Bluetooth headphone mod....

[spraggih]

I was thinking (not sure if this would work) but an iPod connected via RCA in to an amplifier. The output on the amplifier to the Bluetooth (BT) transmitter and the headphones connected to the BT receiver.

But I guess that would not work as the transmitter is the piece doing the work and the amplifer could not be connected.

Still if there is a device that takes a 1/4 or 1/8 plug then you could connect your amplifier out to it and transmit to the BT receiver that is connected to your headphones and walk around (for up to 30 ft or so - whatever the distance is for BT).

No perfection solutions, huh?

 

[Eagleboy]

Quote:

Originally Posted by spraggih I was thinking (not sure if this would work) but an iPod connected via RCA in to an amplifier. The output on the amplifier to the Bluetooth (BT) transmitter and the headphones connected to the BT receiver. But I guess that would not work as the transmitter is the piece doing the work and the amplifer could not be connected. Still if there is a device that takes a 1/4 or 1/8 plug then you could connect your amplifier out to it and transmit to the BT receiver that is connected to your headphones and walk around (for up to 30 ft or so - whatever the distance is for BT). No perfection solutions, huh?

Well, that's essentially what my Jensen BT kit is...
http://www.buy.com/retail/product.as...272&adid=17662

The little box is the transmitter - this plugs into your MP3 player or any source for that matter with a 1/8" plug. This then transmits the BT signal to the headphones pictured. No wires dangling from your head. This design is fantastic, I feel, but lacks a quality headphone to translate with. This is what I'm hoping to fix.

That's my plan - I guess I could have explained that MUCH better at the beginning of the thread, but there it is now.

So, right now I'm trying to figure out what headphone to put the BT receiver in (removed from the Jensen headphones). I'd prefer to stick with a 30 Ohm can, because I really don't feel like double-amping the signal, as the bluetooth module I removed from the headphones already contains an amp...

I really think that the ES7's will work quite well, but they seem to be a bit expensive, and I don't know how much room inside the can's shell I'll have to put these components... I'm open to any other suggestions here. No turning back now - these Jensen headphones are now completely disassembled (some breaking of the casing required, heh, so no reassembly of the original product. Must move foward!).

 

[The_Duke_Of_Eli]

Well, the problem with Bluetooth is that it uses high-frequency waves to communicate between the transponder and the receiver to send a low-quality sound signal. You just can't expect to get to cabled-quality without wires. Its faster, and doesn't need alogarithms to decode then recode. For voices like on cell phones it's fine, but I'm not sure I'd invest my money in any Bluetooth technology today, unless I absoulutely needed it for something like exercise where wires absolutely suck. Otherwise, it's probably best to wait until wireless USB is standardized (still waiting for it...).

 

[The_Duke_Of_Eli]

Quote:

Originally Posted by spraggih This sounds really cool - sounds like (no pun intended) it would work with any headphones as the transmitter and receiver are separate components versus integrated into a headphone. Ten Technology naviPlay: Designed specifically for the Apple iPod, this is a Bluetooth transmitter and receiver (called a "remote") set but no headphones. Instead, users plug their own headphones into the remote pack, which also sports an internal microphone for voice application/mobile phone connectivity. The remote has buttons for Power/Play and a multi-function "Navi" button for controlling volume, track navigation, and call answer. naviPlay's transmitter pack clips onto the iPod and is incompatible with other audio players. One advantage to the iPod customization is that the track navigation controls on the remote work. Although the transmitter and receiver are paired, they can be unpaired so that each can communicate with other Bluetooth-enabled devices. Ten Technology markets the naviPlay as a wireless product for headphones, powered speakers and other applications requiring wireless connectivity (such as connecting an iPod to a home stereo system). Other specs: The audio codec is SBC. LiPolymer batteries power the remote and transmitter up to 8 hours (4-hour charge time). The packaging has an AC adapter and FireWire charging cable. The remote weighs 46 gr. MSRP $239 US.

That's probably the worst system ever. The idea of bluetooth is to cut the wires. OOOOHHH....now you have a microphone, big woopdydoo. Ipod can only do 8 bit recordings, which in other words sucks. THe idea of bluetooth is to lose the wires, that only adds them. And for 239$+tax, you might as well just get some decent cans instead.

 

[spraggih]

Quote:

Originally Posted by Eagleboy Well, that's essentially what my Jensen BT kit is... http://www.buy.com/retail/product.as...272&adid=17662 ... That's my plan - I guess I could have explained that MUCH better at the beginning of the thread, but there it is now. So, right now I'm trying to figure out what headphone to put the BT receiver in (removed from the Jensen headphones). I'd prefer to stick with a 30 Ohm can, because I really don't feel like double-amping the signal, as the bluetooth module I removed from the headphones already contains an amp... I really think that the ES7's will work quite well, ...

Got it - missed how far along you were. Please keep us posted.

And I guess sound quality will be a risk area but its worth a shot!

 

[kramer5150]

I dont understand why you would want all this "hardware"???

Some of these systems, as neat as they are... are still bulkier and have more wires than a small flash player and a pair of earbud phones. You can buy 512M flash players for really cheap now too.

What am I missing????

Also, don't most bluetooth transmitter have ~10 feet of range? That doesn't seem like a lot of real estate?


???

 

[milhouse6]

Think LIVE FEEDs people. Radio. Television. DVDs. Streaming audio. Walking around the office listening to the radio. A belt pack with your favourite headphones plugged into them. Simple.

Granted, the source audio of streams/radio/tv is generally poor, but crap source through your favourite heaphones is better than crap source through crap headphones.

Hell, even an MP3 player with an integrated bluetooth receiver would do the trick...

BTW Eagleboy, I've got the ES7s and I highly doubt there's any room in the housings for adding anything. They're only maybe 3" diameter X 3/4" deep.

 

[Eagleboy]

Quote:

Originally Posted by spraggih And I guess sound quality will be a risk area but its worth a shot!

Right-on, thank you for pointing that out! This whole thing is a huge experiment with lots of risks (I bought the bluetooth headphones for $56 with shipping, and I'm talking about the ATH-ES7's, which you just can't really find used... $120).

I need to remove all wires for certain listening applications. I build guitars in my spare time, and I need headphones to wear when I work - headphones that I can't accidentally cut the cable on, headphones that can't snag on my workpiece and accidentally bring it crashing to the floor. In the darkroom, I've had headphone cables get in the way of my work method before... cables snag on the cardboard pieces I use to burn and dodge.

Maybe I won't be able to do this seamlessly in the ES7's, but I certainly can expand the housing depth with some metal (I have access to a metal shop), PVC, or some wood (I have access to some really exotic woods that might compliment the ES7's really well, along with high-quality finishes). I have the ability to make it look real classy and almost seamless, as I have the technical skills and the access to tools and materials.


Millhouse - what good would an MP3 player with an integrated Bluetooth receiver do? The bluetooth receiver end is meant for the headphones... If you mean transmitter, my goal is to also integrate the Transmitter box with a Shuffle or some other cheap flash MP3 player, so I'll only have two small units to complete a higher-quality portable system. PS - do you like the ES7's? And... would you mind parting with them in a couple of weeks?

Please realize that I'm not really investing my money in a headphone - I'm investing my money into an idea. The market doesn't have wireless headphones that meet my standard, so I will take the initiative myself. If my experiment doesn't work well on the ES7's, I'll un-mod them, and start over again with a new pair of cans. It might take a while to accomplish a good, working pair of bluetooth headphones, but I really don't mind spending the cash and the time to attempt this project of mine. When it finally works, it will be worth all of the costs and time involved, because it's something that I created and something that nobody else has. And if it works well, who's to say that I can't do it again for a head-fier who also needs a wireless headphone?

 

[milhouse6]

For your use, no, a player with receiver wouldn't help. I'm thinking for myself -- I wouldn't have any problem with a cable to a belt pack (hence no need to mod). I'm looking for just enough freedom to be able to get up and walk to the fridge, go to the bathroom, etc. Also the freedom to swap amongst favourites.

I really love the ES7s, thanks for asking. Be warned I'm not really much of an audiophile and have very little experience with higher-end headphones as of yet. They are my favourite out of everything in my sig, but mostly because the bass is deepest. I wish I could wear them for longer than 4 hours though -- the clamping force eventually bothers my ear cartilege. Isolation is probably only about half that of A900s but it's decent enough.

Even with my minor complaints there's not a chance in hell can you have mine. They're keepers!

 

[Eagleboy]

Quick question...

I just found another set of headphones that are rated at 32 Ohms...

The ATH-EM7GH

1. Anybody have any experience with the sound on these? Good or bad purchase for $51.49? (Bringing my total investment up to about $100)

2. Are these style cans from Audio Technica comfortable? I'm a little reluctant, but if they are comfortable for a couple hours at a time, I'll buy them ASAP to mod over the weekend.

http://shopping.redorbit.com/product...n=Froogle+Feed


Thanks guys, I'll let people know how the mod goes, and I'll have pictures of all of the steps as well.
-Tom


EDIT: Now looking at the ATH-EQ77, as well. About the same price, seems to have a more even tonal response (from the über-brief reviews I've read), and 22 ohms to boot, being much easier to drive off of the existing amp in the circuity... Opinions on this?

 

[kramer5150]

How about an FM modulator to transmit FM signals. Use any headphone with a built in FM tuner...?

Probably not the best sound quality, but it should work.

Garrett

 

[Eagleboy]

Major update to the thread:

I have begun construction of the bluetooth headphones.

I started out by taking apart the Jensen's to see what I was dealing with in terms of circuitry:
http://img.photobucket.com/albums/v7...toothwhole.jpg

About a MONTH went by (probably more), and I received a pair of Grado SR60's. Took them apart and soldered the Grado drivers into the bluetooth circuit. The drivers work perfectly when the bluetooth circuit is started up. YAY I didn't mess up the Grado drivers!
http://img.photobucket.com/albums/v7...a/IMG_0243.jpg


Then, I began construction on the new chambers to house the circuit boards. Details are somewhere on this page. I used a dremel with a binding attachment instead of the makeshift router jig, though:
http://www.headwize.com/projects/sho...=grado_prj.htm

Only difference is that the chambers from the 1.5" repair couplings are SLIGHTLY too small to house the circuitboards, so I shaved a bit of the inside away with a dremel.
http://img.photobucket.com/albums/v7...a/_MG_0245.jpg
http://img.photobucket.com/albums/v7...a/_MG_0244.jpg

Then, I drilled holes in the right chamber for the power plug and the on/off switch:
http://img.photobucket.com/albums/v7...a/_MG_0253.jpg

Now, the charger's adapter fits right into the hole - but the on/off toggle is unreachable through that hole - so I exteneded the on/off switch. I carved this small piece out of maple, and glued it onto the on/off switch with Duco Cement. The maple piece has a small hole drilled into it that fits right over the plastic switch, so there won't be any play while switching it.
http://img.photobucket.com/albums/v7...a/_MG_0247.jpg
http://img.photobucket.com/albums/v7...a/_MG_0249.jpg

Now that that chamber is all done (minus the paint and the cover, to come later), the other chamber needs work...

The volume buttons are in this chamber. VERY small momentary switches control the volume. I started to fashion maple button extensions, but ended up going with some modeling plastic.
http://img.photobucket.com/albums/v7...a/_MG_0252.jpg
I sanded the ends of the modeling plastic flat to glue easily to the momentary switches, and used Duco Cement to bond the two together. VERY sparing amounts were used to prevent the cement from bonding things that shouldn't be bonded. Why Duco Cement? Duco Cement contains a bit of acetone in it, which melts plastic for a moment. This creates a great bond between plastics (and even plastic - wood). I trust it with bonding the binding to my guitars, so I trust it here in this micro-sized application.

After it dried to a tacky-level, I rested the circuitboard upright, allowing the cement to cure overnight. After I install this circuit board in the chamber, the plastic pieces will be trimmed to a very narrow height, so as not to get caught on anything.


Still to do:
-Paint the chambers (glossy black)
-Drill the volume "button" holes in the left chamber
-Fashion chamber covers


For the chamber covers, I am considering two options: Using the SR60 ring, and replace the plastic grill with aluminum screening; or make rings out of maple or indian rosewood, with aluminum screening for the center. Opinions?


This will be completed in a couple more days, so at that point I will laugh at my doubters. Well, if I don't totally screw something up between now and then!

 

[Nicola Fankhause]

hi

to have a really good sounding wireless solution, you need the following:

1. a bluetooth 2.0 transmitter, accepting digital PCM data (44.1khz, 16bit, 2 channels: 1.4mbit/s + some error correction)

2. a bluetooth 2.0 receiver, with built-in DAC and headphones amp.

if you leave the digital domain before transmitting over the air, you'll end up doing a DA->cable->AD->air->DA conversion, which obviously sucks.

chosing good components and using a good design, this would make for an interesting DIY project, as it'll give you wireless headphones that sound identical to conventional wired headphones.

regards
nicola

 

[Eagleboy]

Quote:

Originally Posted by Nicola Fankhause hi to have a really good sounding wireless solution, you need the following: 1. a bluetooth 2.0 transmitter, accepting digital PCM data (44.1khz, 16bit, 2 channels: 1.4mbit/s + some error correction) 2. a bluetooth 2.0 receiver, with built-in DAC and headphones amp. if you leave the digital domain before transmitting over the air, you'll end up doing a DA->cable->AD->air->DA conversion, which obviously sucks. chosing good components and using a good design, this would make for an interesting DIY project, as it'll give you wireless headphones that sound identical to conventional wired headphones. regards nicola

Somehow, I don't think I'm going to notice one 4" cable that seperates the MP3 player and the BT transmitter. If this 4" cable means that I'm using an obviously inferior system that sucks, then so be it - I'll still have wireless Grados and you won't.

With my use, any minute signal loss from the BT transmission will be outweighed by my concentration. This setup will be used primarily in the darkroom - I'll notice the Grado sound, but I'm sure I won't notice a 4" cable and the BT signal loss. I'm in the darkroom every single day, so I want to treat myself to something that sounds half decent... something those original Jensen WBB100 drivers didn't do.

 

[Nicola Fankhause]

eagleboy, I was generally speaking, as highend-wireless-audio is an interesting field where commercial hardware is simply missing AFAIK. I fully understand that you need a working solution and no silver bullet, so I'm happy for you that you have wireless Grado and I don't. I have wired HD-650 and don't really car what others have...

regards
nicola