[MayaTlab]

MacBooks, iPhones, and iPads should all have very similar, if not identical implementations of AAC encoding. That likely isn't the location of the differences for those hearing it.

That's what I'd be inclined to presume too... but who knows exactly ?
Some Apple devices with Apple silicon have a hardware audio encode / decode capability, but I have no idea whether it's available or not for audio over bluetooth in the first place.

As far as I'm concerned if there are differences, they're small enough to me that I'm not confident that I'd be able to A/B them, and I find them negligible anyway relative to much more important concerns such as FR, so I don't sweat too much about it to start with.

 

[Bytor123]

Both the source and the receiver matter.

I believe that Soundguys' article shows that even with the same bitrate, two audio streams over bluetooth using the AAC codec, from two difference sources, decoded by a single receiver, can have, for example, a different noise floor because of how well implemented or not the AAC encoding is on the different sources they tested. The difference in noise floor would be "baked in" the audio stream that's transmitted. The receiver decode the AAC stream and, as it can't know whether or not that raised noise floor was part of the original file or a by-product of the poor encoding on the source's end, it won't discard it.

I would guess that, just like what's happening with various sources, AAC over bluetooth implementation on the receiving devices varies just as much as with various sources. So if you combine both a decent AAC over bluetooth source + a decent receiving device (presumably Apple's I'd guess), you get something decent. If you combine a crap AAC over bluetooth source + a crap receiving device, you get something crap. And if you combine a crap source with a decent receiver or vice-versa, you get something... not decent ?

Thanks! I don't have the APM (I have the B&W P7W amongst other Bluetooth headphones). If the APM is a decent AAC receiver I don't get why that shouldn't be the final arbiter of the quality of sound - if it's sent AAC, why wouldn't it deliver AAC? The point being, how would there be a difference in sound between devices sending AAC to the APM? (Assuming all devices are functioning correctly...no...condensation...)

 

[MayaTlab]

Thanks! I don't have the APM (I have the B&W P7W amongst other Bluetooth headphones). If the APM is a decent AAC receiver I don't get why that shouldn't be the final arbiter of the quality of sound - if it's sent AAC, why wouldn't it deliver AAC? The point being, how would there be a difference in sound between devices sending AAC to the APM? (Assuming all devices are functioning correctly...no...condensation...)

https://www.soundguys.com/the-ultimate-guide-to-bluetooth-headphones-aac-20296/

 

[tinyman392]

Hello but with Spotify High Quality and AirPods max will you feel the differences compared to the quality of the current files? Or will it be up to use an external dac? Thank you. Andrew

Spotify MP3 will be decoded then encoded into AAC before being sent to the AirPods Max. Spotify high quality is likely a FLAC (or similar) that will be decoded and encoded to AAC before being sent to the AirPods Max. You likely won't hear the differences between the FLAC and AAC, but the MP3 encoded into AAC may be audible.

That's what I'd be inclined to presume too... but who knows exactly ?
Some Apple devices with Apple silicon have a hardware audio encode / decode capability, but I have no idea whether it's available or not for audio over bluetooth in the first place.

As far as I'm concerned if there are differences, they're small enough to me that I'm not confident that I'd be able to A/B them, and I find them negligible anyway relative to much more important concerns such as FR, so I don't sweat too much about it to start with.

The AirPods have hardware specifically designed to deal with audio, likely though something like an FPGA (I could be wrong though). I'm not certain their iPhones, iPads, or MacBooks have specialized hardware for audio, most of their focuses have been on getting ML and AI working efficiently. With the new M chips it'll not make much sense to use a different implementation across devices as time goes by.

Thanks! I don't have the APM (I have the B&W P7W amongst other Bluetooth headphones). If the APM is a decent AAC receiver I don't get why that shouldn't be the final arbiter of the quality of sound - if it's sent AAC, why wouldn't it deliver AAC? The point being, how would there be a difference in sound between devices sending AAC to the APM? (Assuming all devices are functioning correctly...no...condensation...)

If you feed a better sounding/mastered recording into something good it'll sound better. Even if you send it to something bad, it may still sound better depending on how bad that device is.

 

[Bytor123]

https://www.soundguys.com/the-ultimate-guide-to-bluetooth-headphones-aac-20296/

OK. So they're saying that the source of AAC matters. So...APM...it's not the headphone that sounds good (or not), it's dependant on the source..? An Android source sounds worse....? I can't see in that article what headphone they are using, just the sources.

 

[MayaTlab]

OK. So they're saying that the source of AAC matters. So...APM...it's not the headphone that sounds good (or not), it's dependant on the source..? An Android source sounds worse....? I can't see in that article what headphone they are using, just the sources.

The point is that they're using a single receiving device (I'm not sure which one, just not a pair of headphones, as it's directly connected to some piece of audio testing equipment capable of this sort of measurement) and different sources all using 256kbps AAC, and that single receiver + test equipment measures what these different sources actually output. And it's different.
I presume that the quality of the AAC implementation on the receiving device can also vary.

 

[Bytor123]

The point is that they're using a single receiving device (I'm not sure which one, just not a pair of headphones, as it's directly connected to some piece of audio testing equipment capable of this sort of measurement) and different sources all using 256kbps AAC, and that single receiver + test equipment measures what these different sources actually output. And it's different.
I presume that the quality of the AAC implementation on the receiving device can also vary.

OK, thank you. So what does that say about APM? That the source matters more - the same, less? - than the headphone?

 

[nunomeneses]

That's what I'd be inclined to presume too... but who knows exactly ?
Some Apple devices with Apple silicon have a hardware audio encode / decode capability, but I have no idea whether it's available or not for audio over bluetooth in the first place.

As far as I'm concerned if there are differences, they're small enough to me that I'm not confident that I'd be able to A/B them, and I find them negligible anyway relative to much more important concerns such as FR, so I don't sweat too much about it to start with.

And you are about right. i tested in Apple Music on all devices and if there are differences they are small. Once more my mistake and the differences exist with Spotify premium maybe less efficient ogg to aac on iOS than macOS ...

 

[MayaTlab]

OK, thank you. So what does that say about APM? That the source matters more - the same, less? - than the headphone?

Nothing specific of that nature. I was simply responding to your question trying to understand why different sources could produce different results with the same pair of headphones, using AAC implementation as an example (among other variables).
Well I can't really say why this or that device implements AAC better or worse than another one, but we have measurements that suggest that differences do occur.
As Tinyman392 wrote though, I am too not certain that Apple's iDevices differ enough in terms of their AAC implementation for it to be the determining factor.

 

[Bytor123]

Nothing specific of that nature. I was simply responding to your question trying to understand why different sources could produce different results with the same pair of headphones, using AAC implementation as an example (among other variables).
Well I can't really say why this or that device implements AAC better or worse than another one, but we have measurements that suggest that differences do occur.
As Tinyman392 wrote though, I am too not certain that Apple's iDevices differ enough in terms of their AAC implementation for it to be the determining factor.

Thank you, appreciate your replies

 

[yticolev]

So I have iPhone 11 Pro, iPad Air 2020 and MacBook Pro 13 2017. And I definitely ear better response using macbook. Firstly I thought it was because of Spotify, subscribed Apple Music and getting diferences in sound... am I the only one and am I dreaming? because I like the sound through MacBook but treble response and lack of body on iPhone is getting me buyers remorse...

Interesting. There are a number of reports early in this very long thread of just the opposite, iPhone>APM sounding better than Mac>APM. Is it possible that you have headphone accommodations enabled on your iPhone, or equalizer enabled on your Mac? That could easily account for what you are reporting.

 

[nunomeneses]

Interesting. There are a number of reports early in this very long thread of just the opposite, iPhone>APM sounding better than Mac>APM. Is it possible that you have headphone accommodations enabled on your iPhone, or equalizer enabled on your Mac? That could easily account for what you are reporting.

In Apple Music yes that’s true but with Spotify is the opposite but far worse quality on iOS for what I’m experiencing...

edit : maybe I always had this with Bluetooth but revealed worse on apm because of not so real treble/compressed?

edit 2 : so I’ve found my source problem. Spotify on iOS wasn’t on max quality stream for some reason on iPad and on iPhone i had to take it to a genius so a restore defaults made settings go to auto from max quality.... ashamed to annoy you with this. No complaints now. Enjoying sound so far but still prefer aonic 50 treble.

 

[MacedonianHero]

Well, my APM arrived today and I'm listening to them now. Gotta say, they are way more comfortable that I thought they'd be. Sure they're not WH1000XM4 or QC35 comfortable, but they are very good overall and seem to heat up my ears less.

Sound quality is really good so far with a tighter presentation than the Sony's or QC's and the NC is on par with the XM4s (which is to say among the very best).

 

[justanut]

OK, thank you. So what does that say about APM? That the source matters more - the same, less? - than the headphone?

Isn’t that true of all headphones? The source always matters... TOTL headphones may even sound worse playing poor sources than entry level headphones, because TOTL headphones extract and amplify artefacts in poor sources etc.

 

[Mark-sf]

This may be a silly comment, but...I don't understand why the sound of a Bluetooth headphone sounds different depending on the source of the music - won't everything depend on the headphone? Doesn't the APM default to AAC whatever the source?

Are you perhaps using different EQs under the Accessibility Settings? I believe they are stored locally on the device.