Readressing Latency In NestMT ~ Some Big Resets 16Aug24

I sensed and heard something was not right with the NestMT using Vinyl or the JRiver streamer. In the Nest Music Theater,

everything is completed:

• the entire custom 8 driver Fostex EΣ speaker array is completed, and a sub is in place,
  
• the core design functions with three different amps (mains, center channel, surrounds) running and synched,
  
• three solid sources: JRiver MC on Linux (flac, mp3, dsf), ProJect phono through ADC A>D, and Roku are used,
• room correction from miniDSP is installed on the mains, and
• discrete and derived 5.1.2 signaling is available.

It is time to remeasure and adjust delays for the latest design choices and audio paths. While Roku/YouTube sounds fine, I remeasured it first. The impulse measurement with no delays suggests a 183msec delay be added to the CC & Surrounds. That's where it was already set via the "LipSync" feature in the Yamaha AVR (and where it was set again for the 2nd measurement). The Yamaha is where I needed to make the delay adjustment for Roku/YouTube given all the audio regarding this path is on HDMI.

I measured the other sources (phono & JRiver) to view the impulse responses ~ I wanted to get the time delta from signal rendering by the Mains and the Center Channel (I disabled Surrounds for these measurements). From these I found stuff I didn't expect... I measured multiple times and the data is right in the current configuration. The impulse responses showed the latency was opposite/negative and the Mains need to be delayed in each case. Hmmm... I know there must be latency from the Felston itself and the Yamaha but golly. I removed the Felston and directly sent streamer and phono signals to the "amps." The results were different but similar ~ the Mains need to be delayed... what the heck am I going to do?

Before going crazy I pulled the Felston out of the current audio paths... and then reinstalled it "in reverse" so that the streamer and phono signals would be delayed before being sent to the miniDSP. Viola, it worked. I measured again with no delays then set the Felston to delay the Mains by the suggested times.

All is right with the world and the NestMT again. I never rejiggered delays after adding the Yamaha... dumbass. All sources sound fantastic but next I think I will tackle reviewing the integrated SPL curve, the Dirac, and subwoofer integration again ~just to ensure everything is well balanced. In any event, here's the latest connection diagram.