Which HDMI cable to get?

Guden Oden

Senior Member
Legend
The ones I've looked at have either been crazy silly expensive, and with no ferrite bead EM filters, or, el cheapo-looking (but probably not bad) with no ferrite bead EM filters.

Don't HDMI cables HAVE any beads on 'em?

Which cable is it recommended to get anyway? It does NOT have to be long. In fact, it's probably better if it isn't all that long... 2-3M or so.
 
Get the cheapest cable you can find that looks like it was contructed properly. Don't buy the Monster Cable brand cable, as it will perform identical, but costs 3x more. Not to mention that Monster is a horrible company that sues small companies for using the name monster even if they aren't a competing product.
 
µCOM-4 said:
Dude you can get a clip-on ferrite filter for like $5. What's the big deal?
The clip-on approach might be an option, except it would obviously not look (nearly) as good. I like cables looking professional. Also, I believe the conductors actually need to be wound around the ferrite ring for it to have more than a cursory impact, and that is obviously not possible with a clip-on device...

Also, I'm not about to buy any monster cable, those are crazy overpriced, and I bet if I was to cut one of their overpriced items open, it'd be no different than a cable costing 1/10th as much or maybe even less, maybe apart from a fairly pointless gold plating on the connectors.
 
Also, I believe the conductors actually need to be wound around the ferrite ring for it to have more than a cursory impact, and that is obviously not possible with a clip-on device...

AFAIK monitor cables are not wound around the filter nor any of the other cables that comes with game consoles. The only cable that is actually wound around the filter are some telephone cables for modems. In fact I have NEC-Tokin snap-on filters that you simply snap-on to the cable. It has two halves that you clamp onto the cable and snap together. It's made for big cables and the instructions clearly state that the cable goes straight through. There's no way you can wind a big cable through a small filter unless you break it into indivdual strands.
 
Anyone has any links for some clip-on filters? Would be cool to check out just for kicks... Preferably some online store that ships internationally, or else it'll be ONLY for kicks in case I feel like opening up my purse and splurge. :)
 
A good cable doesn't need ferrite around it. But it might make a cheap cable better. As for winding it through and around the ferrite: that would depend on what you want to do with it. It mostly makes a smaller ferrite core function better, so it's only about cost reduction.

Some background: if you take a plain, dual-wire cable that carries the signal and ground, it suffers from EM interference. You can shield it, which takes care of the interference, but makes the cable more expensive. Another way to remove the interference is, to have one wire carry the signal, and the other one the opposite (negative) image of the signal. Like, when the signal is +1 V, the other one will be -1 V. And when the signal is +2 V, the other one will be -2 V. That way, any interference will have the same impact on both, and to restore the original signal, it is sufficient to use the difference between them as ground. Other solutions alike that one are used as well.

The first type of cable (shielded) is best, but it does create impedance (resistance, -dB). And it is more expensive. That's why we use UTP (Unshielded Twisted Pair) as Ethernet cables. And the "Twisted pair" bit is because you want the signal pairs to be as close together as you can get them, and as equally exposed to the interference as you can make them.

As for the ferrite cores around the cables: they damp high peaks in the signal. They cause a moderate bit of impedance (which reduces the quality of the signal a bit), but remove sharp peaks that might damage the electronics.

As all monitors and televisions nowadays are auto-adjusting, the peaks are filtered in any case. So you're left with the choice between shielding and unshielded. Which is only a problem for signals over medium or long distances and severe EM interference. So you choose shielded for those, and unshielded, but good quality twisted pairs for everything else nowadays. Add some more grounded wires to be able to make pairs, if required. Even without using opposite signals on both wires that make up a pair, you get a good signal by using a comparator between the ground and signal ones to extract the signal.

You could compare the ferrite coils with a blur filter: it smooths everything out a bit, including the signal itself. So they don't improve the signal quality.
 
Last edited by a moderator:
Diguru: thanks for the awesome explanatory post. I was looking for a cable with ferrite beads on it because bloody EVERYTHING is beaded these days. Almost anyway. Heck, even joypad cables have beads on them now, I assumed it was for EM emission standards compliance, and thus wanted my HDMI cable to have it too, but it seems it actually doesn't really need it. At least according to you. :)

HDMI uses differential signalling with twisted pairs and an accompanying ground as well I believe, and I would expect all cables to be shielded too, to some extent anyway. :) Heck, most PC cabling IS shielded. I'm not sure about SATA though, those might be unshielded, considering the connectors are all plastic.

CNCAddict:
Thanks for the linkie, but at the moment newegg doesn't ship internationally... I don't really need a HDMI cable anyway right now, as it's meant for hooking up the PS3 I'm intending to buy next year (hopefully :D) to my TV using a HDMI to DVI dongle (which I haven't purchased yet either. I just like to be prepared, that's all...heh.
 
uh... beads?

I am probably behind the cable times, considering I still use lamp cord to connect my speakers (what? they're not very good to begin with, so it sounds fine).
 
Back
Top