Topping BC3 Review (Bluetooth Receiver) & BT CODECs

[Pdxwayne]

@amirm , did you adjust your LDAC quality in developer option menu when doing your tests with your phone? Actual music listening impression?

 

[JohnBooty]

LDAC is not an exclusively lossless format. On lower bitrates it's operation is related to ADPCM or Wavpack hybrid's scheme which modulates the noise floor according to the input.

Thanks for pointing that out. Sorry; I meant lossy and not lossless... I'll fix that.

There would be little point to testing lossless codecs. And those are easy to test. Just need to do input.WAV ➡ (some lossless codec) ➡ output.wav and check to see that input.wav and output.wav are the same.

 

[dorirod]

So I've got some dumb dumb questions, I'm a smooth brain audio guy.

With Apple coming out with lossless audio next month for Apple Music I assume any Bluetooth implementation would be a bottleneck. Question is would I be able to get CD level quality with a Bluetooth device such as or similar to this?

Maybe not directly to your question, but worth noting for those that don't know:

https://www.imore.com/what-apple-devices-are-compatible-apple-music-lossless

"However, you can't listen to the ALAC format over Bluetooth, so there are no Apple headphones that will work. Not even the AirPods Max, even if you connect it with a wire. You need wired headphones to listen to ALAC format music."

https://support.apple.com/en-us/HT212183

"You can listen to lossless on an iPhone or iPad updated to iOS or iPadOS 14.6 using:

• A wired connection to headphones, receivers, or powered speakers
• The built-in speakers
• To listen to songs at sample rates higher than 48 kHz, you need an external digital-to-analog converter."

 

[JohnBooty]

With Apple coming out with lossless audio next month for Apple Music I assume any Bluetooth implementation would be a bottleneck. Question is would I be able to get CD level quality with a Bluetooth device such as or similar to this?

Probably "very close to CD quality."

Controlled tests show that when done properly, high bitrate lossy audio is quite difficult to distinguish from the original. However this assumes that the source material is lossless.

However, even people with tin ears such as myself often don't love current BT solutions because you're generally taking lossy audio (file you download or stream from Apple/Spotify/wherever) and running it through another lossy codec. Sort of like recompressing a JPG. Now you have artifacts piling up on artifacts.

(Disclaimer: Unlike lossless➡lossy conversions, I haven't seen any controlled listening tests for lossy➡lossy audio compression, so the preceding paragraph is just anecdotal opinion )

So to answer your question, theoretically and anecdotally I would have every reason to believe that lossless Apple Music tunes will be very close to CD quality when piped over a decent BT codec. If you truly want literal CD quality though, you do have to ditch Bluetooth. You'll have to rely on a lossless wifi streaming solution.

 

[SEKLEM]

You'll have to rely on a lossless wifi streaming solution.

Simply put I'm interested in such a solution that's simple set up and use that doesn't require the use of HDMI. Preferably a device with SPDIF.

 

[JohnBooty]

Maybe not directly to your question, but worth noting for those that don't know:

https://www.imore.com/what-apple-devices-are-compatible-apple-music-lossless

"However, you can't listen to the ALAC format over Bluetooth, so there are no Apple headphones that will work. Not even the AirPods Max, even if you connect it with a wire. You need wired headphones to listen to ALAC format music."

Wow, I'm stunned. My first reaction is, "that's absolutely stupid."

Why should the headphones "care" what the source format is?! It is the job of the playback device/software to understand the source format and convert that into the appropriate BT codec. Why would the headphones need to know or care if it was a FLAC, AAC, ALAC, whatever? I do not understand.

 

[JohnBooty]

Simply put I'm interested in such a solution that's simple set up and use that doesn't require the use of HDMI. Preferably a device with SPDIF.

I've been using AirPlay via Wifi+Airport Expresses for well over a decade. That's lossless and they have optical outputs.

Setup is minimal. You can use them wired, or wireless. Wired is pretty much plug and play. Wireless setup is as minimal as possible -- like any Wifi device you have to tell them which network to use and what the password is. After that things pretty much "just work" with Macs (at a system level, for all apps) or with individual applications like Apple Music.

I believe Roon fits the bill as well with more features and a higher price tag. But it seems painless enough.

 

[SEKLEM]

I've been using AirPlay via Wifi+Airport Expresses for well over a decade. That's lossless and they have optical outputs.

Setup is minimal. You can use them wired, or wireless. Wired is pretty much plug and play. Wireless setup is as minimal as possible -- like any Wifi device you have to tell them which network to use and what the password is. After that things pretty much "just work" with Macs (at a system level, for all apps) or with individual applications like Apple Music.

I believe Roon fits the bill as well with more features and a higher price tag. But it seems painless enough.

I guess I'll seek out a gently used last gen Airport Express. Thanks!

 

[Atanasi]

Why should the headphones "care" what the source format is?! It is the job of the playback device/software to understand the source format and convert that into the appropriate BT codec. Why would the headphones need to know or care if it was a FLAC, AAC, ALAC, whatever? I do not understand.

The case where the format makes a difference is AAC pass-through: if the source and BT receiver both support AAC, the media stack may pass AAC through without re-encoding.
I think Android also prefers AAC pass-through if all conditions are met: a single AAC stream playing at the same, no DSP etc.

 

[somebodyelse]

Any more details on exactly which SBC settings this was using? The high bitrate Dual Channel modes seem to perform well,but it looks like you need a 3rd party Android replacement like LineageOS, or linux (with patches?) to use it.
https://habr.com/en/post/456182/
https://habr.com/en/post/456476/

 

[weasels]

I must be particularly smooth brained today, but what is the use case for a product like this? Add BT to a system that otherwise lacks BT?

 

[amirm]

@amirm , did you adjust your LDAC quality in developer option menu when doing your tests with your phone? Actual music listening impression?

View attachment 132256

Your answer is in the review.

 

[Robbo99999]

saw the panther and thought, "What? Topping missed the mark?!"

didn't realise it was actually a good review. phew!

Yeah, I thought egg on foot was a bit like egg on face! Seems like a decent little product with some convenience factor.

 

[Pdxwayne]

Your answer is in the review.

So you always selected 990kbps option? Not sure how this correlate to 16bit and 24bit.

 

[JohnBooty]

The case where the format makes a difference is AAC pass-through: if the source and BT receiver both support AAC, the media stack may pass AAC through without re-encoding.
I think Android also prefers AAC pass-through if all conditions are met: a single AAC stream playing at the same, no DSP etc.

Preferring passthrough makes 100% sense!

But it makes no sense to me to just completely disallow playback of lossless Apple Music audio over BT when the phone could simply transcode it, like it does with every other format.

I guess maybe they just want to protect people and wireless carriers from folks downloading absolute scads of additional data, if they don't actually have the setup to potentially benefit from it. But, if that's their goal, this seems like a very hamfisted way to do it.

 

[PeteL]

So I've got some dumb dumb questions, I'm a smooth brain audio guy.

With Apple coming out with lossless audio next month for Apple Music I assume any Bluetooth implementation would be a bottleneck. Question is would I be able to get CD level quality with a Bluetooth device such as or similar to this?

My receiver is pre-HDMI so the AppleTV 4K is run through the television and optical to the receiver. The AppleTV will be supporting the lossless audio update in June, but I really hate having the television being on while I listen to music. I can at the very least turn the display on the TV off and use Airplay to cast from my iPhone to the AppleTV. Ideally I'd prefer to get a device that allows me to bypass the television all together that I can control with the iPhone that doesn't cost $500 that will allow me to tap into the Apple Music lossless audio. Is this device from Topping a viable option?

Short answer is no. There is however a handful great R&D firms that are as we speak able to stream lossless trough Bluetooth "like" technologies in the 2.4 GHz band, by Bluetooth like I mean low power, and point to point not IP based like WiFI. But by the time this gets integrated in phones and headset, the licencing and business model sorted, It will be years. Bluetooth is not dying soon and to be frank is adequate for the vast majority. Big bucks there, you don't oust away such a large ecosystem easy, but it's limited and will stay limited.

 

[Oukkidoukki]

I must be particularly smooth brained today, but what is the use case for a product like this? Add BT to a system that otherwise lacks BT?

Yes

 

[amirm]

So you always selected 990kbps option? Not sure how this correlate to 16bit and 24bit.

No. As I said in the review, I left it in adaptive mode and despite moving my phone some 20 feet away, the measured results held:

I had the codec in adaptive mode by the way so it could have switched encoding rates but I saw no glitches to indicate it did so. Your mileage may vary of course depending on the implementation of Bluetooth transmitter in your device.

Other than one test the rest of the LDAC measurements were in 24 bit mode.

 

[amirm]

On questions regarding test tones, yes, that is too simplistic of a test to assess fidelity with music. However, the non-LDAC codecs screwed up even that simple tone so LDAC at least does that right. And as such, can rise up to that level of performance whereas the others can't.

 

[poopy]

UAT codec developed by Hiby should beat the LDAC codec.

SMSL DACs like the SU-9 and M200 are compatible with UAT.

The most difficult is to find a phone or even device compatible with this codec. Apparently new Huawei phones are (some).