We had good wireless audio technology in the 19th century. Why can't I find an easy and cheap way to send a signal (either digital or analog) to my sub and surround speakers?
The ideal setup would take a SPDIFF or HDMI input and broadcast it digitally. I would be able to add any number of devices that could receive the digital signal, and have their own logic to decide which audio to play, DAC, amplifier and speaker drivers. I could almost build this with what is available for active crossovers and arduino type devices, but all the "wireless" I can find seems to be focused on TCP/IP which is overly expensive and probably not a good way to stream audio.
An acceptable setup would take 5 channels of analog and broadcast a wireless analog signal to 5 receivers that had to know which channel to listen on and include an amp, crossover (active or passive) and drivers. The Dayton Audio Sub-Link XR 2.4 GHz Wireless Audio Transmitter almost does this job. I'd need 3 of them which would cost $208.50 and have such a mess of wires and boxes as to defeat the whole purpose of doing this.
The ideal setup would take a SPDIFF or HDMI input and broadcast it digitally. I would be able to add any number of devices that could receive the digital signal, and have their own logic to decide which audio to play, DAC, amplifier and speaker drivers. I could almost build this with what is available for active crossovers and arduino type devices, but all the "wireless" I can find seems to be focused on TCP/IP which is overly expensive and probably not a good way to stream audio.
An acceptable setup would take 5 channels of analog and broadcast a wireless analog signal to 5 receivers that had to know which channel to listen on and include an amp, crossover (active or passive) and drivers. The Dayton Audio Sub-Link XR 2.4 GHz Wireless Audio Transmitter almost does this job. I'd need 3 of them which would cost $208.50 and have such a mess of wires and boxes as to defeat the whole purpose of doing this.
Perhaps you meant 20th century? There was very little wireless in the 19th century, apart from thunderstorms interfering with telephones.
Wireless audio links are available at various costs and various levels of sophistication from cheapo rubbish up to professional. They often use similar (or identical) technology to wireless mikes.
Wireless audio links are available at various costs and various levels of sophistication from cheapo rubbish up to professional. They often use similar (or identical) technology to wireless mikes.
Guglielmo Marconi transmitted wireless audio over a mile in 1895. I am not sure when the first experiment that covered the size of my living room was, but much earlier, I am sure.
I would say most of it is rubbish and none of it is cheapo. By now we should have something that a) costs very little, b) does multiple channels, c) digital or analog, d) supports audible frequencies with no detectable loss of frequency, and e) integrates easily with other devices and technologies.
The only thing that I can find for a) is cheapo FM transmitters on e-bay. I don't think anything at any price fits e).
No. He was using spark transmitters to send Morse code in 1895. Audio came in 1915 when valves had been invented. "Good wireless audio technology" came in the 1920s?bvbellomo said:
If you want very cheap reliable technology which does exactly what you want then you need to read science fiction. In the real world reliable high quality technology is rarely cheap.
Other than bandwidth, what is the difference between this and digital audio? This was probably closer to a digital signal than the analog broadcasts that followed. According to wikipedia, Enrique Telémaco Susini started broadcasting music and voice over radio for entertainment in 1920. So I said I am frustrated because I feel like I am using 19th century technology, and you corrected me by saying I am really frustrated about using 1920's technology. The 20's will be here again before someone makes progress.
If Tesla had his way, we wouldn't even need the amplifiers in the satellite speakers, they'd be able to receive an amplified signal via air and work without any wires at all. Unfortunately, even if I built something like that, none of my other equipment would work around it.
Back to my problem at hand: I can't find any digital wireless technology that isn't TCP/IP or Bluetooth based that can send 5+ channel audio. I don't see anything analog that is better than the FM (1933 technology) like the Dayton device I listed, and the cheapest Chinese version is still $28.86.
I'm not sure how far back I need to start in explaining the difference between an untuned spark transmitter and modern digital audio.bvbellomo said:
Most people complain if digital stuff isn't standards-based. You seem to complain when it is standards-based. The solution is simple: develop your own protocols and interfaces, develop the hardware and software to implement them, debug and then use. You may then understand why decent stuff is expensive.
Why should there now be anything better than FM? The relevant laws of physics and maths haven't changed since 1933. Good quality FM audio links are available, but you have to pay proper money for them.
I am complaining that either appropriate standards don't exist or I can't find them.
Do you know of anyone who has done this? If I had $10 million and 10 years, I could be a billionaire. You'd think since 1930 someone else would have tried.
FM stands for Frequency Modulation, which is used to send an analog signal. There may or may not be a better way to send an analog signal, but this is not what I am asking, and I am well aware I can pay more money to do a better job transmitting analog. What I want to do is transmit digitally. If I can't do that, I would like something small, cheap and reliable to send a single channel analog, or 1 device that sends more than 2 channels.
SPDIFF is transmitted unidirectionally with LED through fiber, so doing the same through the air should work just fine. A strong IR diode should provide enough bandwidth, yet be perfectly safe to use.
Trouble with radio is bandwidth. There are no free channels in low microwave and lower frequencies available for transmitting a signal with bandwidth of ~6MHz. Going higher misses the point, i.e. no real edge over using infrared, and using any 2-way digital technology is a mistake because of packetisation and unpredictable delays.
Trouble with radio is bandwidth. There are no free channels in low microwave and lower frequencies available for transmitting a signal with bandwidth of ~6MHz. Going higher misses the point, i.e. no real edge over using infrared, and using any 2-way digital technology is a mistake because of packetisation and unpredictable delays.
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Thanks! The reason not to use IR is I don't want line of sight to be a requirement. Packetisation and unpredictable delays are a reason not to use TCP/IP.
For the cost and time, I will probably stick with analog, but hope someone puts serious time into this area.
As you are aware from your searches, there are many transmitters and matching receiver's in the 2.4 and 5.8GHz, but usually single channel.
Some have put some serious time into this, but as you stated, cost is a big factor. Putting just one or two transmitters in a box is problematic, putting more in pushes the costs up significantly (never mind the certification costs).
The other concern for domestic use is having enough free channels and interference, tried some of the TV senders in the past, until a neighbour got internet over their mains wiring, then I just got irritating interference!
I also suspect that the available devices leave a lot to be desired as most are advertised for sub woofer or surround speakers, which leaves me thinking that as these channels are less arduous, that there may be some loss of quality for main left right channels.
The final problem is this is not a project you could DIY (unless you have lots of money to spend), cheaper to have all the wiring embedded in the walls and redecorate.
People claim to have sent S/PDIF over wireless video links, since video has enough bandwidth. If bandwidth allowed, you could mux in more channels.
However, you still need to power the speakers and the wireless receivers, which could be more difficult and dangerous than speaker cables due to the higher voltages involved.
I believe Reginald Fessenden was the first to broadcast voice and music back in 1906. He had a high-frequency alternator to generate a high power sine wave, and modulated it using a carbon microphone in series with the antenna lead.
However, you still need to power the speakers and the wireless receivers, which could be more difficult and dangerous than speaker cables due to the higher voltages involved.
I believe Reginald Fessenden was the first to broadcast voice and music back in 1906. He had a high-frequency alternator to generate a high power sine wave, and modulated it using a carbon microphone in series with the antenna lead.
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