- Manufacturer & Model
- Spatial Group's Spatial Audio Calibration Toolkit (SACT)
Thirteen sections of test files devoted to the calibration of home theater systems, helpful graphics that add visuals to sounds during tests, accessible to novice and experienced enthusiasts, well written plain-speak user guide.
Billed as the first immersive sound calibration disc, the Spatial Group's freshman effort is excellent. All thirteen sections on the disc are useful, giving enthusiasts access to valuable tools for both system calibration and confirmation. Priced at $99, the SACT is expensive... but it's worth it.
Earlier this year, home theater YouTubers Joe Mariano (Joe-N-Tell) and Channa De Silva (Techno Dad) brought their collaborative audio project, the Spatial Audio Calibration Toolkit (SACT), to market. Sold under the banner of the Spatial Group, the disc is billed as the “first calibration disc for Dolby Atmos.” By my count, it is, indeed, the first disc dedicated to calibrating Atmos systems, but is it the only option? The answer to that is a bit more muddy. The new Spears & Munsil Benchmark UHD calibration disc carries high-level Atmos files, and useful audio tests can be found on DTS:X, Atmos, and Auro-3D demo discs. So, there are other sources of immersive test files out there, but nothing comes close to being as complete and comprehensive as the SACT.
Priced at $99 for a physical Blu-ray disc or access to a digital file for download (bundled for $150), both versions have the same 160 tracks encoded in lossless Dolby TrueHD. All purchases include access to a dedicated Discord group that’s currently 360-ish members strong and a 24-page PDF instruction guide.
This review is based on the disc version of the release, which is multi-region for compatibility with players worldwide. The digital version is friendly with MKV-compatible devices such as Zappiti, Plex, and Zidoo, along with a range of M2TS-compatible players. That said, be sure to read the Spatial Group’s FAQ before purchasing a digital copy; some devices, such as Xbox Series X, PlayStation 5, and popular Panasonic disc player models, have varied levels of compatibility with the two file types.
Several reviews of the disc exist on YouTube, so if you want to watch reviewers click through menus and test screens, that’s where you should go. For this review, I decided to take a slightly different approach by spending quality time with the disc using a Panasonic DP-UB9000 player feeding a 7.1.6 array, assessing who, what, and why factors as they relate to the product. The result is a breakdown of who should buy the disc and which of its features stand out. In addition, I’ll tell you if it’s worth buying both the SACT and the new Spears & Munsil UHD Benchmark disc – a question that quite a few members of the community have asked.
Overview and General Impressions
The SACT is a collection of unique audio tests and visual cues explicitly developed to calibrate and confirm proper speaker and layout functionality. While it’s marketed for immersive home theater rooms, it can be used with basic 2-channel systems up to 3D audio arrangements consisting of a sub or subs, nine bed layer channels, and six height speakers (9.1.6). So, from that perspective, it has tremendous value as a set-up aide.
Most buyers looking at this type of product will likely have equipment with advanced automated calibration software, shifting SACT’s utility toward confirmation tool territory. But it certainly can be used by the DIYer that prefers a more homegrown calibration approach or the 2-channel enthusiast running a system devoid of correction processing. Adding to that versatility is a layer of usability that makes it suitable for casuals who’d prefer to use the disc and their ears to run through tests, in addition to advanced users that plan on using a hand-held SPL meter, calibrated microphone, and measurement software like Room EQ Wizard.
The disc has a professional look and feel, despite a few rough edges that popped up during use. The menu system is intuitive and easy to navigate, tho I did find myself wishing my remote’s track skip buttons (or arrow keys) were active and able to move test tones to a new speaker or set of speakers during use. Some of the tracks play for 30 seconds before sending you back to the menu system to select another speaker or audio pattern, and the only available remote functions are fast-forwarding or returning to the menu. Hopefully, future versions will offer more sophisticated in-test navigation features.
One feature that deserves a thumbs-up is a six-second pause that plays after a test track has been selected. These pauses are filled with a film leader and beeps (just like those familiar grainy numerical countdowns at the beginning of old reel movies) and give your system a chance properly work through any delays that might cut off a test tone. It works and eliminates the frustration of interruptions, tho there are a few places where the pause period lacks a film leader graphic, jumping directly to a test track’s graphic interface while countdown tones play. No biggie because the spacer is still technically present, but it’s another area that could use a bit of polish on future versions of the disc.
What’s on the Disc
The disc’s test files are spread over 13 sections. Here’s a quick rundown of each section as detailed by the SACT’s Quick Start Guide:
1. Intro Welcome: Start here. This will instruct you to set up a comfortable listening volume.
2. Call Outs: This helps to ensure that your speakers are working and connected properly.
3. Level Matching: Set the proper levels for each individual speaker.
4. Polarity Test: Check to see if your speakers are working together or against each other.
5. Timing Test: Check to see if your speakers are acoustically time-aligned.
6. Crossover Point: Find out the lower limits of each speaker's frequency response.
7. Speaker Pairs: Listen to how speakers work together to ensure balance and coherence.
8. Tonal Balance: Voicing your system is one of the most important things you can do.
9. Object Panning: Dial in your imaging using precise object movements in a 3D space.
10. Torture Test: Find out if your audio system can accurately reproduce the movements shown on-screen. Very few can.
11. Professional Calibration Tool, Impulse Response: A chirp is played from the reference left speaker, followed by a full-range sweep. You can record phase, magnitude response, and timing with this.
12. Professional Calibration Tool, Sweep Test: Find the frequency response of your speaker. Sweeps are played three times consecutively.
13. Professional Calibration Tool, Periodic Pink Noise: 16K Periodic PN for use with a Real Time Analyzer (RTA).
The included user guide, which isn’t available for public consumption, does an excellent job of explaining set-up requirements and test objectives for each section. Its plain-speak style keeps things less technical, making it great for users learning the ropes. And that welcoming nature compliments the disc’s visuals that show speaker and sound positionings during the various tests, along with a multi-channel digital VU meter and other pertinent information. So, from a “who” perspective, the disc can be used by just about anyone, being both novice and expert-friendly.
From a “what” perspective, the SACT offers an impressive amount of tools to fine-tune or verify various factors that autocalibration attempts to handle independently. Hardcore and technically savvy users likely have go-to methods that can achieve similar results, and several test sections can be recreated using pink noise generated by an AVR. But there’s something to be said for having an organized workflow and pre-packaged audio files.
The first four sections of the disc quickly establish if your speakers are hooked up and positioned correctly. I found the “Call Outs” and “Polarity” sections particularly helpful. The pacing of voiceovers calling out speaker positions in the “Call Out” section is perfect – succinct and quick. And the mere fact that specific speaker positions are identified throughout the test period improves upon the typical pink noise generated by an AVR. As for "Polarity," the entire test procedure uses your front left channel as a baseline comparison, allowing you to best judge the loudness (indicating in-phase or out-of-phase) of other channels in your system.
Other sections that are executed exceptionally well, not to mention useful, include the “Crossover Point” and “Torture Tests.” For the former, rolling low-frequency tones help identify the natural crossover point of each speaker in your system as it interacts with your room. Of course, this test is less useful if your AVR only allows for a single, global crossover point. But, even in that scenario, it might convince you to pick a frequency other than the standard 80Hz.
The “Torture Test” files might be my favorite test tracks on the disc. Much like Spears & Munsil Benchmark UHD disc, pink noise is floated around the room as an object is visually represented on the screen. But SACT ups the ante by allowing users to replace the pink noise with voice callouts. It’s quite the trick, making the process sound more natural and real-world. You can set the pink noise (or voice) to follow a variety of patterns, including an X pattern that cycles through three different horizontal planes.
As it stands, the SACT is practically the complete package. Aside from a few tiny operational wrinkles that could use some ironing, my only wish would be the inclusion of reference movie clips. Yes, I’m talking about actual Hollywood-grade movie clips. It’s a dream scenario, I know. The cost would likely be too high, and most of us have reference tracks earmarked in our collections. But, in the name of convenience, having them packaged with the rest of the disc would be icing on the cake.
The only downside to the SACT is its price. Landing at $99, it’s roughly $50 more than the new three-disc Spears & Munsil set, which is widely regarded as the gold standard of video calibration. And let’s not forget that Spears & Munsil also contains immersive audio files created in conjunction with Dolby. So, from those perspectives, the SACT is a tad on the expensive side. That said, the disc will stand as a go-to tool in my disc collection and definitely one that I'll revisit as review equipment cycles through.
If budget allows, the SACT is a no-brainer buy, particularly for enthusiasts who like to tinker and better understand their equipment. It’s unique enough that I’d recommend buying it in addition to Spears & Munsil, giving it priority status if you’re purely looking for audio calibration capabilities. Excellent.
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