It has 5V stepdown converter and Li-Po charger as well as amplifier integrated on board. Cheap USB-C Li-Po chargers lack neccessary 5.1kOhm pull-downs and therefore work only with USB-A->USB-C cables. Soldering them onto charger PCB is borderline impossible, while adding them to most USB-C sockets is fairly easy (usually there are free pads to solder 5.1k SMD resistor). You then connect 5V and GND from USB-C socket to BT module and it handles charging the battery that is connected to separate pads.
I don't really understand why article recommends board without amplifier, I tried using CSR8675 board without one and it was waaay too quiet.
With 500mAh battery salvaged from old BT speaker I get over 20h of loud playback, which is fine for me.
I don't understand why article recommends board without amplifier, I tried using CSR8675 board without one and it was waaay too quiet.
It depends on the drivers; if they're low impedance, the result may be deafeningly loud. Yours seem to be available in 32, 80, and 250 ohms, the ones in the article are 32.
Thinking of doing a similar mod to my shp9500. Have you tried pairing this with an android phone yet? I'm also curious how it sounds on aptx instead of aac.
These look nice! I have also been making my own headphones. I recently posted a twitter thread with build instructions if anyone wants to make them. [1]
Notable difference is that mine are simpler to build, though less integrated. I use an off the shelf bluetooth to 3.5mm adapter rather than one of those integrated boards (I did recently buy an integrated board to test out). The off the shelf bluetooth adapter just plugs in to the short 3.5mm cable I build in to the headphones, which has the advantage that you can make them wired headphones with a simple extension, which sometimes has its use. Anyway take a look!
I very much appreciate that your design incorporates the ability to use them wired as well.
While I’m out/in transit, of course there’s nothing particularly terrible about Bluetooth.
When I’m at home, however - I produce music a lot more than I consume it.
I also mainly consume music at home on my record players anyway, which obviously I don’t use Bluetooth for.
As any audio producer will tell you; the latency introduced be even the newest Bluetooth standards makes producing music in a DAW a frustrating experience at best.
I love the ‘best of both worlds’ headphones with optional latency-free wired support. I can take them on the go and use Bluetooth on the bus, I can connect a wire at home; and produce in bliss.
I would absolutely love to create my own headphones from the ground up sometime, choosing my drivers and cushioning carefully, and ideally modelling/3D printing my custom design, based on taking measurements of the shape of my head and size of my ears. (I prefer over the head headphones as even the most comfortable buds tend to hurt my ears after a short while.)
Aww I’m glad you like the design! Feel free to use mine as a jumping off point, it’s all open source and I just want people to benefit however. Onshape is free and I’ve got like six different headphone designs in the Onshape design files linked in the thread.
But yeah I use the wired mode a lot. On one of the headphones I got a TRRS splitter and added a microphone and I can plug the TRRS cable into my Xbox controller and use it as a gaming headset. It’s a very flexible system!
Personally, the next thing I would like is SDcard + USB mass storage support (+ USB sound card support to listen while plugged in), so one could upload a podcast and listen to it later...
(also 18650 cell, as someone above already mentioned).
> They sound awesome – on par with pairs that cost around $200
I don't know. The problem is that $20 pairs often sound on par with ones that cost around $200. But the ones that cost around $200 have much better ANC than the $20 ones. You can definitely tell on an airplane. And these don't have noise cancelling at all.
> Bluetooth audio isn't fantastic in my experience.
I had been thinking the same but then I still gave it a shot and bought some new headphones with Bluetooth (and aptX support), in my case the Sennheiser Momentum True Wireless 2 (in-ear), and the Sennheiser Momentum 3 (over-ear). Turns out they can easily compete with (or are even better than) the cable-bound ~$250 in-ears I used to have.
When playing FLAC music over aptX HD, the next step for improvement is to avoid any resampling. The music is generally at 44.1 kHz and the default for Android is 48 kHz.
It requires root to change the audio config file to 44100, and it's also necessary to change the bluetooth settings (in the developer options).
Something similar goes for Linux.
The resampling shouldn't matter much in theory, but in practice it's pretty noticeable. It seems to be optimized for CPU usage instead of audio quality.
You can get OEM bluetooth in-ear buds straight from China quite easily these days. They are cheap and punch well above their weight. My wired ear buds are subjectively better sounding to me. My wired ear buds connected to a BT receiver also sound better. But the OEMs cost on the order of 50AUD/35USD...
Do you play on team / communicate using your microphone? Man, was I bummed out when I realized that the microphone only works over Bluetooth and neither via USB or the audio cable. :(
Such a mindblowingly stupid product decision – it makes my blood pressure rise every time I think about it.
If you don't care about latency, like listening to music or watching a movie, Bluetooth audio can be as good as wired. The maximum bandwidth for Bluetooth audio is 576kbps (aptX HD) which is way above the point at which you can tell the difference.
On the other hand, if latency is important, like on a call, then you can get kind of reasonable latency if you almost give up on quality (34ms from aptX Low Latency) But you're much better off sticking with wired (low single digit milliseconds) since latency matters so much for good conversation.
> The maximum bandwidth for Bluetooth audio is 576kbps (aptX HD)
100% pure unadulterated USDA-certified Prime grass-fed gluten-free all natural organic free-range BS, as the LDAC codec for BT comes in 330, 660, and 990kbps flavors and has even lower THD than aptX HD and an even wider frequency response (essentially to 20KHz). The catch is, only a few really recent and expensive chips have support for it, so almost nobody has heard (of) it, literally.
I'm glad there's an even higher bandwidth option I didn't know about! But at this point no one is hearing the difference, and this isn't a reason to go with wired over Bluetooth, as long as you can get hardware that supports a good enough codec.
SBC is practically transparent at these bitrates anyway, or at least on the level of other 320kbps codecs. The differences are so inaudible that even listening tests have a hard time telling the different codecs apart. http://soundexpert.org/encoders-320-kbpshttps://habr.com/en/post/456182/
These talks about replacement, higher-bitrate codecs always have always been very dubious.
The trick is, though, even though SBC is only marginally worse than lossless, because it's the lowest common denominator codec, you tend to see it with worse DACs that also have to do with the end audio quality. When you use codecs like LDAC, you tend to also see them with high quality components that would make it seem like it's LDAC that's doing the work, but it's in reality just a bonus.
Apologies for hijacking the thread. If anyone is interested in building high quality digital uncompressed and very low latency phones, speakers and other audio devices, I've found a while ago this doc about a pair of modules promising some impressive performance.
I like the idea of a vertical mount in the earcups: If the battery dies you click it open, slide out the dead one, slide in a fresh one, click it closed, and listen for a bunch more hours
At a quick glance the hardware for this is compatible with Lithium Ion chemistry so go for it. Just need to make some minor mods to put a battery holder on.
More specifically, just about any headphone with a LiPo (flat square) battery could be modified to accept an 18650. The charging voltages are the same, so you would just have to snip the old battery out and wire in an 18650.
I don't mind them as long as the weight is balanced out with clamping force or higher up the band. There's even smaller sized cells which go into electric toothbrushes as well. The point is to have cells that can be sourced easily & replaced without much fuss which these LiPo packs do not enable.
If it's just for calls, look at DECT headphones. I have a Jabra model, don't know if they still make them.
Coverage is great, I can walk around my parents' house, and even out in the garden, without loss of signal. They live in a hundred-year-old stone house.
Sound quality is great for calls. Music is ok-ish. They don't have any kind of ANC.
Another drawback is the big-ass base that for some reason requires a dedicated power cord.
Thanks for that, I am looking at POTS audio interfaces and POTS simulators. Looks like with DACT I can do what I want cheaper than using multiple body packs.
And to support what sibling said, I open the Teams app on my phone, not dial in, join the meeting and go walk the dog around the neighborhood. Unless you simply don’t have a smartphone (or an app for your meeting software), I can’t see how one would more simply solve your problem.
This rules! I have one of this bluetooth chip but mine didn’t come with the breakout pre-soldered & I’m struggling to solder them myself, thinking I should try paste + heat gun.
I believe you can also can change the name that the BT module broadcasts if you have an FTDI to USB cable (or something with UART pins like an Arduino). (You can also just change the “display name” on your iOS device bluetooth settings but it is just the name your device shows. I’m guessing this is doable on Android and everything else too.)
I believe the CSR chipsets have some programming tools available as well, so you can change things like the voice prompts to your liking (many of the cheap modules seem to come with the infamous "the Bluetooth device is ready to pair" meme sound) and adjust the device name.
How practical is homebrew open codec support, like building Bluetooth headphones or receivers with software/hardware Opus decoding support (as opposed to conflict-of-interest proprietary codecs that the Bluetooth standards authors add to the standards, then profit from license fees)?
Is Opus optimized for latency, battery usage, and widely supported in common hardware? I don't mind paying a royalty fee if it affords me a better experience when actually using the product.
Opus is one of the lowest-latency frequency-domain codecs out there (not including ADPCM-style codecs), as well as being the best-sounding voice and music codec at a given bitrate, beating MP3 and AAC (excluding ultra-low-bitrate voice, and recent neural codecs). In listening tests, LC3 is only better than Opus when Opus is deliberately misconfigured to compress audio badly.
Looking around for battery usage, https://news.ycombinator.com/item?id=21982964 claims LC3 is no simpler to decode in specialized low-powered hardware than Opus, while https://hydrogenaud.io/index.php?topic=118692.msg979046#msg9... claims LC3 is "basically Opus with a few marginal gadgets thrown in". In that case, I think the only reason Opus couldn't be as widely supported as LC3 is that there isn't money to be extracted from the system.
Thanks for the explanation. So it's a different situation from e.g. hardware H264 decoders, where the extra silicon makes a dramatic difference.
Then the main concern remains interoperability. I'd still pay a bit more to make sure my friend's random device has a better chance of working at all. Bluetooth is already a tire fire so I wouldn't like to add another layer of interop issues.
Hardware Opus decoders are completely unnecessary for desktops, and probably so for laptops or even phones I think. It's possible it substantially improves battery life in small-battery headphones and such, or it's physically impossible for headphone Bluetooth chips to support CPU decoding. But I doubt Opus is any harder to implement in hardware (or DSP firmware) than LC3 (which I don't know if it's easy to implement, but I assume they're trying to get hardware to support it).
I stocked up on Urbanears Plattan 2 during the last sale, they are both bluetooth and cable headphones but you need to buy the cable yourself, I bought kramer cables.
For $25 a pair they are easily the best headphones I have ever had, my last pair was a Plattan 1 that lasted 8 years!!! (cable broke once)
Oh wow, the price has gone down a lot. These are great headphones, but they're a relatively small on-ear profile. They would have me as a customer forever if they had an over-ear model. The best thing about them in my opinion is that they are very easy to take apart and clean.
I used to have a Plattan myself in 2010, but had to sell it because the pads felt painful when wearing them longer than 30 minutes… A lot of people posted reviews with the same issue.
I regularly use four devices (phone, tablet, laptop, desktop) and I have two pairs of headphones (in ear and over ear).
Since it’s 2022 and we have so much amazing technology all around us, these are the two things I’m missing: I’d like to be able to use any combination of these without pairing again and I’d also really like to stay connected while I’m listening to something or having a conversation.
Is this really too much to ask for? Now the funny thing is that it doesn’t matter if I spend $20 or $200. I’ve heard AirPods may be better as long as you stay in the apple ecosystem, but that’s one constraint too much.
It would be more interesting if we started threads about TFA instead of rehashing the same generic complaints about X just because X appears in the title.
Ok let me rephrase that: can anyone explain why this common scenario doesn’t work and if there’s any way to solve this? Would a homebrew device running my own software help?
To echo the sibling comment -- Apple has largely solved this problem, within the Apple ecosystem. If you want to avoid Apple, then you're up to the will of N vendors want to try to solve the problem their own way, so...
For Apple, the key feature is iCloud. Your headphone bluetooth information is stored in iCloud, so any headphones that have been paired with one device, are paired with all other devices. This is the secret sauce that make the system work. But even here, there can be issues. My Airpods connect to all of our Apple TVs, but my wife's don't. My iCloud account is the primary one, but I haven't figured out how to get my wife's headphones to transfer over as easily. So, even here -- when things work, they work great. When they don't -- you're stuck.
As far as using custom firmware, I'm not sure how much that would help you. The CSR8645 module from the article has its own firmware already installed and running. It looks like customizing would require some kind of license from Qualcomm. But, even then -- the secret sauce for migrating headphones from device to device isn't in the headphones. It's in the devices. So, that's where you'd need to add some custom code.
> If you want to avoid Apple, then you're up to the will of N vendors want to try to solve the problem their own way, so...
Isn’t this the whole idea of having a standard?
> For Apple, the key feature is iCloud. Your headphone bluetooth information is stored in iCloud, so any headphones that have been paired with one device, are paired with all other devices.
The pairing itself, while a bit annoying isn’t the whole problem, it’s having to connect and disconnect all the time and sometimes pair again. Now I’m not sure how iCloud is necessary for this, the device should already know my regular devices (in fact I think one of the headphones I have can be paired to nine devices, but only connect to two at the same time). The annoying thing is that it stays connected to devices I don’t use, e.g., the closed laptop, the desktop I’m not even logged in on or a different user is actively using. In an ideal world it would connect to all and figure out what to play. In an ok world I’m fine with it always connecting to my iPhone and the other device I’m actively using.
> Now I’m not sure how iCloud is necessary for this, the device should already know my regular devices
It isn’t the headphones that have the issue. AFAICT, it’s that your devices aren’t releasing the headphones from the connection. For this, you require coordination between your phone and tablet. The headphones can just be along for the ride. Your devices try to keep their connection as stable as possible. If your tablet doesn’t know your phone now wants to play a video, why would your tablet disconnect from the headphones?
Maybe it isn’t iCloud that does this (but iCloud definitely stores the Bluetooth ids so you only have to setup the headphones once). But there is some OOB communication between the devices. This is the Apple secret sauce and why they can have the feature, but other vendors struggle.
Say I'm connected to devices A and B. Now C starts playing something, so via iCloud through one of the connected devices, the headphones get the message to disconnect and connect to C.
So A, B, C need to be connected to some server, otherwise they won't have the information on the state of A, B and C and to take actions to connect or disconnect.
Now one alternative would be to have two Bluetooth controllers to stay connected to four devices, but that would increase size and battery consumption. Another would be to periodically rotate connections to idle devices, but that risks not being connected when needed.
If I were designing this, I'd make some sort of a "partial connection", not the full protocol that sends audio, but something that can broadcast to previously connected devices that triggers a full connection.
I have. It doesn’t work for us. I think it’s probably something with her account, where she doesn’t have a setting right. But I try to stay out of her technology as much as possible… it’s just easier that way. :)
I can’t imagine dealing with the shit show of BT outside of the Apple ecosystem in 2022.
You’re not going to like the obvious answer - get into the Apple ecosystem and buy Apple headphones.
They seamlessly switch between my iPhone, iPad and Mac. If I am watching something on my iPad and my iPhone rings, they automatically switch. If I start watching a video on my iPad and then start playing a video on my iPhone, they automatically switch.
Not to mention if I’m using my AirPods with my AppleTV at night and my wife starts talking to me, I just take one side out and the TV pauses.
Of course they work in just the opposite manner. If I put them in, audio switches to them.
I’m not sure if auto switching from my watch. But since I can take phone calls on it anyway. It doesn’t matter as much.
Also if I pair to any device connected to my Apple ID, all of my other devices automatically show them as an option - iPad, iPhone, AppleTV, Watch, Mac.
PLA and PETG start to soften at lower temps, 60C and 80C respectively. But ABS is up at 105C, so it won't have any chance of deforming in a hot car or something.
I still think 80C on PETG should be high enough, and it's a much nicer material to print.
The whole bluetooth headhones situation is a little ironic.
Us Linux types remember how long it took until the MP3 patents expired for us to stop having to add non-free repos everywhere and being treated as the ugly cousin because we couldn't support such a universal codec out of the box.
Fast forward today, and we're back at square one because everyone and their mother wants some new codec to make bluetooth audio quality suck not so bad. (Bluetooth couldn't do better than SBC out of the box? really?)
The only difference between yesterday and today is that, we Linux folks are much better at quickly enabling support for proprietary codecs out of the box.
It has 5V stepdown converter and Li-Po charger as well as amplifier integrated on board. Cheap USB-C Li-Po chargers lack neccessary 5.1kOhm pull-downs and therefore work only with USB-A->USB-C cables. Soldering them onto charger PCB is borderline impossible, while adding them to most USB-C sockets is fairly easy (usually there are free pads to solder 5.1k SMD resistor). You then connect 5V and GND from USB-C socket to BT module and it handles charging the battery that is connected to separate pads.
I don't really understand why article recommends board without amplifier, I tried using CSR8675 board without one and it was waaay too quiet.
With 500mAh battery salvaged from old BT speaker I get over 20h of loud playback, which is fine for me.
[1] https://www.reddit.com/r/headphones/comments/r32ru2/yet_anot...