HydrogenAudio

CD-R and Audio Hardware => Audio Hardware => Topic started by: lylew on 2017-11-27 22:07:17

Title: Bluetooth receiver to HDMI
Post by: lylew on 2017-11-27 22:07:17
I am searching for a Bluetooth to HDMI dongle/device so I can connect my phone to my receiver wirelessly. I do not want to use a Chromecast as that is application dependent or Miracast device (I have a Roku). Just plain Bluetooth.

I found an optical solution at https://aluratek.com/universal-bluetooth-optical-audio-receiver-transmitter but was hoping for HDMI. Any suggestions?
Title: Re: Bluetooth receiver to HDMI
Post by: andy o on 2017-11-28 07:37:43
It's very unlikely that someone would make that. It's an extremely niche use case for this. The easiest way to achieve this seems to be to get a video to HDMI converter and then plug a BT adapter to that device's audio inputs. I'm not sure if HDMI works without a video feed though, that could depend on your receiver or even TV.

But depending on your phone, you can use a Chromecast to cast all phone audio the same way as you would use BT and not depend on an app. Besides that, app support for Chromecast is very wide and you can usually offload the playing and processing to the Chromecast thus not draining your phone battery, and not depending on your BT connection quality. Can you be more specific on what apps you use and how do you use them?

Besides that, why HDMI and not other widely available options like analog or even SPDIF? I know I'd rather not use up yet another HDMI port in my receiver, but I have an older one with only 3 inputs. You're out of available analog/digital audio inputs?
Title: Re: Bluetooth receiver to HDMI
Post by: LithosZA on 2017-11-28 18:58:20
Does your receiver have an optical input? I'm also wondering why it should be HDMI.
Title: Re: Bluetooth receiver to HDMI
Post by: lylew on 2017-11-28 19:07:06
But depending on your phone,
That is what I am trying to avoid. I'm looking for the most universal way to do this, which IMO, would be Bluetooth.
I mainly use FB2K on my phone.

Why HDMI? 1. I was hoping for a "stick" (like the original Chromecast) 2. Less chance of quality/packet loss than analog or SPDIF (that's probably a lil' OCD). 3. Only using 2 of 4 HDMI ports on my receiver.
The device I linked to is SPDIF and analog.
Title: Re: Bluetooth receiver to HDMI
Post by: Audible! on 2017-11-28 19:15:39
Do you know which version of Bluetooth your phone supports?

Depending upon which "optional" features (AptX) and version of bluetooth, there is a definite possibility that you are going to lose audio quality, as it will often recompress the signal in a lossy fashion (https://www.lifewire.com/what-to-know-about-bluetooth-3134591). If you're playing an already lossy-encoded file, this might become noticeable.

Unfortunately, I suspect that a bluetooth HDMI adapter is going to be quite expensive, if such a thing exists.
Title: Re: Bluetooth receiver to HDMI
Post by: lylew on 2017-11-28 19:45:30
My phone has Bluetooth 4.1 and the device I linked to is 4.0 so the sound should be OK for general listening (no lossy audio codec tests). I am aware of the quality loss with Bluetooth (although I hear with 5.0 it's near lossless or something like that). The Bluetooth to Optical device I linked to is $70, was hoping for something cheaper since Chromecast is $35.
Title: Re: Bluetooth receiver to HDMI
Post by: LithosZA on 2017-11-28 19:55:04
Less chance of quality/packet loss than analog or SPDIF (that's probably a lil' OCD).
Both HDMI and optical would give perfect lossless audio unless something is seriously wrong.
Unfortunately with Bluetooth you can only transmit audio with lossy compression which could degrade the audio quality that might be audible. The devices might negotiate a low bitrate mode. One of the devices might also not support aptX and will fallback to SBC.
Title: Re: Bluetooth receiver to HDMI
Post by: Audible! on 2017-11-28 20:02:26
Glad to see you're familiar with the idiosyncrasies of Bluetooth audio transmission.

Since the Chromecast is a thoroughly mass-market device, and your preferred solution is a much more niche application, I'd be very surprised if such an adapter would be cheaper. 
Title: Re: Bluetooth receiver to HDMI
Post by: lylew on 2017-11-28 20:05:54
I found a similar device (minus the cables) on Amazon for cheap ($22.91) that claims Bluetooth 4.1 support so I'll probably just go with that.
https://www.amazon.com/Bluetooth-Transmitter-Receiver-Wireless-Headphones/dp/B071R2ZM9K/
Title: Re: Bluetooth receiver to HDMI
Post by: Audible! on 2017-11-28 21:12:45
Nice, with AptX no less. Interestingly shaped 5V DC charging port; almost like HDMI. Hope it works out for you!
Title: Re: Bluetooth receiver to HDMI
Post by: lylew on 2017-11-28 22:14:16
Interestingly shaped 5V DC charging port; almost like HDMI.
That's a micro USB charging port. You must be an Apple guy. I kid! I kid! :)
Title: Re: Bluetooth receiver to HDMI
Post by: Audible! on 2017-11-28 22:47:36
Ooh how embarrassing!
I guess I wasn't paying attention to the dimensions of the box; that thing is quite diminutive indeed.
Happily, that means certain TVs might be able to power the thing directly.

Of course I'm a PC guy; EAC isn't available for Mac OS! :D

In fact, I'm eagerly awaiting what the lauded audio subsystem implementation (ALC1120, L/R channels routed on separate PCB layers, ludicrous capacitors (http://products.nichicon.co.jp/en/pdf/XJA043/e-fg.pdf)(pdf), a TI NE552 dedicated headphone opamp (http://www.ti.com/product/NE5532/datasheet/detailed_description#SLOS075535)) on the ASRock Taichi X370 (https://www.newegg.com/Product/Product.aspx?Item=N82E16813157757&ignorebbr=1) sounds like in my Ryzen desktop build.
Title: Re: Bluetooth receiver to HDMI
Post by: kode54 on 2017-11-29 03:31:27
I find EAC to be ludicrous to configure. I'll take XLD or any Linux frontend that houses cdparanoia any day.
Title: Re: Bluetooth receiver to HDMI
Post by: Audible! on 2017-11-29 03:48:10
EACs interface is certainly counter-intuitive in a number of ways, no doubt about it.

Does XLD do optical drive feature detect these days?
This always seemed like an eminently useful, and rarely duplicated function with EAC.
Title: Re: Bluetooth receiver to HDMI
Post by: kode54 on 2017-11-29 08:04:56
It retrieves the offset from an online database, but I don't know if it does feature detection. It's been a while since I last used it, actually.
Title: Re: Bluetooth receiver to HDMI
Post by: andy o on 2017-11-30 03:09:22
My phone has Bluetooth 4.1 and the device I linked to is 4.0 so the sound should be OK for general listening (no lossy audio codec tests). I am aware of the quality loss with Bluetooth (although I hear with 5.0 it's near lossless or something like that). The Bluetooth to Optical device I linked to is $70, was hoping for something cheaper since Chromecast is $35.
Pursuing newer BT versions for audio streaming is somewhat of a red herring. BT versions since 3.0 (maybe even 2.1) don't do anything for audio quality or highest bitrate. BT 4.x was pretty much only BT Low Energy for peripherals like smartwatches and beacons, and BT 5 improves on that. AptX could be done in BT 3.0 as far as I can tell.

The bitrate and range improvements much touted about BT 5 are very misleading in the way they've been presented by most of the media. First of all, they're mutually exclusive so you can have the range or the throughput improvement, but not both at the same time (or probably a combination of both where there's an inverse correlation). Second, they are applicable for BT LE, which has no bearing on audio streaming (A2DP). The publicized max bitrate of BT 5 even is lower than what BT 2.0 + EDR already could do (2 Mbps vs. 3 Mbps theoretical).

See this video (https://www.youtube.com/watch?v=T-CPobBQi6E) and read Gary Sims' articles about BT 5. That video, even though he's polite enough to not mention it, seems to be mostly in response to a terribly misinformed video (https://www.youtube.com/watch?v=0n1x-wxESaM) by MKBHD in which he pretty much said nothing correct (not even the name, it's supposed to be "Bluetooth 5" not "5.0" ¯\_(ツ)_/¯. To be fair the misinformation has been regurgitated by pretty much 99% of tech sites, but he's one of the tech personalities with the most reach.

What we can hope for is for the BT SIG to come up with an updated A2DP that takes advantage of the new BT LE throughput capability which it seems to be good enough for quality audio transmission, when before (BT 4.x) it was probably too slow. It wouldn't make it better quality (though I guess it'd be an opportunity to upgrade the mandatory codec), but it would be more power efficient. But as far as I know there's no plans announced for that.
Title: Re: Bluetooth receiver to HDMI
Post by: Soap on 2017-11-30 11:22:48
What we can hope for is for the BT SIG to come up with an updated A2DP that takes advantage of the new BT LE throughput capability which it seems to be good enough for quality audio transmission, when before (BT 4.x) it was probably too slow. It wouldn't make it better quality... but it would be more power efficient.

Now that BT audio streaming is moving towards devices with "micro" batteries (Garmin and Fitbit activity watches for example.) this would be greatly appreciated and I can't believe there isn't high pressure to do this.

For example the Garmin 645 (watch) appears to be claiming 5 hours of battery life when GPS logging and streaming music to bluetooth headphones.  The Garmin 235 (same battery size) gets 11 hours of battery life when GPS logging alone.
Title: Re: Bluetooth receiver to HDMI
Post by: andy o on 2017-11-30 13:00:36
Yeah, and especially since "truly wireless" earphones are getting more popular, and battery life is one of their weaknesses.