Subject:24/48 audio recording

Posted by: joelboy

Date:12/31/2002 10:55:55 AM

I'm sure this is an "old" topic or not applicable to ACID for some of you, but:
I just recorded a couple of tracks in 24 bit / 48khz into my computer. (Vocal and electric guitar alone ) I was hoping for a significant improvement in sound quality compared to the same material recorded in 16 bit. I can't really hear a big difference. Does anyone have comments/advise? What do you think about this Setup: Acid 4.0, Vegas 3.0, Pent 4, lots of plugins, M-Audio Duo-spdif out to Audigy Spdif in. I monitor from the Audigy analog outs. ( I couldn't get the DUO to work well in USB!)

Is 24/48 not all that great for "pop" music? Should is stick to 16/24 because of the Audigy card? Thanks for any responses.
JB

Subject:RE: 24/48 audio recording

Reply by: Ted_H

Date:12/31/2002 12:52:55 PM

Recording a 16-bit file at 24-bit resolution is not going to improve the sound quality at all. The 24-bit version will sound exactly the same as the 16-bit version.

Ted

Subject:RE: 24/48 audio recording

Reply by: Iacobus

Date:12/31/2002 1:23:47 PM

Correct me if I'm wrong, but doesn't the Audigy do 16-bit/48 kHz internally, even via its S/PDIF? That could be why you don't see a major difference.

If that's the case, you're wasting your Duo's true 24-bit/96 kHz capability. (What's the problem with recording via the Duo's USB? I can record via USB just fine.)

Offhand, most people don't notice a difference between 16-bit vs. 24-bit, depending on the recording. The difference is most often noticed on acoustic recordings, but any recording can benefit from the extra headroom that 24-bit provides, especially for post-processing. A 24-bit recording dithered down to 16-bit, for example, sounds better than a recording that was done in 16-bit straight through.

For more info, check out iZotope's guides on dithering.

HTH,
Iacobus

Subject:RE: 24/48 audio recording

Reply by: spesimen

Date:12/31/2002 2:52:14 PM

i think md is correct, it's not clear that you're actually listening to the 24-bit signal at all! if the audigy is your monitoring then maybe anything you are hearing is being chunked down to 16 bit anyway..

signal paths aside.. there is a HUGE difference in recording quality between 24 and 16 bit when everything is setup properly...BUT..it's not so simple as just saying "24 sounds better than 16" because it doesn't necessarily.

even a highly skilled listener will have a difficult time telling the difference between a single recording at 16-bit with one made at 24-bit.

the place where that extra accuracy helps is when doing fx processing and mixing. compression and dynamics plugins in particular will react much more accurately (and sound better imho) when working with 24-bit files.

similarly, if you are mixing a dozen 16-bit files together and a dozen 24-bit files together, the final result in the 24-bit version will be a more accurate representation of the sound. it's kind of like rounding errors in math..say you have three tracks you are mixing:

.1 + .2 + .3 = .6 (16-bit)

.09 + .18 + .25 = 0.52 (24-bit)..when you dither down to 16-bit you get 0.5 instead.

now, that math is a gross oversimplification, and the accuracy difference is not nearly an order of ten like in the example there, but i hope that sorta explains it..

Subject:RE: 24/48 audio recording

Reply by: drbam

Date:12/31/2002 3:23:25 PM

The difference in 16 and 24 bits can be very quite dramatic if you have a good "front end" to adequately capture it (mic, mic pre, converters, etc). I've noticed the difference on ALL acoustic recordings I've done (primarily vocals, drums/percussion, flutes, and ethnic instruments).

drbam

Subject:RE: 24/48 audio recording

Reply by: joelboy

Date:12/31/2002 5:49:25 PM

When I used the Duo as a stand alone USB device, I couldn't monitor the audio I was sending into the computer. I could either monitor the music in my software or the inputs, but not both. Is there a way to have "full duplex"?

These comments are correct, the Audigy doesn't really function as a 24 bit card. I was up too late last night messing around. The "24 bit" comes from its ability to play 24bit material from DVDs? (who knows!?) Long story short, I thought I was recording in 24 bit from the Duos' SPDIF connection out, but I see that my card wasn't recording 24 bit. Any advice on using the DUO in USB would be helpful...
Thanks.

Subject:RE: 24/48 audio recording

Reply by: Iacobus

Date:12/31/2002 10:01:15 PM

I wish. From my research, the Duo should be at least able to handle two 24-bit stereo streams in and out. (That's all you can get out of the unit anyway.) I still think it's a driver issue.

Case in point: I'm sure you've tried this. You've noticed you can hear playback of the project when it's routed through the Duo, right? You've also noticed that when you record, the monitor meters for recording move along just fine (and whatever you're recording gets recorded) but you can't hear anything you're recording via the Duo until after the fact. Why can't the recording signal be mixed with the main playback output?

Iacobus

Subject:RE: 24/48 audio recording

Reply by: joelboy

Date:1/1/2003 8:03:03 AM

Exactly.
This is why I quit using the USB connection and started using the SPDIF. I think I'll write M-Audio an email- for what its worth.