Is there any way to reduce audio latency?

logictree

MY Chain:
Apogee Jam->iPad 4th Gen->Audiobus->Jamup Pro->Multitrack DAW

I experienced significant latency.
Jamup and Multitrack DAW both have tolerable latency without Audiobus. So I think the latency came from Audiobus.
Is there any way to reduce latency?

sonosaurus

This is something that will likely affect a lot of people who want the lowest possible monitoring latency with JamUp effects. With JamUp in the filter slot (the only one possible right now) Audiobus does add buffering latency which cannot be avoided.

I have a suggestion to the JamUp developers that they should allow JamUp to be in the Input slot as well, and to handle monitoring post-fx themselves (sending directly to coreaudio output) and of course notifying audiobus of that fact so it doesn't attempt to double monitor it. This way you can still record your JamUp playing via audiobus but the live monitoring latency is the lowest it can possibly be. This helps a large number of people who are using JamUp with real instruments via hardware inputs.

It is also possible that when using Audiobus, JamUp's buffersize is forced to be higher than it would be if running standalone, so that could also be contributing.

Ryan

I don't know.. I have iPad 3rd gen and a iPhone 4s and I can play JamUp with MT DAW with no noticeable latency on both.. Doesn't seem right that an iPad 4 can't handle it. You sure you didn't mean iPod 4 @logictree ? You have other apps running in the background?

logictree

Ryan, it is not typo. Latest iPad, connecting Apogee Jam with an 30pin-lighting-adapter. So it is very frustrating. And no, no other apps in background.
Maybe it was little exaggerated when I said "significant latency", cause I was very frustrated yesterday. But it is definitely NOTICEABLE. What audio interface are you using?

Thanks, sonosaurus. So it seems like there is nothing I can do but wait.

Ryan

@logictree Sorry about questioning if you had made a typo or not.. Just seemed so weird. I just own iRig.. Yes i am aware it's not good but it's the only thing available where i live without ordering away. Anyhow.. I can't notice any latency at all with just JamUp and MT daw, when I start to add other stuff then things start going whacky... Maybe it's an issue with how the pin connection audio is being handled as opposed to the microphone input? Obviously @Sonosaurus knows a lot more about this then I do. Just surprised me that you were having problems with such a limited set-up and felt like I should chime in ;-) I hope you figure this out soon. Maybe when/if Ampkit supports Audiobus you'll have better luck with that.

yowza

I confirm this as well. I am using the Apogee Jam and noticed a bit of latency when plugging my guitar into Jam and using Jamup Pro in the effects slot in Audiobus.

I suspect sonosaurus is correct, if there is a buffer in Audiobus in that middle slot it could be causing this latency (it's noticeable but I can probably work around it) .
I would like Jamup in the first AB slot anyway so that I can add other effects after Jamup and if it would allow monitoring after the first slot and eliminate the latency that would be great!!

Have the Jamup folks been told of this, are they lurking here? I can enter a request on their support page.

jonmoore

From what I understand, Audiobus runs internally at a fixed latency of 256 samples. On anything other than an iPad 4 (I'll discuss this further in a bit), 256 samples is a good compromise between audio latency and CPU hit.

However when running guitar sim plugins on a desktop system many guitar players are unhappy with anything higher than 128 samples (on a high end Mac/PC with a good quality soundcard this will add up to a combined input & output latency of around 10ms) and many insist on 64 samples or even lower. The reality even on a powerful desktop system is that you'll need to compromise between your tracking latency set-up (live input of stuff like guitars) and your playback latency set-up (multi-track mixes with associated effects etc).

The Auria IOS app is only able to achieve the things it does because it has an internal playback buffer setting of 4096 samples (which is massive by modern day standards but was commonly used when desktop DAW's first hit the market). However when tracking, it allows the user to set buffer size according to their devices capabilities (default setting of 256 but as low as 128). This is one of the reasons that an Audiobus compatible version of Auria has yet to hit the app store.

Audiobus has to service the needs of many different usage scenarios/hardware capabilities and to keep the system as simple to use as possible the Audiobus developers decided on a fixed latency of 256 samples. IMHO this fixed latency decision causes more problems than it solves and the compromise hurts different Audiobus user groups for different reasons - those users looking for live tracking solutions find the latency too high and those users looking to play back/sequence multiple virtual instruments find the latency to be too low.

To complicate things even further each app in the Audiobus chain may add it's own latency beyond that of Audiobus's default 256 samples. This is solved on desktop DAW's through the use of PDC (plugin delay compensation). I know that Auria has PDC built in so you can make use of the various plugins that are are available as IAP's but I haven't seen any kind of delay compensation discussed with regard to Audiobus (that's not to say it doesn't exist, but seeing as it isn't documented I can't discuss it here).

It's very early days for Audiobus, and I'm sure a sure product spec will develop over time as Seb & Michael learn more about their customers needs (both developers and end users). For the moment I'm happy that a solution such as Audiobus even exists!

jm

http://soundcloud.com/leftside-wobble

Lasse

iPad 3, Jam Up Pro, Alesis iOdock, Fender Bassman Ten. I hear a little latency as playing live.