jammr Forum

So I just received my recordings from today's jam session where eb_liveDrums and friends unleashed the tightest jazz-funk quartet I've yet heard on Jammr.

I pull up my fader and wow, am I ever out in timing… I'm no click master like eb, but something was wrong there.

Thank god my percussion was super low!

So I'm direct monitoring off my Soundcraft USB mixer: I have channel 11/12 as the return from my computer, streaming everything from the room back in on 11/12 on the mixer; this is routed to the Master Mix, which I'm monitoring via cans on the Soundcraft's headphone out. I have “hear my playback” disabled in the Jammr settings.

Anything I send to the room is via channels 9/10, where I'm using the Group Outs to physically loop back out and back in again (my USB can't “tap” off of the Group Outs unfortunately, so I have to do it manually).

All good, so I thought, but I just compared my recording (in Reaper, where I selected the Master Mix as the source) where I sound exactly as a played, pretty bang on, not perfect obviously, but totally normal…

.. compared to emailed .ogg file I got of everyone where I'm totally out.

There is no echo here: that's solved by using the Group Out routing method, but I'm wondering if that ~5ms is throwing off the intervals, so it's trimming off my audio stream and slowly getting worse over time.

Is this because I can't use my zero latency monitoring in the analog mixer, I have to monitor what's returned from the room, myself included? I can't imagine that 5ms would be enough to throw it off that much.

Or is it because I came in late, despite being in time, so it truncated the end of my interval? Like does it have a volume threshold before I starts recording the interval “loop”?

Listen to the attached mp3; I'm playing shaker on the beat for a 4 bar chunk here. The first part is fine; pretty much spot on: this is me recording what I heard, coming from the master mix on my mixer.

The last part is what the room heard and something is odd because my “interval” only comes in on the 3rd bar and is totally out.

Attachments:
Good-then-bad-shaker.mp3 (1.1 MB)

Ok so found another nugget of wisdom from Stefan and Jammr only sends your interval, start to finish, and then again when the next interval comes around.

So why is that my shaker, which is playing quarter notes right on top of the room’s quarter notes, not in time? There is no “interval” here to get wrong, like chords.

Make sure you have unchecked the “hear my playback” checkbox. If you’re on windows then try selecting a different driver, I believe the WDM kernel one or whatever is in the windows thread. If you have a mac, use that instead. I had to get jammr working on a windows machine for a presentation and it was a nightmare, I had forgotten how terrible windows is with audio interfaces.

I monitor my drums through my mixer, no latency. I have an aux send from my mixer to my audio interface input, just my drums sending to the session. The output of my audio interface (the jammr session and metronome) returns to my mixer on its own channels, so I have separate volume controls for what I hear and they dont affect the levels I send to jammr.

I think you’re confused on the interval. If you mimic my setup above then you should be in sync.

The recordings may not be reliable, they’re stitching the audio together as it is played from all streams, not as you heard it when you played it. A better test is to grab two computers and put them in a session, but again, if you mimic my setup you should be in sync. Next time we are both online I’d be happy to grab a room and we can try it together.

Edited eb_liveDrums (April 20, 2020 06:06:30)

eb_liveDrums
Make sure you have unchecked the “hear my playback” checkbox.

Yeah, I do.

eb_liveDrums
If you’re on windows then try selecting a different driver, I believe the WDM kernel one or whatever is in the windows thread. If you have a mac, use that instead. I had to get jammr working on a windows machine for a presentation and it was a nightmare, I had forgotten how terrible windows is with audio interfaces.

I think I changed the driver to WASAPI from WDM-KS, which I had previously been using successfully for days, because the WDM-KS drivers just stopped working: open/closed a bunch of times, couldn't hear the room's metronome, so flipped to WASAPI to try/join a new room and then people started piling in and jamming, so forgot and left it like that.

eb_liveDrums
I monitor my drums through my mixer, no latency. I have an aux send from my mixer to my audio interface input, just my drums sending to the session. The output of my audio interface (the jammr session and metronome) returns to my mixer on its own channels, so I have separate volume controls for what I hear and they dont affect the levels I send to jammr.

Ok, so that's essentially what I'm doing, so no issues direct monitoring then, which I didn't think would cause any issues if the “hear my playback” is disabled.

eb_liveDrums
I think you’re confused on the interval.

I could be, but I think that staying with the intervals when you're playing interval-based music is important for chord changes, not so much for quarter note patterns like a woodblock or a cowbell played on top of the click; it shouldn't matter where it was stitched or not: if I'm in time, it should come back into the room on time. But could be that driver change.

Here is what Stefan says about it in a sticky post:
https://forum.jammr.net/post/3612/

jammr takes a different approach: it is an interval-based jamming system. The latency problem is solved because you hear what others played last interval and they hear what you played last interval. This means everyone hears a different time-shifted version of the jam - but everyone can play live even though it's not real-time.

The interval is the number of beats that jammr for transferring audio before it is played back. Usually the interval is at least 16 beats long and this comes to 8 seconds of audio when playing at a tempo of 120 beats per minute. This makes jammr immune to internet lag because 8 seconds is plenty of time to transfer data over the internet. However, now you are hearing what others played 8 seconds ago instead of what they are playing right now.

So that to me sounds like it has to work off of the room's interval, so it knows where to buffer to, before transmitting:

eb_liveDrums
If you mimic my setup above then you should be in sync.The recordings may not be reliable, they’re stitching the audio together as it is played from all streams, not as you heard it when you played it.

I think the multitrack recordings I received were fine actually. They all lined up perfectly when compared with my own recording of the time frame; it was only mine that was messed up, but I'm going to try my Macbook Pro out, which will allow me to see the interval/chat better anyways.

In this thread, Twinwave (Paul) had the exact same issue, but Stefan said it's what happens when you're not playing at the correct BPM/BPI:

twinwave
Hi, I played on a jam for the first time the other night (Sat 3 March) and though I felt that I stayed at the right BPM but when I listened back to the track recording I was way off (I mean really way off). Was I doing something wrong? no one seemed to object to the playing but I am not sure what happened to the recording. I would love to set up a drum/percussion test with some other tight percussionists that I know but need to know if there was any glitch in the recording? cool jam by the way, I enjoyed the live stuff, best regards paul

stefanha
Hi Paul,What you described is exactly what happens when the tempo (BPM) or beats per interval (BPI) are not set to match the playing. If you follow the advice of this post then jams will be in sync.

but I was following the room's metronome to a tee; you can hear the click in the first part of the attached .mp3 in my recording where I'm on the quarter notes, then what the room “hears”, was way off. Hopefully it was the audio driver glitch, but these kinds of unpredictable results are what frustrates/loses members, so I'd like to nail it down if possible.

eb_liveDrums
A better test is to grab two computers and put them in a session, but again, if you mimic my setup you should be in sync. Next time we are both online I’d be happy to grab a room and we can try it together.

Cool, thanks.

Edited captaincancel (April 20, 2020 13:28:40)

Definitely use your Macbook Pro and these problems will likely go away. Coreaudio is so straightforward and doesn’t have the driver issues that windows does. I’m not sure why ASIO isn’t listed as an option in Jammr, but that may be part of the problem. I know I had an easier time on windows working with ASIO in Reaper than I did usind WASAPI or WDM in Jammr. On the Mac “it just works”.

Edited eb_liveDrums (April 20, 2020 15:57:48)

eb_liveDrums
Definitely use your Macbook Pro and these problems will likely go away. Coreaudio is so straightforward and doesn’t have the driver issues that windows does. I’m not sure why ASIO isn’t listed as an option in Jammr, but that may be part of the problem. I know I had an easier time on windows working with ASIO in Reaper than I did usind WASAPI or WDM in Jammr. On the Mac “it just works”.

I think it's because ASIO is incompatible with the GPL open source licensing that Jammr uses.