How low is "Low Latency Mode" in HDN??

[propower]

For example:

At 96kHz
Buffer 64 = 1.8ms Round Trip (RT)
Buffer 128 = 3.12ms

If I engage LLM does anyone know what RT latency is reduced to?

[propower]

I broke out the oscilloscope and function generator and answered my own question

Using an input on an Avid 16x16 and an output on an OMNI and measured time delay from Analog in to Analog out.

96kHz I/O RT
64 samples ---- 1.80ms
128 ------------- 3.12ms
256 ------------- 5.8ms
512 ------------- 11.12ms
LLM ------------- 0.47ms (regardless of Buffer)

44.1kHz I/O RT
32 samples ----- 3.35ms
64 --------------- 4.80ms
128 -------------- 7.68ms
256 -------------- 13.52ms
LLM -------------- 1.9ms (regardless of Buffer)

[chrisdee]

Thanks for sharing.

Is it possible to measure the time delay for direct monitoring ?

[propower]

What is "direct monitoring"?

And so sorry - I am using a Mac system and mistakenly put this in the Windows forum.

I did measure the Low Latency Monitor path (LLM) and it is the lowest 96kHz performance of any interface I know. Is that the "direct monitor path" you are referring to?

[Greg M]

True direct monitoring should have zero delay since that implies all signals are in the analog domain. So, if you are monitoring with headphones, you won't have any delay. If you are monitoring with speakers, then the delay will depend on how far away you are standing from the speakers.

Hope this helps,

Greg

[nst7]

With most interfaces, including HD Native, direct monitoring, or low latency monitoring, is basically a function where the interface acts like a normal analog mixer. The signal from your input goes directly to your output, without going through the analog to digital and digital to analog conversion that introduces delay (although it still does this as well, but you're not hearing it while it happens in this mode, it's basically going both ways).

Most interfaces have software that allows you to set this up, such as Focusrite's Mix Control software, or Apogee's Maestro software, etc. For HD Native, it's just done as a choice in the I/O setup when Protools is open.

[Shan]

The Avid published throughput latency measurements. More measurements from Avid here.

Shane

[mattrixx]

Pretty sure that the LLM mode in ProTools, which bypasses plugs and paths for a selected record channel and routes it to the LLM path (i.e., headphones) is only available on HD OMNI, Digi002 & 003 series). Is that right?

Regards,
Matt

[guitardom]

Originally Posted by mattrixx

Pretty sure that the LLM mode in ProTools, which bypasses plugs and paths for a selected record channel and routes it to the LLM path (i.e., headphones) is only available on HD OMNI, Digi002 & 003 series). Is that right?

Regards,
Matt

almost, it is not specific to hardware such as the Omni as it is just a converter, not an actual interface like a 002/003. In that case it is specific to the "audio card" the interface is hooked up to. In the Omni case it would be an HDN or HDX.

[mattrixx]

So LLM (as seen in the 'Options' when using a 003 for example) is available when using a 16 I/O?


Edit: Nevermind! ;-)