Avid Pro Audio Community

Avid Pro Audio Community

How to Join & Post  •  Community Terms of Use  •  Help Us Help You

Knowledge Base Search  •  Community Search  •  Learn & Support


Avid Home Page

Go Back   Avid Pro Audio Community > Pro Tools Hardware > Eleven Rack

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 05-31-2011, 11:36 AM
derker derker is offline
Member
 
Join Date: Jan 2010
Posts: 622
Default 11r and latency revisited

So.... I'm convinced that lowering the latency of the sound could *really* improve the feel of our beloved 11r. I got a chance to A/B my 11r with my buddy's AxeFX (I know, I know...) the other day through a full PA with floor monitors, and the difference in feel due to latency was pretty significant. Tone completely aside, there was a perceivable latency when I plugged into my rig. I could stand farther away from the PA and still feel connected to the tone while playing through the Axe, my 11r felt 'far away' despite standing closer to the speakers.

The PA itself has no digital components, so it shouldn't be adding any latency, and both modelers were plugged in with the same signal path to eliminate variables; i.e. if there was any latency due to the PA, both modelers were equally subject to it.

Now, I'm often a high-gain player (even though I've made patches with all sorts of different tones) and this experience has let me to a possible theory as to why some high gain players have avoided or traded away their 11r...it's not the tone, it's the latency! Palm mutes and fast passages need to feel 'tight', and with the modeling's natural compression already squashing the transients, the additional (however minuscule amount of) latency is enough to affect the player's perception, altering the timing/feel/technique in attempts to compensate. This is less noticeable when timing is less important, such as home noodling where you're sitting right in front of your nearfields at ear level, playing without a backing track, using clean/lower gain tones that still have their transients intact, etc.

I plan on measuring the difference in latency between the two, next time I'm at my buddy's house. I'm sure the difference isn't any more than 2-3ms, which is equal to a few feet of additional distance from the speaker, but I'm sure there are other factors that affect the player psycho acoustically.

Anyone have any thoughts on the subject?
Reply With Quote
  #2  
Old 05-31-2011, 12:53 PM
Karl Houseknecht Karl Houseknecht is offline
Member
 
Join Date: Apr 2011
Location: Palmyra, VA
Posts: 51
Default Re: 11r and latency revisited

Put all this latency stuff in perspective:

Speed of sound in air at 78 degrees F: 1136.657 ft/s

Distance of guitar player from amp or sound source: 10 ft

Observable latency in ms (just due to air): ~8.8 ms

Adding another 2 or 3 ms in there one way or the other isn't really going to feel that significant. Moving around on stage is going to have more effect than optimizing the latency in the gear. If you move 5 feet one way or another, you shave off or add ~4ms.
Reply With Quote
  #3  
Old 05-31-2011, 01:08 PM
MyerzMedia MyerzMedia is offline
Member
 
Join Date: Mar 2011
Location: Dallas USA
Posts: 35
Default Re: 11r and latency revisited

But those are all constants.... which doesn't do much to explain the delta between the Axe-Fx and the 11R. Right?
Reply With Quote
  #4  
Old 05-31-2011, 01:17 PM
Karl Houseknecht Karl Houseknecht is offline
Member
 
Join Date: Apr 2011
Location: Palmyra, VA
Posts: 51
Default Re: 11r and latency revisited

Sure. But look at the magnitude of difference and how distance from the source affects the latency perceived by the user. And that's for a normal amp. You're not going to feel 2-3 additional ms of latency and translate it into "my palm mutes don't feel right" when compared to the natural latency deriving from the distance from your amplification source. If that really bothers you, stand a little closer to your amp or monitor. :)
Reply With Quote
  #5  
Old 05-31-2011, 01:47 PM
derker derker is offline
Member
 
Join Date: Jan 2010
Posts: 622
Default Re: 11r and latency revisited

Quote:
Originally Posted by Karl Houseknecht View Post
If that really bothers you, stand a little closer to your amp or monitor. :)
Sure, that works on paper (or in a forum) but it's a little tougher in a live situation, don't you think? Should I glue myself in front of my monitor at the cost of looking like a stiff? What about if I try to go in-ear to avoid any latency due to proximity, but the transmitter/receiver add their own?

My point is that a little bit of optimization may go a long way. If the difference between the two devices is perceivable to me then there must be something happening other than a few feet's distance worth of latency.

Of course my observations weren't measured and are subject to the fallibility of human perception, which I realize can easily be tainted. Tonight I'm gonna try and observe the difference in latency between the two devices by hooking them up to my buddy's 002 outputs, running a signal through them back into the 002's inputs, and measuring any difference between the two.
Reply With Quote
  #6  
Old 05-31-2011, 01:59 PM
Karl Houseknecht Karl Houseknecht is offline
Member
 
Join Date: Apr 2011
Location: Palmyra, VA
Posts: 51
Default Re: 11r and latency revisited

I was trying to be funny with the standing closer comment, hence the smiley.

My point here is that there are parts of your "signal chain" that add considerably more latency than any you could possibly squeeze out of the 11R through optimization, and that when compared to the total of what you experience, it's probably not worth going after.
Reply With Quote
  #7  
Old 05-31-2011, 02:12 PM
derker derker is offline
Member
 
Join Date: Jan 2010
Posts: 622
Default Re: 11r and latency revisited

I know, I apologize if it seems like I took it too seriously. It's definitely not like that.

I realize and accept that my ear is fallible, that's why I'm gonna do my little experiment tonight. I know that there are plenty of variables at work here that can affect my perception.

I'm also trying to figure out if loudness affects the perception of latency. We all know that the speed of sound is constant (neglecting temperature, humidity, etc), but do our ears perceive the speed to be constant at different amplitudes?
Reply With Quote
  #8  
Old 05-31-2011, 02:15 PM
Karl Houseknecht Karl Houseknecht is offline
Member
 
Join Date: Apr 2011
Location: Palmyra, VA
Posts: 51
Default Re: 11r and latency revisited

Quote:
Originally Posted by derker View Post
We all know that the speed of sound is constant (neglecting temperature
Temperature has the largest contribution to the speed in the conditions where you want to study it (due to air density):

http://www.sengpielaudio.com/calculator-speedsound.htm

Also, it's not dependent on amplitude.
Reply With Quote
  #9  
Old 05-31-2011, 02:33 PM
derker derker is offline
Member
 
Join Date: Jan 2010
Posts: 622
Default Re: 11r and latency revisited

Quote:
Originally Posted by Karl Houseknecht View Post
Temperature has the largest contribution to the speed in the conditions where you want to study it (due to air density):

http://www.sengpielaudio.com/calculator-speedsound.htm

Also, it's not dependent on amplitude.
Of course the speed of sound is not dependent on amplitude...but my question is- is human perception of the speed of sound affected by the loudness?
Reply With Quote
  #10  
Old 05-31-2011, 03:03 PM
Deny Deny is offline
Member
 
Join Date: Mar 2011
Location: São Paulo, Brazil
Posts: 169
Default Re: 11r and latency revisited

I did a few measurements myself a while ago and got 3.67ms at the amp output, configured to "rig out" (different configurations/measurement points yield different latency readings), although Chris has reassured me it's actually 3.2ms - I didn't redo my measurements because I honestly don't care since the difference is pretty negligible.

Now the POD HD500 according to my measurements has exactly 2ms of latency and the AxeFX has "around 1ms" according to Cliff and more like 1.6ms according to a user who actually took the time to measure it - I'm more inclined to believe the later.

I've put a suggestion on ideascale for a "low latency mode", in which certain features that are only useful for recording (like reamping) can be disabled in order to reduce latency, it has received only 22 votes so far:

http://protools.ideascale.com/a/dtd/...ode/31215-3779
__________________
Deny
My SoundClick Page
Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
PT8-HD Latency...Revisited Imagine Pro Tools TDM Systems (Mac) 9 05-29-2009 09:28 PM
HFS vs. HFS+ -- revisited ? jeremyroberts Pro Tools TDM Systems (Mac) 8 08-16-2001 10:09 AM
P4 for ya, revisited. bob_walker 003, Mbox 2, Digi 002, original Mbox, Digi 001 (Win) 1 04-28-2001 10:28 PM
Duplicate Revisited... trombino Pro Tools TDM Systems (Mac) 11 03-24-2000 12:51 PM
Latency Revisited CCash 003, Mbox 2, Digi 002, original Mbox, Digi 001 (Mac) 1 01-09-2000 06:48 PM


All times are GMT -7. The time now is 09:13 PM.


Powered by: vBulletin, Copyright ©2000 - 2008, Jelsoft Enterprises Limited. Forum Hosted By: URLJet.com