Are 4K HDMI Cables All The Same?
4k hdmi cable signal errors

I was wrong about 4K HDMI Cables? Or Was I?

I just ran into a situation hooking up 4K HDMI cables that caused me to re-think a strongly held position. I’m usually an easy-going type of person, but once in a while, a few things really bother me.

As a consumer, and later as a product manager / marketing manager at several high tech companies, I have always had the customer’s interest at heart.

As a smart home systems integrator, I am upset when I see shady business practices or questionable sales tactics focused on profit (and greed).

Charging What The Market Will Bear

Selling grossly over-priced accessories, especially 4K HDMI cables, has often put me on a mission to educate the regular guy or gal and set the record straight.

I have been vocal in telling friends, clients, and customers that there is no difference in HDMI cables. Under most circumstances, the least expensive no-name cables provide the same result as the expensive fancy brands.

That used to be true, but now I must admit, I learned the hard way that the answer is “it depends”.

Gold-Plated AV Cables

If you’ve been around the consumer electronics and stereo industry, then you’ve probably come across the salesperson trying to sell you gold-plated (literally!) AV cables.

Whether it’s speaker wire with 100% pure, oxygen-free solid copper wire, or simply connection wires for your DVD player or other device with RCA jacks, there are always several grades to choose from.

When you ask for the cheapest option, the store will show you their basic house brand or generic/unbranded cable and then proceed to tell you all the reasons why it is a bad choice.

Sleazy Retail Sales Pitches

“You are investing a lot in buying this fancy stereo. Do you really want to hook it up with a junkie cable that will ruin the sound?”

“You need these solid-gold cables to really hear the music. Isn’t that why you are buying this system to replace that little speaker you have now?”

“The gold-plated is ok, but I think you should really get the solid-gold wire. Isn’t quality sound worth just a little more?”

And then there’s my favorite, “A chain is as strong as the weakest link. Your spending $XXX on a great system, don’t ruin it by skimping on the wires and connections.”

A Nugget of Truth

The reason they got away with this is because there is a glint of truth in everything they were saying. Speaker wires and connecting cables were (and still are) analog wires.

They carry an infinitely varying signal (voltage) that is an electrical representation of the sound (or video) signal.

I’ll probably make engineers and physicists reading this cringe, but in a great oversimplification, analog signals are very delicate. The signal weakens as the cable gets longer and the signal can be affected by nearby electrical or magnetic interference.

The quality of everything going into a typical analog AV cable makes a difference.

Metal purity, wire thickness, insulation materials, connectors, and wire soldering

Every one of these factors, and many more, can *theoretically* affect the sound that you hear from your stereo. I say theoretically because it takes certain conditions for these differences to be noticeable.

Physical Factors That Affect HDMI Cable Quality

Distance and interference are the two big ones. If you are running long av cables and they run near motors (air conditioning, refrigerators) or other electro-magnetic devices (fluorescent lights), it is much more likely they can pick up electrical noise that interferes with the signal.

Unless you are an audiophile, you probably, like me, can’t hear the difference.

Although theoretically those $100 or even $1,000 speaker wires might be a little better, the store brand $5 wire will usually work just as well.

I’ve read stories of people taking lamp cords and using them instead of speaker wires. Not something I would even consider, but interesting anecdotes.

Digital Wires – It’s all about the 1’s and 0’s

HDMI (which stands for High Definition Multi-media Interface) is a digital transmission system, it is not analog.

My engineer buddies may cringe at this simple analogy, a digital cable either delivers the signal or it doesn’t; there is no in-between.

If the post office delivered mail like HDMI cables deliver TV signals, you either receive a letter or your don’t. You wouldn’t receive a letter with a dirty or torn envelope and the contents is unreadable.

How To Tell If An HDMI Cable Works?

My rule for using HDMI cables (until now) was very simple. Buy any cable you like, plug it in, and if it works then you are all set. If it doesn’t work, then you need a different cable.

When an HDMI cable doesn’t work, you’ll know it. Because the signal “didn’t get delivered” your TV has no choice but to display a blank dot on the screen.

So when you see a snowstorm on your screen instead of a picture, you know you have a cable problem.

If the audio is not received properly the TV will auto mute so you’ll simply hear silence.

Not Just My Opinion

This wasn’t just my personal opinion. Although not widespread, there have been articles published that explained why you didn’t need to spend big bucks on fancy HDMI Cables.

Now in fairness I do need to say that digital cables such as HDMI will also have transmission issues when using fairly long cables around 30 feet or more. In that case, higher quality cables can make a difference, but again, it either works or it doesn’t.

Digital versus analog

The reason digital transmission of signals is more reliable can be explained with an analogy. Digital information consists of 1’s and 0’s. The signal is converted into a number and that number is transmitted across the wire – not the actual voltage level of the signal.

Think of it this way: If someone asks you if it is day or night, you look out the window and if you see any light you answer “day”, if it is dark you answer “night”. Early dawn, the mid-day sun, or late afternoon are all “day”.

The amount of light doesn’t matter. Very dim or very bright is still “day”. Although clouds, fog, or haze affect the amount of light, you can still tell it is daytime.

Clouds, fog, haze and other weather conditions are like distance and noise on a signal line. With a digital transmission, it affects the signal, but unlike analog, doesn’t prevent understanding the value (on or off, 1 or 0) at the far end.

Only major interference, like a total eclipse of the sun, would change the results. Use digital cables within their distance limits and you’ll have almost no problems.

For very long distances and use inside walls or large home theaters there are specialized HDMI cables which are called “active cables”. These cables have electronics incorporated into the cable itself to amplify and strengthen the signal so it can be sent over longer or thinner cables.

Active HDMI cables are more expensive if you need the increased distance or thinness, but for most consumer applications they aren’t necessary.

4K and HDR Changes Everything

As technology continued to evolve and we went from HD (sometimes called 1K TV) to 4K TV (often called UHD or Ultra HD TV) everything changed.

Although we are still using HDMI cables, sending so much more data down the same set of wires is really a magic trick of amazing proportions.

So much had to be changed “under the hood” of HDMI to make this work and work well.

In addition to more raw data, the introduction of HDR (high dynamic range) and wider color gamut (more colors in the picture) has put even more demands on the transmission system.

It’s All About The Data

Now the huge increase in data requirements means we need to use higher quality HDMI cables. Ok, you’re probably thinking “No big deal, just do like before. Buy the cheapest cable, try it out, and if it doesn’t work, just get a better one”.

That was a good strategy in the past, but no longer. The problem is that 4K isn’t a single specification or standard, it is a range of features and performance with different bandwidth and data rate requirements.

If older HDMI cables were like a good one-lane road, then it didn’t matter if you were on a 2-line, 4-line, or multi-lane freeway, they would almost always work because the road was always *at least* one lane wide.

The challenge now, which I learned the hard way, is that newer TV standards like 4K and HDR are too flexible for their own good. The devices will adjust to the lowest common denominator, often silently.

If the HDMI cable between your video source and your TV can’t handle the bandwidth for 4K running at 60 frames per second (fps), the TV might automatically shift to a lower frame rate.

You will still see your program on your TV, but you won’t see the quality you expect.

Similarly, if your HDMI cable is capable of supporting 4K but doesn’t have the added bandwidth for HDR, your TV will simply shift to displaying a regular 4K non-HDR picture (sometimes called SDR – standard dynamic range).

Currently, HDMI bandwidth ranges from 10 Gbps up to 18 Gbps for full quality 4K video. Work is already underway to support 8K video and beyond with bandwidth requirements up to 48 Gbps!

If you want to see more of the nitty gritty details (with all the various combinations of 4K) Belden has great info.

To continue with the day/night example, with HDR, 4K resolution, and high frame rates up to 120 Hz, it’s like we are constantly looking outside during dawn or dusk – right at the edge of the transition between day and night. Look the wrong way, and you’ll make the wrong choice.

What You See Is What You Get

I have to thank Apple for helping me realize what is going on with HDMI. I hooked up an Apple TV 4K media player to an amazing LG OLED TV and was a bit disappointed by the quality of the image.

After checking settings and fiddling around trying to get the Apple TV to display the 4K HDR video I expected, the message above flashed on the screen

After, what I admit was a knee-jerk “WTF” reaction, I realized that my existing HDMI cables purchased many years ago from unknown sources with unknown brand or quality, were simply not up to the job.

How To Shop For Quality 4K HDMI Cables

Certified HDMI cables

Only buy certified cables. These are cables that have been tested by an outside agency such as DPL-Labs to insure the cables actually can do what the seller claims. Look for the official certification label on the package.

Look for HDMI cables that support at least 4K, 60fps, 18 Gbps bandwidth, and HDR. You may find some cables that support even higher bandwidth, but anything that supports these three key metrics will be able to handle just about anything you can throw at it.

Avoid cables that claim to be 4K but nothing else. Low-end, cheap cables that only support 10 Gbps of bandwidth are allowed to claim they support 4K but that is barely the truth.

For typical distances up to 30 feet use passive cables. Don’t venture into the relatively murky waters of active cables or fiber optic cables unless you really need very long cables. (If you do, I suggest working with a consultant or company that has experience in this area as long cables are also much more expensive so you don’t want a costly mistake.)

Don’t Worry about ARC, eARC or Ethernet features. Some HDMI cables advertise their compatibility with extra features such as ARC (audio return channel) and integrated Ethernet networking. Although these are an important distinction for non-4K cables, all HDMI cables that meet 4K/60/18 Gbps specs will always also support ARC and Ethernet so you don’t have to specifically look for these additional capabilities.

Be careful buying online or at big box stores. Online websites and big box retail stores don’t understand what you now do. Most cables sold do not meet all the minimum specs of 4K/60/18 Gbps, and they do not carry DPL labs certification. You can find quality cables, but you can also find them happily selling junk.

This is an example of an online listing for a 4K/8K certified 10-foot HDMI cable.

My last advice is optional. Never buy a cheap non-certified HDMI cable again. Even if you don’t have 4K TV or streaming media devices now, it is prudent to start planning for the future buy 4K/60/18 Gbps certified HDMI cables.

Document your work

Bonus tip – label your cables. Take the time to put a label right on the cable that summarizes the tech details. In a few years, that perfect cable you bought now might need to be replaced again.

Put a label on each end of the cable with all the relevant details. You don’t need to buy a fancy label machine. Just make sure it is durable, won’t fall off, and the writing won’t smudge or fade.

I still use my trusty Brother label machine which costs less than $40, for my general purpose labels. It’s fast and convenient to use.

For professional use, where I have to label Ethernet cables, coax, speaker wire, and other low-voltage cables, I use a task-specific commercial label maker. It’s more expensive, but has presets for the types of cables I frequently use and has different label material options for heavy duty use.

I suggest putting two labels on each one. One label describes the technical details of the cable itself (4K, HDR, 18 Gbps, etc.) and the second label described the use “LG TV HDMI Input #1”.

It is likely that you may swap cables or move them around and forget to update the usage label, but at least the tech specs will always be accurate and stay with the cable itself.

Your increased cost of buying certified HDMI cables is worth the peace of mind and future proofing. The newer 4K/60/18 Gbps cables will always work flawlessly with your existing older equipment.


Automation technologist and problem solver

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