Latency

Help please.

I have Audacity installed on my desktop and on my laptop.
Prior to installing the new version a couple of weeks ago, I used to adjust the latency by opening the click track and then recording the click track. I could use the resulting recording to measure the line length using the feature at the bottom of the screen. After installing the new versions, my latency settings disappeared. S to be on the safe side I decided to use the click-track-recording technique to measure the amount of latency required. However, for some reason, the system will no longer record the click track. Not on my desktop (XP) nor on my lap (a newer operating system (7 I think). I used a microphone and an instrument to check the latency but it is not as accurate as the click track method. Any ideas what has gone wrong please?

Anton

Firstly, latency compensation is only important if you are making overdub recordings. Is that what you are doing?
Secondly, when making overdub recordings, the latency test should be performed using the recording input that you will be recording with. The latency for “What U Hear” or “Stereo Mix” may be different from the latency when recording with a microphone.

How are you doing that?

Thank you very much for your reply.
I use two inputs, via the Scarlett interface, to play mandolin, acoustic guitar, bass guitar and sing (sometimes with harmonies).

I plug my mandolin and bass into one put with a lead and record the acoustic guitar and my voice through the mic in the other input.

When I aligned two click tracks, everything worked really well but, as I say, since downloading the latest version of Audacity, I am unable to use the click track alignment technique

Why not? What’s the problem?
Does anything here help? http://manual.audacityteam.org/o/man/latency_test.html

The problem is Audacity will not record the click track anymore. I looked at the link you sent me and the reference to the click track is exactly what I do. The settings look the same to me so something have been reset in installing the new version of the program!

Anton

Is the click track playing through your headphones when you record? If it is, then just put the headphones over your microphone to record the click track.

Well, I am sorry to have wasted your time. I was listening to the click track through headphones but when recording the click track I took them off. In fact the click track wasn’t playing as Audacity was recording. I tried to record something else off the Internet. It recorded. So I looked at all the various settings and discovered the “overdub” facility was not turned on, so obviously it would not overdub (now I will have to try with my laptop, which is the one Ialways use for recording, as I have been able to overdub guitar, etc.).

I hope that works, if not I will use your tip. Thanks a lot for your help.

Anton

Recording the clicks through your headphones will probably give more accurate results than recording “sounds playing on your computer”. In some cases, recording “sounds playing on your computer” may have a different amount of latency to when you are recording a physical input (such as your plugged in mandolin or microphone).

(and yes, “overdub” needs to be enabled).

Thanks a lot for your help. I just tried my laptop and the overdub facility is on but it still will not record the click track, so I guest I will have to use the headphones. How much latency do you reckon is tolerable if I am doing so many overdubs, do you think?

Thanks for your time

Anton

The errors don’t add. If you use the same click track, drum or other rhythm reference for all the instruments, it doesn’t matter how many instruments you perform.

The truly obsessive will want to get the errors down to the single cycle, but I don’t know that kind of accuracy is required.

How many bands do you know where all the instruments start playing on the same cycle of waveform?

Koz

I understand. But I am bit obsessive. When I started using Audacity a year or so back I didn’t know anything about latency. I thought it was just like a tape recorder. So I couldn’t understand why I could play in time with myself. Then when my son also pointed out my being out of synch I started using the click track only to discover that I still couldn’t keep in time with myself. After some searching around on the Internet, I discovered I had to correct for latency. What a huge different it made. Hence my obsession.

Anton

The other problem with obsession is the settings might not stay there. You’re not recording on a Digital Audio Workstation. You’re recording on a PC designed for Skype and spreadsheets. Depending on about a hundred other conditions, the settings may not stay cycle-accurate.

Koz

Thanks, I will bear that in mind.

Anton

I don’t know if this will help anybody.
Fiddling around with Audacity on my laptop today, I went into Edit, preferences, devices and changed MME to WASAPI and then (for the “recording” box at the bottom) I changed Scarlett in (Scarlett is my interface appliance) to Scarlett out). I can now record my click track. But as you said, comparing the click track recording with a recording of an instrument against the click track there is quite a bit of difference with the latency.
Odd as well, because Audacity on my desktop computer is set to MME and Realtek Audio Input and it records the click track without any problem.

Anton

WASAPI “should” have lower latency than either MME or Direct Sound.

As I understand it, support for “recording what is playing on your computer” is gradually being phased out from MME. Whether it is available or not depends on the sound card drivers. “WASAPI loopback” should be available on all Windows computers from Vista onward and is not dependent on specific drivers (provided that the drivers work) as WASAPI loopback is provided by the operating system rather than by device specific drivers.

Well, the strange thing is, I can record sound from the click track or the Internet when WASAPI is enabled but I have to turn it back to MME to record myself and my instruments!

Self-recording the click track is never going to give accurate latency values. It will always be missing the delays in the headphone and microphone systems.

Then when you put human musical reaction in the mix, it’s going to get even worse.

Koz

“NME” is the name of a magazine.
“MME” is the name of Microsoft’s “Multimedia Extension”.

Most (all?) Windows systems from Vista onward support “WASAPI loopback”, which is specifically for recording what is playing through the sound card.
“Some” systems (depending on hardware and drivers) support “WASAPI” for recording and playback (not just "looping back the signal).

Sorry, you are right it is MME not New Musical Express.

I think my laptop has Vista but it still has MME and will not record me if I use (bear with me I might spell this wrong) WASAPI instead of MME

I am a translator, which is why I am seem to be on my computer all the time, by the way. I am not a computer freak.

I am not a computer freak.

You should be on your phone all day like normal people.
Koz