We checked the published specifications for 15 current AV receivers and 18 loudspeakers. Three receivers commit to a 4-ohm load. Fourteen of the speakers dip below 4 ohms. That gap is the subject of this article.
Last verified: 8 August 2026
The finding
We went through the published specification pages for every receiver and speaker in our gear database and recorded two things: whether the amplifier manufacturer publishes a power rating or impedance-compatibility statement at 4 ohms, and what minimum impedance the speaker manufacturer publishes.
Here is what came back.
Of 15 amplified AV receivers, three publish an explicit 4-ohm rating:
| Receiver | What the manufacturer publishes |
|---|---|
| Onkyo TX-NR6100 | Speaker impedance 4–16 ohms |
| NAD T 778 | 170 W continuous into 4 ohms; 280 W IHF dynamic into 4 ohms |
| Arcam AVR11 | A full parallel rating set: 100 W into 4 ohms with 2 channels driven, 120 W at 1 kHz, 85 W with 7 channels driven |
Twelve are silent on it. All five Denon models we checked publish ratings at 8 and 6 ohms only. All four Marantz models: 8 and 6 ohms only. All three Yamaha models: 8 ohms only.
That is not a criticism of those receivers. It is a statement about what their manufacturers will and will not commit to in writing, which is a different and more useful thing to know.
Meanwhile, of 18 speakers that publish a minimum impedance, 14 drop below 4 ohms:
| Minimum | Speaker | Nominal impedance claimed |
|---|---|---|
| 2.9 Ω | Focal Vestia N°3 | 8 Ω |
| 3.0 Ω | Bowers & Wilkins 603 S3 | 8 Ω |
| 3.0 Ω | Q Acoustics 5040 | 6 Ω |
| 3.2 Ω | KEF Q3 / Q6 / Q7 / R7 Meta | 4 Ω |
| 3.3 Ω | Q Acoustics 5020 | 6 Ω |
| 3.5 Ω | KEF LS50 Meta | 8 Ω |
| 3.6 Ω | Polk Reserve R700 | not published |
| 3.7 Ω | Bowers & Wilkins 606 S3 | 8 Ω |
| 3.7 Ω | Wharfedale Diamond 12.2 | 8 Ω |
| 3.8 Ω | Polk Reserve R200 | not published |
| 3.9 Ω | Polk Reserve R350 | not published |
Look at the right-hand column. The Focal Vestia N°3 is sold as an 8-ohm speaker and drops to 2.9 ohms. The B&W 603 S3 is sold as 8 ohms and drops to 3.0. The KEF LS50 Meta is sold as 8 ohms and drops to 3.5.
Nominal impedance is close to meaningless as a purchasing input. It is a marketing-adjacent average. The minimum is the number your amplifier has to survive, and it is routinely half the nominal figure.
Why this matters, stated precisely
A loudspeaker is not a resistor. Its impedance varies with frequency, and it varies a lot — typically dipping near the port tuning frequency and again somewhere in the crossover region. When impedance halves, the current the amplifier must supply at a given voltage doubles.
Two consequences follow, and only one of them is the one people worry about.
The one people worry about: protection shutdown. An AV receiver driving a load below what its power supply and output devices are designed for will get hot. Most modern receivers respond by muting or shutting down rather than failing. This is annoying and it happens at high volume during the scene you most wanted to hear, but it does not usually destroy anything.
The one that actually breaks things: clipping. An amplifier asked for more current than it can deliver does not fail gracefully at the waveform level. It flattens the peaks. A clipped waveform contains high-frequency harmonic content that was not in the signal, and that content goes straight to your tweeter, which is a small coil of wire with very little thermal mass. Tweeters killed by “too little power” are killed by clipping, not by insufficient watts.
This is why the standard advice to buy more amplifier than you think you need is correct, and it is also why an amplifier that will not commit to your speaker’s load is worth taking seriously rather than shrugging at.
What “silent on 4 ohms” actually means
It does not mean the receiver will fail. Denon, Marantz and Yamaha receivers drive 4-ohm-minimum speakers in thousands of rooms every day without incident.
It means three specific things:
One: the manufacturer has not published a number you can hold them to. Denon publishes 105 W into 8 ohms for the AVR-X3800H and 135 W into 6 ohms. They publish nothing at 4. If you want to know what it does into a 3.2-ohm dip, the manufacturer has declined to tell you, and any number you find elsewhere is somebody’s measurement or somebody’s guess.
Two: most of these receivers have an impedance setting in the menu, and it is not a solution. Setting a receiver to “4 ohm” or “low impedance” typically reduces the rail voltage to keep the amplifier within thermal limits. It protects the receiver by making it quieter. That is a legitimate engineering response and it is not the same as being rated for the load.
Three: it is a decision input, not a veto. Plenty of people run KEF Q Metas off a Denon happily, at moderate volume, in a small room, with a subwoofer taking the bass load. The question is not “is this allowed.” It is “how close to the edge does my particular combination of speaker, distance, target level and room put me,” and that is arithmetic.
Working out whether it applies to you
Impedance risk is only a real problem when you are also asking the amplifier for a lot of level. A 3-ohm dip at 75 dB is nothing. The same dip at reference level in a large room is where receivers shut down.
So the useful question is not “is my speaker 4 ohms” in isolation. It is whether your amplifier has enough headroom that it never has to work near its limit into that dip.
Run your combination through the System Headroom Calculator →
It takes your speaker, your receiver, your listening distance and your target level, and returns how many decibels of margin you have. It also flags the impedance mismatch specifically: if your speaker dips below 4 ohms and your amplifier publishes no 4-ohm rating, it says so and quotes what the manufacturer does publish.
Two rules of thumb the arithmetic supports:
- If you have 6 dB or more of headroom, a sub-4-ohm dip is a non-issue for you. The amplifier is loafing and never approaches the current demand where the load matters.
- If you are at or below target, the dip compounds a problem you already have. You are asking an amplifier that is already at its limit to also deliver more current than its manufacturer will vouch for.
What to do about it, in order of cost
1. Change nothing, and check your headroom first
The cheapest fix is finding out you did not have a problem. If the calculator gives you comfortable margin at the level you actually listen at, stop reading.
2. Cross the speakers over higher
If you run a subwoofer, setting your mains to “small” with an 80 Hz crossover removes the bass from them entirely. Since the impedance minimum on a ported speaker frequently sits in the bass region near port tuning, this can take the hardest part of the load off the receiver without spending anything.
This is genuinely the highest-value free change available and most people with a subwoofer already have the setting available in their menu.
3. Add external amplification to the channels that need it
Every receiver in our database with 9 or more amplified channels has pre-outs, which means the front left and right — the channels doing the most work — can be handed to an outboard power amplifier while the receiver keeps driving surrounds and heights.
This is the standard upgrade path and it is why the pre-out count matters more than the watt count when you are choosing a receiver you intend to grow into. From our database:
| Receiver | Amplified channels | Pre-outs | Can hand off fronts? |
|---|---|---|---|
| Denon AVR-X1800H | 7 | not published | Verify before buying |
| Denon AVR-X2800H | 7 | 2 (subwoofer only) | No |
| Onkyo TX-NR6100 | 7 | sub + Zone 2 only | No |
| Marantz CINEMA 70s | 7 | 7 | Yes |
| Denon AVR-X3800H | 9 | 11 | Yes |
| Marantz CINEMA 50 | 9 | 11 | Yes |
| Yamaha RX-A6A | 9 | 11 | Yes |
| Denon AVR-X4800H | 9 | 11 | Yes |
The Denon AVR-X2800H is the trap here. It is a capable receiver at $1,299 with seven amplified channels, and its only pre-outs are the two subwoofer outputs. There is no upgrade path. If you buy it with difficult speakers, your next step is replacing it rather than supplementing it.
4. Buy an amplifier that commits to the load
If you already know your speakers are hard to drive, the three receivers above that publish 4-ohm ratings are the ones whose manufacturers will stand behind it. The NAD T 778 and Arcam AVR11 in particular publish something almost nobody else does: an all-channels-driven power figure, so you know what the amplifier delivers with everything running rather than with two channels doing the work.
That honesty is itself worth something. It is a great deal easier to plan a system around a manufacturer who tells you the uncomfortable number.
The one thing we are not going to tell you
We have not listened to any of these receivers and we are not going to tell you which one sounds better. Competently designed amplifiers operated within their limits are very difficult to tell apart in level-matched listening, and our opinion on the question would be worth nothing because we do not have one.
What we can tell you is which manufacturers publish which numbers, what those numbers mean, and what your particular combination computes to. That is the whole of what this page claims.
If you want listening impressions, What Hi-Fi and Stereophile have heard these. If you want measurements rather than manufacturer specifications, Audio Science Review has bench-tested several of them and their data is free.
Sources
Every figure above comes from the manufacturer’s own product page or specification sheet:
Receivers: Denon AVR-X1800H · AVR-X2800H · AVR-X3800H · AVR-X4800H · AVR-A1H · Marantz CINEMA 70s · CINEMA 50 · CINEMA 40 · Yamaha RX-V6A · RX-A4A · RX-A6A · Onkyo TX-NR6100 · NAD T 778 · Arcam AVR11
Speakers: Focal Vestia N°3 · B&W 603 S3 · B&W 606 S3 · Q Acoustics 5040 · 5020 · KEF LS50 Meta · Q3 Meta · Q7 Meta · R7 Meta · Polk Reserve R700 · R200 · Wharfedale Diamond 12.2
A note on completeness. Fifteen receivers is not the whole market. We excluded Anthem’s MRX series because Anthem’s own specification pages returned errors when we checked, and we will not publish a manufacturer’s power ratings on the strength of a retailer listing. If you know of a receiver that publishes a 4-ohm rating and is missing here, tell us at corrections@hifisystems.net and we will add it.
Related: System Headroom Calculator · How we work · The gear database