Subject:24-bit recording in Acid Pro

Posted by: Illogical

Date:8/13/2007 5:47:03 PM

Besides setting the project to 24-bit, what else do you have to do in Acid to be able to render to a normal 16-bit file when recording and mixing in Acid?

Thanks in advance!

And am I the only one still using 16-bit?

Subject:RE: 24-bit recording in Acid Pro

Reply by: AZAZEL36

Date:8/13/2007 6:43:42 PM

Cant tell you, im new to this, where can you see the bit rate at??then i can tell you what i use.

Subject:RE: 24-bit recording in Acid Pro

Reply by: Illogical

Date:8/13/2007 6:48:16 PM

Bit-depth is in the Properties bit from the File menu...select that, then switch over to the audio tab. That's where you can set the sample rate as well.

Subject:RE: 24-bit recording in Acid Pro

Reply by: pwppch

Date:8/13/2007 10:13:03 PM

Not sure I follow you....

What is it that you are actually trying to accomplish and why do you believe the project bit depth is important?


Setting the projec to 24 bit is not the limiting factor in how you render it. Rendering is completely independant of the project bit depth. The project bit depth will be used as the default rendering bith depth - when the format permits this - but it is not limited to this. (Same goes for sample rate.)

With many loops being shipped at 24 bits, and softsynths generating floating point data (which is essentially 25 bit) you will be better served to work at this depth and then dither down to 16 bit when you render.

Bit depth is more important when recording, but this is a limiting factor of you hardware. Obviously you should record at the highest bith depth that your hardware permits. However, even at 24 it is unlikely you have a ambient noise level that will permit you to use all of those bits effectively. There is also the limitation of the converters you are using. Still, with harddrive space as cheap as it is, just record at 24 bit and be happy with the extra zeros.

The recording sample rate is another story. Too high and you will use a lot of space. If your final goal is 44.1 16 bit, then you should try to max out at 88.2. If you have a really good tool for resampling - Sound Forge - then you can record at 96 or even 192 and then resample a master mix to the sample rate of delivery.

So, set your project bith depth to the best your hardware can support.
Set you sample rate to a reasonable working rate. 48, 88.2, or 96. (192 is overkill IMHO)


Peter

Subject:RE: 24-bit recording in Acid Pro

Reply by: Illogical

Date:8/14/2007 9:09:10 AM

Cheers for all the information, Peter. I guess what holds me back is this whole dithering bit. I don't quite understand it...do you only have to dither when you render out a 16-bit wav? Do I render, then dither, or vice versa? And can I render a 24-bit wav of a mix and then convert that directly to mp3 or wma without dithering?

And if I'm working with the project set to 16-bit, is that limiting the internal processing depth/accuracy for fx and softsynths in any way, or just recording data at 16-bit?

To answer your initial question, I'm mainly mixing in the box, using synths and loops, but also with recorded instrumentation and vocals over the top. I usually render mixes to a wav, then open that up in a new project, apply any mastering effects, and re-render to mp3 and wma.

Thanks again!

Subject:RE: 24-bit recording in Acid Pro

Reply by: jbolley

Date:8/14/2007 12:05:35 PM

for most applications I would think 24 bit would be your project setting. On the master buss set the plug ins to be post fader (this is a right click menu) and add a dither to 16 bit as your last effect in the master section. You want to dither as your absolute last step before reducing bit depth.
With the project at 24 bits you'll have the extra resolution for applying your effects and combining your audio tracks.

Hope this helps!

Jbolley

Subject:RE: 24-bit recording in Acid Pro

Reply by: pwppch

Date:8/14/2007 1:50:48 PM

ACID uses 32 bit floating point internally. Always has.

The project bit depth tells the hardware what it is running at. Internally everything is converted and processed at 32 bit floating point.

Dithering is up to you. We do a decent job with out any dithering plugins. There are a number of really good ones ($$$) available commercially.

If you do use a dither plugin, place it on the master bus as the very last thing you do. Don't put and gain or other control AFTER the singnal path going into the dither plugin.

MP3 - what's the point? It is a lossy conversion that is really independent of "bit depth".

Do a Google on Dither and Bith depth. You will find volumes of information.

Peter

Subject:RE: 24-bit recording in Acid Pro

Reply by: pwppch

Date:8/14/2007 1:53:02 PM

>>With the project at 24 bits you'll have the extra resolution for applying your effects and combining your audio tracks

Not really. We run everything internally at normalized 32 bit floating point so the "24 bitness" is lost in all of this. The important aspect is as you stated : Where to place the dither plugin.

The second most important aspect is that the master bus (the render bus in ACID) does NOT clip. Normalized floating point permits "overs" that will get clipped when you render to a fixed point file (or hardware.)

Peter

Subject:RE: 24-bit recording in Acid Pro

Reply by: RobertCorrell

Date:8/15/2007 1:37:20 AM

I agree with what's been posted, but will add my 2 cents.

Bits = dynamic range @ 6db per bit. 16 bits = 96db, 24 bits = 144db of dynamic range.

Where this matters most is on the recording end (once you process it you're working above 24 bits in ACID and when you render it most likely it's to 16 bits), but realize that improving your maximum dynamic range doesn't affect the high end (clipping is still clipping) but the low end. Increasing the bit depth to 24-bits can have a noticeable improvement in the quality of your audio, assuming your noise level (hum, electric noise, whatnot) isn't too high to begin with. Listen to a reverb tail or very quiet passage and compare the difference.

So why record at 24-bits when you're going (most likely) to render it to 16-bits or to an MP3 file? Because you'll capture less noise and more signal when you record. When you reduce this down to 16-bits of dynamic range in rendering, you're including less noise as a proportion of signal to noise, than if you recorded at 16-bits. Once you record noise, it doesn't matter how many bits the program uses to process or render it... it's still noise.

Also, make sure your hardware can handle 24-bits. It doesn't matter what you set the bit-dept in ACID if your pre-amp (or whatever interface you're using) can't record at 24-bits.

Subject:RE: 24-bit recording in Acid Pro

Reply by: jbolley

Date:8/15/2007 8:40:55 AM

thanks for clarifying. I didn't realize the project bit depth had such little impact.

Jbolley

Subject:RE: 24-bit recording in Acid Pro

Reply by: Illogical

Date:8/15/2007 12:13:54 PM

Discussion = everybody wins.


To go back to something Peter had said, though, I was asking about mp3's because that's the format my music ultimately ends up in. I assume that if I render to 24-bit wav, I don't need to dither since the bit depth remains constant. So if I render a 24-bit stereo wav from my 24-bit stereo project, can I then take that 24-bit wav, open it in a new project, and render straight to mp3 without dithering, or do the same (mysterious) issues still apply?

Subject:RE: 24-bit recording in Acid Pro

Reply by: RobertCorrell

Date:8/15/2007 5:41:58 PM

I don't think there is such a thing as a 24-bit .mp3, but I could be wrong.

Dithering is a process that transforms digital "quantization noise" into something closer to analog tape hiss. You should only do this once, and it should be the last plug-in in your chain as you render your final file. You can re-dither and the world won't end, but most people recommend doing it once.

A popular misconception is that you only need to dither when rendering down from a higher bit-depth to a lower one. The truth is, you still benefit when dithering at the same bit depth. The point is to lower the perceived noise floor. 16-bit material dithered can appear to have a greater depth, but 24-bits will too (albeit with diminishing returns).

Ultimately, I'm not sure it matters. If the material is recorded, mixed, and mastered well, the difference between dithering or not dithering may only be discernible to someone with a lot of mastering experience in perfect acoustic conditions with incredible monitors.

You are benefiting from rendering 24-bit to 24-bit because you're preserving the dynamic range of the original material and then as a last step rendering it to an .mp3. I would go ahead and dither at that point.

Robert

Subject:RE: 24-bit recording in Acid Pro

Reply by: pwppch

Date:8/15/2007 8:22:39 PM

No simple answer here.

If you render to 24 bit wave (uncompressed in anyway) and then load that file into a new project you MAY still have to dither. It depends on what you are doing to the "singnal".

If you load this file onto a track, set the track's gain to 0dB, set the pan to balance, set the bus(es) to 0db, then you dithering would be redundant. Why? Because you didn't alter the "bits".

Not much point (or fun) in doing this though.

So, if you process in anyway - including simple gain changes - then you have altered the signal and may have added bits along the way , so dithering COULD be needed again.

So, it depends on what you did. Reverbed it? Most likley.
If you just cut some freq (not boosted) then probably not.

Still if your workflow is to render a final mix, that is then loaded back into ACID (or Forge) for mastering and delivery conversion, then render in ACID to 32 bit floating point. This way you have your mix exactly as ACID let you "mix it". You then use that un-dithered mix as your best starting point for finaly mastering.

That is, don't render to a MP3@320 bit (so called CD quality) and then convert that to say ATRAC or some other lossy compression (and NEVER MIX with it.) Work with your raw mix and then use a tool like Sound Forge to prepare (Master) as many different formats as you need.

It should also be noted that mastering for CD can be VERY different than mastering for MP3 or web streaming type delivery. They affect the overall sound so you may have to compensate for this when preparing your mixes for MP3 type delivery. Again, Forge is great for this kind of thing.

Peter

Subject:RE: 24-bit recording in Acid Pro

Reply by: buckaroo

Date:1/24/2008 1:58:16 PM

Just a Q?

If I record and have my Acid Pro project at 24 bit in the properties, instead of having a dither plug in, could i just render in Acid at 24 bit and do all the ditthering in Soundforge??

IE: could i import the final Acid 24 bit master into Soundforge and just resave as new files in Soundforge ie: 16 bit WAV as a master and subsequent 128k MP3 version for emailing/web etc?

Would this work?

Subject:RE: 24-bit recording in Acid Pro

Reply by: Kennymusicman

Date:1/24/2008 2:40:57 PM

Almost. Acid --> SF @ 24bit. No dither.. yes

Simply save as in SF? - no. You'll need to resample which will apply the dither process.

Then save.

Subject:RE: 24-bit recording in Acid Pro

Reply by: buckaroo

Date:1/25/2008 12:59:38 AM

Right so just for clarity :

acid 24-bit render, into Sforge as a 24 bit file..

Then with the 24 bit file in Sforge, go to RESAMPLE option and use 16 bit WAV file?

Once thats done i can then make the mp3 copies etc?