This is the deep dive behind ART setup. It covers how to group speakers, who should support whom, what the support settings do, and how to judge a result. It pulls together Dirac’s own documents, StormAudio’s installer guidance and a community ART calibration guide, and notes where Denon and Marantz receivers behave differently.
Do your first ART calibration with Dirac’s defaults and listen to it for a few days. Dirac’s own advice is that the defaults work for most systems. Only start tuning once you know what you’re trying to fix.
The short version
Beginner
- Work in order: measure, check what each speaker can really play, set up groups, then support ranges, then support levels. Leave target curves until last.
- Start with all subwoofers in one group. Dirac recommends separate groups for subs of different capability, or identical subs in very different spots. Many users find one group works better, so test both and keep whichever measures better.
- Never let a speaker support lower than it can safely play.
- Change one setting at a time, press Calculate, and compare before changing anything else.
- Judge each change by the spread in the graph and by listening, not by how flat the line looks.
- More support isn’t automatically better. Too much can make bass sound thin and close in the sense of space.
These points appear in Dirac’s technical guides and are repeated by StormAudio and experienced installers.
How ART thinks about your speakers
Advanced
Every group in ART is a main group: the speakers in it play their own channels. Any other group can be switched on to support it, playing a small, precisely timed signal below Fsiso that shapes how the main group’s bass arrives and decays. Above Fsiso, normal Dirac Live correction applies.
- Every speaker in a group shares the group’s target curve and support settings, but still gets its own filters.
- Target curves belong to main groups. A subwoofer moved out of the LFE group has no target of its own. It only helps other groups reach theirs.
- There’s no crossover in the usual sense. The low end is shared between each speaker and its supporters, limited by the support ranges you allow.
- Filters are limited. The counter at the bottom right shows how many you’ve used, and every support connection costs some. See the filters used counter.
More on the counter: The ART filters used counter.
Work in the right order
The community ART calibration guide sets out an order that stops one change undoing another. Target curves come last, because they should never be used to cover up mistakes earlier in the chain.
- Take the measurements.
- Set each speaker’s limits from what it can really play.
- Create the groups.
- Set curtains and Fsiso.
- Set the support ranges.
- Adjust support levels.
- Design target curves.
Know your speakers first
ART will use any speaker you allow, as low as you allow it. Push a small speaker too low and distortion rises and ART’s solution gets worse, not better.
- Don’t rely on the Dirac sweep for a speaker’s low limit. Room modes distort it. A close-mic (near-field) measurement in REW shows what the speaker itself does.
- Without a near-field measurement, take the -3 dB point from the data sheet and add 10 to 15 Hz. That’s your F-support Low for that speaker.
- Ported speakers need extra care. Below the port tuning frequency the driver moves a lot for little output.
- Dirac’s automatic range won’t start below 50 Hz for non-subwoofer speakers, but check it against the speaker anyway.
Grouping
| Situation | What to do | Source |
|---|---|---|
| Subwoofers of different models | Dirac recommends separate groups, so each gets its own support range and level. Many users get better results with one group, so compare both. A sub in its own group has no target curve of its own | Dirac technical guide, user reports |
| Identical subs, but one in a corner and one by an opening | Separate groups. Walls change how much bass a sub delivers | Dirac technical guide |
| Left and right pairs | Optionally split into left and right groups so each side leans on its own side. Needed for directional bass | Dirac technical guide, StormAudio |
| Surrounds and back surrounds | Grouping all four is simplest. Splitting them lets, say, the left surround support the right surround without involving all four | Community guide |
| Speakers of the same model and role | Keep together unless you have a reason to split. Every extra group is more settings to manage | Community guide |
StormAudio’s Sebastien Gailleton adds a caution: lots of single-speaker groups can limit ART’s freedom to use the speakers evenly. If stereo music suffers, keep a second calibration in another slot for music.
Who should support whom
Filters run out, so StormAudio’s installers work through the groups in priority order. This is practitioner guidance, not a Dirac rule.
| Priority | Main group | Supported by | Notes |
|---|---|---|---|
| 1 | LFE | Other subwoofers. Front left and right only if they play well down to about 40 Hz, or if the subs struggle between 120 and 150 Hz | Aim for focused LFE with no sense of where it comes from above 80 Hz. Keep small speakers off the LFE group |
| 2 | Front left and right | All subwoofers, then other ear-level speakers if needed | The speakers that benefit most |
| 3 | Centre | Subwoofers and front left and right only | Don’t enable Infra bass on subs supporting the centre. Don’t let the centre support anything |
| 4 | Surrounds | All subwoofers, then other ear-level speakers | |
| 5 | Heights and tops | Ear-level surrounds. Not left, centre or right | Subs only if the heights measure down to about 80 Hz |
Support levels
Support Level is a limit on how much ART may lean on a group, not a volume control. The range is -24 dB (most support) to -1 dB (least). Change one group at a time and calculate after each change.
| Where it comes from | Less support | Normal | More support |
|---|---|---|---|
| Dirac technical guide | -6 dB | -18 dB | -24 dB |
| Community ART calibration guide | -6 dB | -18 dB | -24 dB |
StormAudio’s Matthew Trinklein gave these starting points while calibrating a system at MWAVE 2024. The idea is less support from speakers in front of you and more from behind, where it’s harder to notice.
| Speaker giving support | Support Level |
|---|---|
| Front left, centre, right and wides | -5 dB |
| Top front and top middle | -6 dB |
| Side surrounds | -6 to -9 dB |
| Rear surrounds and top rear | -12 dB |
| Main LFE subwoofers | -24 dB |
| Other supporting subwoofers | -19 to -24 dB. He avoided -18 dB, which he found too dry |
One AVS Forum user reports that keeping front left and right between -5 and -1 dB keeps the stereo image intact, and that going to -6 dB or lower can collapse it towards a phantom centre. The same collapse can help surrounds, making the individual speakers disappear.
Support ranges, curtains and Fsiso
F-support Low and High set the band where a group helps. Curtains set where Dirac may correct at all. Fsiso is the ceiling for all ART support. The community guide’s rule is: support range, within the curtain range, within Fsiso.
- Don’t make support ranges narrow. A 120 to 150 Hz range forces steep filters at both ends and leaves ART little room to work. Give it the widest range the speaker can handle.
- For subwoofers, F-support High acts like a low-pass filter. If a sub can’t play cleanly to 150 Hz, or is close enough to a seat to be heard, lower it and let nearby speakers cover the top.
- If you can hear a support speaker, lower its F-support High first, then its Support Level.
| Speaker | Typical curtain range (community guide) |
|---|---|
| Subwoofers | 20 to 120 Hz |
| Front left, right and centre | 40 to 300 Hz |
| Surrounds | 60 to 200 Hz |
| Heights | 80 to 150 Hz |
An example starting matrix for 7.2.4
This is the community guide’s conservative starting point, not a prescription.
| Group | Supported by | Support range | Level | Curtains |
|---|---|---|---|---|
| Subwoofers (including LFE) | Themselves | About 20 to 120 Hz | -18 dB | About 20 to 120 Hz |
| Front left and right | Subwoofers | About 50 to 120 Hz | -18 dB | About 40 to 300 Hz |
| Centre | Subwoofers, front left and right | About 60 to 120 Hz | -18 dB | About 50 to 300 Hz |
| Surrounds and backs | Subwoofers | About 70 to 120 Hz | -18 dB | About 60 to 200 Hz |
| Heights | Subwoofers (optional) | About 80 to 120 Hz | -18 dB | About 80 to 150 Hz |
The guide suggests about 130 Hz for Fsiso. On Denon and Marantz that isn’t possible, as the table below explains.
The community guide and Denon and Marantz behaviour, side by side
Where Denon and Marantz receivers behave differently from what the community guide describes, we show both.
| Topic | Community ART calibration guide | On Denon and Marantz |
|---|---|---|
| Fsiso | Adjustable. Start around 130 Hz, anywhere from 120 to 150 Hz | Locked. The field accepts a new value but reverts to 150 Hz |
| Curtains | Set both ends per speaker, using the ranges above | Only the upper curtain matters in ART. We set the subwoofer upper curtain around 200 Hz |
| Subwoofer self-support | A sub group supporting itself is a valid set-up | Every group needs at least one other group supporting it. Self-support alone wasn’t enough |
| Centre as a support speaker | The example lets the fronts support the centre and doesn’t use the centre as a supporter | The centre never supports other speakers in a cinema set-up, which matches StormAudio’s advice |
Denon and Marantz specifics
- Set the receiver’s Directional Bass setting to Standard. With directional bass on, Dirac says it interferes with ART, and forum users report they can’t edit the subwoofer groups’ support levels.
- If Dirac reports too much support, look for the coloured dots in the support area. Users report they flag the cross-connections causing it, and removing one clears the error.
- ART filters apply in stereo modes too, but users report the receiver’s 2-channel playback setting needs to be Auto, or you can keep a separate slot for music.
- Settings such as crossovers, levels and distances are locked while an ART filter is active. Adding EQ afterwards is not recommended: StormAudio warn it upsets ART’s precise timing.
Target curves with ART
- Use the same bass shape on every group. Big voicing differences between speakers weaken panning and object placement.
- The community guide suggests a smooth rise of 3 to 6 dB below about 80 to 100 Hz, with 80 to 300 Hz kept flat and no sharp shelves.
- Keep the target within about 4 to 5 dB of the measured average. Asking for more makes Dirac boost into nulls.
- If bass sounds lighter than before, that’s usually ART and Bass Control accounting for all the subs together. Raise the target below 100 Hz by a few dB.
Reading the spread graph
The spread graph is the shaded band showing how much the response varies across your measurement positions. After each change, calculate and compare the corrected spread with the previous one. Screenshots side by side make small changes easy to see.
- Aim for a narrower corrected spread in the bass.
- Check above Fsiso too. One AVS Forum user found that adding surround support smoothed the bass but made the spread worse above 150 Hz, because ART had changed the phase there.
- Watch for the band narrowing between about 40 and 120 Hz in a way that sounds thin. Heavy support can reduce decay so much that bass feels lacking.
- Then listen. Use stereo music with no upmixer to check you can’t hear surround speakers helping, and a panning test such as Dolby’s Leaf demo to check effects still move freely.
How you know you’re done
The community guide’s checklist: tighter, cleaner bass, less boom, a more even sound across seats and better clarity. Don’t chase a perfectly flat graph or a dramatic change. In an already good room, ART’s improvement can be subtle.
The Denon and Marantz behaviour is reported by users on current firmware and isn’t documented by Dirac, so treat it with some caution.
Sources
- Dirac Help Centre: ART Setup Guide
- Dirac Help Centre: ART channel group and support settings (technical guide)
- Dirac Help Centre: ART FAQ
- Dirac: ART use case definition and setup guidelines
- Practical Dirac Live Active Room Treatment (ART) Calibration Guide (community guide)
- Dirac Live Guide (community, 2025): StormAudio MWAVE 2024 tech talk notes, group priorities, spread graph analysis
- HCFR podcast with StormAudio: Dirac ART (French)
- StormAudio: How to perform a Dirac Live ART calibration (video)
- Marantz: Dirac Live manual, locked settings
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