User selectable buffer size, with latency compensation

[Trout]

I am a studio musician in Nashville . I purchased the multitrack along with a blue mikey for recording DUMMY song ideas on the go with my iphone 3gs. I record songs for a living and I OWN and have a lot of experience with almost all major Daws so I am a veteran at playing and recording. I am putting this out there because I don't want you to think the timing issues I am having is do to lack of experience and/or my playing ability.
The Harmonicdog website states {User selectable buffer size, with latency compensation} but I cant find away to adjust it even after checking the forums for a answer. When I record with the metronome sixteenth notes or even a fast drum beat track when it plays back it is just slightly out of time with the metronome.,when i record the other tracks they are slightly out of time with the first track and even more out of time with the metronome. the best solution I found was to record the tracks only to the metronome without listening to the others for reference and the timing comes out better. This issue drives a musician nuts, and I do not have these timing issues on the daws i work on. I was wondering how can I tweak to get rid of the latency issue, because right now it is not ideal for multitracking. I love this app and the idea of tracking ideas were ever I am inspired and I will purchase the extra 16 tracks as soon as I can find out if this is fixable. Thanks for reading

[kyanit]

You will find them in your iPhone settings. Chose "Settings", scroll down and you will find additional settings for MultiTrack. There is a submenu for Buffer Length with three predefined values for different devices. They don't seem to be adjustable, just a choice between three buffersizes. I use MultiTrack on a 3GS and the installation had defaulted the buffersize to a 3G device which is twice the buffer compared to 3GS. Happy recording, and please report back if changing the buffers makes any difference.

[Trout]

Thank you It worked ,that was the fix I was looking for.I I was going crazy at first thinking my timing was slipping a little, I even set up a test on my daw with the same timing and click track just to make sure it was not me. Its amazing what a few milliseconds can do to ones timing. THIS APP IS GREAT it blows the others like it away. Thanks for the info because I would not have found it in the settings without you

[kyanit]

[Trout]

The only thing that is still a issue is that when I delete a tracks audio sometimes it still plays in the background when recording a new take unless I completely delete the track. Other than that issue, it works great now. Any ideas?

[kyanit]

Referring to problems with "undo" in another post, it's a known bug that has been fixed in a release that has been submitted to Appstore so it should be available any day now. All according to pwnified.

[Trout]

Cant wait.,thanks for the info you have been a big help

[jackmac71]

Whenever you were able to adjust the buffer did that take all of the delay that you hear back threw the system out, I'm new to recording with computers the only thing I've ever really used is a Boss br8 and it is starting to give problems once again with that lousy ZIP drive setup, have tried a couple programs with my computer and that's how I learned about the whole buffering and latency thing, that delay coming back through the system and trying to play with it really throws you off I guess what I'm asking is, could this be a replacement for the br8 there is only two of us that jam together I play guitar, bass, and a Roland gr30 guitar synthesizer and my friend plays a set of Roland electric v-drums, I would like to make sure that we both could get a good sound out of this, thinking about using the BR8 just for inputs for the instruments then run that into the iPhone and then out to the stereo thanks for the help in advance

[pwnified]

Referring to problems with "undo" in another post, it's a known bug that has been fixed in a release that has been submitted to Appstore so it should be available any day now. All according to pwnified.

This has been fixed in the 2.0.2 update

Whenever you were able to adjust the buffer did that take all of the delay that you hear back threw the system out,

Well, the latency can be adjusted from 512 to 256 and even 128 if the hardware can keep up (iphone 4 and ipad have no problem with 128 sized buffer). The latency calculation is the buffer size times 2 plus another constant (a larger constant for USB audio on the ipad). But if you try to set a buffer size too small for a devices cpu speed, you'll get dropouts and stuttering. I've found 3G devices can't really lower the buffer to less than 512 and the 3G in general is starting to act pretty bad with the new iOS4.

Round trip latency for iPhones and iPods:
512 * 2 + (215) / 44100 = 0.028 (28 milliseconds)
256 * 2 + (215) / 44100 = 0.016 (16 milliseconds)
128 * 2 + (215) / 44100 = 0.011 (11 milliseconds)

11 milliseconds is very low, you can feel it a tiny bit, but I don't really complain much about it (to put this in perspective, sound travels at about 1 foot per millisecond, so 10 milliseconds is like moving 10 feet away from the monitors). Usually we wear headphones during the overdubbing process anyway, so any extra feet from the speaker to the ear is removed from the equation. If you usually play a guitar through an amp at 10 feet away, it will be identical latency.

BTW the buffer size in MultiTrack is defaulted to 512 for all devices, so you'll have to go into the settings if you own a faster device and want a lower latency.

[alphadingo]

any chance of getting that down to 64?