SBC vs. AAC on Bluetooth headphones - pls help?

user16

Novice Member
Hey everyone,

I'm still confused about the SBC & AAC codecs and their potential benefits.

I have a Macbook and Bluetooth headphones that support both SBC & AAC. By default, all music from Macbook plays via SBC but I found that with the dev tools you can force Macbook to always use the AAC codec (see screenshot).

A large portion of my iTunes library has been ripped from my own CD collection using either LAME CBR 320 kbps or LAME VBR (high -q 2 260 kbps) which is the highest possible quality VBR, but some of my older rips use lower bitrate ranging from 128 kbps to 192 kbps.

My headphones support the SBC bitpool of 52.

I'd like to ask you the following:

1. Given that most of my music is in .mp3 format rather than .m4a or .aac, does it even make sense to force my Macbook to use the AAC codec? Would ordinary mp3s really sound better over AAC, or is it only the files in e.g. .m4a or .aac format that would actually benefit from it?

2. If I played ordinary mp3s over AAC codec, wouldn't that mean that my Macbook would first autoconvert audio from my mp3s into AAC format each time I listened to them over Bluetooth and possibly cause tiny artifacts in the sound? And since AAC (if I'm not mistaken) only supports bitrate up to 250 kbps or so, my 320 kbps mp3s would actually be reduced to below 300 kbps over AAC codec? Or is my understanding incorrect?

3. SBC on the other hand supports bitrate of up to 319 kbps over my headphones apparently (see attached graph), so would in my case still be more reasonable to actually use SBC instead of AAC format?

It's really confusing as to what one should do... so I'd really appreciate if someone could advise about this.

Thanks!
 

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iamsludge

Active Member
What are the headphones?
That might make the bigger difference.

AAC is often considered better than SBC for sound quality.
But don’t use AAC on an Android phone.

Then again, you personally might not be able to hear the difference anyway.
 

iamsludge

Active Member

user16

Novice Member
What are the headphones?
That might make the bigger difference.

AAC is often considered better than SBC for sound quality.
But don’t use AAC on an Android phone.

Then again, you personally might not be able to hear the difference anyway.
The headphones aren't some high-end cans - Anker Soundcore Life Q30.
 

iamsludge

Active Member
I’ve heard they’re good headphones if you get a good pair.

Given that you’re using bluetooth and not high-end cans I probably wouldn’t worry much and would just use AAC as I think bluetooth itself is likely the weakest spot in the chain.

That said, I understand that AAC takes more processing so if you have concerns about that then go back to SBC and see if you notice any audible difference.

I‘ve recently been evaluating some new in-ear-monitors and a couple of bluetooth receivers. Namely Etymotic ER4XR and ER4SR with a cheap bluetooth receiver and the higher end Etymotion bluetooth cable. I found that I can tell the difference between the low-end £12 receiver and the £180 receiver (that includes a DAC) but the difference is not what I would call dramatic. I prefer the higher end one as much due to battery life and comfort/convenience as the improved sound. I think my missus would think I’m mad for thinking the difference in quality is worth the difference in price.
 

Jules Tohpipi

Well-known Member
@user16
I understand absolutely everything you are saying but there is no way of determining the better route on paper.

Apple’s implementation of AAC is excellent and should give generally good results.

SBC is generally implemented very poorly but is capable of giving very good results if the manufacturer knows what to do with all its various settings (most don’t and mess the sound up). Congratulations on being the first ever person I’ve seen mention the bitpool setting for SBC on a forum! 52 is not the highest setting and is quite typical for headphones.

Like it or not, to be transmitted via Bluetooth, your files will have to be converted prior to transmission - be that to SBC or AAC. SBC uses some ancient psycho-acoustic algorithms in its encoding. Don’t expect bit perfect. AAC also uses psychoacoustics in its encoding but more modern ones. So don’t expect bit perfect digital transmission there either just because you’re within a similar sampling range. Both codecs are going to re-jig the audio encoding for Bluetooth transmission.

When all is said and done there are too many unknowns about how both codecs can be configured by the hardware manufacturers to make an informed ‘right’ choice. Your ears are going to have to do the decision making.

This is where aptX and aptX HD shine because Qualcomm don’t give the hardware guys the rope to hang themselves with. You can be much more confident in what you get from product to to product with those codecs compared to SBC, AAC and LDAC.

In your case AAC is possibly the safer bet as Apple has nailed getting the best out of that codec.
 
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