SBC-XQ: When SBC is better than LDAC... since 2019

Equipment / Electronics / Gear / Accessories Source Gear / Other
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Okay, this is awesome. And the only reason why it’s not known by everyone is… AptX/LDAC codec money going to Qualcomm and Sony instead.

TL,DR: If you got a linux-based source (Raspberry Pi?) or an Android phone (with LineageOS, for example – not a stock Android phone: Google don’t care), there’s a patch allowing you to simply send 452kbps to 730kbps of data to any of your devices supporting SBC. Yes. SBC. The old, shitty codec. Well, guess what. You don’t need a new receiver with AptX, AptX HD, LDAC, or AptX Lossless… but what’s interesting is, SBC might even sound better than all of em.

You want good audio via Bluetooth, no compromises?

Well, there’s LDAC, but LDAC isn’t one audio quality level, it’s… three (330kbps/660kbps/990kbps). And most of the time, your source won’t allow you to lock it to one “level”. It will just… ping-pong around. One big problem: 330kbps actually measures/sounds worse than SBC (yay, hi-res™ :roll_eyes: ).

A few (like, maybe 25 devices on the entire planet?) now support “AptX lossless”. Wanna laugh? AptX Lossless is variable bitrate and can go down to 140kbps. This is quite laughable, even if it means “10 seconds of lag before your bit-perfect audio plays”.

AptX HD is 576kbps. Only. Set-and-forget. Great. This is probably the best option right now. Well, what if it is not? And what if your receiver doesn’t support AptX HD?

The website above allows you to hear the differences between bluetooth codecs… By encoding and decoding files straight into your web browser. So, with your own reference system, your all wired dacs, amps, speakers, headphones.

The first codec is SBC… the second codec option is SBC at 452kbps “Wha? This is AptX territory.” Well, this is SBC-XQ EDR2 (452kbps for 16bit/44.1khz, 492kbps for 16bit/48khz). You can even bump the SBC “bitpool” to 47 for what is called SBC-XQ EDR3 (551kbps for 16bit/44.1khz, 600kbps for 16bit/48khz).

Actually, if you have LineageOS, you can do setprop persist.bluetooth.sbc_hd_higher_bitrate 1 for the lowest possible quality to be 595kbps. This is higher than AptX HD.

On the website, even Aptx HD, to my ears, sound “nasally”. It is lacking low-mids compared to SBC-XQ. Even at 452kbps. But good luck hearing a difference between “None” (original, full-quality FLAC files) and SBC-XQ. Even with your headphones on your reference system.

The secret to high-quality audio via SBC is that almost all modern BT headphones, speakers, receivers support SBC bitrates up to 730 kbit/s just out of the box (and this is a quote from 2019). Bluetooth allows it. Your old receivers can do it. It’s just NOT implemented in your devices (bluetooth sources / players).

If you have anything bluetooth, it has SBC (this is the standard, mandatory codec) and therefore it is compatible with SBC-XQ. This got the potential to revive a lot of your old or forgotten bluetooth speakers/headphones that “sounded like shit”… and make em sound way better.

Well, enjoy! :musical_note:

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This was quite interesting for me for a few reasons:

  • I want good sound at an apartment, but my Bluetooth receiver only supports SBC.
  • I was searching for new Bluetooth receivers, wanted AptX HD for the convenience and peace of mind of 500-something-kbps-all-the-time-or-nothing.
  • But I need a new phone, and I already wanted LineageOS on it. So SBC-XQ will already be in it.
  • I found out AptX HD sounded, to my ears, worse than even the “lowest” SBC-XQ option.

More tests to do, which you can do even with your own .mp3/.wav/.flac files on the website above, but that discovery was unexpected, to say the least.

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Oh, LHDC might also be a contender. But guess what, no info whatsoever about how it works. It claims 24bit/192khz via bluetooth. It claims 140dB of distortion-free audio. It even advertises itself at “LHDC Lossless” sometimes.

I call BS. No infos whatsoever on their website on how it is achieved and what is the threshold from lossless to lossy. Chances are, like all the others codecs, even your damn poor 128kbps mp3 will be re-encoded again by (ex.) the LDAC 990kbps codec for the mp3 to lose data again because LDAC (like everything else) is a lossy codec which means your 128kbps mp3 will be losing bits by being re-encoded again as mostly-empty, bigger but of lesser quality, 990kbps “dot LDAC file” packet sent in the air to your receiver.

I understand the encoding does a “negligible” difference (as I said earlier: good luck comparing the .flac to the SBC-encoded version, for example). It’s just that… they say it’s lossless. On multiple websites and items. Ehh, [citation needed], guys.

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Yep :wink:

LE:
I mean “yep, you can set SBC to work at way higher bitrate and perceived quality”, but I don’t actually agree with this topic title - LDAC forced to work at 909 kbps (16/44.1) still transmits about 66% of the data vs. uncompressed raw PCM (wav), and I’ve seen no evidence that SBC-XQ should be expected to sound better at 551.2 kbps or whatever is supposed to be achievable on most devices today.

You could argue SBC-XQ is practically better if you can show both are transparent and then SBC wins… on connection stability and power consumption maybe. But you can’t say SBC would “sound” better, since both are using similar non-psychoacoustic encoding principles, the one allocating higher bitrates should sound better, if there’s any difference in sound.

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I just saw your answer. Sadly the website does not allow you to “A/B” compare LDAC to SBC-XQ. But, anything allowing you to lock the bitrate is a plus, and, for me, a necessity, considering how much bluetooth can suck at low kbps. AptX HD sounded worse than SBC-XQ to my ears. I’d need more time (…and a new phone) to compare to LDAC. I believe the Fiio BTR5 app allows you to lock the signal to LDAC 990kbps. Sadly Android does not, AFAIK.

By the way Darko just did a video about the new “aptx lossless” codec…

TL,DW: You need both “Snapdragon Sound”-enabled phones and headphones/IEMs, and they go beyond the bluetooth specification to achieve “lossless” quality, which means NONE of your headphones/IEMs (and smartphones) you already have will ever support it… all that to pair em and see “AptX adaptive”, because AptX lossless is LOSSY when the signal isn’t strong enough. :man_facepalming:

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SBC actually follows a specific “curve”. It uses a different “noise profile”. AptX and LDAC just don’t use any noise profile, they’ll just cut 10khz+ when there’s not enough bits (edit: 5khz+ actually – augh). This can be the reason why I’ve found SBC-XQ to sound better, even if it’s lower bitrate than AptX HD.

TL,DR again: SBC gives you spikes of distortion. AptX HD, even LDAC, gives you a blue wall of distortion (the following graph is not SBC-XQ, just original SBC – I’d be curious to see the SBC-XQ graphs – spikes in the audible range could be rare and sparse).

SBC-Bluetooth-Noise-560x368.jpg

aptX-HD-Noise-560x368 (1)

LDAC-990-Hi-Res-Noise-Floor-1-358x235.jpg

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Anyway, ignoring all the problems with aptX for a second, my point was I don’t see any good evidence that it’s worth worrying about setting up SBC-XQ just to have it working at 551 kbps, once I have LDAC available and can set it to 909 kbps (I don’t have a problem setting it manually once per listening session, but AFAIK there’s some app as well that does it automatically, just doesn’t work for old Android versions). I don’t care what slightly better bit allocation is done in SBC, it’s not going to perform better at 551 vs. 909, or it’s not probable enough to be worth any effort to change my setup.

If I didn’t have LDAC (like if my BTR3 died), sure, that would be another story.

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Oh, yes, sorry. If you can lock LDAC at 990kbps, there’s a strong chance it’s the best bluetooth codec right now (including even AptX-lossless-cash-grab-not-lossless-but-actually-adaptive-to-even-141kbps), and don’t worry about SBC-XQ.

On the opposite, I’d be curious to compare LDAC with SBC-XQ at 595kbps or more. But we might be splitting hairs, and above all we might be making big mistakes throwing away old bluetooth receivers, or not buying, for example, a Yamaha RS202BL or a WiiM Amp, “because they don’t support LDAC”, when SBC-XQ is a possibility – but “we just did not knew” because Sony/Qualcomm money.

Does SBC-XQ sound better than LDAC? I don’t know. “Splittin hairs” territory, especially at 2 meters of your speakers. So why did I say SBC was better? 100% compatibility with everything bluetooth because SBC is mandatory on everything bluetooth-equipped. 100% good sound all the time because SBC-XQ is 595kbps-or-nothing. No distortion “wall” above 5khz because there’s no wall, just scattered spikes of distortion instead, chosen using psycho-acoustics. Add to that the feeling of having been scammed for years, forced to listen to crappy standard SBC audio (oh, the horror! :grin: ), when hardware was SBC-XQ compatible, but just not implemented in Android.

But again, if you can lock LDAC at 990kbps, you’re in luck, enjoy the music y’all, and don’t bother with all these shenanigans. :headphones: :sunglasses:

I just happened to have an old BT receiver without LDAC, and to want a new phone with LineageOS in it already, and to learn about SBC-XQ by stumbling upon a forum post about the WiiM Amp, then being like “Why haven’t I heard about that!”.

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By the way, if you JUST want to lock LDAC to 990 on android, this app might help:

I’ll see tomorrow if it works with my Nvidia Shield. Might have some SBC-XQ parameters too? I don’t know. My phone is too old to install it lol.

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Yeah, that was the one I meant, and same here - phone too old (OS too old).
But since LDAC only matters for critical listening and those sessions aren’t a daily (or weekly) thing, and since it only requires setting it manually once before starting the 1-2-3 hours of listening… I can live without the app.

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I’m going to bump this topic because if the new Koss PortaPro are using SBC then this might apply to them. I’ll have to look into it.

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This is all super interesting. But as my wireless listening is from an iPhone to Bluetooth receiver, if I’m happy with AAC, I’d probably be just as happy with all these other options. I’m a ‘320kbps MP3’ kind of person.

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Well, at least you got the good end of the “some phones yes and some phones no” - AFAIK the Apple implementation of AAC sounds significantly better than most Android implementations, so in your case there might be less to worry about with missing out on quality if you can’t get SBC-XQ.

And yeah, I still have a lot of music in 320-MP3 from when Google Play Music was selling downloadable files, and I’m not worried there are magical things that I’m not hearing because it’s not lossless. Even what I buy lossless I down-convert to VBR AAC encoded with NeroAAC, for space saving. I use Q=0.8 and they come out around the same 320-ish kbps on average (but since it’s VBR it really depends on each song’s complexity), just with a smarter algorithm than MP3, AAC being basically MP4-audio, the next generation.

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As @abm0 mentioned, AAC on Apple devices are a LOT better than on Android, which can vary from better than SBC to worse than SBC.

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Oof, just stumbled on some more concrete data on this: if you have a new-ish iPhone its dedicated HW encoder for AAC is already giving you audio quality on the level of max-bitrate LDAC. :exploding_head:

I guess that’s what performance should look like when you’re using the next generation smart (psychoacoustic) codec that’s better than MP3, vs. all these others like SBC, aptX and LDAC which use no psychoacoustics beyond simply allocating more bits for rough frequency bands humans are on average more sensitive to. Buuut then again, cost savings - no fast HW encoder for complicated codecs, cheaper phone. :slightly_smiling_face:

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I have an iPhone 11 like they tested. Makes sense of why I’ve never found the sound to be lacking through a receiver then!

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But the other interesting thing in part 1 of his test is that not only did SBC perform way the hell better than Android-AAC (which can be expected in most cases, and mirrors Z’s experience listening to the TWS PortaPro) but it already hit aptX HD quality, without being SBC-XQ. :open_mouth: That 2019 Huawei sure as hell didn’t have SBC-XQ patches in it when people were just barely starting to discuss its existence online.

LE:
Nope nope, I can’t rely on his conclusions until he adds more clarifications, he’s reading some sussy conclusions from those graphs, if I look closely aptX HD is still a bit cleaner than SBC, just due to having fewer distortion spikes, even if they do reach as high as the SBC ones.

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AAC varies a lot from different brands, it depends a lot on their implementation. SBC is much more consistent and is usually the safer one to use.

Although AAC should have longer signal range (although drains more battery) than SBC so depends on what you need I guess.
Source: My own thesis: https://his.diva-portal.org/smash/get/diva2:1672233/FULLTEXT01.pdf