[golemB]

How would I rig a wireless link to a portable amp? I'd like to be able to use my portable amp and cans (rather than buying a specialty wireless headphone). The portable (battery operated) amp would be like a little iPod for the house, with the nice home-size source connected.

Ideally, it would support both digital and analog broadcast, but either would be workable.

Digitally, I'm thinking something like a portable Squeezebox. Are there any wifi-enabled PDAs that have digital-out? Are there any decent portable battery amps that have a DAC? (Or PDA with USB-out so I can attach a 2006 Total Bithead? Hmmm... maybe the OQO, although a bit pricey?)

Or how about a pirate home broadcast of satellite radio frequencies, to a portable sat radio?

Analog would be tougher. How hard would it be to hack apart an existing RF wireless headphone to feed a line level to a portable amp?

 

[mono]

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Originally Posted by golemB How would I rig a wireless link to a portable amp?

Considering the volumes of replies, it is likely becoming obvious that you wouldn't... that if you knew more about the underlying technologies, enough to begin doing it, you'd realize there are too many issues to enumerate, making it hardly worth the bother.

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I'd like to be able to use my portable amp and cans (rather than buying a specialty wireless headphone). The portable (battery operated) amp would be like a little iPod for the house, with the nice home-size source connected.

Best advice- buy the wireless headphones then gut them for the receiver if you don't like their sound as much, putting the receiver inside your amp if there is room inside, else you have it dongled before the amp in it's own custom case.

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Ideally, it would support both digital and analog broadcast, but either would be workable.

Ideally you can get it to work at all. One is not picky when starting out unless you are a competent RF engineer. That's why the above suggestion is to at least benefit from an engineer's work and buy the headphones, reusing what you can of them.

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Digitally, I'm thinking something like a portable Squeezebox. Are there any wifi-enabled PDAs that have digital-out?

So now you want a DAC too? Build it one piece at a time.

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Are there any decent portable battery amps that have a DAC? (Or PDA with USB-out so I can attach a 2006 Total Bithead? Hmmm... maybe the OQO, although a bit pricey?)

Build the amp and the DAC, it'll be good practice before you undertake your RF project.

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Or how about a pirate home broadcast of satellite radio frequencies, to a portable sat radio?

How big of a fine do you want? They do hunt people down if transmitting enough power to be useful for much. I hope you don't consider a portable sat radio hi-fi either. The audio will only be as strong as the weakest link, you are considering all kinds of expensive and time consuming propsitions when the original wireless headphones already made will probably sound better. Also recognize that part of why they might not sound as good is because they're wireless, that you could redo everything and end up with same diff. in sound but much more bulky, expensive, and time consuming. If it were so simple as wishing it, and a reasonable performance and price, the product would be on shelves already.


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Analog would be tougher. How hard would it be to hack apart an existing RF wireless headphone to feed a line level to a portable amp?

No analog would be an order of magnitude (if not a dozen) easier. Hacking up the RF headphone would be quite easy compared to anything else. 2nd easiest would be using good ole FM band transmitter and plain FM stereo tuner. Considering that you can buy both of the latter parts premade, it might be the easiest.

 

[golemB]

Mono, thank you for addressing each of my queries. Is it really so hard, though? Maybe it doesn't count as "DIY," but I was thinking of putting together off the shelf components to make this work. Digital shouldn't be THAT hard, considering that a Squeezebox gets you wireless lossless digital streams over standard 802.11g. A PDA or ultra-small PC that has a reasonable line-out (or a digital out that could go to a portable DAC) would fit in a fanny pack with a portable amp. Ugly, but effective, right?

I'd want better than FM quality, and I'm assuming that satellite radio sounds at least as good as MP3 - I've heard it in a car once, but not with a great audio system. Do existing wireless cans sound better than FM? Better than satellite radio (assuming a good source)? I'm assuming they don't sound as good as my stationary listening rig in terms of amplification and the headphones themselves.

 

[threepointone]

If you want quality, just get a PDA with wifi. I don't have one myself, but I'm pretty sure that with wifi, all you need is a bit of high-level hacking (or none at all, if the portable windows pdas work with file sharing). Just play the music over the wireless 802.11g network, plug in your amp to the lineout/headphones out (still much better quality than streaming over FM and far easier than trying to design your own wireless system), and there you go.

hacking the DAC on something already designed to be so small is not going to be easy. I'm not aware of any pdas with USB ports.

If you want another way, I heard of a DIY network MP3 streaming device on hackaday.com. I think it had line out and digital out, but with the additional DAC and amp, it'll be a pretty big system to carry around. you might be able to change the DAC for it. As I remember, it was designed for wired networks, i think there might be ways to adapt wired to wireless.

If you're trying to do long distance streaming, it might be possible with some cellphone internet nonsense, but that'd take a lot of airtime (and thus a lot of $$$$$)

 

[joostoo]

this was on hackaday today:
http://gadgetfreak.typepad.com/gadge..._speakers.html

its a hack for modding regular speakers to get a bluetooth interface. its not the exact thing you are looking for, but it could give you an idea or something.

 

[mono]

Quote:

Originally Posted by golemB Mono, thank you for addressing each of my queries. Is it really so hard, though? Maybe it doesn't count as "DIY," but I was thinking of putting together off the shelf components to make this work. Digital shouldn't be THAT hard, considering that a Squeezebox gets you wireless lossless digital streams over standard 802.11g. A PDA or ultra-small PC that has a reasonable line-out (or a digital out that could go to a portable DAC) would fit in a fanny pack with a portable amp. Ugly, but effective, right?

You are overlooking the main issue, that these are *computers* that just "happen" to use this to communicate, and you seem to want just the communication but not the computer that is doing all the work. IF all you want is to use a PDA or ultra-small PC and connect a portable amp to it, then I don't understand the reason for this thread at all, wouldn't you just do that?

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I'd want better than FM quality, and I'm assuming that satellite radio sounds at least as good as MP3 - I've heard it in a car once, but not with a great audio system.

Reasonably good FM stereo reception is higher quality than MP3. Mediocre FM reception is higher fidelity but dropping SNR. With that in mind, perhaps your goal should be to use a transmission band that is not already allocated to these other uses, so you can use higher power transmitter before your government tracks you down.

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Do existing wireless cans sound better than FM? Better than satellite radio (assuming a good source)? I'm assuming they don't sound as good as my stationary listening rig in terms of amplification and the headphones themselves.

It depends on each part, since there are several that could degrade things. Any way you look at it, wireless implies batteries and many are meant for low power, light batteries in a worn-on-head set. They are only receivers though, the strength of the signal is going to dictate the SNR to a large extent. You can tack any amplification circuit you want onto the receiver you choose.

I'd imagine there are digitally transmitted wireless headphone sets. If you want digital, so be it though you would again be reverse engineering something already made, not trying to look at only one communication method of a computer system as a singular device since it can't exist on it's own.

 

[golemB]

Good input - I'll let you know once I do a bit more research and decide which path to take.