In Part 1, I wondered if you could hear any differences in Dolby Atmos surround sound on the various movie streaming services and movies downloaded from Kaleidescape, and decided to do a comparison between Vudu, Apple TV, and Kaleidescape to find out.
After an afternoon of listening tests, here are my results.
I have a pretty high-end audio system, consisting of the new Marantz AV8805 flagship preamp/processor, two Marantz seven-channel amplifiers, and a 7.2.6-channel speaker configuration that includes Definitive Technology Mythos ST-L tower
speakers, a Definitive Trinity Signature Reference sub, and an SVS SB-16Ultra sub. I watched all of the movies at the same volume setting: -15 dB.
For source material, I used my Kaleidescape Strato to handle the Dolby TrueHD audio on movies downloaded from the movie store, a Microsoft Xbox One S to stream content from Vudu, and an Apple TV 4K to play movies from the Apple Store.
I mined my movie collection to find multiple titles I owned across all three services that featured Dolby Atmos soundtracks. This allowed me to cue up the scenes on all three devices and fairly quickly listen to each scene in the different formats.
I watched a number of scenes from six films I’m familiar with: Ready Player One, Baby Driver, Blade Runner 2049, Gravity, Venom, and Jumanji: Welcome to the Jungle. After A-B-C’ing each scene multiple times, I can definitively say two things: 1) the TrueHD audio mix always sounded better, and 2) audio from the Apple TV 4K sounded substantially quieter and more compressed.
By far the most readily noticeable audio differences were in the low frequency range. Consistently, film after film, scenes with low-frequency activity were far more dynamic and impressive in TrueHD. The low end had more physical impact, producing frequencies I could feel, as well as pressure waves that rattled doors and windows.
The opening “Bell Bottoms” scene from Baby Driver is a perfect example, where the bass notes in the song were thin and indistinct with the Dolby Digital Plus (DD+) on Apple TV and Vudu, and the shotgun blasts had little weight. With TrueHD, the bass was articulated, and the shotgun plumbed far lower and louder.
The bass-heavy Blade Runner 2049 also offered multiple scenes that showcased the superiority of the TrueHD soundtrack. The pistol Deckard uses in his fight with K in old Vegas had far more impact, as did the rushing water, thunder, and air vehicles flying at the pump station. The fantastic Benjamin Wallfisch and Hans Zimmer soundtrack also sounded richer, producing notes that were more musical and real, with better tone and decay.
Textural sounds also had far more dimension and realism with TrueHD. The first challenge race from Ready Player One was a perfect example, featuring a lot of different vehicles with unique-sounding engines. The multi-layered sounds of the engines, crashes, crunches, and explosions had more detail and separation, being less distinct in the DD+ version. The motorcycle chase in Venom exhibited this same sonic loss in DD+, as with the sounds of the drones flying, or the details of bullets striking. It was similar with the crunching and thrashing from the hippo attack in Jumanji.
As mentioned above, the audio levels on Apple TV were significantly lower across every film—often 10 dB or more. This was obvious on everything, but especially noticeable on Gravity, where the opening dialogue chatter between Stone and Houston was virtually inaudible, making it completely unintelligible when played at the same levels as the Vudu and Kaleidescape versions.
Even with volume levels raised to compensate, the Apple versions of the films just seemed far more compressed, lacking dynamic range. This was similar to what I experienced on the Taylor Swift Reputation Stadium Tour streamed from Netflix, making me wonder if there is some issue with the way the Apple TV 4K handles Atmos audio.
Now, while the TrueHD mix was definitely better, that doesn’t mean the streamed mix was bad. Just not as good. This was especially noticeable when played back to back, where the TrueHD audio had a wider, airier, more natural presentation. Outdoor scenes like in the jungles of Jumanji just felt more open and like you were in the actual environment, while the DD+ audio felt more centered on the screen.
For luxury cinema owners who’ve invested in getting the best experience possible, there are definite, noticeable audio improvements to be had by purchasing content in the lossless format.
Probably the most experienced writer on custom installation in the industry, John Sciacca is
co-owner of Custom Theater & Audio in Murrells Inlet, South Carolina, & is known for his writing
for such publications as Residential Systems and Sound & Vision. Follow him on Twitter at
@SciaccaTweets and at johnsciacca.com.