Brainstorming needed... merging sound systems.

[torclausen]

So, I have a group of friends that enjoy building bicycle sound systems. We ride on huge, city sponsored rides here in Portland Oregon, and throw dance parties at the end of the ride. Merging our signal has been difficult. We have run a 5 watt fm broadcaster with mixed success. And when we have stopped, we have aux splitters, but even that can be problematic, different systems want different line levels.

Is there any other way that 5-10 of us can play the same songs in unison, with no delay?

What about a hacked bluetooth? Or what of this new airplay? We are dying to sync it together.

How would you do it?

Thanks! Tor

[greenbot]

The problem I see with this is that if you are a distance apart the delay issues will be very real. How far apart do you usually ride( speakers separated from one another)?

[torclausen]

greenbot,

Thats exactly what the other guys were saying they had problems with. Wouldn't the fm signal be instant? and the bluetooth as well? Would the airplay really have a delay?

We can ride as close as 50 feet but would love to be further.

T

[torclausen]

Smoke signals? Telegraph wire? Hacked megaphones?

Does anyone have experience with airplay? All these guys have iphones... wait is it only iphone 4s?

Tor

[dangus]

For the highest quality, I'd investigate using wireless video links to send S/PDIF. That could be absolutely lossless and real-time. The problem is that video links aren't all that common or cheap... I've yet to score one from a yard sale or thrift store. And you'll need DACs on each bike... about $20 from eBay.

FM has a lot going for it from a practical standpoint. Try using more sophisticated receivers, if you haven't already. Factory car radios can have very good quality tuners, and should cost next to nothing at auto wrecking yards. Some support diversity reception with two antennas, but that's rare.

[sofaspud]

As greenbot wrote, if you're any distance apart the delay will be very real. Not much you can do with the sound waves once they are in the air. If the delay is inherent to the various digital playback gear, you won't have an easy time sync'ing them together. Virtually any wireless technology should work if the rest of the system is correct. Adding attenuators to the splitters will allow you to balance the amps when parked.

PS: Transmitting 5 watts of FM should be more than plenty, to the point of questionable legality. After a few complaints from passing cars' cell phones, the man might be waiting for you at the county line.

[dangus]

Further thoughts: wireless headphones transmit sound wirelessly with high fidelity so maybe they can be modified or at least used as inspiration.

Some use radio. Presumably the range could be extended if you enhance the antennas.

Some use infrared. That seems like technology that can be supersized without too much trouble, although dealing with sunlight or flickering streetlights might be a problem. Instead of a few 5mm LED emitters, try 1W LED stars with optics that produce a wide horizontal beam pattern. Something like this is used for infrared hearing systems in auditoriums; maybe studying Sennheiser's literature will give a better idea of how feasible it is.

[Speedskater]

Delay won't be a problem. Each sound system speaker will be very low powered, so the spectators will only hear the nearest bike.

[torclausen]

Great thoughts! I've been using terrible little radios with antennas and headphone out. But the work fine with local radio stations... I'll keep at it.

Ah yes, I forgot about the sound delay, I think speedskater is right, as we distance ourselves, we will not overlap much.

No word on airplay. Can it not work in this way? Maybe not.

T

[Oddpixel]

Just stumbled over this thread...how about using one of these: http://pages.ebay.com/link/?nav=item...obalID=EBAY-GB just a thought