Excellent article, Andrew! I totally agree regarding the limitations of streaming sources, as well as the variability of Atmos mixes. Yes, the 2L recordings are excellent with my current favorite being Borders by Henning Sommero ... also Picturing the Invisible by Jane Ira Bloom. Having a high resolution system makes a huge difference .... both is demonstrating the superior sound of TrueHD as well as revealing the limitations of low bitrate streaming. I have attended several Philadelphia Chapter AES webcasts with engineers mixing for Atmos, and it is evident that not all follow best practices. All have discussed record company pressure to cater to earbuds/headphones. I have found the quality of all of the speakers as well as placement per the Dolby spec to have a huge impact on the imaging, soundstage and overall quality of the experience. I even hang Magnepans from the walls and ceiling to accomplish this :-)
Excellent, informative overview; many thanks. But here’s what I don’t understand: have those many Apple Music listeners who don’t mind lossy sound still gone to the trouble of setting up a complex system like yours Andy? Or do they listen to Atmos streams in some other way?
There are many ways to listen to Atmos with Apple Music: soundbars, home theater setups, TV. Apple assumes you’ll drive these with Apple TV. You can also use Atmos via Apple earbuds and headphones, and on any headphone via iPhone. You can also play Atmos on iPhone or iPad via the speakers. There is seemingly very little limit to how much the reproduction quality and cost can be lowered from Andy’s system. I recently visited him for a demo of Atmos, and I see the promise, but the bridge that remains is a tricky one to build.
Spatial processing to one degree or another. First, let’s start with soundbars and home theater setups. They have multiple speakers, so we assume they are ‘different from ordinary stereo’. Or can be. But the kicker comes when you understand that two speakers can produce a 360 degree sound field. ‘Ordinary stereo’ messes this up, so some form of processing is needed to remove the spatial distortions added by stereo playback. My BACCH4Mac reviews on the TAS YouTube channel go into this in some depth. Atmos takes a mixed approach and does 2 channel spatial processing for headphones and devices. It uses more speakers for fancier systems. In part the extra speakers may be needed for the Dolby assumption of multiple listeners in multiple positions. A tentative thought is that BACCH is spatially superior for a sweet spot listener (and it allows all recorded stereo music from 1958 on to be used), but Atmos is potentially better for multiple listeners and - maybe - for music video. To summarize: it is headache-inducing, but the assumption that we need multiple speakers (beyond 2) to properly render musical space is…wrong.
Thanks again. I reviewed your BACCH material and found it very helpful, but you’re right my head is exploding. Brings to mind Arthur C Clarke’s observation that any sufficiently advanced technology is indistinguishable from magic.
Yeah, sorry. But it is helpful in so many ways to shift from “speakers create the image” (an unspoken assumption often adopted by intuition) to “phase information on the recording creates the image” together with “and thus we need the speakers and room not to screw up the image data already in the recording”. Switching assumptions is hard, but at least benefits from practice.
Excellent article, Andrew! I totally agree regarding the limitations of streaming sources, as well as the variability of Atmos mixes. Yes, the 2L recordings are excellent with my current favorite being Borders by Henning Sommero ... also Picturing the Invisible by Jane Ira Bloom. Having a high resolution system makes a huge difference .... both is demonstrating the superior sound of TrueHD as well as revealing the limitations of low bitrate streaming. I have attended several Philadelphia Chapter AES webcasts with engineers mixing for Atmos, and it is evident that not all follow best practices. All have discussed record company pressure to cater to earbuds/headphones. I have found the quality of all of the speakers as well as placement per the Dolby spec to have a huge impact on the imaging, soundstage and overall quality of the experience. I even hang Magnepans from the walls and ceiling to accomplish this :-)
Excellent, informative overview; many thanks. But here’s what I don’t understand: have those many Apple Music listeners who don’t mind lossy sound still gone to the trouble of setting up a complex system like yours Andy? Or do they listen to Atmos streams in some other way?
There are many ways to listen to Atmos with Apple Music: soundbars, home theater setups, TV. Apple assumes you’ll drive these with Apple TV. You can also use Atmos via Apple earbuds and headphones, and on any headphone via iPhone. You can also play Atmos on iPhone or iPad via the speakers. There is seemingly very little limit to how much the reproduction quality and cost can be lowered from Andy’s system. I recently visited him for a demo of Atmos, and I see the promise, but the bridge that remains is a tricky one to build.
Thanks for the reply. But I still don’t get it. In the absence of multiple speakers, how is Atmos different from ordinary stereo?
Spatial processing to one degree or another. First, let’s start with soundbars and home theater setups. They have multiple speakers, so we assume they are ‘different from ordinary stereo’. Or can be. But the kicker comes when you understand that two speakers can produce a 360 degree sound field. ‘Ordinary stereo’ messes this up, so some form of processing is needed to remove the spatial distortions added by stereo playback. My BACCH4Mac reviews on the TAS YouTube channel go into this in some depth. Atmos takes a mixed approach and does 2 channel spatial processing for headphones and devices. It uses more speakers for fancier systems. In part the extra speakers may be needed for the Dolby assumption of multiple listeners in multiple positions. A tentative thought is that BACCH is spatially superior for a sweet spot listener (and it allows all recorded stereo music from 1958 on to be used), but Atmos is potentially better for multiple listeners and - maybe - for music video. To summarize: it is headache-inducing, but the assumption that we need multiple speakers (beyond 2) to properly render musical space is…wrong.
Thanks again. I reviewed your BACCH material and found it very helpful, but you’re right my head is exploding. Brings to mind Arthur C Clarke’s observation that any sufficiently advanced technology is indistinguishable from magic.
Yeah, sorry. But it is helpful in so many ways to shift from “speakers create the image” (an unspoken assumption often adopted by intuition) to “phase information on the recording creates the image” together with “and thus we need the speakers and room not to screw up the image data already in the recording”. Switching assumptions is hard, but at least benefits from practice.