OP
- Thread Starter
- #21
I'm not suggesting "saving". I'm suggesting an alternative which may prove superior in a few respects, and let the market decide if those advantages are worthwhile.
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A thought that could improve the acceptance of active speakers
- Thread starter Steve81
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- Jun 5, 2016
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Not sure why PoE is better than a centralized amp rack (which you basically have to have anyway for the PoE injectors!) and standard speaker cable.
Ooh! An audio question where my IT background is relevant! Let's assume we're talking about ethernet cabling and connectors.
To get the cable count to 1 per speaker, the modern answer is wireless powered speakers like the KEF LS60. Still it's interesting to look at why PoE doesn't work very well as a solution.
Unless this thing is to be totally proprietary you need the digital output to be AES50 (https://en.wikipedia.org/wiki/AES50) for audio over ethernet. At which point each endpoint needs a full ethernet stack, which means each endpoint is now a computer. Or you go full AES67 and use IP networking, which requires a full OS on that computer. At that point, why would you not go with DLNA or similar?
And then you need PoE++ for 100W per port. And PoE++ switches with a total power budget over 200W really only exist in 16 port or larger configs, due to the size of the power supply required. So the cost for the power and signal distribution climbs to at least USD500.
To get the cable count to 1 per speaker, the modern answer is wireless powered speakers like the KEF LS60. Still it's interesting to look at why PoE doesn't work very well as a solution.
Unless this thing is to be totally proprietary you need the digital output to be AES50 (https://en.wikipedia.org/wiki/AES50) for audio over ethernet. At which point each endpoint needs a full ethernet stack, which means each endpoint is now a computer. Or you go full AES67 and use IP networking, which requires a full OS on that computer. At that point, why would you not go with DLNA or similar?
And then you need PoE++ for 100W per port. And PoE++ switches with a total power budget over 200W really only exist in 16 port or larger configs, due to the size of the power supply required. So the cost for the power and signal distribution climbs to at least USD500.
this is exactly right
OP makes some interesting points... he's not even advocating for actives
rather how to make actives more attractive to an audience
but moving from say a power cable, a single speaker cable and a line in -> to a single rj45 is a neat trick but its not going to push product
OP
- Thread Starter
- #25
Hi! Fellow IT guy here. As I see it, each endpoint in an active system is functionally a computer anyway. I’ve got some subs with rather sophisticated software built in and accessible by USB, and the application of all those filters, limiters, etc. presumably requires a bit of computing power on hand.
I’m also asking with respect to industry wide adoption vs a personal project, so essentially producing a lineup of switches with 2 - 11 PoE ports to cover stereo up to 7.x.4.
@jhaider
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I am a big fan of my 300B SET which has single digit watts. This works for near-field listening or listening with high efficiency speakers at modest volumes. It can be very engaging even at lower SPLs!
But for home theater, there are challenges.
1) POE 100W means that the receiving device gets 71W. But when you divide that by multiple channels, you suddenly run into insufficient power.
So then if you need multiple POE injectors, it gets really complicated.
If you look at IEC cables, there is an amp rating for a given thickness of wire. As much as we like to say that cables don’t make a difference, a 15A cable on a 20A circuit won’t give you 20A. Along those same lines, there’s a physical limit (safety limit) to much more power you can pass over Ethernet or similarly sized cables.
2) Once the recipient of the PoE gets 71W, some of it gets used by the circuitry to handle PoE and the audio of the DAC/DSP which we’ll say 5W. So now you have 66W. Then we say you lose 10% to heat for your Class D amplifier, and you’re working with 60W.
That’s not horrible. The Marantz Cinema 70S is a great bedroom setup with <60W, but someone going through the trouble of running all active speakers is going to want to take full advantage of some sort of premium audio performance that requires a ton of power in the host processor.
OTHERWISE, you could just get a Sonos Amp and use a pair of wireless rear speakers. What Sonos needs to do is come up with Sonos Era Amplifier so that you can pair it with a bunch of Era 300’s for your surround channels and then use their room correction software to address your front speakers.
3) Fundamentally, an active speaker just has a factory tuned EQ/crossover. Presumably, as is the case with the SDP-75 and JBL/Revel speakers, you can very easily create a setup built around a JBL M2 and just run a 4-wire cable from amplifier to the M2. What we should be asking for is not a PoE for active speakers, but a standardized PEQ or IIR filter based off aneechoic data. You could use anechoic data for correcting issues above the transition frequency And use a microphone to address the room.
But for home theater, there are challenges.
1) POE 100W means that the receiving device gets 71W. But when you divide that by multiple channels, you suddenly run into insufficient power.
So then if you need multiple POE injectors, it gets really complicated.
If you look at IEC cables, there is an amp rating for a given thickness of wire. As much as we like to say that cables don’t make a difference, a 15A cable on a 20A circuit won’t give you 20A. Along those same lines, there’s a physical limit (safety limit) to much more power you can pass over Ethernet or similarly sized cables.
2) Once the recipient of the PoE gets 71W, some of it gets used by the circuitry to handle PoE and the audio of the DAC/DSP which we’ll say 5W. So now you have 66W. Then we say you lose 10% to heat for your Class D amplifier, and you’re working with 60W.
That’s not horrible. The Marantz Cinema 70S is a great bedroom setup with <60W, but someone going through the trouble of running all active speakers is going to want to take full advantage of some sort of premium audio performance that requires a ton of power in the host processor.
OTHERWISE, you could just get a Sonos Amp and use a pair of wireless rear speakers. What Sonos needs to do is come up with Sonos Era Amplifier so that you can pair it with a bunch of Era 300’s for your surround channels and then use their room correction software to address your front speakers.
3) Fundamentally, an active speaker just has a factory tuned EQ/crossover. Presumably, as is the case with the SDP-75 and JBL/Revel speakers, you can very easily create a setup built around a JBL M2 and just run a 4-wire cable from amplifier to the M2. What we should be asking for is not a PoE for active speakers, but a standardized PEQ or IIR filter based off aneechoic data. You could use anechoic data for correcting issues above the transition frequency And use a microphone to address the room.
OP
- Thread Starter
- #27
Just to clarify, I’m not actually suggesting using extant PoE standards for loudspeakers. New standards fit to the purpose would need to be developed. Still, if the goal is to improve the state of the art, it seems worthwhile.
Yep, understood. It'd be great if such a thing existed, but there are good structural economic and market reasons why it doesn't. The thing is existing AES50 hardware is typically a ferociously expensive Xilinx FPGA. You'd need to get volumes up above 10m units/yr to make it worthwhile doing a dedicated chip. So for now you are stuck with a full IP stack, and now your real time processing is shot to bits for anything like a home theatre application.
An analog solution using large gauge AES/EBU cables with PoE-style DC power over the signal pins over could be easily hacked together, but going above 48V DC brings stringent safety requirements, so power will still be limited. If you want high power delivery you need AC and, well, that's called a mains socket.
Hmm, how about using the Powerline Ethernet standard? That would allow you to swap the problem around and deliver the signal as ethernet over the power cable. But then again if you do that you might as well go wireless for the signal delivery.
OP
- Thread Starter
- #29
It’s just a personal opinion based on the fact that I’m disinclined to have an electrician come out to install multiple outlets (and presumably a fresh circuit) to feed a multichannel active system. For a SOTA/cost no object rig or a new buildout, sure that works. For everyone else…less so.
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OP
- Thread Starter
- #30
I could accept the power limitations; efficient class D amps and lack of losses due to no passive XO would help compensate vs the current AVR/passive speaker paradigm, correct?
With respect to the custom chip idea, this seems potentially feasible since I’m aiming idea this towards the mass market as much as anything.
So, now I need 16 places to plug in the speakers in my 1968 home, which means completely rewiring the house? Uh, not only no but HELL NO!!!
OP
- Thread Starter
- #32
Processing this, what if we modify Powerline Ethernet to a lower voltage, avoiding aforementioned issues of AC/DC conversion and regulatory/safety concerns. I’m not looking for kilowatts, just enough to potentially supplant the average 100W AVR / passives common today.
I will NEVER switch for convenience. That is the whole point of audio for me, SUB 20Hz to at least 20Khz. As to surround sound, no desire. I had 6.2 in 1990. It wasn't hard, I saw no benefit over 4.2 QUAD plus subs that I had before & at the time, I had a huge house, so speakers all over the place were not a problem.
But, until the amps can be swapped out on active speakers (and if their is a battery, that is 100% no go, if I wanted a battery in my system, I'd attach it to a laptop, which will never happen unless it is NOT connected and nor could it be connected to the internet. As to a TV, my wife & I haven't owned one scince 2007.
I have all 20 AMP outlets (came with the 1968 house) & I have gone though & put new things as needed.
I have 500 or more watts available at each (of 2) passive speaker & the same for the pair of subs. In this tiny house (by my standards) there will never be more than a 4.2 or 4.4 system.
In my previous home, I could have had a 16 speaker system but would never put a system like that in there.
As to powered speakers, very few would get to the levels that I routinely get to at my house. But, unless they become standardized for swapping out amps, uh, NO.
Lots of people have the Sonus & the like, (although I do not know any) and certainly would not have something that cheesy in my home.
Maybe they don't clear the bar for any of folks that I know.
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Again, the current hardware is cheap because it is standardised and super high volume. As soon as you modify it you are back to low volume high expense.
Even as a thought experiment, I'm not really feeling it. Ethernet, Wifi, mains power - these are truly high volume low cost things, and nothing proprietary can compete at consumer prices.
I think for development of a complete new standard and implenentation in product, the market is not big enough.
Compare with the IT world where similar technologies have been developed - high end audio speaker market is tiny.
Nice idea, but as others point out I don't think this is the main reason people don't switch to actives. RCA or XLR cable fastened together with a AC cable with strips isn't really bigger than a fancy loudspeaker cable. And most people would have power outlets available close to their system (that after all requires power too) at least for a 2 channel system. I see how it would be a bit messy in a huge surround system with like 14 channels.
@rogu3 @Focus SE With regards to serviceability: This is no longer necessarily true. Not only are reliability generally good, many manufacturers also have speakers that can be serviced / components replaced. So you don't necessarily have to send it in, and not throw it away either (if it ever fails).
@rogu3 @Focus SE With regards to serviceability: This is no longer necessarily true. Not only are reliability generally good, many manufacturers also have speakers that can be serviced / components replaced. So you don't necessarily have to send it in, and not throw it away either (if it ever fails).
OP
- Thread Starter
- #37
Hi! For a 2 (or presumably 3 if we add a center) channels, you are absolutely correct. It’s really the surround/immersive sound environment where things become more difficult.
Appreciate the thoughts and civil discourse folks!
Littletycoon
Member
8-port switch 295W POE budget.
And more can be found. This one a bit expensive though. But you can have 2 switches with combined POE around 400W < 500 USD.
Littletycoon
Member
There is a significant switch towards actives. Wireless speakers are also actives. Multichannel above 5.1 is still complicated, but in many houses it's not uncommon to have electrical sockets in the 4 corners of the room.
