Beyerdynamic DT231 bluetooth mod
Jan 28, 2008 at 9:52 AM Thread Starter Post #1 of 17

Captain ?degard

Member of the Trade
Joined
Feb 11, 2007
Posts
573
Likes
14
The problem about bluetooth headset isn't the technology, but the headphones. SO I wanted to test how a simple cheap $25 USD AVRCP/A2DP reciever would sound paired with a decent heaphone. I modded my DT231 with a 3.5mm female jack so I could still use wires, and got the reciever. It works very well, I would really like to try it with a player like the P2 as my cell generally sounds bad, but even so I'm pleasantly surprised what this $25 thing can do. Will make a smaller cord later, this one is just temporary.
Comments welcomed

01.jpg

02.jpg

03.jpg

04.jpg
 
Jan 28, 2008 at 12:55 PM Post #2 of 17
thats a pretty cool idea, but i mean the bandwith of bluetooth is pretty limited

in bluetooth 1.1-1.2 you are limited to a maximum of 721 kbit/s. Most flac's will be at 1k+ kbit/s so thats them rid of, i guess it might work ok with 320kb/s VBR mp3's. Whats your experience with connection speed?

But thats a sweet idea for $25
 
Jan 28, 2008 at 2:48 PM Post #3 of 17
Quote:

Originally Posted by lordmozilla /img/forum/go_quote.gif
thats a pretty cool idea, but i mean the bandwith of bluetooth is pretty limited

in bluetooth 1.1-1.2 you are limited to a maximum of 721 kbit/s. Most flac's will be at 1k+ kbit/s so thats them rid of, i guess it might work ok with 320kb/s VBR mp3's. Whats your experience with connection speed?

But thats a sweet idea for $25



Um using flac for BT would be like eating a 10 course meal with plastic ware... Besides it doesnt transmit the flac signal anyways, as no reciever has a flac decoder, so its converted to something (god knows what) before sending. AND the fact that you have no flac players with built in BT transmitter except for computers. Adapters use the headphone jack, hence analog signal, so that wont matter either
tongue.gif
BT technologuy still has a long way to go, there is a significant difference between wired and BT sound, but IMO the wirelessness of BT makes up for less audio quality when youre on the run. Audiophiles will use wire until the day they die anyways (i mean, they pay hundreds of dollars for cables that only increses placebo effect, no way in hell they are ever gonna believe wireless is as good as wired :p ), but for normal people i'd definately recommend this mod - it outplays any stock BT headphone by miles
 
Jan 28, 2008 at 3:17 PM Post #4 of 17
yeah i know flac ain't really doable. But it would be cool...

and it could be ok for audiofiles, because you could use wifi to transmit a wireless signal in digital form, and then have a dac on the headphone that would convert it. ok some extremists are gonna say that wouldnt be as good, but in real life it would be awesome.

Damn this has me thinking. and i didnt think that bt audio would be in its own special format, never played with bluetooth audio... but i'm gonna research wifi audio cause that could be cool.

Brendan
 
Jan 28, 2008 at 3:57 PM Post #5 of 17
Quote:

Originally Posted by lordmozilla /img/forum/go_quote.gif
yeah i know flac ain't really doable. But it would be cool...

and it could be ok for audiofiles, because you could use wifi to transmit a wireless signal in digital form, and then have a dac on the headphone that would convert it. ok some extremists are gonna say that wouldnt be as good, but in real life it would be awesome.

Damn this has me thinking. and i didnt think that bt audio would be in its own special format, never played with bluetooth audio... but i'm gonna research wifi audio cause that could be cool.

Brendan



Yeah im wondering about BT too, is it analog or digital etc... Anyways, updated the first post with new pics, made a smaller jack for the dt231 connection, one that doesnt stick out
 
Jan 28, 2008 at 4:19 PM Post #6 of 17
Quote:

Originally Posted by Captain Ødegård /img/forum/go_quote.gif
Yeah im wondering about BT too, is it analog or digital etc... Anyways, updated the first post with new pics, made a smaller jack for the dt231 connection, one that doesnt stick out


It's definitely digital, but I can't find too much info about how it actually works. It seems pretty flexible though, and I believe the playback device enumerates the formats it can decode, and the source device sends content in those formats. Apparently some devices can decode MP3 and AAC directly, but this is not required. The only codec that is required is specially designed for Bluetooth (SBC), and probably doesn't sound as good as comparable normal codecs. I bet that this is the only one commonly implemented.

Again though, can't find too much info on it.
 
Jan 29, 2008 at 10:03 AM Post #7 of 17
That's what DIY is all about Cap'n. Congratulations on your efforts. Worthwhile I'd say.
In 1906 Lee DeForest started with a screw in light bulb looking gadget called the Audion, the first amplifier, a Triode. Oh yeah, BTW, they are still around.

Wireless USB has far more bandwidth than is needed for FLAC and High Quality portable USB amps are already around. Keep workin'...............................
biggrin.gif
 
Jan 29, 2008 at 11:28 AM Post #9 of 17
Quote:

Originally Posted by h4n9m4n /img/forum/go_quote.gif
What's powering those? Considering the size of that bluetooth reciever, i can't imagine that rig lasting very long...


Dunno, im guessing maybe 2-3 hours. If im out longer than that I wont use them anyways so not really an issue, but its not something you bring on a trip without a charger thats for sure
 
Jan 15, 2010 at 10:35 PM Post #10 of 17
sorry for waking up an old one..

did you make a smaller one?
cant se the pictures anymore.

I wanna do something wireless for my HD-25´s and cowon D2.
need an all day batterylife tough,use my portapble gear at least 15 hour a day
smily_headphones1.gif


was thinking FM-transmitter?
you seem like the guy to ask these things Captain,do you have any ideas?
 
Jan 15, 2010 at 11:25 PM Post #11 of 17
Put the pics back up so they display again.

Bluetooth isn't a good idea when you have gear as high end as a D2 and HD25s I'm afraid. There also aren't many bluetooth receivers with battery life like that
 
Jan 16, 2010 at 11:59 AM Post #12 of 17
FM-transmitter and a small radio?

I just need the sound from my pocket to my head :p
I get stuck on the cable once to often
frown.gif

been reading and trying to figure out.

love yours, exaktly something like that I want mine to be.

Thanx for the quick answer..
If you have any brigth idea´s pleas PM me or something
smily_headphones1.gif

I´ll post here if I get something working
smily_headphones1.gif
 
Jan 17, 2010 at 4:04 AM Post #15 of 17
The magic of Bluetooth audio is twofold -- 1) It is easy to find both transmitters (players) and receivers (headphones, etc) 2) CODEC chips are available so you don't need to do custom work. Sound quality isn't on that list.

The protocol is the problem -- Bluetooth uses http://en.wikipedia.org/wiki/SBC_(codec) , which was patented in 2005 and is a spiritual successor to mpeg layer 2 audio. In other words, it's a bit like a homebrew MP3. What's worse is that because your source is likely not in SBC, it's got to be transcoded. Transcoding a signal is likely to amplify the shortcomings of the the original encode.

Wireless can a good thing, regardless though -- I like to wear a nice noise canceling phone when I work outside, but I'm constantly having low hanging limbs and hedges rip the phones off my head. I lost a pair of iGrados to this nuisance. I wouldn't mind being able to detach a cable completely and jack in a little Bluetooth module.
 

Users who are viewing this thread

Back
Top