I think it's good to leave just so all can see how wrong it can get things. Perhaps EDIT at the bottom to acknowledge that. Others might have other preferences though.
-
Welcome to ASR. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!
Active Room Treatment (ART) by Dirac
- Thread starter Flak
- Start date
Delete it.
ThELiZ
Active Member
I’ve added a note at the top of the post
You might think it's harsh...until someone designs a bridge with AI (and collapses) or gives advice on better brakes (and crashes).
I still stand by my statement: play stupid games, win stupid prizes! (not a personal attack, just words of wisdom)
ThELiZ
Active Member
I get the sentiment.
I just want to know why I’ve splashed out on Dirac ART and lost a set of speakers
I just want to know why I’ve splashed out on Dirac ART and lost a set of speakers
Right now, my suspicion is user-error. Your issue is new and I've never heard anyone else complain. There are tons of 3800 ART users over at AVS. You can try posting there!I get the sentiment.
I just want to know why I’ve splashed out on Dirac ART and lost a set of speakers
lessthanjoey
Member
- Joined
- Mar 3, 2023
- Messages
- 43
- Likes
- 57
I prefer to delete it too - I don't think it serves any purpose and can only confuse people who don't read carefully.
I reported the post but admin doesn't see the need to delete it. So, in the future every search engine will point to your posted totally false info. Way to go!
lessthanjoey
Member
- Joined
- Mar 3, 2023
- Messages
- 43
- Likes
- 57
Huh? ART doesn't make you lose speakers. Can you restate what the issue is?I get the sentiment.
I just want to know why I’ve splashed out on Dirac ART and lost a set of speakers
I agree with the admin. It is very educational post. If people don't read the rest it is at their own peril. But it does show how shallow and wrong the bots can be.
lessthanjoey
Member
- Joined
- Mar 3, 2023
- Messages
- 43
- Likes
- 57
You could keep it educational by saying you asked chat GPT and it gave a bunch of wrong data. The issue here is that this post gets ingested by google and spat back out as a quick answer. That's still google's fault, but I still don't think that wrong wall of text is needing.
In English if you don't mind. And to to the actual point?
So it's OK to just add an explanation with small font and leave the huge bold text AI BS message there?
ThELiZ
Active Member
I have a 7.2.4 system. I’ve ran a Dirac ART calibration. I can measure each speaker independently with REW and see the correction working.
The problem comes when I am watching content. I’ve checked the ‘info’ button on my AVR and every channel is active, apart from my rear surrounds. It looks like Dirac ART isn’t using these speakers. Nothing is coming out of those speakers.
I’m sure it’s user error, but I’ve no idea what I’ve done wrong.
ban25
Major Contributor
- Joined
- Nov 5, 2022
- Messages
- 1,355
- Likes
- 1,472
Can you try another slot with just DL/DLBC, play the same content, and verify that all channels are active?
Another possibility is that Zone 2 is active, which would probably disable the rear surround speakers.
ThELiZ
Active Member
Thanks bud. I’ll give that a try tomorrow. It gets a bit much with this stuff sometimes!
lessthanjoey
Member
- Joined
- Mar 3, 2023
- Messages
- 43
- Likes
- 57
Ah, gotcha - yeah has to be some setup/configuration thing. I like ban25's suggestions.
I think subwoofers are generally more cost effective bass source so you probably want to invest in more subwoofers than in bigger speakers and amps if space allows.
If this is proven false, as I suspect there's a good chance it's going to be, Dirac and D/M ought to sue OpenAI for distributing false and damaging information.EDIT: This info from ChatGPT includes a lot of incorrect statements. It’s left here both as a reminder not to trust the bots and to potentially use as needed for investigating the issue I’m having.
All the channels engage fine when independently measured with REW. But they are not active when playing Atmos content. This led me to ask the ever dependable ChatGPT (which is never wrong):
If you tell me your AVR/processor model (and whether it’s Onkyo, Arcam, NAD, etc.), I can tell you exactly whether your unit’s ART implementation currently supports playback from those rear surrounds — or whether it automatically repurposes them as assist channels.
You said:
Denon x3800H
ChatGPT said:
Perfect — that explains it completely
Your Denon X3800H only supports Dirac ART (beta) in a limited channel configuration, and that’s why your surround back (rear) speakers are silent.
Here’s the breakdown:
Why Dirac ART Disabled Your Rear Surrounds
1. Current Dirac ART Support on the X3800H (as of Oct 2025)
The top layer (Atmos) and sometimes rear surrounds get reclassified as “assist” channels — used internally for pressure balancing, but not actively driven with playback content.
- Denon and Marantz’s ART implementation (on X3800H, X4800H, A1H, etc.) only supports ART for up to 7 main speakers + subwoofers.
- That means 7.1 (or 7.2) is the maximum active playback configuration under ART.
- When you run a 7.2.4 calibration, Dirac ART includes all 11 speakers in its control network, but only uses the 7 “bed layer” channels for actual playback correction.
In other words:
Your rear surrounds still contribute to ART’s room control, but Dirac has muted them for normal listening to stay within the hardware’s ART processing limits.
2. AVR Resource Limitation
The X3800H’s DSP cannot currently run ART across a full 7.2.4 speaker array.
So while you can measure all 11 channels, the AVR only processes ART for up to 7 + subs — the rest are silent (or assist).
- ART uses continuous, real-time feedback loops between speakers and mics — extremely CPU-heavy.
- Denon intentionally restricts ART to bed layer + subs to maintain stability and latency within HDMI audio specs.
3. Firmware Behavior
In most X3800H units:
This is why your AVR shows those channels “active” in the input layout (it’s receiving a 7.1.4 signal), but you hear nothing — the ART runtime disables them.
- ART calibration accepts your full layout.
- The exported filter then “drops” the Surround Back L/R channels during runtime.
- You’ll still see them in the UI and hear them during test tones, but not during playback.
Your Options
Option 1 — Use Dirac ART (7.2 only)
- Keep ART enabled for your main 7 speakers + subs.
- Enjoy the full benefits of real-time room control (it’s a big improvement).
- Understand that your surround backs are acting as assist speakers, not playback channels.
Option 2 — Switch to Dirac Live or DLBC
If you really want all 7.2.4 speakers to play content, switch to:
- Dirac Live Full + Dirac Live Bass Control (DLBC) instead of ART.
That allows the full 7.2.4 playback chain, though without ART’s active feedback system.Option 3 — Wait for Firmware Expansion
Dirac and Denon have hinted that future updates may enable full 7.2.4 ART on X4800H and A1H, but the X3800H likely won’t get enough DSP headroom for that.
Still, worth checking firmware notes periodically.
TL;DR
Feature Dirac ART (now) Dirac Live + DLBC Max Active Channels 7 bed + subs 11 (7.2.4) Rear Surrounds Disabled or assist-only Fully active Real-Time Feedback No
Best Choice if you want… Maximum room control Full Atmos playback
Would you like me to show you exactly how to re-export your Dirac project to use Dirac Live Bass Control instead of ART, keeping your full 7.2.4 channels active?
That would restore your rear surrounds immediately.
You said:
Doesn't the x3800H use the same SHARC chipset as the x4800h?
ChatGPT said:
Excellent question — and you’re absolutely right to be skeptical here.
Yes — on paper, the Denon X3800H and X4800H both use Analog Devices SHARC DSPs — but the way they’re implemented and allocated makes a huge difference in Dirac ART capability.
Let’s dig into the real reason why the X4800H can eventually support more advanced ART configurations, while the X3800H currently cannot
The Technical Breakdown
1. Both Use SHARC DSPs — but Not Identically
This distinction is crucial.
- X3800H: uses a single Analog Devices SHARC+ (ADSP-21593)
- X4800H / A1H: use dual SHARC+ DSPs (two 21593 chips)
One SHARC DSP means all tasks — audio decoding, upmixing, bass management, and Dirac processing — must share limited real-time processing headroom.
Two SHARC DSPs allow Denon to dedicate one chip almost entirely to Dirac Live/ART computations, with the other handling decoding and matrixing.
So even though the architecture is the same, the X4800H has literally twice the DSP horsepower.
Dirac ART is not just an EQ or FIR filter like Dirac Live — it’s a closed-loop control system that:
2. Dirac ART’s Load Is Massive
That kind of algorithmic load scales exponentially with channel count.
- Continuously analyzes acoustic pressure from all speakers
- Computes inter-channel corrections in real time
- Updates speaker output dynamically (hundreds of times per second)
Running ART on 11 channels (7.2.4) takes roughly 2–3× more cycles than on 7 channels.
So:
- On the X3800H, there’s just enough room for 7.1 ART
- On the X4800H or A1H, Dirac can unlock 7.1.4 ART because of the second SHARC processor
3. Firmware Limits Are Hard-Coded for the 3800H
Denon’s firmware for the X3800H currently enforces:
Even though the chip could theoretically handle a little more, Denon doesn’t allow higher channel ART processing on the X3800H to:
- ART → max of 7 bed channels + subs
- ART + Atmos → disables surround backs
So this is both a hardware and product segmentation decision.
- Maintain reliability and low latency
- Prevent overheating or DSP overload
- Differentiate it from the X4800H and A1H tiers
4. Future Possibility?
Denon has not announced plans to unlock full 7.2.4 ART on the X3800H — and given the single-DSP limitation, it’s unlikely to happen.
All current ART firmware (as of late 2025) limits the 3800H to 7 main playback channels.
Feature X3800H X4800H A1H DSP Configuration 1× SHARC+ 21593 2× SHARC+ 21593 2× SHARC+ (higher clock) ART Max Channels 7.1 (bed only) 7.1.4 (full 11ch) 9.1.6 (full ART) Rear Surround Playback under ART Dirac Live + DLBC
So, yes — same family of DSPs, but different count and allocation, which is why your X3800H mutes the rear surrounds when ART is active.
Would you like me to show you how to confirm (in your Dirac project and AVR) whether your surround backs are assigned as “Assist” channels, so you can see this behavior directly?
Nice way to further destroy the planet we live on.
Similar threads
