How to? iPhone --> USB dongle DAC --> [BT LDAC/Aptx] --> BT headphones?

[L00P]

Hi all,

Notoriously, iPhones lack LDAC and Aptx codecs for their Bluetooth connections. They are limited to AAC, which is lower quality.

Are there dongle DACs I could connect to my iPhone via a USB cable that would:
1. Receive lossless music from Apple Music via USB
2. Then broadcast a Bluetooth signal to my Bluetooth headphones via Aptx or LDAC?

This way, the iPhone and DAC could sit neatly in my pocket whilst I go for walks, without a cable running up to my headphones.

I have had a look at some portable DACs, like the Qudelix 5k and Khadas Tea, but they seem only to be Bluetooth receivers only (i.e. the BT connection is between the phone and the DAC, not the DAC and the headphone, which means that the quality of the music is bottlenecked by Apple's AAC at the start). Please correct me if I'm wrong about that.

How do people solve this problem? I would be most grateful for any recommendations.

 

[Roseval]

iPhones lack LDAC and Aptx codecs for their Bluetooth connections. They are limited to AAC, which is lower quality.

Really?
AAC is the only one exploiting the full extend of the psycho acoustic model, LDAC and APTX don't. So don't use bitrate as the right criterium to judge audio codecs as advanced codecs like AAC can beat side band codecs even if these codecs run on a higher bitrate.

The quality we see using the iPhones with AAC 256kbps is better than aptX-HD previously tested and at least equivalent to the higher bitrate LDAC >900kbps on Android. There's certainly something to be said about Apple focusing on a single standard and doing it well!
https://archimago.blogspot.com/2023/08/part-ii-comparison-of-bluetooth.html

 

[dunring]

I buy songs on Qobuz and play them direct at 44.1khz 16bit, which is the Sony Redbook standard and covers the entire range of human hearing. Keeping it simple with a phone BT connection is going to be easy if you use 44/16 lossless.

 

[Roseval]

Keeping it simple with a phone BT connection is going to be easy if you use 44/16 lossless.

Wonder what you are trying to convey.
CD=2x16x44.1= 1411 kbs.
Due to the limited bandwidth Bluetooth is not even able to transmit CD quality lossless.

 

[BS5711]

Hi all,

Notoriously, iPhones lack LDAC and Aptx codecs for their Bluetooth connections. They are limited to AAC, which is lower quality.

Are there dongle DACs I could connect to my iPhone via a USB cable that would:
1. Receive lossless music from Apple Music via USB
2. Then broadcast a Bluetooth signal to my Bluetooth headphones via Aptx or LDAC?

This way, the iPhone and DAC could sit neatly in my pocket whilst I go for walks, without a cable running up to my headphones.

I have had a look at some portable DACs, like the Qudelix 5k and Khadas Tea, but they seem only to be Bluetooth receivers only (i.e. the BT connection is between the phone and the DAC, not the DAC and the headphone, which means that the quality of the music is bottlenecked by Apple's AAC at the start). Please correct me if I'm wrong about that.

How do people solve this problem? I would be most grateful for any recommendations.

Can you set up a test between AAC vs LDAC ?

Preferably get someone to help you compare them blind and volume matched of at least over various listening volumes to help remove perceptual differences due to volume.

In “audiophile” circles Apple’s use of only AAC gets a lot of criticism but Apple are not stupid and have massive resources to develop this stuff. They didn’t land on AAC because it was “near enough”.

I have tried AAC vs LDAC and can’t hear any difference. Well technically I can and that is when LDAC drops out if I am a little further from the phone and the connection starts dropping out well before it would on AAC.

I suspect if you blind tested it you might find you are looking for an answer to a problem that doesn’t exist.

 

[L00P]

Can you set up a test between AAC vs LDAC ?

Preferably get someone to help you compare them blind and volume matched of at least over various listening volumes to help remove perceptual differences due to volume.

In “audiophile” circles Apple’s use of only AAC gets a lot of criticism but Apple are not stupid and have massive resources to develop this stuff. They didn’t land on AAC because it was “near enough”.

I have tried AAC vs LDAC and can’t hear any difference. Well technically I can and that is when LDAC drops out if I am a little further from the phone and the connection starts dropping out well before it would on AAC.

I suspect if you blind tested it you might find you are looking for an answer to a problem that doesn’t exist.

- sorry I posted this by mistake. See below.

 

[L00P]

It seems I've provoked a greater desire to dynamite the premise of my question than to help answer it (it was about hardware).

@Roseval and @BS5711 : FWIW, I have been shopping around for ANC Bluetooth headphones with a friend (a musician and music engineering graduate). During the "perineal holidays" (between Christmas and New Years), we used her portable DAC to test a pair of Sony WH-1000XM5 (AAC vs LDAC), a pair of Bowers & Wilkins PX-8 (AAC vs Aptx) and my own pair of Dali IO-12 (AAC vs Aptx). We didn't do them all on the same day, and it was a bit fiddly to get the settings right back-and-forth for a comparison. However, we both agreed that AAC never sounded as clear as the other codecs for all the headphones (except the PX-8, for which she "hated" the sound signature in both cases). I would say that I perceived a vanishingly small difference between AptX and LDAC, if any. In either case, I'm not basing my desire to access AptX or LDAC from my iPhone blindly (nor deafly).

Admittedly, @Roseval , we did not listen to any graphs. I accept perceptions in sound quality are subjective, but it seems many agree with my friend and me that LDAC sounds better (including many audiophiles). I don't feel the correct approach is to "prove" to anyone's hearing that it's wrong using charts on a blog, any more than it would be for me to play you a sound to convince you that you're not reading the words that you, in fact, are.

All this notwithstanding, I'd be grateful to learn how I might achieve a connection that goes:
iPhone -> [via USB] -> DAC transmitter -> [via AptX/LDAC] -> Bluetooth headphones.

My friend does not have an iPhone and she did not know the answer to this. I can't continue the search with her because after New Years she travelled back to the US (I live in Sweden). I am committed to the iPhone for many reasons that extend beyond listening to music, so I'm trying to make the best of the hand I've been dealt.

I imagine other audiophile iPhone users must have wondered the same as me, but I've struggled to find the solution.
Again, I'd be grateful for suggestions.

 

[BS5711]

I think "dynamite the premise of your question" is a stretch, rather point out that technically you might not really need it.

It is also very easy to be fooled into thinking you hear differences that don't exist simply because you are listening for a difference, especially if you are approaching the comparison with the idea that one is worse than the other, hence the recommendation for a blind test. Perhaps you did that already.

Regardless, if you have decided that is the way forward then it would be a good starting point to indicate what model iPhone you have, it it lightning or USB-C ?

At a 10 second Google search a FiiO BT11 pops up as a likely solution, assuming a late model iPhone with USB-C.

 

[L00P]

I think "dynamite the premise of your question" is a stretch, rather point out that technically you might not really need it.

It is also very easy to be fooled into thinking you hear differences that don't exist simply because you are listening for a difference, especially if you are approaching the comparison with the idea that one is worse than the other, hence the recommendation for a blind test. Perhaps you did that already.

Regardless, if you have decided that is the way forward then it would be a good starting point to indicate what model iPhone you have, it it lightning or USB-C ?

At a 10 second Google search a FiiO BT11 pops up as a likely solution, assuming a late model iPhone with USB-C.

I agree "dynamite" is a stretch. I was reacting in quite a tired way more to the other answer than to yours, and after many frustrating experiences (e.g. from Linux forums) where nearly every technical question attracts instantly experts keen on undermining it, rather than helping. I appreciate you aren't one of them.

My iPhone is 14 Pro Max, which - sadly - is still lightning. I anticipate upgrading it when the 17 comes out, in about a year.

I did find the FiiO BT11 online this morning, but I could not find any info about whether it can be connected successfully simply via a converter cable, nor whether any such cable would do the job, since I know that different cable types can be more or less suitable for carrying music of different quality (although I don't understand the nuances of this fully, either). I imagined there must be a strong and long-lasting desire for iPhone users to access AptX and LDAC, so I imagined there would be a general and, perhaps, more proven solution preceding the FiiO BT11, which seems relatively new. But I will definitely dig into it.

 

[BS5711]

I agree "dynamite" is a stretch. I was reacting in quite a tired way more to the other answer than to yours, and after many frustrating experiences (e.g. from Linux forums) where nearly every technical question attracts instantly experts keen on undermining it, rather than helping. I appreciate you aren't one of them.

My iPhone is 14 Pro Max, which - sadly - is still lightning. I anticipate upgrading it when the 17 comes out, in about a year.

I did find the FiiO BT11 online this morning, but I could not find any info about whether it can be connected successfully simply via a converter cable, nor whether any such cable would do the job, since I know that different cable types can be more or less suitable for carrying music of different quality (although I don't understand the nuances of this fully, either). I imagined there must be a strong and long-lasting desire for iPhone users to access AptX and LDAC, so I imagined there would be a general and, perhaps, more proven solution preceding the FiiO BT11, which seems relatively new. But I will definitely dig into it.

All good.

While the BT11 popped up in a search on your behalf I did see comments later that it can be buggy, no surprise for newer FiiO gear, perhaps they have implement new firmware ??

I suspect your best way is to take a leap of faith and get the BT11 and an adapter cable and hope they work well together, or at all. Having been down similar roads with Lightning cables before getting an iPhone 15 I understand your hesitation about it being seemless.

The ddhifi TC28 lightning to USB-C female adapter worked with everything I ever tried but the geometry may not work readily and you might end up with a messy three piece arrangement.

Good luck.

 

[Erkil]

The BT11 just plugs directly into the phone, and transmit the different Bluetooth codecs to your TWS/Headphone. No need for a cable. (As long as you have iPhone 15 or 16. You can choose codecs in the Fiio app.


Edit: Messed up the iPhone numbers

 

[Erkil]

I didn’t hear any advantages btw

 

[L00P]

All good.

While the BT11 popped up in a search on your behalf I did see comments later that it can be buggy, no surprise for newer FiiO gear, perhaps they have implement new firmware ??

I suspect your best way is to take a leap of faith and get the BT11 and an adapter cable and hope they work well together, or at all. Having been down similar roads with Lightning cables before getting an iPhone 15 I understand your hesitation about it being seemless.

The ddhifi TC28 lightning to USB-C female adapter worked with everything I ever tried but the geometry may not work readily and you might end up with a messy three piece arrangement.



Good luck.

Thanks for the recommendation. It looks like at that angle the FiiO would bump against the iPhone. I will investigate further. I appreciate your input.

 

[L00P]

The BT11 just plugs directly into the phone, and transmit the different Bluetooth codecs to your TWS/Headphone. No need for a cable. (As long as you have iPhone 15 or 16. You can choose codecs in the Fiio app.


Edit: Messed up the iPhone numbers

Great! Thanks for the info. I was curious how selecting the codecs might work. I guess it's AAC vs the other codecs where you didn't find the difference. Which headphones was that with?

 

[Erkil]

https://www.dustinhome.no/product/5...8aJj67MWC7LcRGPANsakJT27g44fEZmsaAuw8EALw_wcB