Bouncing in Logic9

[djbobm]

Hi Everyone!

Thanks in advance for all your expert comments.

This question arose when I was reading some posts and articles on dithering. I think I have a grasp on that, maybe not. I need "Dithering (and other things) For Dummies!"

Anyway, I have been bouncing to 24 bit in Logic9. Why? I don’t know – it was the default setting. (That must mean it’s good, right??!!) I just read that you should only do that if you are having the music professionally mastered. Should I re-bounce everything to 16 bit? What difference will it make? Do libraries want it a certain way?

I record using EWQL Goliath and Symphonic Orchestra Gold, which I believe are 16 bit. When I record live guitar, it is set at 24 bit. Does that make a difference in the way you bounce?

I’ve been working with Logic for 2.5 years now. There is so much to learn.

Thanks again.

Bob

[orest]

I don't think libraries want 24 bit, if they need higher quality it's 16 bit 48 kilohertz (DVD quality).
Otherwise, bounce it in 16 bit, 44.1.
You can always ask them what they want.

I think Logic 9 has the "normalize" box marked as well, you should make sure it's not marked. It's better to use other software if you want to gain the volume.

[Len911]

Bob, most DAWS now days even allow you to use 32-bit floating which is really the overall best way until you have a need for dithering to a final mix. It gives you more headroom for processing and effects. Even if your converters are only 24-bit or 16-bit. The 32-bit floating is only used internally though. I believe you use a little more hard drive space, not much, if that might be a problem. Once I panicked and thought that I should dither before making mp3's, but I tried different ways with and without, and it didn't make any difference, confirming what others that answered my post said. When you say "bounce down" I take it to mean the very final mix before a cd, not each and every process?

[mojobone]

"Dither once; dither last", is the rule, so you only need to do it when you put the music in its final form. (you only need to dither when you downsample; i.e., when converting from 24 to 16-bit, upsampling doesn't add or subtract anything, it's just an extra step for the microprocessor)

Libraries are all over the map, in terms of what formats they'll ask for, but most stuff for film/TV will end up at the DVD standard 24-bit, 48kHz. (so if your project is 24/48, you needn't dither at all, unless it's to be delivered at 16 bits, for some reason)

When you use 16-bit samples in a 24-bit environment, your DAW or sampler has to up-convert the samples on the fly; this may limit the number of instruments your DAW can play back at once, but may be worthwhile, if you're also capturing live audio to mix with the sampled instruments; you get more detail, which is preserved when (if) you downsample post mix stage.(though upsampling does nothing to improve the sound of the sampled instruments; it doesn't hurt, either, but it can slow down your DAW a bit) You can limit the CPU/RAM hit by 'freezing' virtual instrument tracks, if your DAW has this function. (most do) When you bounce your VIs to audio, you eliminate this CPU/RAM hit entirely, because you've effectively re-sampled the VIs at the higher bit depth, so the DAW no longer needs to upconvert.

If you're recording amplified electric guitars, there's probably little need to record at 24-bit resolution, unless you're trying to preserve a sense of the space around the instrument/amp; for pop recording, the object is usually to take out the room in the name of maximizing the signal-to-noise ratio. (it doesn't add much, but doesn't hurt anything, sonically, though the recordings will take up more drive space, and your CPU works a little harder at the higher bit resolution)

Recordings of relatively quiet acoustic instruments like harps, zithers, vocals and acoustic guitars can benefit from capture at 24 bits; the additional bit depth can also squeeze better performance from your DAW's EQs and compressors. (I could explain why, if you have an extra hour or so, heh)

DAWs in general will perform best when all elements in a project are at the same sampling frequency (Hz) and bit depth, but there are exceptions, such as Nuendo and Vegas, which are designed for mixed media from the ground up; they're used in post-production, where a lot of elements can come from very different sources.

As was mentioned above, some DAWs have up to 64-bit internal processing precision; (it's why they can sound better than ProTools, heh) Reaper, Tracktion, and Sonar are among them. (not sure about Logic, I'd have to check, and this post is getting long already, heh)

That said, bouncing everything to 24/48 as you're doing now can't hurt you, at least not by much; jes' leave off dithering, unless they ask for delivery at 16 bits.

[djbobm]

Thanks Alex, Len and Mojo for the detailed information. It helps.

Have a nice day.

Bob