Moving Sound Around

Recently I decided to free the music trapped in my computer. MP3s, streaming WFMU, internet radio - all of it stuck where my computer is, in my office. Though I have a good set of digital speakers (Roland DM-2100, not pictured) hooked up to my Mac I wanted the option to hear its audio in other rooms. I thought first of running a long cable from the analog out on my computer to the kitchen, where my Teac radio/CD player (pictured right) has an auxiliary input. But that would be a RPITA (Royal Pain-In-The-Ass) and I doubt the signal would make it that far (25 - 30 feet) without serious degradation. I decided to try a wireless approach and bought an AirPort Express Base Station with Air Tunes. It's a wi-fi router that allows you to (among other things) "broadcast" anything playing in iTunes. There's an 1/8" stereo jack on it so you can patch it into your home stereo. But beware: you can't simultaneously send audio to your computer speakers. I patched it into the aforementioned Teac stereo and hated the results. Because my computer's CPU is situated under my all-steel desk I was experiencing lousy connectivity that caused many audio drop-outs. I even tried an expensive extender cable to move the computer's antenna from under the desk but it didn't help much. And the damn thing kept freezing up on me, needing constant re-booting. I decided to try a third approach that would take advantage of the dozen or so FM radios I have in my apartment: low-power FM transmission.

First I tried the small C. Crane FM transmitter I've used with my iPod and found it can throw a signal reliably in a ten-foot radius and that's it (you might get better results where you live but I'm in an area with lots of FM "competition"). I've used many of the commercially-available FM "sound feeders" from manufacturers like Belkin, Griffin, etc., and find them all to be fairly anemic and unsuitable for moving audio more than a few feet. What was needed for my purposes was something more robust. I began looking where all quests begin in the internet age: eBay. Searching on "FM Transmitter" brought up nearly 7,000 items, almost all of which are the aforementioned "sound feeder" type, good for use in the car or covering short distances in the home. A revised search on "FM Stereo Transmitter" came up with a much more reasonable 131 items, most of which are junk. But scrolling through three pages of results also reveals a few models by Ramsey, like the FM25B and the FM30. These are available directly from Ramsey Electronics as kits but if you're not good with a soldering iron you can buy an assembled version on eBay, usually for $15 - $30 more than the kit.

Checking the results further brought me to the transmitters from Landmark Audio Technologies, including the model I eventually purchased, the FM350 USB (left). As its name implies, it patches into a USB port on your Mac or PC and draws audio and operating voltage - no power adapter needed. The FM350 USB is easy to set-up (full instructions are included): choose your desired operating frequency (do us a favor and stay out of the non-commercial end of the spectrum, below 92 mHz), hook up the USB cable and "Part 15" legal antenna and tell your computer to recognize the FM350 USB as a pair of digital speakers. Before you know it your computer has become an FM station.

My first test was streaming Fool's Paradise via wfmu.org through iTunes. I hit on one of Rex's "bubbling" mic. breaks and it sounded so right coming through the green rubber Lexon in my shower (the first test because it may be the most important radio in my apartment). Next I switched on my second bathroom radio (yes, even in my tiny W.C. I've got two radios). Again I was amazed to hear WFMU loud and clear in my apartment. My building is located in a "reception trough" and I barely get WFMU over the air but here it was, coming through every radio in my house: the kitchen table Tivoli Model One, the Beach Boy I got from Miriam at Norton Records, the SABA 300 in my office and even my tiniest radio, the Precision PS-700 purchased at the Meadowlands Flea Market. All I needed to do now was get the audio back to my desktop speakers, the Roland DM-2100 speakers mentioned earlier. Roland thoughtfully provided two inputs, each adjusted by its own volume control, so I connected a Tivoli PAL to the second input (the first is patched to a TV's audio) and I now have the same strong low-power FM signal carrying WFMU to my desktop.

The FM350 USB is a very "musical" transmitter, smoothing out my computer's audio and giving it back it's "radio-ness". It's also available as the FM350-U (right), which has an AC power supply and uses RCA jacks so it can be hooked up to any kind of audio device (it comes with an RCA- to-1/8" adapter cable). I've got it connected to my satellite radio receiver and it moves that audio through my place on a different frequency from the FM350 USB (one caution: using these devices might create interference to nearby radio users, so be aware). All I have to do to switch between the output of my computer and my satellite radio is turn a tuning dial.

If you need to move sound around, definitely look into low-power FM as an audio distribution option. Why not take advantage of all the radios you now own?

Comments

[M.G.]

Geez, thanks for the info!

I wonder if you can boost the signal with another amplifier.

I guess the FCC would not like it too much.

[rta2]

Chris, I can sympathize with your efforts. I been trying to get the sound out of my computer to different rooms of my apartment for a few years now.

Tried to build an FM transmitter from kit, but my soldering skills let me down.

My current setup is to use the C. Crane FM transmitter for low bit rate internet streams where the quality doesn't matter too much. I can get about 20-25 feet of range. (North side of Chicago is also an area with lots of FM "competition"). My office is in the center of my apartment, so I can hit all of my radios. Though, the quality of the C. Crane FM transmitter leaves a lot to be desired.

For most of my library and high quality streams ('FMU broadband MP3 stream ) I use the AirPort Express Base Station with Air Tunes. Don't have the dropout problems you have. The one catch is that it'll cost you at least $125 per Apple AirPort Express Base Station, so I have to move the "AAEBS" to a different room/reciever to use it elsewhere. That said, the quality is much better than the C. Crane FM transmitter.

Also use Griffin Technology Airclick USB Remote Control unit to control iTunes remotely.

[toadhall]

Here's tip on the Belkin, with the writing on the back right-side-up, open it and see the 'springy' battery connector to the right, that is the antenna connection! We had already run line-level wires out to the deck, but rather than rock the neighbors, wanted to use the Tivoli PAL as a portable radio so we could keep the volume low but still hear it. Tried connecting the antenna of the Belkin to the shield of the line-level cable, and voila! I walked around the edge of the yard with the radio and made sure there was no reception out in the street, it's still low power, but with 10 to 20 feet range from anywhere along that long wire, it is perfect for the back yard. The bonus is that the home stereo and bathroom radio pick it up too!

[Joesey]

Thanks for the tips, I'm always looking for better ways to distribute my sounds.

I ended up buying a Saitek A-250 wireless 2.1 speaker (fancy way of saying 2 speakers and a woofer). It's tiny and slightly anemic, but it's bluetooth and has fairly good range throughout my place. It can work off batteries or AC. And the cool thing...it has Next and Previous buttons that can control your media player through the bluetooth transmitter attached to your PC's USB port (Windows 2000/XP only). So you can have a playlist of MP3s or radio stations that you can change remotely. Some dropouts but generally pretty reliable for the range I use it, about 20 feet.

Also has an input for regular MP3 player, but no output so you can't plug it into something with a little more oomph!

http://www.saitekaudio.com/en/a250.asp

[st. vincent]

You might find the folks at the site below to be interesting, they make a wifi device called the Squeezebox that's not precisely what you want, but it's close:

http://www.slimdevices.com/

FWIW, the last few years I've been collecting cheapo stereo amps and small speakers at thrift stores and garage sales to use with my iPod. I now have an excellent set up in my garage: A small 70's-era Panasonic stereo amp that takes a line level input and two small Realistic speakers, all of which I bought for $10 at the local Goodwill. I plug my iPod into it with a headphone-to-RCA cable. It sounds great for what it is, and if it craps out or gets swiped (my garage isn't terribly secure), I can replace it easily enough. No more tapes or CDs in the garage and the expensive part (the iPod) goes inside with me at night. I'll bet you could do something similar with the Squeezebox.

Now, they just made a Squeezebox that was in a portable boombox configuration with rechargable batteries... then you'd really have something.

st v

[Steve PMX]

Chris, you're a f*ckin pimp!

p.s. LOL @ your shower. Kinda creepy head, though.

[Fatherflot]

By the way, the C. Crane transmitter can be easily modified to put out a much stronger signal.

Found here -- http://www.xmfan.com/viewtopic.php?t=3257&postdays=0&postorder=asc&start=0

This simple mod will let you increase the range of the CCrane FM Stereo transmitter.

1 - Remove the 2 screws under the two little round rubber feet on the back of the case just on the top left and right sides of the label.

2 - Open up the battery compartment and remove the small screw.

3 - Carefully remove the back cover. There are some thin wires so be very carefull not to break them.

NOTE:If you do not want to remove the cover. You can remove the label on the back with the radio specs and find the little hole and adjust VR2 though the hole in the case.

4 - Locate the VR2 pot just to the top left of the Antenna connection. (See attached Picture)

5 - Using a small screwdriver rotate this pot control all the way to the right as far as it will go (Fully Clockwise). Be carfull not to break it.
(See attached picture for location details)
The picture shows what VR2 looks like before the MOD has been done.

6 - Place the cover back and then screw the cover back on.

After I did the MOD. the range went from 20 feet to 100 feet.

There's also a $10 discount you can get when you order it directly from the company website:

"If you put "Dave Graveline Discount" in the special offers line, you can get a $10 discount. Graveline is a FL tech talk show host and was running a promotion on the transmitter."

[amy]

I'm totally new to all the FM transmission stuff, and the thought of taking apart electronic equipment is totally bizarre to me(!), but i've basically gone through the exact same series of ideas that you did, Chris. I looked at the basic Griffin FM transmitter online but was skeptical about sound quality...how much better would you say the one you ended up with is? my big question, though, is if hooking up the transmitter precludes sound from simultaneously coming out of my cheap (came with the computer) speakers. I'd like to be able to have the same music coming out of my desktop and my much nicer stereo in my bedroom, and i was wondering also if there was any lag time? Thanks so much, everyone, for all the great tips...
Amy

[Chris T.]

Dear Amy:

The two transmitters I ordered from Don Person (his seller name is gear123 on eBay) have exceeded my expectations. They're a little expensive but I'd rather get something that works than waste time with "toys".

About the computer speaker situation: if you use the USB transmitter to broadcast from your PC or Mac you can't simultaneously use your comptuer's speakers. I keep an FM radio near my Mac so I can listen on that.

[murcury]

Landmark also makes a listening assistance/Japanese FM band Transmitter (which transmits below 'normal' FM band, starting @72 MHz) which is great if you have concerns about your neighbors listening in. You have to get a TV audio radio, or this one, which receives FM from 76 MHz. (The Sirius radio I have does transmit to FM 88-108MHz quite far, so I like to keep it to myself, so down to TV-lo band I go).

[Alan]

So overall what's the best fm transmitter you suggest that is legal?

[blopa]

Thank you. This is great info. I've been thinking about this for months now and I'm ready to buy the Landmark. Gear123 has one on sale now for $200, so I'll give it a try. BTW, I've got a Squeezebox and Airport Express. The slimbox is wonderful, but I listen to my Tivoli PAL in the kitchen and my Tivoli One in my bedroom. What I might do is output my Squeezebox to the Landmark and have the best of both worlds everywhere I go.