Denon X3400H w/ Apple TV 4

[Brian Alexander]

This has baffled me for the greater part of a month now, and I'm really unsure what the issue is.

I have a Denon X3400H, Elac Unifi towers with matching center channel, some inexpensive surround speakers, and an HSU VTF-3 MK5. Really love the way it all sounds together. Most of my listening is music in stereo with the Unifi towers and the HSU sub. If I play through the receiver using HEOS, bluetooth, airplay, or my computer, everything sounds great.

But, I have an Apple TV 4th gen (Not the 4k one that released most recently). It connects via HDMI directly to the Denon in the CBL/SAT HDMI connection since It is basically my cable TV replacement. But, there is a measurable 0.5 to 0.75 second delay between when something happens on screen and when the audio is heard. IE: A menu click is heard a split second after the menu item has been selected, for example. The other thing is that the low-frequency being output by the Apple TV is utterly terrible. There is low frequency, but I have to put the gain way up on the HSU to get any meaningful low end. I even tried lowering the crossover frequency for the towers down to 40 Hz to see if it was perhaps the receiver not giving the subwoofer enough signal, but even the towers don't put out nearly as much as they do with exact settings when using HEOS, Bluetooth, or other sources.

The two issues may not be related, but I noticed them about the exact same time about a month ago. The firmware for both my receiver and the apple TV is up to date, I've explored and tinkered with all of the audio and surround settings on the Apple TV, done the same with the Denon (It has much more settings but I've tinkered with a great many of them to try and find if one of them is the culprit), tried different sound modes, swapped cables, everything.

Does anyone know why the Apple TV would have this issue? I'm at a loss on trying to figure this one out.

 

[snakeeyes]

So if you set the AVR lip sync delay at half of that difference, does that work better?

 

[Brian Alexander]

Looks like it was an operator error. Going to the Audio > Audio Delay screen, I assumed the "Adjust" button was for adjusting the lip sync delay. Apparently they are completely independent, as the delay can be set with or without Lip Sync enabled, and turning Lip Sync off doesn't actually disable the delay. That makes me wonder what the Lip Sync does if it doesn't have its own customizable delay.

EDIT: Also, the anemic low frequency was fixed by enabling Dynamic EQ. Why this only affected the Apple TV and nothing else, I do not know. If the EQ curves were flat without it on (Which I'd assume they would be), I would think I'd get the same sound profile from all sources, not just one.

So, all my problems seem to be solved. Until I tinker with things again.

 

[Bucknekked]

Anytime you pair up a computer running an app with a sound system there is the potential for the two signals, video and sound, to get just a touch out of sync. The human ear is a marvel at detecting sound so its pretty hard to fool somebody if there's any sort of delay.

Garageband (a sound processing app for teaching people to play instruments like guitars etc) is one of those examples like an Apple TV. If the sound of the student striking the string on a guitar is just a teensy bit off from the actual strike of the string, it drives you nuts. Been there, done that. Getting all the delay out of the system is possible and there are remedies. It is aggravating for sure while its happening.