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Comment by rsync | Hacker News Reader

Just some food for thought…

If you are doing long speaker cable runs and are using 12 gauge wire anyway… At some point it occurs to you, why not just use Romex ?

And, in fact, it’s a very good choice. 12/3 romex - typically used in three Way lighting circuits - gives you two speaker pair in one nice package.

Two downsides:

First, it can be confusing for future electricians, etc., who do not expect romex in the wall to be used for low voltage.

Second, stereo terminal connectors are not typically designed for solid copper and that can get a little frustrating and complicated.

… but then you think about it a little more and it occurs to you:

why not just build terminal blocks and make connections with WAGO lever nuts ?

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Romex is grand at audio frequencies but what's even better is just sticking the amplifier in the speaker.

What you get from vanilla integrated speakers today is something that would have cost tens of thousands in the 90s and would not have been available in the 70s: dedicated amplifiers for each speaker element, with electronic crossovers and, if you want it, room correction.

If you stick the amplifier in the speaker, then you have much lower voltages and currents in the cable to the speaker, so you are, perversely, much more sensitive to noise that couples into your wiring.

As a silly and dramatic experiment, touch a wire connected to a passive speaker (without power applied — don’t zap yourself!). You won’t hear anything. Now touch the center pin of an RCA wire leading to a powered-on speaker with appreciable low frequency response, e.g. a subwoofer. Bzzzzzzzzz!

No I have a digital connection to the speaker, because I am modern and rational.

This is why balanced cables exist.

I really don't know why stereo components do not communicate digitally via ethernet cables. The only thing that won't work for is the output of the power amp.

My stereo is the usual rat's nest of various cables and connectors. I also have a tub full of various plugs, adapters, etc. Wouldn't it be nice to have a receiver that just had an ethernet connector on the back? Run it to an ethernet switch, and plug your turntable, TV, cassette player, into the switch?

One cool consequence is your components could be anywhere in the house, as any component could play over any powered speaker in the house.

> I really don't know why stereo components do not communicate digitally via ethernet cables.

If you’re building a new pro audio setup today, be it studio or even live sound, that’s likely how you’re doing it.

Even 20 years ago we had digital audio routers that worked pretty decently (not great, but well enough). This was a recording studio of course, not a home audio setting.

The reason we don’t have this in consumer audio is almost certainly cost. Now you need to add a ADC, Ethernet, and a small chip to run it all. Meanwhile nobody wants to run cables anymore and WiFi is everywhere. But of course putting WiFi in everything drives cost too.

I've used a couple of single/dual/tri-band wireless transmitters to hook up speakers, and I'd say I'm not really a fan. You have to be ok with dropped packets from interference (which happens pretty frequently if you're also sharing your 2.4/5/6ghz spectrum with WiFi), which is audible as silence or wrong sounds.

Or you're using a protocol that does retransmission/buffering, which introduces noticeable latency with the video or even between speakers.

WiFi is not so good as a replacement for wires — the latency is too high. The main contenders seem to be Dirac and AVB, both of which run over Ethernet. Dirac uses entirely ordinary Ethernet, and AVB wants some fancy extensions, which will bump up the price of your switches quite a bit.

For good audio, you want known, controlled latency, preferably with quite precise timing. For live audio, or for a fully convenient replacement for analog cable, you want that known latency to be very short.

And you either need no drops or you need an entire drop + retransmit cycle to fit within your latency. (Hmm, FEC could be used, I suppose — encode packets such that an entire lost packet could be recovered from the preceding packets plus the next couple packets.)

In the professional world, Dante seems to be taking over as the Audio over Ethernet solution.

I stream TV and music over the intertoobs all the time. It works fine. The bandwidth on a home network is much higher, so it should be fine.

The $10 Lightning to 3.5mm dongle for my iPhone has a microcontroller with RAM and an ADC, and the $20 lightning to Ethernet adapter has an Ethernet phy in it, so it's just a matter of someone getting funding, building it, and selling such a product. Latency would be a concern, but get a good firmware engineer on it.

It should be noted that the wifi version of this is sold by Sonos though I don't think they do surround sound for movie watching, but are focused on multi-room audio.

Sonos does surround audio with their sound bars, and you can connect them with Ethernet. There's also a hack to take the IKEA Sonos bookshelf speakers and connect them to different speakers, eg https://makezine.com/article/maker-news/hacking-the-sonos-ik...

There are wireless standards for this, no need for ethernet

https://www.wisatechnologies.com/speakers

I tried wireless speakers. They had poor fidelity and the music was often interrupted by static and dropouts.

The same thing happens with my Roku remote when I plug headphones into it.

No thanks.

Sonos works over WiFi just fine.

Doesn’t twisted pair solve this problem? You can encode signals in the difference in voltage between the two wires which means that any noise which occurs in both wires cancels out?

We have gotten pretty good at sending low voltage signals over wires with little to no noise so it seems like we can apply similar principles to audio gear?

Balanced signals are widely used in professional gear, and twisted pairs indeed reduce loop area, but it’s not perfect. I once helped out in a sound booth where the cables picked up AM radio, and some nonlinearity in the system made it audible.

The mechanical design of pro audio balanced cables is poor and it's common to end up with a bad one in the field. A balanced amplifier with one input connected to a long unterminated wire is way worse than a single-ended cable would be under the same conditions. Even in consumer home use XLR cable ends will fail. We're stuck with it unfortunately unless you want full custom gear.

Genelecs and other pro-audio gear can get their signal via AES/EBU. Digital all the way through the chain up to the speaker is fantastic!

> I once helped out in a sound booth where the cables picked up AM radio

This right here is part of the reason the "coathanger versus cable test" annoys me so much. All these wonderful graphs "proving" that cables don't matter never take environmental noise into account, which is frustrating because in reality that's exactly what you're testing.

The fact that you could pick up AM radio inside a sound studio means that, for experimental purposes, that environment is simply not good enough.

Are expensive cables mostly bullshit? sure. Do better cables still make a difference? My personal experience tells me absolutely yes, just usually not enough to matter to 95%+ of people.

Pro audio “snakes over cat5” seem to be thing now. Performers will probably connect their gear to the stage box using analog cables for the foreseeable future, but the big connection to the mixer seems likely to be digital in most new installations. (Just an analog snake cable, materials alone, may be more than the complete installed cost of a digital replacement.)

It's digital to the active speakers, and everything necessary happens there. I have a pair of genelec 8361a actives. They can become anything you want.

Meridian Audio have been making active digital speakers for over 25 years.

SPDIF input to every speaker with custom DSP to do digital crossover tuned to the cabinet and particular cones.

Assuming it's well designed. If so, this cant be beat.

Arent studio monitors this?

A lot of professional audio gear uses 5.08mm connectors. I bet WAGO makes some of them!

But be careful with NM-B cable. I didn’t find an exact reference in the NEC, but I bet that Article 200 and friends would not approve of the reuse of the bare conductor for anything other than ground and might also disapprove of using the white conductor for anything other than neutral. (If you’re not installing the cable in the wall, maybe it’s not subject to the NEC.)

Get some nice TC cable instead.

I wonder if we're misunderstanding each other ...

I am not suggesting you dual-use your high voltage romex and also send audio signals on it ...

I am suggesting you run additional runs of romex dedicated solely to audio.

This would be NEC compliant.

Would it? You’re allowed to use chapter 3 wiring methods for audio, but two speaker circuits is four “ungrounded conductors.”

Red and black are fine for this purpose. I’m not so sure about white and bare.

Can you tape the ends red and black in this case? I thought there were some provisions for options there in case you had some super heavy cable but wrong color

The rules are different for <=4 AWG wires versus smaller wires. I don’t know why.

You can use tape or heat-shrink to re-identify a wire if its 4 AWG or greater or if it's part of a multiconductor cable (which NM-B is).

The reason for the 4 AWG rule is probably an economic one. Having spools of larger conductor cables in a variety of colors is not inexpensive. Allowing the reidentification seems reasonable, though I'd probably argue the cutoff could be thinner than 4. The multi-conductor cable exception is a practical [and economic] one. You might not be able to get multi-conductor cable assemblies with the exact color coding you need.

Ahh - makes sense - high amp cables get insanely expensive

> using the white conductor for anything other than neutral.

Where the NEC applies, you can use the white conductor in a multiconductor cable for anything as long as it is "permanently reidentified", that is color coded where it is exposed. cf NEC 200.7.

I used 14ga (IIRC) security wire to wire all the ceiling speakers in my house back to the central amp.

It’s stranded copper with 2 conductors. Easy to run, fits in all the connectors, is cheap, and comes on big spools.

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