True Wireless Stereo (TWS) Bluetooth for Speakers

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#222
I came across the Nvarcher DSP while I was looking for something discrete that could do parametric eq on the cheap, it was either this or $100(!) for a qudelix 5k which is insane when I wanted was something that could do peq outside of software for my desktop. How is the process to getting one of these set up? Is there any thing I need to do to make it function as a usb sound card? It's quite difficult to understand the sellers description.
 
#227
sven_nilsson said:
I will post an update when I'm able to figure out these issues that I'm having:
  • The device seems to hang/crash when used as USB audio device, mostly when the volume is cranked up - maybe depending on the audio filter config and preamp gain.
  • I hooked up the bass channel and L/R channels to separate TPA boards, which gives me a severe 250hz hum noise - if I disconnect one of the boards, all is fine. A ground loop filter would probably help but I don't understand why I would need one.
  • The audio configuration does not seem to give a consistent output volume. A minor issue, but I'm worried there are other bugs that makes the filters not match the graph shown in ACP.
Click to expand...
Update: The hang/crash as well as the hum noise happens if you have a bad power supply for the power amp. If the supply is not 100% galvanically isolated, the AMP will tend to draw some of its power from the USB, causing the BLenhance supply voltage to drop when you crank up the bass, and the device will crash. The big giveaway was that the power amp was running with just the positive lead connected. It was obviously receiving its ground via the USB cable.

So, I purchased three 180W 12V LED power supplies for the bargain price of 5 dollars each and connected them in series to get 36V for the TPA3251. This solved most problems, except that there is still some digital chatter noise from the BLenhance. Way too much to qualify as hi-fi, but OK for music on the go. There is slightly less noise if I power it with batteries instead, indicating that these power supplies are not ideal either.

The third issue is still unsolved, it is minor but I'm going to post my ACP config files later, in case anyone wants to dig deeper.
 
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#228
Are there any Bluetooth TWS devices that support the Ldac codec? All I have seen can at most only go up to AptX.
I got one of the new ESS 9039 q2m Dacs and was really surprised that Ldac was slightly better than USB. Comparison was done via an ordinary laptop and no special USB gimmicks used. Neverdeless impressive to say the least.
What's also interesting is the fact that I can't decern a difference between Ldac via my Android phone vs. Ldac via the laptop.
This performance gives me hope that future Bluetooth chips and codecs have the potential to rival dedicated audio transmitting devices.
Multi channel Bluetooth would be awesome.

Greets Klaus
 
#230
The Bluetooth codec options are quite a quagmire. First there's Qualcomm with AptX, AptX-HD, AptX-Adaptive and now AptX-Lossless. Not to mention AptX-Low Latency for gamers/video buffs.. Then there's Sony with LDAC. AFAIK you have to use a Qualcomm chip to get any of the AptX variants. I believe Sony will license LDAC since codecs are just software. I've only seen TWS advertised on Qualcomm devices and I believe it requires a particular firmware with typically 3 buttons for the TWS pairing. All the codec specs require you have a connection that supports the required bandwidth. And don't forget Bluetooth Multipoint! This is just from my limited experience with Bluetooth devices. I've used TWS/AptX and was impressed by it, but the myriad of codecs turned me off. Today there are nice budget WiFi streamers (e.g. WiiM Mini) that replace the Bluetooth mess.
 
#231
Radian said:
What's also interesting is the fact that I can't decern a difference between Ldac via my Android phone vs. Ldac via the laptop.
This performance gives me hope that future Bluetooth chips and codecs have the potential to rival dedicated audio transmitting devices.
Multi channel Bluetooth would be awesome.

Greets Klaus
Click to expand...
BT via laptops (I'm assuming Windows ones) is a huge gotcha. 90% of the time, it's transmitting in SBC or a similarly old BT codec (at least on Windows 10, you have to use a piece of software to force AptX usage).
 
#232
I had to download a specific driver to transmit Ldac on my laptop with W10.
Works like a charm though.
My dac shows the codac so no guessing there.
Wonder if clean power to the Qualcomm chip and a good clock would up the game even more.
 
#235
Auracast is a reality now!
I bought 4 of these:
https://a.aliexpress.com/_EyquWnr

And so far ~30min it’s been stable, nice sounding and no worries.

I have so far tried to connect one as transmitter with 3,5mm in and added three as receiver. And they are synced and surprisingly good reception.

I walked around with two pairs of headphones with one receiver per headphone.
One for the left signal and one to the right. But each receiver gets stereo of course. I only listened to one channel per headphone. And they are in perfect sync.

I also connected on as transmitter via 3,5mm.
And at the same time connected a separate one via usb to a Mac and it works as a usb transmitter. So two transmitters at the same time.
Triple click and the receiver looks for another broadcast and connect. No issues.

With nothing connected thru the 3.5mm and it’s in transmission mode it works as a wireless microphone.

Now I only need to build three amps with dsp and a true wireless 2.1 system is a possible solution.

Edit: I’m 99% sure this is the same product.
https://www.moor-audio.com/products...62632&pr_ref_pid=8325457543464&pr_seq=uniform
 
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#239
Thanks for info on latest developments regarding Bluetooth Auracast Nissep!

I am currently testing out Eiffelton TPA3126 Bluetooth TWS amps in a 2.2 project i am working on. Here is a link to a thread i Norwegian about the project. https://www.hifisentralen.no/forumet/threads/diy-modular-audio-design.108491/#post-3955208

Mono amps with Bluetooth Auracast and DSP seems like the perfect solution solution for projects like this going forward.

I just setup the front speakers today for a test and the amps sound very good but i had to use passive crossovers. My plan is to also link a pair of subs an connect both the subs and fronts to a bluetooth transmitter/wifi streamer.
 

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#240
So I've just received a 2.1 DSP board from a seller in thailand JPS Audio. It's called the DSP-200. Seems similar to the NVarcher/Effelton boards. But for the life of me I can't seem to get audio out of the line/auxiliary input. The seller hasn't sent me the software link but found one on the internet. The Bluetooth and Soundcard inputs work fine. Infact if I make changes to filters, etc in the ACPWorkbench app I can hear the differences in realtime but just can't figure out how to enable line input.

This is the link to the board in case anyone has any experience with something similar https://www.lazada.co.th/products/200-21ch-dsp-tws-jps-audio-i4597473569-s18828060065.html
 
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