Koz, and I’m a ToffeeDoodle Compulsive.”
“Hi, Koz.”

I got it to pass and sound more natural, but it won’t pass ACX Check because the clip has no half-second or more of room tone. About the best I could find is 1/3 second and that’s not enough for the noise part of the tool to chew on. I did a manual noise check (the old way) and the clip really is into the -68dB range and passes, not -42dB that the tool thinks.

So, while you’re cutting up raw work for the clip posting, can you make one and be sure you include at least 1/2 second continuous room tone. Do not fall to the temptation of creating silence with Command-L. That creates dead, surgically sterile silence and doesn’t count.

I gotta drop out for a bit and do Real Life.


I’m not completely sure which way to go with this. It’s fairly certain that the excessive noise reduction is causing the sound distortion. It’s famous for it. So use your tool pathway but use a lower Noise Reduction number. If you still have some odd, residual sizzly distortion, then try applying the DeEsser at the default settings. This is also where being able to hear accurately what you’re doing is good.

7 - Sometimes I repeat the limiter at this point to bring the RMS down.

That’s bothersome because the job of the limiter (and compressor) is to bring the RMS (Loudness) up. I wonder instead of that what would happen if you just normalized to a lower number. That will reduce distortion, too. The ACX Peak rating is a maximum. You don’t have to hit that one, you just have to not go over it. RMS is a range goal.

LPF (Hz 16000 / Rolloff 48dB)

HPF (Hz 92.5 / Rolloff 48 dB)

Again, that high a reduction dB value is seen as a “brick wall” filter. Musical or vocal tones never get higher than 16000 (a bit crisper than FM radio). That may give you a warm, fuzzy feeling of having achieved your goal, but brick walls can cause sound distortion to the show that’s left. Better to use lower numbers such as 36dB or 24dB.

I admit to being suspicious at your settings. 92.5Hz and 16000 Hz are not values that a New User would magically divine on their own. You had help, right?


Hi Koz. My name is Claire and I am a soft-serve ice-cream with gooey toffee sauce compulsive.
“…Hi, Claire.”

You are too kind :slight_smile: I have just read at least a gazillion forum posts and googled the hell out of this. I hate wasting time and ineffective mastering is a massive waste. Plus I don’t want to sound amateurish because then people won’t buy my recordings and…(deep breath)…I’ll have to go back to working in an office. In HR. Again (shriek!).

I did try to find an “Audio Mastering for Dummies” book, but it doesn’t seem to have been written yet. (Hint Hint).

I haven’t used the de-esser or de-clicker before, so will defo start doing that. Okay, sooooo my plan will be to normalise to a lower number and reduce the roll-off and see what effect that has. Limit my limiting (ha-ha) and go softer on the noise-cancellation. Passing the acx is such a headache, but this forum has helped so much!

A couple of quick questions:

  • I haven’t been equalising (because the screen confuses the hell out of me) and I thought low pass and high pass filters sort of did the same thing. I’m guessing this is a bit simplistic, in which case should I add equalisation into the process?

  • I live near an airforce base so get jets flying overhead, am I right in thinking it’s the HPF that targets that sort of sound?

Okay, so I’ve uploaded (another) sample with the 0.5s of room tone at the start. I don’t know if you have time to get it to pass the acx check and see if there are any additional issues (with the extra room tone to check), but really appreciate it if you do!



It’s possible to import equalization settings (curves) into Audacity’s equalizer …
The CJ#2 equalizition-curve imported into Audacity.png
CJ#2.xml (106 KB)
Animation showing what CJ#2 does to frequency-content of '''Home Ec - Closing Credits - Rough''.gif
After equalization I think you’re still going to need to apply the DeEsser and DeClicker.

Ok, I think I just fell in love. Thank you soooooo much for that Trebor!

After applying that precise equalization curve, CJ#2 ,
[ which removes the deep valleys from the frequency-response above 3kHz ]
You can make broad-changes to equalization to your taste using Audacity’s “Bass and Treble” control.

NB: that equalization curve, CJ#2 ,is specific for the set-up you were using .
another curve will be required if you use a different microphone.

Ah, okay, good to know. I won’t be changing the mic until I actually start making some money (chicken/egg scenario) but what you’ve done has really helped out so thank you :slight_smile:

ACX is very stern about consistency through the course of the book. So you won’t be changing anything until after the first one. I live in horror of a Producer calling with the idea of scheduling a reshoot of a portion of a recording. “You do remember how you did it, right?” !@#$%^

Effect > Equalization is the completely manual tool. All the others are minors or subsets. They’re prebakes. You can manually drag the curve around toward the left and set the Length Value, yadda, yadda, or you can just use High Pass Filter. All baked in.

Steve’s LF_Rolloff (which I think is called something else now) is a very specific, intentional, custom High Pass Filter, which itself is a pre-bake Equalizer. The joke is Steve has become internationally famous for writing seven lines of equalizer code.

Yes, but those seven lines work really well. If he solves world peace or human hunger, they will pale in comparison.

near an airforce base so get jets flying overhead, am I right in thinking it’s the HPF that targets that sort of sound?

That’s messy. That may be one of the conditions where ACX wants you to stop and wait for the planes to finish going over.

Jets have many different tones. High screaming as they approach (compressor blades in the engine) followed by roar as they go over (airfoil and wing noises) and then rumble after they pass (exhaust noise). They cover many if not all audible tones, not just high or low. You win!

I was in a position to hear the front and rear of a commercial jet. You would think the back of a jet strong enough to fling the airplane into the air would be loud, but it’s nothing against the ear-splitting, demented screaming coming from the front.

I will reference Ian, the current champion of long forum postings. He lives on a noisy corner and records at night. Even I try to record at night. I can hear traffic passing in the background of my presentations. I know what it is. It’s my non-sound proofed window. I just haven’t gotten up enough effort to design and build a panel to cover it up. I’m not reading for bux, either.

“Audio Mastering for Dummies” book

Nobody’s racing to write that book because it’s too open ended. Mastering for what? AudioBook is a tiny subset of audio production.

“Well,” you might well say, “write that one.”
That’s not what you or anybody else really wants. What everybody really wants is “Foolproof Disaster Recovery for Dummies.” The goal is buy a Blue Yeti, record an audiobook on the kitchen table, become internationally famous and retire to a villa on Côte d’azur.

So not happening. There was a recent posting from someone promising “easy pro audio filters.” What he meant was how to filter your “soundproofed studio recording” for sale. Not your kitchen table recording. Note the commercial grade soundproofing panels behind him. This was a difficult image to get, but I wanted that idea.

Everybody arrives with different problems and damage, so it’s really hard to pre-bake rescues.

ACX itself has videos about how to do this. Step one: build a studio. Kitchen table need not apply.



You’re something of a special case because you arrived already closer than most people. My bag of tricks ran out. You’re not disaster recovery. You’re already close. That may actually be harder.