latency problem

sck312 · Post by **sck312** » Sat Feb 23, 2008 4:57 am

Please help me! I was recording with the buffer at 256 but was getting occasional cracks/pops. So was I right to increase the buffer size? I did that (increased to 512 then 768) but then there was a weird delay.

So I turned the monitoring to off and the delay was gone. So I recorded the track, but during playback thru the computer I was really off from the metronome which makes me think the delay was still there in the computer when I recorded but since I was monitoring thru my interface I didn't hear it.

Am I correct? If so, how do I adjust it so I get no clicks/pops but there is no delay. Please help me out.

thanks,

scott

Tone Deft · Post by **Tone Deft** » Sat Feb 23, 2008 7:11 am

sound cards always introduce latency. the audio signal has to pass through circuitry and software shuffles the bits around, there's a delay or latency that's inevitable. there's 'stuff' between the outside world and Live.

the bigger the audio buffer, the higher the latency. the incoming data is like a water pipe, a stream of audio. the audio buffer is like a water bucket. the bigger the bucket the more delay there is in Live getting each bucketful of audio. it also means the audio is smoother cause it's not coordinating a bunch of small buckets.

higher sample rates mean the buckets (buffers) fill faster but means more load on CPU.

bigger buffer = more latency
bigger buffer = smoother audio
higher sample rate = more CPU load
higher sample rate = lower latency

it's all a bit of a juggle until you find that sweet spot you like to work with.

1mS of latency is like standing 1 foot from your speaker.

audio cards also lie about the mS of latency, connect an audio out to an audio in on your sound card and record the out to the in. open clip view for the recording and look at the bottom of the screen to see that value in mS.

also rtfm 'track delay' to see how to send an audio recording out early so it plays in time. (if you have 50mS latency, set track delay to -50mS so that track plays out 50mS ahead of time to compensate.)

hope that's more of less accurate, getting later here. if it's accurate we should sticky this... what say?

Lo-Fi Massahkah · Post by **Lo-Fi Massahkah** » Sat Feb 23, 2008 7:16 am

That bucket analogy is the best I've ever heard. Good work, teacha'!

Tone Deft · Post by **Tone Deft** » Sat Feb 23, 2008 7:19 am

thanks! it's not stuff anyone would inherently know but it's time we got one definitive answer to refer n00bs to, if laid out right a good answer can save a lot of time and be easier to give if we can copy and paste. this is one of those standard questions I've answered dozens of time. no disrespect to the original poster, it's a good question.

gjm · Post by **gjm** » Sat Feb 23, 2008 7:58 am

Tone Deft wrote:

bigger buffer = more latency
bigger buffer = smoother audio
higher sample rate = more CPU load
higher sample rate = lower latency

What does bigger or higher mean in reference to the processes these numbers are describing? Is 256 higher or lower than 512? Kinda like 1 is lower than 10 but 10 is bigger than one, and 1 can be higher up the scale or chart than 10 and 10 can be lower than 1

Tone Deft · Post by **Tone Deft** » Sat Feb 23, 2008 8:08 am

good question.

smaller like 1 is smaller than 10.

the buckets (samples) are 16, 24 or 32 bits deep.

44.1kHz, 16 bits means that
- 44,100 times a second a sample is taken of the audio, like a snapshot
- each sample is a 16 bit number

a buffer size of 256 means 256 buckets are filled before being shuffled off to the Live interface. that interface is a 32 bit floating point 64 bit summing audio engine proprietary thingy out of Germany.

and higher sample rates and higher bit depths means more disk space will be used.

gjm · Post by **gjm** » Sat Feb 23, 2008 8:27 am

Tone Deft wrote:good question.

smaller like 1 is smaller than 10.

the buckets (samples) are 16, 24 or 32 bits deep.

44.1kHz, 16 bits means that
- 44,100 times a second a sample is taken of the audio, like a snapshot
- each sample is a 16 bit number

a buffer size of 256 means 256 buckets are filled before being shuffled off to the Live interface. that interface is a 32 bit floating point 64 bit summing audio engine proprietary thingy out of Germany.

and higher sample rates and higher bit depths means more disk space will be used.

So in keeping with the water theme
1. Each bucket can have a set volume ie.16,24,32
2. A certain amount of buckets ie. 256,512 are collected before the truck takes them to the water tank where they are dumped.
3. Then the truck comes back for more buckets.
So latency is the time taken to empty the buckets into the water tank and return for more water?
4. So lets say the truck that takes your water is your gear or sound card. Depending on what this is, a hummer or an Elcamino, you have to make provision for the vehicles ability to take the water to the tank. So sometimes you have to adjust the bucket size and or the amount which you take to the tank that best suits the vehicle taking the water.

Am I on the right track?

Tone Deft · Post by **Tone Deft** » Sat Feb 23, 2008 8:43 am

ohhh man, it's getting hourer here by the drunk... I should not be answering this shit.

gjm wrote:So in keeping with the water theme
1. Each bucket can have a set volume ie.16,24,32

google dynamic range. each sample can be a 16, 24 or a 32 bit number that's a measurement of the volume of the signal at that instant. (google sigma delta conversion for a real snore), more bits make for a wider dynamic range, basically it's finer detail in the audio. dynamic range is a dB measurement of the quietest the audio can get compared to the loudest. more bites=more dynamic range = more drive space used.

2. A certain amount of buckets ie. 256,512 are collected before the truck takes them to the water tank where they are dumped.

basically

3. Then the truck comes back for more buckets.
So latency is the time taken to empty the buckets into the water tank and return for more water?

nope, no return trip necessary. now you're being silly.

4. So lets say the truck that takes your water is your gear or sound card. Depending on what this is, a hummer or an Elcamino, you have to make provision for the vehicles ability to take the water to the tank. So sometimes you have to adjust the bucket size and or the amount which you take to the tank that best suits the vehicle taking the water.

at which point you put the bong down and
Take a little trip, take a little trip
Take a little trip and see
Take a little trip, take a little trip
Take a little trip with me
http://www.youtube.com/watch?v=Y6c3emqC6aw

gjm · Post by **gjm** » Sat Feb 23, 2008 8:52 am

Fuck. Back to the drawing board http://www.youtube.com/watch?v=pgX-hiQdfFw

Tone Deft · Post by **Tone Deft** » Sat Feb 23, 2008 8:56 am

gjm wrote:Fuck. Back to the drawing board http://www.youtube.com/watch?v=pgX-hiQdfFw

lmfao!!! wtf????

the horror... the horror...
http://www.youtube.com/watch?v=_5npYWfRlkw

gjm · Post by **gjm** » Sat Feb 23, 2008 9:03 am

no latency here http://www.youtube.com/watch?v=dfoqZBGXXAU

Tone Deft · Post by **Tone Deft** » Sat Feb 23, 2008 9:09 am

gjm wrote:no latency here http://www.youtube.com/watch?v=dfoqZBGXXAU

there's a few decades of latency in that performance.

better jesus song
http://www.youtube.com/watch?v=gC0GWKh26jU