Sample offset measurement between 2 audio tracks?

Cubase
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Hello folks,
Could anyone advise on the best way of working out any sample offset between two tracks’ audio events inside Cubase please? (rr with any freebie plug-in etc.)

My example use case - I want to test the phase coherence (time alignment) of a neat kludge I’m planning to add extra mic pre input capability to my aging Alesis Multimix Firewire 16 interface which is hooked up as my only audio interface to my MacBook Pro. This only has 8 mic inputs with phantom, but it does have another 8 line inputs - that I hardly use.

So I currently have on test / sale or return a Behringer Ultragain ADA 8200 ADAT Expander & Mic Preamp unit. The way I want to use the ADA8200 is kind of a neat kludge - by default this unit doesnt pass the signal directly from its Mic inputs to its balanced XLR outputs (see link below)

https://www.sweetwater.com/sweetcare/articles/my-behringer-ada8200-is-not-passing-signal-from-the-analog-inputs-to-the-analog-outputs/

But you can get this functionality using the ADAT output looped back via a short TOSlink cable into the ADAT input on the device - I’ve tested it and I get audio through the unit in this manner just fine.

I’ve been reading an interesting thread on the theoretical/actual ADAT processing delay (A>D and D>A) here:

and it seems logical that there’ll be a very small processing delay due to the A>D and then D>A conversion in the unit before the balanced output feeds the audio out to my Alesis interface. But given the speed of light and the high speed of conversion I’d hope this would be almost non-existent, esp. when compared to the latency of the interface itself.

I wanted to see if I could test and quantify this at all, so had the idea of splitting a signal recorded from one source - say a snare drum hit - by routing it to 2 separate channels, the first being a direct mic input into my Alesis audio interface and onto Cubase , the second being via the ADA8200 mic pre > ADAT loop > ADA8200 output > Alesis line input and onto Cubase as usual.

It then struck me that aside from looking at the two waveforms to see (when zoomed in) if there’s any visible timing difference/delay, I dont know how to actually measure that difference. Is there a way I can use something like a range selection tool or something to see if any delay exists and if it does, how many samples it is?

Any ideas gratefully received, many thanks and Happy Xmas.

David

2

Hi David

Why overthink it ? just zoom in and you will see the individual samples as you say.

And you are correct - A/D D/A will introduce delays (usually a few samples)- as will spatial difference in microphones etc.

In many instances this isn’t too much of a problem. If you are working with multiple mics and you do need to align them then try auto-align from soundradix - they have an ARA2 version too.

Also - always struck me as odd that Behringer didn’t do an internal loop back on those boxes…bypassing all the A/D/A stuff.

3

Hey there, thanks for the quick reply - appreciate it. Yeah, I may just have to be happy with the visual check… I think I am probably over-thinking it a bit as you say - in the grand scheme of things the A>D>A is likely going to be less of a worry than phasing between multi-mics round (for example) a drum kit. I’m just curious to see really, being a bit of an audio/electronics nerd :slight_smile:
Ta also for the plugin info, I will check them out.

It does indeed seem like a missing bit of functionality not to have the ability to bypass the A>D>A stuff and allow the 8200 to act as a multi mic pre, but hey this kit is only £150 or so, only so much bang for buck that even Behringer can give you…

Cheers
David

1 Like
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Update - I tested this using the split signal as described previously. The delay for the A>D>D ADAT optical loopback/passthrough is sub 1mS.

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