[RWP] Latency, is shorter always better?

Keith Hinton keithint1234 at gmail.com
Tue Jul 22 23:42:19 EDT 2014 

Things might suck, but with the wonderful laber of love that Jim still
does in the form of HotSpotClicker, he's made the world a brighter
place for those of us who want to create music, amongst other uses of
HSC. That's got to be a bright spot, in the darkness of suckyness. We
can't dwell too much on what sucks for us, but do what we can. We
won't ever have absolute perfection in this world, so forget a 100
percent accessible never broken buggy system; that won't happen,
unless Jesus himself makes it. Only the day of the Resurrection for
those of us who believe will be that day of perfection. For blindness
will be a thing of the past then. Never forget what scripture clearly
says either. That all things of this Earth are temporary.
What we can see will last only for a short time.
But what we cannot see, will last forever.
Think on that.
Blessings.

On 7/22/14, Jim Snowbarger <Snowman at snowmanradio.com> wrote:
> well said.
>
> ----- Original Message -----
> From: "Chris Belle" <cb1963 at sbcglobal.net>
> To: "Reapers Without Peepers" <rwp at reaaccess.com>
> Sent: Tuesday, July 22, 2014 9:02 PM
> Subject: Re: [RWP] Latency, is shorter always better?
>
>
>> Plus, there are very few coders left who know how to think in machine
>> language, they just glue modules together now.
>>
>> NO wonder everything sucks so bad.
>>
>>
>> On 7/22/2014 12:10 PM, Jim Snowbarger wrote:
>>> Would a 30 billion gigahertz processor talk fast?
>>> I think we have almost reached the physical limit on processor speed.  It
>>>
>>> has to do with the speed of light, and the distances of the connecting
>>> lines that connect up your various components, plus the inevitable
>>> capacitence that such lines represent, and how that interacts with
>>> frequency.   And yes, Keith is right, more power is required to drive
>>> such attempts.
>>> Basically, we're going to have to go lazar now in order to get any
>>> significant increase in speed.
>>> Either that, or stop writing such crappy, bloated software. Hmmm.
>>> Imagine that possibility.
>>> Nope, that won't happen.  Time to market would suffer, and we would all
>>> fall asleep from bordom.
>>> Can't have that!
>>>
>>>
>>> ----- Original Message ----- From: "Keith Hinton"
>>> <keithint1234 at gmail.com>
>>> To: "Reapers Without Peepers" <rwp at reaaccess.com>
>>> Sent: Tuesday, July 22, 2014 10:48 AM
>>> Subject: Re: [RWP] Latency, is shorter always better?
>>>
>>>
>>>> We expect a little baby toy  computer to become a huge, furry kitty
>>>> cat with paws waving around and a tail that swishes and a meow to
>>>> escape the voicebox of the CPU. LOL just kidding.
>>>> Couldn't resist.
>>>> Fun thread for sure, I'm liking reading all about this stuff.
>>>> I didn't know digital audio was so latency-crazy.
>>>> But apparently it is.
>>>> As for 30 Gigahurts?
>>>> Why not 1 billion gigahurt processors? LOL!
>>>> Could you imagine how high your electrical bill would be?
>>>> one billion gigahurts with a quadrillion cores.
>>>> Bet you couldn't even run something like that. LOL.
>>>> Not realistically.
>>>>
>>>>
>>>> On 7/22/14, Jim Snowbarger <Snowman at snowmanradio.com> wrote:
>>>>> Tape decks with a moveable playback head?  Very nice.  I didn't know
>>>>> about
>>>>> that.  But, that would have been great for adjusting the rate of
>>>>> regenerative feedback to match the tempo of a song.
>>>>> Another way to do that was to vary the speed, except that it had
>>>>> frequency
>>>>> response implications as well.
>>>>>
>>>>> An interesting experiment with DAWs, record a series of clicks into
>>>>> track 1.
>>>>>
>>>>> Arm track 2, and route the playback of track 1 into the input for track
>>>>>
>>>>> 2.
>>>>> Do it externally, rather than inside the computer, so you get the
>>>>> benefit of
>>>>>
>>>>> the entire chain of processing.
>>>>>
>>>>> Now, play tracks 1 and 2 back together.  Listen for the time delay
>>>>> between
>>>>> the clicks on the two tracks.  Ideally, they will be coincident.
>>>>> On reaper here, it isn't quite perfect, but it is pretty darned good.
>>>>> Last time I tried Audacity, they arrived in different time zones.
>>>>>
>>>>> ----- Original Message -----
>>>>> From: "Chris Belle" <cb1963 at sbcglobal.net>
>>>>> To: "Reapers Without Peepers" <rwp at reaaccess.com>
>>>>> Sent: Tuesday, July 22, 2014 12:46 AM
>>>>> Subject: Re: [RWP] Latency, is shorter always better?
>>>>>
>>>>>
>>>>>> One more thought  about this latency thing.
>>>>>>
>>>>>> And us old farts who used to play with tape decks will remember this.
>>>>>>
>>>>>> How about those 3 head decks where you could listen to play-back
>>>>>> while
>>>>>> recording?
>>>>>>
>>>>>> YOU could hear the input while it was going down, and listen to your
>>>>>> playback head, and some of those were moveable.
>>>>>>
>>>>>> So you could change the latency between when something got recorded
>>>>>> and
>>>>>> played back by moving the head closer or further away from the
>>>>>> recording
>>>>>> head.
>>>>>>
>>>>>> That was on the commercial machines.
>>>>>>
>>>>>> I never had one of those, but i did have a very nice 3 head cassette
>>>>>> deck.
>>>>>>
>>>>>> This is, in fact, somewhat similar to what hapens in your daw,
>>>>>> even if your not recording but just listening to the signal comming
>>>>>> back
>>>>>> from your daw once it goes through the internal processing, and any
>>>>>> plug-ins you might have,
>>>>>> and they add their own latency you can bet, and most modern daws
>>>>>> compensate for that under the hood.
>>>>>>
>>>>>> Sonar had automatic plug in delay compensation
>>>>>> way before many daws, including protools ever had it.
>>>>>>
>>>>>> Yes, you go back and listen to first episodes of the home recording
>>>>>> show
>>>>>> on protools 9 and 10,
>>>>>> and you can hear them talking about lining up tracks manually after
>>>>>> the
>>>>>> fact, to make the audio come out right, after going through all the
>>>>>> processing plugs.
>>>>>>
>>>>>> Boy howdy, now, isn't that a real pain in the posterior?
>>>>>>
>>>>>> INteligently keeping up with when in the time line a recording starts,
>>>>>>
>>>>>> and
>>>>>>
>>>>>> how to play it precisely in the right way to account for plug-ins
>>>>>> latencies, and then play it properly again when you take plugs of is
>>>>>> not
>>>>>> an easy task, but your daw does that all for you under the hood, if
>>>>>> it's
>>>>>> worth a squat.
>>>>>>
>>>>>> People sometimes get in real trouble even with this automatic
>>>>>> stuff going on by not routing their monitoring right,
>>>>>> because there are certain ways of routing and recording which makes
>>>>>> it
>>>>>> impossible for your daw to implement delay compensation properly.
>>>>>>
>>>>>> So this is why I tend to like to not do plugs until after I've laid
>>>>>> my
>>>>>> audio.
>>>>>>
>>>>>> Not always possible, you can't lay that heavy rock guitar track
>>>>>> easily
>>>>>> only hearing plink, plunk, twang,
>>>>>> but you can believe your daw is doing the latency shuffle dance when
>>>>>> you
>>>>>> have many tracks playing and you are laying guitar amp simms which
>>>>>> has
>>>>>> latency going both ways, because remember, you are going audio in,
>>>>>> and
>>>>>> audio back out,
>>>>>> and this is why with mastering plugs which cause a lot of latency,
>>>>>> especially multi-band compressors with look ahead and back in my
>>>>>> early
>>>>>> early days of learning this stuff it used to drive me nuts, why are
>>>>>> my
>>>>>> midi tracks being delayed so much when I press a note but they play
>>>>>> just
>>>>>> fine on playback?
>>>>>>
>>>>>> Well, it's that delay compensation working for you.
>>>>>>
>>>>>> Imagine having to figure out how much delay you had and fixing all
>>>>>> that
>>>>>> manually?
>>>>>>
>>>>>> You can get interesting things happening when using reverb in projects
>>>>>>
>>>>>> by
>>>>>>
>>>>>> turning off delay compensation,
>>>>>> you get a built in pre-delay, which is a setting on high quality
>>>>>> reverb
>>>>>> units, the reverb doesn't start right away, and
>>>>>> this helps make room in the mix when you don't wan the verb in the
>>>>>> way,
>>>>>> and it kicks in after the initial atack of your audio.
>>>>>>
>>>>>> Or do we remember real world latency,
>>>>>> and the days when distructive editing was the only kind you did, if
>>>>>> you
>>>>>> wanted to process an equalizer, or chorus fx, you hit the button, and
>>>>>>
>>>>>> then
>>>>>>
>>>>>> go have a sandwich and waited for your 486 to process that track, and
>>>>>> you'd come back 10 minutes later and maybe have a wet and dry track.
>>>>>> and you could do interesting things with that by time delaying the
>>>>>> wet
>>>>>> track 'grin'.
>>>>>>
>>>>>> When I do drum replacement by generating midi tracks from transient
>>>>>> points
>>>>>>
>>>>>> of an audio drum track and then feeding it to a audio bus with
>>>>>> samples, I
>>>>>>
>>>>>> have to time align the new track to match the old one,
>>>>>> at least in the old days we had to do more of that before delay
>>>>>> compensation was automatic.
>>>>>> in most daws.
>>>>>>
>>>>>> Still, most daws will only do this in a certain range, see above,
>>>>>> where I
>>>>>>
>>>>>> mention mastering plugs,
>>>>>> linear phase equalizers are also notorious for introducing way too
>>>>>> much
>>>>>> delay to use them in real time.
>>>>>>
>>>>>> So are transient  processors, shapers.
>>>>>>
>>>>>> Maybe when we get processors running at 30 gigahertz
>>>>>> we'll be able to do that stuff in real time, and did I hear silly
>>>>>> people
>>>>>> want to make a daw out of an ipad?
>>>>>>
>>>>>> Right now in 2014, an ipad will just barely run a guitar simm with
>>>>>> low
>>>>>> enough latency
>>>>>> \to be playable.
>>>>>>
>>>>>> Well, what do you expect from a little baby toy computer?
>>>>>>
>>>>>>
>>>>>> On 7/21/2014 9:33 PM, Jim Snowbarger wrote:
>>>>>>> Now and then, I feel like a slight departure from topic..  And, this
>>>>>>>
>>>>>>> is
>>>>>>> one of them.  So, stand bye with your delete key ready as I carry
>>>>>>> on.
>>>>>>>
>>>>>>> This probably belongs over on MidiMag.  But, I don't feel like
>>>>>>> joining
>>>>>>> just so I can post this once in a blue mooner.
>>>>>>>
>>>>>>> One of the great things that digital audio processing has brought to
>>>>>>>
>>>>>>> us
>>>>>>> is so-called latency.  You might just call it delay.  but, in the
>>>>>>> 21st
>>>>>>> century, we like to use clever names.  It makes us feel smarter.
>>>>>>> So,
>>>>>>> let's co-opt the term latency, which had a totally different meaning
>>>>>>> before the techno-gods got hold of it. And, let's now define latency
>>>>>>>
>>>>>>> as
>>>>>>> the act of being late.  But, however you slice it, it comes down to
>>>>>>> delay.
>>>>>>>
>>>>>>> Digital devices impose delay mostly because data consumers, like
>>>>>>> sound
>>>>>>> cards, or recording devices, have learned to be defensive, knowing
>>>>>>> full
>>>>>>> good and well that data providers, such as input sound cards, or
>>>>>>> other
>>>>>>> streaming devices, can not be counted on to keep up a steady stream
>>>>>>> of
>>>>>>> data.  Internet congestion, or scheduling congestion inside your own
>>>>>>> machine, can temporarily block the normal flow of things. Sound
>>>>>>> playback
>>>>>>>
>>>>>>> requires a rock-solid comsumption rate of the data. The sampels need
>>>>>>>
>>>>>>> to
>>>>>>> keep flowing. You might not get that next buffer load of data in
>>>>>>> time.
>>>>>>> so, it pays to keep a backlog.  The more backlog, the safer you are.
>>>>>>> But, if the backlog is too great, you get, latency, that annoying
>>>>>>> delay.
>>>>>>>
>>>>>>> I recently picked up one of those fine Computers Chris is always
>>>>>>> talking
>>>>>>>
>>>>>>> about from StudioCat.com.  That is one very fine box. And, now that
>>>>>>> I
>>>>>>> also own Chris's Delta 1010, I was enjoying fine-tuning my latency
>>>>>>> down
>>>>>>> to acceptable levels,  not carefully measured, but clearly less than
>>>>>>>
>>>>>>> 10
>>>>>>> milliseconds.
>>>>>>>
>>>>>>> Most of the recording work I do involves a microphone and headphones.
>>>>>>>
>>>>>>> I
>>>>>>>
>>>>>>> am quite typically listening to my own voice as I speak. If you have
>>>>>>> listened to the Snowman Radio Broadcasts, you know the kind of
>>>>>>> multi-track microphone work I'm guilty of.
>>>>>>> When living on machines where such short delays were not possible,
>>>>>>> my
>>>>>>> habit was to listen to my own foice direct out of the mixer, and not
>>>>>>> going through Reaper.  So, I kept the reaper monitor off. What was
>>>>>>> annoying about that is that, if I panned my various character voices
>>>>>>>
>>>>>>> in
>>>>>>> the stereo  mix, then, my direct microphone sound would not be panned
>>>>>>>
>>>>>>> the
>>>>>>>
>>>>>>> same as the character voice track I was recording into. So, when it
>>>>>>> played back, it came from elsewhere, and was more than a little bit
>>>>>>> confusing.
>>>>>>>
>>>>>>> But, with delay this short, I find that I switch off the direct
>>>>>>> sound,
>>>>>>> and now can monitor the signal coming back from reaper with the
>>>>>>> monitor
>>>>>>> turned on.  So, I'm now listening to a delayed version of my voice,
>>>>>>> and
>>>>>>> it is panned to the same place where that character voice sits,
>>>>>>> which
>>>>>>> helps me keep track of who I am supposed to be right now. And, I can
>>>>>>> more easily tell now whetehr a track is armed, and even if one is
>>>>>>> armed
>>>>>>> that should not be. It's nice to be able to work like that, just
>>>>>>> listening to reaper's output.
>>>>>>>
>>>>>>> But, here is the cool thing.  The exact amount of latency you
>>>>>>> provide
>>>>>>> affects the quality of what you hear in your headphones.
>>>>>>>
>>>>>>> No matter how good your phones, the sound that you hear when you are
>>>>>>> listening to yourself speaking live into a microphone, is actually
>>>>>>> the
>>>>>>> composite of at least two signal paths, and maybe more. Yes, there
>>>>>>> is
>>>>>>> the direct signal coming through Reaper. Then, there is bone
>>>>>>> conductivity, the sound of your own voice coming through the
>>>>>>> structure of
>>>>>>>
>>>>>>> your head, which will very somewhat with density.  If you don't get
>>>>>>> any
>>>>>>> of that, you might wonder about that density stuff.
>>>>>>> And maybe even, there is leakage around the ear muffs.  In all, it is
>>>>>>>
>>>>>>> a
>>>>>>> complex sond that actually reaches your ears.  And, the phase
>>>>>>> relationship between all of the various contributors will affect the
>>>>>>> frequency response of the final signal that you hear.
>>>>>>>
>>>>>>> In the old days, we knew about the affect that phase would have on
>>>>>>> such
>>>>>>> things.  Having your head phones out of phase with your microphone
>>>>>>> left
>>>>>>> you feeling empty headed, due to the phase cancellation that took
>>>>>>> place.
>>>>>>> But, since delay was in the nanoseconds, we didn't get to know so
>>>>>>> much
>>>>>>> about the effect that delay would have, despite our compulsive
>>>>>>> preoccupation with tape delay.
>>>>>>>
>>>>>>> Phase is mostly a frequency independent phenomenon.  Yes, we know
>>>>>>> that
>>>>>>> some systems, especially mechanical transducers, or even cheap
>>>>>>> equalizers, which will have a reactive component to their impedance,
>>>>>>> introduce a variable amound of phase shift, depending on frequency.
>>>>>>> But,
>>>>>>>
>>>>>>> usually those effects are at the far ends of their usable range.
>>>>>>> In general, especially in mixer land, where things are nice and
>>>>>>> linear,
>>>>>>> and where impedances are strictly non-reactive, if you put something
>>>>>>>
>>>>>>> 180
>>>>>>>
>>>>>>> degrees out of phase, you will get perfect cancellation, all across
>>>>>>> the
>>>>>>> frequency band.
>>>>>>>
>>>>>>> Enter the digital age, and the new innovation, latency.
>>>>>>> The relationship between signal phase, and a delay is frequency. For
>>>>>>> example, a delay of 4 milliseconds is one full cycle of a 250 Hertz
>>>>>>> tone.
>>>>>>>
>>>>>>> But, it is only half a cycle of a 125 hertz tone.   It is all still a
>>>>>>>
>>>>>>> 4
>>>>>>> millisecond delay.  But, the phase impact depends on the frequency.
>>>>>>> Combining the pre and post delays of these two tones with that 4ms
>>>>>>> delay
>>>>>>>
>>>>>>> will have completely different effects. The 125 hertz tone would be
>>>>>>> nulled out.  The 250 hertz tone would actually see a 6 db increase.
>>>>>>>
>>>>>>>
>>>>>>> The result is that, if you put a delay in front of your headphone
>>>>>>> mix,
>>>>>>> you will cause what is referred to as a comb filter effect on the
>>>>>>> perceived headphone signal.  It is a filter that has a frequency
>>>>>>> response
>>>>>>>
>>>>>>> curve that looks like a rola coaster, with hills and valleys.  If
>>>>>>> you
>>>>>>> were listening to an audio tone sweep, one that you would actually
>>>>>>> need
>>>>>>> to sing, in this case, in order to get that bone conductivity thing
>>>>>>> happening as well, As you move steadily up in frequency, the sound
>>>>>>> would
>>>>>>>
>>>>>>> be much stronger at some frequencies, and much weaker at others.  As
>>>>>>>
>>>>>>> the
>>>>>>>
>>>>>>> tone rises, you would hear rising and falling of the net response.
>>>>>>> And,
>>>>>>>
>>>>>>> changing the amounbt of delay slides that comb up and down the audio
>>>>>>> spectrum.
>>>>>>> Depending on several things, the frequency range of your voice,
>>>>>>> response
>>>>>>>
>>>>>>> of your headphones, your ears, the density of your grey matter, your
>>>>>>> preferences, and on and on, you might have preferences about the
>>>>>>> optimal
>>>>>>>
>>>>>>> position of that comb.  What frequencies do you like to accentuate?
>>>>>>> And,
>>>>>>>
>>>>>>> which to attenuate.
>>>>>>>
>>>>>>> The cool thing is that, by fine-tuning your headphone latency, you
>>>>>>> can
>>>>>>> position that comb how you like, and can optimize your headphone
>>>>>>> experience. The latency needs to be short enough to not give you a
>>>>>>> delay
>>>>>>>
>>>>>>> echo effect. But, beyond that, the shortest possible latency may not
>>>>>>>
>>>>>>> give
>>>>>>>
>>>>>>> you the headphone experience you like.  Instead, relax it a little,
>>>>>>> and
>>>>>>> see what enriching tones come your way.
>>>>>>> Silly you.  And you always thought shorter was better. And now you
>>>>>>> know.
>>>>>>> TROTS.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> RWP mailing list
>>>>>>> RWP at reaaccess.com
>>>>>>> http://reaaccess.com/mailman/listinfo/rwp_reaaccess.com
>>>>>>>
>>>>>>
>>>>>>
>>>>>> _______________________________________________
>>>>>> RWP mailing list
>>>>>> RWP at reaaccess.com
>>>>>> http://reaaccess.com/mailman/listinfo/rwp_reaaccess.com
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> RWP mailing list
>>>>> RWP at reaaccess.com
>>>>> http://reaaccess.com/mailman/listinfo/rwp_reaaccess.com
>>>>>
>>>>
>>>>
>>>> --
>>>> Sincerely,
>>>>
>>>> Keith
>>>>
>>>> Home Phone:
>>>> 928-554-3936
>>>> Mobile Phone:
>>>> 928-713-6370
>>>> Primary email:
>>>> keithint1234 at gmail.com
>>>> Twitter:
>>>> @keithint1234
>>>> Facebook:
>>>> http://facebook.com/keith.hinton1
>>>> Skype:
>>>> skypedude1234
>>>>
>>>> _______________________________________________
>>>> RWP mailing list
>>>> RWP at reaaccess.com
>>>> http://reaaccess.com/mailman/listinfo/rwp_reaaccess.com
>>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> RWP mailing list
>>> RWP at reaaccess.com
>>> http://reaaccess.com/mailman/listinfo/rwp_reaaccess.com
>>>
>>
>>
>> _______________________________________________
>> RWP mailing list
>> RWP at reaaccess.com
>> http://reaaccess.com/mailman/listinfo/rwp_reaaccess.com
>>
>
>
>
> _______________________________________________
> RWP mailing list
> RWP at reaaccess.com
> http://reaaccess.com/mailman/listinfo/rwp_reaaccess.com
>


-- 
Sincerely,

Keith

Home Phone:
928-554-3936
Mobile Phone:
928-713-6370
Primary email:
keithint1234 at gmail.com
Twitter:
@keithint1234
Facebook:
http://facebook.com/keith.hinton1
Skype:
skypedude1234

More information about the Rwp mailing list