DTS Virtual:X DTS Virtual:X virtual height and surround processing

What DTS Virtual:X is

DTS Virtual:X is processing that a manufacturer builds into a product to deliver immersive sound without additional speakers. DTS's June 2017 announcement, as reported by audioXpress (which also noted TVs were forecast for early 2018), says it supports any input source from stereo up to a 7.1.4 layout, which DTS counts as 11.1 channels, and is optimized for all DTS codecs including DTS:X, with an upmixer for legacy content. It bundles four tools that a manufacturer can use at the same time: Virtual Height, Virtual Surround, Bass Enhancement and a Multiband Hard Limiter. DTS's DTS:X page describes it as a companion audio processing technology for delivering immersive listening from as few as two speakers.

It is not a format. DTS:X is the object-based soundtrack format; Virtual:X is a renderer that can sit behind any source. That distinction answers most "DTS Virtual:X vs Dolby Atmos" searches: the true Dolby counterpart is Atmos Height Virtualization, not Atmos itself.

How it works

Virtual:X uses psychoacoustic cues to make the ear place sound above and behind the speakers. ecoustics describes it as simulating rear and height speakers without needing wall or ceiling reflections, and says it is less effective than discrete height speakers but better than no surround at all. Yamaha's explainer adds that because the processing is digital, room size and shape do not affect it, and dialogue stays centered while ambient sound seems to surround the listener. audioXpress's launch report says DTS claims the perception of up to 7.1.4 immersive content from horizontal-plane speakers in 2.x, 3.x and 5.1 layouts, replacing the height and rear speakers.

DTS has not published the filters, and I found no lab measurement of the effect, so the claim of a 7.1.4 impression from two drivers is a manufacturer claim, not a measured result. Dolby's equivalent paper names its building blocks (height-cue filters, HRTFs and cross-talk cancellation); DTS's material I fetched names features but not filter designs. DTS's Joanna Skrdlant said Virtual:X lets listeners get height and surround sound from a sound bar alone, which makes immersive audio more accessible and affordable.

DTS Virtual:X vs Dolby Atmos

Atmos is a content format that carries objects, and on streaming services it rides on DD+ JOC; see DD+ JOC. Dolby's height virtualizer then renders the overhead objects to 2 to 7 listener-level channels to suggest 2 or 4 overhead speakers. DTS Virtual:X skips the format question: DTS says it takes any input, so a plain stereo stream gets the same processing as a DTS:X disc. For native decoding limits, the DTS:X page lists up to 5.1.4 decode for streaming and up to 7.1.4 for optical disc. DTS:X itself is hard-coded to 5.1.4 for its streaming profile and suggests 7.1.4 for the disc profile, according to ecoustics. A product with Virtual:X is not automatically a DTS:X decoder, and a DTS:X decoder is not automatically a Virtual:X processor. Amazon states this directly for its 2-channel Fire TV Soundbar: it does not support DTS:X and instead features Virtual:X, over HDMI ARC or eARC.

The overlap with Atmos is practical: both aim at the same living-room problem. For the decoding argument, see DTS:X vs Dolby Atmos.

Which products carry it

The first product was the Yamaha YAS-207 soundbar, which DTS said would go on sale in July 2017 with a Virtual:X firmware update in August 2017. In November 2017, DTS added it by firmware to the Denon AVR-S730H, AVR-S930H, AVR-X1400H, AVR-X2400H and AVR-X3400H, and the Marantz NR1608 and SR5012, which audioXpress said work with layouts from 2.0 stereo up to 5.1 and even 7.1 speakers. Current spec tables still list it: the Denon AVR-X3800H (9 power amps, 11.4 processing channels, 105 W per channel) lists it too. Yamaha's current hub page names the SR-B20A soundbar. Amazon's Fire TV Soundbar is the 2-channel example.

Because the processing runs inside the device (Yamaha says inside the sound bar), Virtual:X is a product feature rather than a content label. Check the spec sheet for the words "DTS Virtual:X," not just "DTS." DTS also said more Denon DTS:X models would follow in January 2018 and more Marantz models in February 2018.

Common confusions

Three DTS names get mixed up. DTS Neural:X is an upmixer that, per DTS's DTS:X page, adds support for up to 32 speakers (30.2); it is for rooms with many real speakers (see DTS Neural:X). DTS Virtual:X goes the other way and starts at as few as 2 speakers. DTS:X Pro is the decoder tier for large layouts (see DTS:X Pro). Only Virtual:X is a virtualizer. As a rule of thumb from those definitions, Neural:X fills out more physical speakers than the source has channels, and Virtual:X suggests more speakers than you have.

Worked example

A 2.0 soundbar plays a stereo stream. Without processing, the listener hears two channels spanning the bar's width. With Virtual:X, DTS says the upmixer and the Virtual Surround and Virtual Height stages treat the source as if it had rear and overhead content, so the result is aimed at a 7.1.4 impression. DTS counts 7.1.4 as 11.1 channels, so a bar with 2 channels is being asked to suggest 11 channels and an LFE feed, about 5.5 suggested channels per physical channel. Doing the same with real drivers takes 11 speakers on 11 amplified channels (7.1.4), more than the 9 power amps in an AVR-X3800H. A receiver such as the AVR-X3800H with five speakers and no ceiling drivers can be set up the same way, but when real height speakers are connected, use them, since virtualization exists for systems that lack them. For a soundbar shopping list, see best soundbars for apartments.