Aloha latency claims

Hi There! I recently discovered Aloha, and there are some very bold claims made regarding perceptible latency. One marketing bullet claims that two people 600+ miles apart had imperceptible latency.

In the past, I’ve tried Jacktrip, Jamulus, and webRTC for these purposes. I’ve never been able to achieve acceptable latency for real time collaboration. The best I’ve achieved is 40mS through Jamulus (with people in the same city as me), and acceptable latency for me is in the sub 15mS range.

I never saw any actual numbers for transport latency and I just don’t know how aloha could get around the current internet infrastructure’s speed shortcomings. Does anybody have any data to back up the marketing claims? I understand that ElkOS can provide roundtrip latency through two stages of conversion of roughly 2mS, but what about transport time?

As far as i understand it, Jamulus uses a client-server model, so audio travels (with data compression) up to a central server from all parties, and is then synchronised before heading back for audition.

ElkOS is <1ms on the Aloha box, and uses an ethernet connection direct to the router, reducing latency compared to WiFi.

The minimum transport speed is limited by the speed of light, so you could calculate how fast light travels 600 miles to get the minimum latency. Don’t forget that in a concert hall there can be over 15ms of audio latency from one side of the orchestra to another, so your sub 15ms range maybe an underestimate of what you’d be comfortable with.

Have you signed up for the beta?

Hello,
i´m interrested in this aswell , because the videos of Elk Aloha sound so good ( fast ) !
I achieved 8 channel transmission in Soundjack with 14.5 ms
( in town ) and I´m waiting on 2 Hifiberry Pi´s with the new XLR Hats to save 6 ms ( avoiding the usb bus) , let´s see …

i signed up for the beta

Hi @berndkeul,
Aloha latency depends on a few parameters of the network connection (average latency and jitter), plus there’s a tradeoff in setting the jitter buffer sizes that depends on how many audio dropouts you are willing to tolerate.

Typically, the end-to-end audio latency (from one musician to another) is c.a. 6-7ms + the one-way network latency (half of the one reported by e.g. ping). With a good consumer network in the same country, this totals to less than 15ms in most situations and often less than 10ms if you’re in the same city.

We run the system at 32 buffer size - Elk could run lower but then the network packet rate will be too high to handle. This gives us a local audio latency slightly larger than 1ms but still way better than most other solutions.

[edit: corrected using “half” of ping latency which is RTT instead than one-way]

Hi Stefano, thank you for this fantastic details .
I have been experimenting a lot with Soundjack and Digital Stage , and I will check out Jacktrip aswell , but these numbers show one of the rare occasions where faster is better …

I will order the Pi´s now with the Elk bundle ( RCA …) because I was told today that the XLR Phantompower Hats will not be available soon …

so again , please consider me becoming a beta tester , I would like to make a video of audio collaboration with midi sync …

Schönen Gruß

Bernd Keul

Gustav Heinemann- Ufer 112/9
50968 Köln
Tel. 0221/324963
Mobil 0177/1628920
E-Mail: BerndKeul@netcologne.de

http://www.youtube.com/user/berndkeul

http://www.vimeo.com/user367470