Rendering from 24 bit to 16 bit audio for cds

:D Ok, here is a topic I have yet to see in the forum. I recorded some wave files in n-track @ 24 bit stereo, and, then used Musicmatch Jukebox to burn the tracks to a cd. Musicmatch Jukebox is a fairly simple-to-use program, and I have it on my machine, so I use it. Well, I did not realize that by leaving the wave files in 24 bit that they would not play on any cd player, and I was under the gun to get my music to a television producer by this morning. I was getting nervous, and then I remembered that n-track could burn a cd right in the "studio"! Yay! So I then list all my tracks in the box, getting ready to burn them, and n-track asks to render them to 16 bit. "Sure", I thought, anything to get this puppy moving. It changed them to 16 bit, and viola, the cd is finished. ( I am blasting through the rendering and burning process because the producer and camerman are leaving town for a week, and I promised him I will get him some tunes.) Racing over to his house, I decide to play the cd just to make sure everything sounds all right. the first track comes on, but right at the very end of the tune there is a distinct, annoyingly loud "Pop", sounding almost like static! I start to sweat, and at the end of the second, third, fourth tracks, etc., is a "pop" . I had no choice but to give it to him, and explain that I can remove the "pop". Later that day, after putting as much thought as I could into the various scenarios, I decide to open Music Match Jukebox, find my n-track files, and re-try a burn. Well, to my surprise I find two 16 bit versions of all the tracks. The difference seemed to be that one track had _1 after it. I burn it, listen to it, and THERE IT IS! "POP". To make sure, I then burn the other 16 bit track that does not have _1 after it.(It was worth wasting the cd's.) Sure enough, It has the clean ending just like I mixed it, with no pops snaps, etc. My question; How can I record in 24 bit (or 32 floating bit), render to 16 for a cd, without this "Pop"?
Any ideas and /or help will be tried and appreciated.
Billy Hopkins
My question; How can I record in 24 bit (or 32 floating bit), render to 16 for a cd, without this "Pop"?

Man - I wished I could help you but I don't use nTrack to do the 24-to-16 conversion. I use Sound Forge and have never had artifacts after the process was complete.


Mr Soul

I do use NTrack pretty much exclusively for rendering and I have never had your problem. I don’t know what causes your pops, but I thought you should know at least that I and a host of others do this process with Ntrack without any drawbacks. I am using 3.3 and I don’t have the burning capabiltiy.

Hey, thanks for your replies! I wonder if Flavio could try to duplicate this, and determine the reason for the pops.
Billy Hopkins

Billy, do you hear the pop if you just listen to the wave file?

Yes, I do. Sorry I took so long to reply. But if I listen to the wave file in n-track, I hear the pop. This is on a wave file converted from 24 bit to 16 bit.

:) Billy do I understand you to say that when you burned a 24 bit CD with musicmatch it also saved two 16 bit files for you? One that has a pop and one that doesn't have a pop? Don't you think that's a little odd? And also that rendering wasn't done by ntrack that caused the pop in the 16bit version that has the 1 after it! Program conflicts? Just a thought!

I'm getting a pretty strong pop playing a 24bit wav file when I click "stop" as if I have a ground issue. I don't know if this relates to your problem or not. Have you noticed any of this? It could be very suttle if your not playing it back loud. And then, I might be, being a little to darn fussy!

I’ve converted a lot of songs from 24 to 16 bit on n-track. I always do it on mixdown-options 16 bit. It will first run the mixdown in 24 bit then convert the song. I then use a separate program to burn the songs to CD. I’ve used HP record now, Real player, Niro and Easy CD creator. They’ve all worked fine with no pops.

Billy, since you hear the pop in the wave files, this has nothing to do with burning to CD. That means you can forget the burning process and concentrate earlier in the sequence: rendering to 16 bits.

First, take one of those 16-bit files that pops and zoom way in on the beginning, where it pops. See if you can see what this pop looks like in the n-Track display and describe it to us.

One problem you might have is a DC offset, and it’s possible that the other conversion program you’re using automatically corrects for DC offsets. (n-Track’s doesn’t, and shouldn’t.) If that is the problem, there are tools to solve it, but it’s usually an indication that that there’s something wrong with your hardware. It’s also a condition that can burn out your speakers.

DC offset is when the your soundcard returns some nonzero value instead of zero for silence. Of course, there’s no absolute silence when your soundcard is recording, but the average value of the noise should be zero and if it’s not you have DC offset.

But first, zoom in on the beginning of the wave file and describe what you see. Zoom both horizontally and vertically. Ideally, there’s nothing of interest to see, other than the background noise (which you’d generally kill before burning to CD anyway, using “destructively silence”).

On a copy of the file, try using destructive silence toolbar button (hold shift or control key when using the button, whatever it says to use for destructive). Do this to a silent section near but not right on the beginning. (Select a portion of the wave by dragging, and then use the tool.) Zoom in vertically and see if there’s a “step” up or down where you did the destructive silence. If so, you have a DC offset.

Another thing you can do: if you have any web space, post the first few seconds of the wave file. (To do this, drag the mouse on the timeline to select the first few seconds, and then use “Offline Mixdown” with “more options”, and check “Use selection” and whatever other settings you normally use. Make sure it has the pop, and post it on the web or email it to me (find my email on my web page, below).

Great Ideas, particularly uploading the wave file so you can hear it, too. It is going to be a few days before i can set aside the time needed to work on this. I will be back with my results. Thanks Everybody!
Billy Hopkins