The No.1 Website for Pro Audio
Why did my song sound distorted when played on the radio?
Old 20th January 2020
  #1
Gear Nut
 

Why did my song sound distorted when played on the radio?

Awhile back, a friend who DJs at a college station played my music (.wav file) on the radio but it sounded clipped and distorted. The files were recorded and mastered using Logic. I'm somewhat newish to mastering, but the plugin chain was basically just very mild compression and then Limiter with a -1dB ceiling. The gain meters were definitely not pegging the red zone while mastering nor did they sound distorted.

My theory, as I've understood from reading, is that -1dB does not allow enough overhead which is required by certain codecs - so whatever adjustments were made in the college radio's streaming system pushed the song beyond 0.0 and distorted it, maybe...?

Here is the song, mastered at about -0.2 True Peak and -12 LUFS:

https://www.dropbox.com/s/lqj2uq5u0x...prise.wav?dl=0

Last edited by deern; 20th January 2020 at 09:19 PM..
Old 4 weeks ago
  #2
It can be the way it was mastered. Was it mastered by someone who knows what they are doing? It can also be the radio station and how the process and compress it before broadcasting it.
Who ever is mastering it, should be using LUFS with short & long term peak measurements, not just RMS, its more accurate...
Old 4 weeks ago
  #3
Gear Nut
 

Quote:
Originally Posted by CJ Mastering View Post
It can be the way it was mastered. Was it mastered by someone who knows what they are doing? It can also be the radio station and how the process and compress it before broadcasting it.
Who ever is mastering it, should be using LUFS with short & long term peak measurements, not just RMS, its more accurate...
It was mastered by me, so not really

I honestly thought -0.2dB overhead was sufficient to prevent clipping in cases where it gets encoded differently, but I'm still learning.
Old 4 weeks ago
  #4
Quote:
Originally Posted by deern View Post
It was mastered by me, so not really

I honestly thought -0.2dB overhead was sufficient to prevent clipping in cases where it gets encoded differently, but I'm still learning.
It could be and sometimes it cannot be enough. It all depends on what and how its encoding.

But what does encoding have to do with playing it on the radio? does the radio station encode it again? Why are they encoding it again?

Did you not supply them whit a file that meets their specifications?
Old 4 weeks ago
  #5
Lives for gear
 
mbvoxx's Avatar
do you have a crappy radio?
lol
seriously though, might want to leave more headroom so the Optimod in the engineering bay doesn't smash the life out of it.
Old 4 weeks ago
  #6
Gear Nut
 

Quote:
Originally Posted by CJ Mastering View Post
It could be and sometimes it cannot be enough. It all depends on what and how its encoding.

But what does encoding have to do with playing it on the radio? does the radio station encode it again? Why are they encoding it again?

Did you not supply them whit a file that meets their specifications?
This is a small college radio station and I think they convert a lot of stuff to mp3 and someone else mentioned that maybe that's what happened.


What I have them is what's linked above: a .wave file, 16-bit, 44100 sample rate, interleaved file type. -14dB LUFS and somewhere between -0.2dB and -0.3dB ceiling on the limiter.

Since trying to learn mastering, I've seen people leave anywhere from -0.1 ceiling to -1dB ceiling and everything in between so still trying to understand how to handle that.
Old 4 weeks ago
  #7
Quote:
This is a small college radio station and I think they convert a lot of stuff to mp3 and someone else mentioned that maybe that's what happened.
I would find out and not assume, then give them what they use. Ask them about all the audio file requirements and master it to that. Mp3's are not the standard for radio airplay, but if that's what they use, then you'll need to give them that and give them the maximum bitrate as well. 320bitrate is the best, see if they accept that.
Old 4 weeks ago
  #8
Gear Head
 
IGotWorms's Avatar
 

Quote:
Originally Posted by deern View Post
This is a small college radio station and I think they convert a lot of stuff to mp3 and someone else mentioned that maybe that's what happened.


What I have them is what's linked above: a .wave file, 16-bit, 44100 sample rate, interleaved file type. -14dB LUFS and somewhere between -0.2dB and -0.3dB ceiling on the limiter.

Since trying to learn mastering, I've seen people leave anywhere from -0.1 ceiling to -1dB ceiling and everything in between so still trying to understand how to handle that.
Spotify recommends a -2db ceiling for loud material and I've seen references that a -6db ceiling can be not enough to prevent clipping in an mp3 conversion.
Old 4 weeks ago
  #9
Lives for snowflakes
 
12ax7's Avatar
 

Quote:
Originally Posted by deern View Post
Why did my song sound distorted when played on the radio?
I take it from the OP that we are talking about standard (analog) FM "terrestrial" radio, in which case the link below would go a long way toward explaining the degradation observed:
What Happens to My Recording When it’s Played on the Radio? (.pdf)
Old 4 weeks ago
  #10
Gear Nut
 

Quote:
Originally Posted by IGotWorms View Post
Spotify recommends a -2db ceiling for loud material and I've seen references that a -6db ceiling can be not enough to prevent clipping in an mp3 conversion.
So are most people in the habit of doing multiple different kinds of exports of their masters?
Old 4 weeks ago
  #11
The WAV file linked in your first post has a ceiling of -1.97 dB TP and integrated loudness of -12.0 LUFS.

Conversion to 320 kbps CBR MP3 (Fraunhofer) did not introduce any artifacts, and the resulting ceiling is -1.94 dB TP.

I've attached the waveform statistics for both the WAV and MP3 files.

These levels would not typically result in clipping or distortion during normal radio playback.
Attached Thumbnails
Why did my song sound distorted when played on the radio?-bulls-reprise-wav.png   Why did my song sound distorted when played on the radio?-bulls-reprise-mp3.png  
Old 4 weeks ago
  #12
Gear Nut
 

I've read that from Spotify's FAQs before: -2dB ceiling for anything louder than -14dB LUFS.

However, in trying to learn production and mastering this past year, I've taken several online courses where all the tell you is to make your ceiling -0.1dB and you're golden. No talk about encoding or other issues later down the line. That's what's made this so confusing.
Old 4 weeks ago
  #13
Quote:
I've taken several online courses where all the tell you is to make your ceiling -0.1dB and you're golden.
They are completely 10000% wrong. do not believe everything you read on the internet. I would never master anything at that ceiling when its going to be converted\
Quote:
So are most people in the habit of doing multiple different kinds of exports of their masters?
No, not really. Find the happy medium that works for everything. Unless its going to Vinyl, then ill do 2 different masters as vinyl needs to be mastered differently than everything else
Old 4 weeks ago
  #14
Gear Nut
 

Got it. Well I appreciate the replies. Reading so much contradictory stuff online is what makes this so hard.

FWIW, I really like performing and I like mixing. But in order to get anywhere with my music, I have to put it online in some semi-decent audio format I'm proud of. But, doing absoutely everything myself unfortunately leads to spreading myself thin, knowledge-wise. I'm unemployed at the moment and do not have any friends who make music or have a home studio so I'm completely isolated in that sense. It's a lot of trial and error and asking forum questions.
Old 4 weeks ago
  #15
Lives for gear
 
SmoothTone's Avatar
 

Look to the arrangement first

It's important to consider the nature of the material before getting lost in conversion and loudness specifications.

This is a droney type arrangement and there are some natural resonances across the midrange. These aren't overpowering in the mix/master, but they're exactly the sort of thing that will start to break up when they hit radio processors (or any extreme loudness processing).

Broadcast processors - just like brickwall limiters - are designed to deal with momentary transients and generally aren't kind with longer tonal elements. Your track is ALL tonal material, so you can start to see why any resonances in the program may start to break up when pushed through the phase rotation, clipping and limiting typical in broadcast processors. Sparse arrangements usually fair much better.

Regarding the confusion about where to set the absolute ceiling and why there is such variation in recommendations and practices, there is a trade-off between managing intersample or encoder overs vs retaining the most dynamic impact when pushing for loudness.

Some engineers give priority to dynamics and set a higher ceiling, accepting this will probably mean higher distortion from ISPs or encoder overs.

Other engineers will give higher priority to minimising intersample/encoder overs with the trade-off being slightly lower loudness or more limiting or clipping.

In my testing, I found that half a dB of extra limiting to compensate for a lower ceiling was often far more audible than the extra distortion from ISPs, which is relatively inaudible in many playback scenarios. That said, I try to strike a good balance and leave some headroom as much as possible.

Some good discussion in these threads:

Peak Headroom

Targeting Mastering Loudness for Streaming (LUFS, Spotify, YouTube)-Why NOT to do it.
Old 4 weeks ago
  #16
Lives for snowflakes
 
12ax7's Avatar
 

Quote:
Originally Posted by deern View Post
I've read that from Spotify's FAQs before: -2dB ceiling for anything louder than -14dB LUFS.

However, in trying to learn production and mastering this past year, I've taken several online courses where all the tell you is to make your ceiling -0.1dB and you're golden. No talk about encoding or other issues later down the line. That's what's made this so confusing.
Just to clear up a question in my mind:

Did you hear this problem on an actual FM ("terrestrial") radio station, or was it an internet audio feed of some sort?
Old 4 weeks ago
  #17
Gear Nut
 

Quote:
Originally Posted by SmoothTone View Post
It's important to consider the nature of the material before getting lost in conversion and loudness specifications....
Wow - I learned a ton just from this one post. Thanks so much!
Old 4 weeks ago
  #18
Gear Nut
 

Quote:
Originally Posted by 12ax7 View Post
Did you hear this problem on an actual FM ("terrestrial") radio station, or was it an internet audio feed of some sort?
It was on their online feed - I wish I knew whether or not people listening on terrestrial radio heard the distortion
Old 4 weeks ago
  #19
Lives for gear
I've had lots of stuff played on commercial radio, (even across the whole country) and it always sounded WAY over compressed and distorted compared to the original master. That's just the way radio is.

But I really didn't care, I mean I was on the radio!

Old 4 weeks ago
  #20
Gear Nut
 

Email response from the station manager:

I can tell you that we do apply some compression-limiting to our FM signal. Same but less for the webstream, which is where our web archives are pulled from. Both of these are to compensate for volunteer DJs who play wildly different audio levels over the course of their shows.

That said, if your songs were already mixed to full blast and the DJ had the fader potted up just a little too high, that could have introduced distortion from the jump.


Now, I mastered this album myself a year ago as I was still learning the basics and it's clear now that I didn't really leave enough headroom. As I'm making this newest album, I'm leaving a ceiling of a full -2dB to not take any chances. Final product is currently around 10-11dB for each song and sounds appropriate for the genre. Will continue tweaking, but this has definitely been a learning experience
Old 4 weeks ago
  #21
Gear Nut
 

In case anyone's reading, today I snuck a copy of a new song to my friend who DJs at that same radio station. The track definitely did not distort this time. In this case there was a full -2dB of headroom on it. This was partially to retain dynamics, partially to experiment with how it would sound on the radio, and partially because I will submit all my stuff eventually to Spotify which says "leave -2dB true peak headroom for tracks louder than -14dB LUFS" (My track is -11dB LUFS).

If anyone has feedback on this, especially that last part, would love to hear it. I've take a lot of advice from Gearslutz folks and chosen not to target LUFS at all, but just to push everything until it sounds medium-loud and good regardless of LUFS. (However I would say, my track sounded quieter than other stuff on the same radio show).
Old 3 weeks ago
  #22
Lives for gear
 
SmoothTone's Avatar
 

Quote:
Originally Posted by deern View Post
In case anyone's reading, today I snuck a copy of a new song to my friend who DJs at that same radio station. The track definitely did not distort this time. In this case there was a full -2dB of headroom on it. This was partially to retain dynamics, partially to experiment with how it would sound on the radio, and partially because I will submit all my stuff eventually to Spotify which says "leave -2dB true peak headroom for tracks louder than -14dB LUFS" (My track is -11dB LUFS).

If anyone has feedback on this, especially that last part, would love to hear it. I've take a lot of advice from Gearslutz folks and chosen not to target LUFS at all, but just to push everything until it sounds medium-loud and good regardless of LUFS. (However I would say, my track sounded quieter than other stuff on the same radio show).
So it turns out the answer to your original question was amateur radio DJs.

It doesn't hurt to leave 2bB of headroom if you're happy with the loudness at -11LUFS. Although I would imagine with your material a higher ceiling would be quite safe. It's heavily clipped/limited material that tends to have more (and higher amplitude) ISPs.

One simple way to test how your audio will fare is to put it through a low bitrate mp3 conversion (e.g. 96kbps). If it survives that without overs then you're pretty safe.

Last edited by SmoothTone; 3 weeks ago at 08:38 AM.. Reason: Correction
Old 3 weeks ago
  #23
Gear Nut
 

A friend sent me this link, regarding codecs and playing music on the radio...

https://www.pro-tools-expert.com/pro...ering-tutorial
Old 3 weeks ago
  #24
Lives for snowflakes
 
12ax7's Avatar
 

Quote:
Originally Posted by deern View Post
A friend sent me this link, regarding codecs and playing music on the radio...

https://www.pro-tools-expert.com/pro...ering-tutorial
Dead link for me.
Topic:
Post Reply

Welcome to the Gearslutz Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Forum Jump
Forum Jump