Cannot get low latency with USB audio gear

[StuartR]

I am having difficulty figuring out the best way for me to setup my gear for playing in jamkazam sessions.

I have an acoustic piano, an old Sony Vaio PC and a newly-purchased Behringer XENYX Q802USB. I have been using Jamkazam predominantly to rehearse with an acoustic bass player who lives not far from me. My observations in this posting are based on Jamkazam sessions with the bass player, though I aspire to play with others at greater distances as well. The bass player has been exclusively using Realtek WMD so far, though he too has recently acquired a Behringer audio interface and may be confronted with similar issues.

I have been considering the following options, which I will discuss below.

• Realtek WMD
  
• WMD USB Audio
  
• ASIO4ALL 
  
• Reaper  ASIO
  
• Native driver
  

(1) Realtek WMD

I first tried the Realtek WMD after initially installing Jamkazam, before purchasing the Behringer, using my PC mic to pick up audio. My latency was low, around 5-6 ms., and my jitter was generally acceptable. Jamkazam’s only “complaint” was that I was using  WMD, not ASIO.  Nonetheless, I bought the Behringer hoping to be able to use a better microphone while retaining low latency, so far without success.

(2) WMD USB Audio

While Behringer recommends using ASIO4ALL for its Q802USB,  many Jamkazam users have noted problems with it, so I tried using the Windows WMD USB Audio driver first. Latency increased  to 20ms, making it difficult to play together. There was a tendency for our tempo to slow down during a tune , so I decided to go back to using Realtek for rehearsals.

(3) ASIO4ALL 

Deciding to check out  ASIO4ALL for myself, I discovered that I could not successfully use the smaller frame sizes (around 2.5 ms.), needing to set my frame size to 10 ms, to get intelligible audio. This resulted  in 31 ms. latency. Inexplicably it seemed easier for us to play together when I used ASIO4ALL than WMD USB Audio. If I retry WMW USB again, would we still have problems playing together?

(4) Reaper ASIO (Rearoute ASIO)

After reading an excellent Jamkazam forum posting by marhdeth ( https://forum.jamkazam.com/printthread.php?tid=537 ) ,  I followed the recommendation, trying the Reaper DAW. Using a 2.5 ms frame size, I brought latency down in the jamkazam test to 5-6 ms. However I was not able to successfully add this gear configuration to my audio profile, failing the I/O rate and variance test. In a response to the marhdeth posting, Nick Blair reported having the same problem, and the thread does not posit a solution.

Nonetheless, this result was  encouraging since I finally obtained low latency for a setup using a superior microphone connected to the Behringer. But it leaves the question of what to do about the I/O test problem.

It seems that my PC may be the culprit. I have observed that the processor utilization percentage reported by Jamkazam for my VAIO using Rearoute ASIO are considerably higher than those for the bass player using Realtek. His PC is newer than mine. 

The CPU of my PC is an Intel® Core™2 Duo CPU T6600 @ 2.20GHz. It has 4.0 GB DDR2 memory, with Task Manager showing 2.1G, 55%, in memory utilization without Jamkazam or Reaper running.

Is there something that I can do with my PC to pass the test? Or must I invest in a new one for the sake of Jamkazam? Obviously, I don’t want to lay out a lot of cash and then discover the purchase does not solve the problem or was unnecessary for addressing it.

(5) Native Driver

Some USB audio interface devices use an ASIO driver recommended by their manufacturer. There are suggestions on the Internet that a driver designed for a different product can be substituted for ASIO4ALL. I tried one such suggestion recommending a Behringer ASIO driver and it did not work for me. I do not think I will try something like this again without first getting approval from someone affiliated with Behringer.

Suggestions from anyone knowing how to best deal with my situation would be appreciated.

Download and run LatencyMon on the PC you're using for JK. Post the results here. Have you followed the recommended PC tuning to get your PC optimized for real-time audio streaming?

https://www.resplendence.com/download/LatencyMon.exe

https://www.dropbox.com/s/der23us3icbbkn...e.pdf?dl=1