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Old 01-29-2017, 11:40 AM
propower propower is offline
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Join Date: Mar 2002
Location: Redmond, WA
Posts: 2,202
Default Re: Thunderbolt via HD Native box vs. Strictly Thunderbolt

The Red 4Pre does not accurately mimic an HD I/O. The D/A and A/D are slightly longer than an HD i/O making all accurate pacing of audio on timeline and inserts off

Data I took when I had a Red 4PRE
Red 4pre

96kHz (HDX)
RTL = 0.576ms no sub master straight in and out
(AVID I/O is 0.48ms)
RTL = 0.62ms with one submaster
(AVID I/O is 0.52ms)
RTL = 0.912ms with loopback error fix
(AVID I/O is 0.52ms)
Loopback error is 35 samples late

About 0.4ms hit for getting loopback working right
Using I/O insert ADAT2 to ADAT1
RTL = 0.912 (one sub master)
Setting HW delay comp to 1.1ms gets loopback error to be zero - no effect on RTL

Logic w/ Thunderbolt - 44.1
RTL = 2.86ms 32 buffer - Logic displays correct value!
Logic 48
RTL = 2.6ms 32 buffer - Logic displays correct value!
Logic 88.2
RTL = 1.84ms 32 buffer - Logic displays correct value!
Logic 96
RTL = 1.7ms 32 buffer - Logic displays correct value!
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Musician: http://www.ivanlee.net/
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