Orren Merton wrote : > Latency ..... > 1) Rec-Enable a stereo track > 2) Plug guitar into one of the stereo inputs (in my case, right) > 3) Route output (in my case, right) into the other input (in my case, left) > 4) Record transients (hitting pickup with piece of metal) > 5) Open region in SE and count the sample distance between the right > and left transients. > > This gives a pretty accurate reading of round trip latency.  I am > recording 24-bit, 44.1k files. > I don't think this is a useful number. You are measuring "roundtrip" latency, but if you are actually recording guitar you can monitor your guitar off the source. If you were playing to a drum loop, then the latency of that playback is only the time that it takes for D-A conversion. On the other hand, if you were playing a midi keyboard to play a softsynth, you would have the midi time, but not A-D conversion.

--- In logic-users@yahoogroups.com, GAmoore@a... wrote: > > Orren Merton wrote : > > > Latency ..... > > 1) Rec-Enable a stereo track > > 2) Plug guitar into one of the stereo inputs (in my case, right) > > 3) Route output (in my case, right) into the other input (in my case, left) > > 4) Record transients (hitting pickup with piece of metal) > > 5) Open region in SE and count the sample distance between the right > > and left transients. > > > > This gives a pretty accurate reading of round trip latency.  I am > > recording 24-bit, 44.1k files. > > > > I don't think this is a useful number. You are measuring "roundtrip" latency, > but if you are actually recording guitar you can monitor your guitar off the > source. Right. Did it occur to you that I was using Guitar Amp Pro on the track? Read down to where it says "CPU usage of 1 rec-enabled track w/guitar amp pro." In this case, you MUST monitor software, because your source IS the sound coming from software. Moreover, many professional engineers always monitor the actual round trip signal, because it's the only way to be 100% sure of what the actual sound being recorded is (its very possible to monitor your source and have it sound great, then play back your recorded signal and realize that it has crackles and pops). They're going to monitor from the source no matter what, because in the professional setting, you can't guess what your DAW is recording, you have to KNOW. If you don't need to know the software monitoring round trip figure, just ignore the test. But this is something lots of guitarists exploring using software amp simulations and professional recordists take VERY seriously, and one of themain things that Pro Tools TDM has over any native system that can't be beat--the ability to monitor the recorded signal at negligable latency (around 250 samples, less than 2ms). Low latency round trip monitoring is one of those core features that seperates the "men from the boys" in audio software, and clearly one area in which Logic is doing very well. Orren