question for mD, as to why, not how -ACID Product Family

Subject:question for mD, as to why, not how Posted by: BayOfPigs Date:12/18/2003 11:19:00 AM mD, you seem to be one of the Acid guru's here, so 1) Thank you ever so much for all these knowledgable posts, you have no idea how helpful it is to Acid newbie weenies like me, and 2) I had a question re: something you wrote here a few weeks ago. --- In response to a tempo question, you wrote: That's probably because ACID is analyzing the track's length based upon how many measures it can divide it into and adjusting tempo to match accordingly. ACID tries to divvy up the track based upon multiples of beats, namely: 4, 8, 16, 32, 64, and so on. (Conversely, this would mean an even number of measures—2, 4, 8, 16, 32, etc.) ******THIS IS ME AGAIN: you go on to write what follows below (to refresh your memory). Anyway, question is -- WHY does Acid do this? I have 1 measure of 4/4 at 100 BPM, let's say, and it plays perfectly. So then I have 1.1 measures of exactly the same thing, or 10 measures, or 10,000 measures: they are all accurately played at 100 BPM -- but they'll all play differently. When Acid does it's "math", it's going to tempo change my sample dramatically. Most posts regarding anything to do with this and answered with: "Just use one-Shot." I understand the differences, but am just curious as to why. I get that Acid tries to match samples (w/ the right settings) to play in the same key and tempo. But, unless I misunderstand, Acid is giving me a radically different BPM if I give it .5 of a measure, versus 8 measures. These are all at 100 BPM, so I can't why Acid's math would handle them so differently. Again, thanks and have a great holidays. ****HERE's YOUR ORIGINAL POST AGAIN: Let's say you have an 8.9 second sample that was divided into 16 beats. That would give us a total of four measures. To get the tempo: (number of measures x 240) / (length of sample in seconds) = tempo so: (4 x 240) / 8.9 = 107.865 BPM You're probably wondering how ACID would determine such a tempo for the sample. I believe ACID tries to get the sample as close to the average tempo of 120 BPM. For example, if the sample were divided into 8 measures (32 beats), you'd get the following result: (8 x 240) / 8.9 = 215.730 BPM If the sample were divided into 2 measures (8 beats): (2 x 240) / 8.9 = 53.933 BPM Both results aren't as close to 120 BPM as if the sample were divided into 4 measures.
Subject:RE: question for mD, as to why, not how Reply by: Iacobus Date:12/18/2003 12:16:22 PM Hi again BOP (and Happy Holidays to you), I believe that's just the way that the good programmers at Sony designed ACID. Do you have Sound Forge? If you do, follow along and I'll try to get as simple as possible to illustrate my point. Create a new file and insert exactly 2.4 seconds of silence. Note how, via Sound Forge's ACID Loop Creation Tools, Sound Forge reports that a four beat selection would give you 100 BPM. Now add six-tenths (0.600) of a second more of silence (which gives us a total of 3 seconds) and select the whole thing. Note how the ACID Loop Creation Tools now report 80 BPM. That's still based on a four beat selection, NOT assuming it's actually five whole beats in a tempo of 100 BPM. This is actually what ACID will do when it reads such a sample without any ACIDization applied. It's actually assuming the sample is four beats long instead of five. If the sample is longer, it's always going to assume that there are four beats a measure. This is probably why I'd totally recommend Sound Forge, because its tools allow you to adjust the sample so that when you ACIDize, you'll have the proper tempo when bringing the sample in ACID. For example, using that same 3 second sample, since I want that sample to fit within a 100 BPM tempo, I'd simply use the Edit ACID Properties command (within the ACID Loop Creation Tools) and tell Sound Forge the sample is 5 beats long. Then when I bring it into ACID, the correct tempo of 100 BPM will be used, rather than the 80 BPM ACID would assume. With Sound Forge, you also won't have to do all that crazy math I keep talking about. ;o) HTH, Iacobus ------- RodelWorks - Original Music for the Unafraid mD's ACIDplanet Page

Subject:question for mD, as to why, not how

Posted by: BayOfPigs

Date:12/18/2003 11:19:00 AM

mD, you seem to be one of the Acid guru's here, so 1) Thank you ever so much for all these knowledgable posts, you have no idea how helpful it is to Acid newbie weenies like me, and 2) I had a question re: something you wrote here a few weeks ago.

--- In response to a tempo question, you wrote:

That's probably because ACID is analyzing the track's length based upon how many measures it can divide it into and adjusting tempo to match accordingly.

ACID tries to divvy up the track based upon multiples of beats, namely: 4, 8, 16, 32, 64, and so on.

(Conversely, this would mean an even number of measures—2, 4, 8, 16, 32, etc.)

********THIS IS ME AGAIN: you go on to write what follows below (to refresh your memory). Anyway, question is -- WHY does Acid do this? I have 1 measure of 4/4 at 100 BPM, let's say, and it plays perfectly. So then I have 1.1 measures of exactly the same thing, or 10 measures, or 10,000 measures: they are all accurately played at 100 BPM -- but they'll all play differently.

When Acid does it's "math", it's going to tempo change my sample dramatically.

Most posts regarding anything to do with this and answered with: "Just use one-Shot." I understand the differences, but am just curious as to why. I get that Acid tries to match samples (w/ the right settings) to play in the same key and tempo. But, unless I misunderstand, Acid is giving me a radically different BPM if I give it .5 of a measure, versus 8 measures. These are all at 100 BPM, so I can't why Acid's math would handle them so differently.

Again, thanks and have a great holidays.

******HERE's YOUR ORIGINAL POST AGAIN:
Let's say you have an 8.9 second sample that was divided into 16 beats. That would give us a total of four measures.

To get the tempo:

(number of measures x 240) / (length of sample in seconds) = tempo

so: (4 x 240) / 8.9 = 107.865 BPM

You're probably wondering how ACID would determine such a tempo for the sample. I believe ACID tries to get the sample as close to the average tempo of 120 BPM.

For example, if the sample were divided into 8 measures (32 beats), you'd get the following result:

(8 x 240) / 8.9 = 215.730 BPM

If the sample were divided into 2 measures (8 beats):

(2 x 240) / 8.9 = 53.933 BPM

Both results aren't as close to 120 BPM as if the sample were divided into 4 measures.

Subject:RE: question for mD, as to why, not how

Reply by: Iacobus

Date:12/18/2003 12:16:22 PM

Hi again BOP (and Happy Holidays to you),

I believe that's just the way that the good programmers at Sony designed ACID.

Do you have Sound Forge? If you do, follow along and I'll try to get as simple as possible to illustrate my point.

Create a new file and insert exactly 2.4 seconds of silence. Note how, via Sound Forge's ACID Loop Creation Tools, Sound Forge reports that a four beat selection would give you 100 BPM.

Now add six-tenths (0.600) of a second more of silence (which gives us a total of 3 seconds) and select the whole thing. Note how the ACID Loop Creation Tools now report 80 BPM. That's still based on a four beat selection, NOT assuming it's actually five whole beats in a tempo of 100 BPM.

This is actually what ACID will do when it reads such a sample without any ACIDization applied. It's actually assuming the sample is four beats long instead of five. If the sample is longer, it's always going to assume that there are four beats a measure.

This is probably why I'd totally recommend Sound Forge, because its tools allow you to adjust the sample so that when you ACIDize, you'll have the proper tempo when bringing the sample in ACID.

For example, using that same 3 second sample, since I want that sample to fit within a 100 BPM tempo, I'd simply use the Edit ACID Properties command (within the ACID Loop Creation Tools) and tell Sound Forge the sample is 5 beats long. Then when I bring it into ACID, the correct tempo of 100 BPM will be used, rather than the 80 BPM ACID would assume.

With Sound Forge, you also won't have to do all that crazy math I keep talking about. ;o)

HTH,
Iacobus
-------
RodelWorks - Original Music for the Unafraid
mD's ACIDplanet Page