AVSForum member 1ofakind asked:
“In terms of receiver(s), what is an affordable way to create a 7.2.4 setup using the speakers I have? Also, in optimal rooms for Atmos performance, how well do up-firing add-on speakers recreate the immersive audio experience as opposed to add-on speakers or other dedicated speakers installed in the ceiling?”
While early Atmos-enabled receivers were a bit pricey (such as Sony’s $2,799 STR-ZA5000ES, which is still on the market, BTW), the past year or so has seen the introduction of several Atmos-capable AV receivers under $1,000 and even a few under $500. The giveaway prize for this AMA, for example, is Sony’s STR-DN1080 AV, which lists at $599. Later this spring, Sony will have four other additions to their custom installer focused ES line of AV receivers that support Atmos and DTS:X, ranging in price from $799 to $1,699. Other good Atmos-capable receiver options include models from Yamaha, Pioneer, Denon, and Onkyo.
As you might expect, receivers that provide power for 11 or more different speakers cost most more than those that support, say, 7 (which is the minimum that you’d need for a 5.1.2 configuration with an unpowered subwoofer output). In fact, one of the most critical specs to check for on AV receivers is the number of power amps available and how they can be configured. Typically, you’ll need to add together the two outer numbers in a desired speaker configuration (5.1.2, 7.1.4, etc.) to figure out the number of amp channels you need. Most subwoofers integrate their own power amp, so they don’t usually figure into the equation, but if you have an unpowered sub (or two), you’ll have to incorporate them into your totals as well. Note that some receivers support the ability to have different configurations—nine power amps, for example, could theoretically support 7.1.2 or 5.1.4 setups—but not all do, so be sure to check.
Also note that some receivers have functions that can emulate more channels than they have actual power amps. For example, the Phantom Back feature on Sony’s receivers will emulate the two extra surround back channels found on 7.1 systems with only five speakers. If the soundtrack has a full 7.1 mix, the two extra tracks will appear to come from two virtual speakers behind you (leveraging some signal processing and psychoacoustic principles) even though they’re actually coming from just your existing surround speakers. If, on the other hand, the soundtrack is a 5.1 mix, it will upmix to 7.1 and then play the virtualized tracks on the virtual “phantom” speakers—sort of a virtualization squared.
In addition, some receivers have the ability, but not the power amps, to support these extra channels. In those cases, you’ll find unpowered surround back outputs that can be sent to a separate power amp (or even an older AV receiver) to drive the extra speakers. You will have to be careful about balancing the levels between your main AV receiver and the extra amp in this situation, but it is an option.
To address the second part of your question, as mentioned in a previous answer, in ideal rooms, four ceiling mounted speakers will likely give you the best possible sound for an Atmos environment. However, that’s a lot of wire to run and ceilings to cut/mount to and in many situations, it’s just not practical. If you have that flexibility, more power to you. If you don’t, however, then you’ll want to investigate the reflection-driven speaker options. You can find offerings from Klipsch, Definitive Technology, Pioneer, PSB and ELAC that can likely meet your needs.