I wonder what devices PSAudio verified works with AptX mode with the Sprout. My Nuforce BTR100 also uses a CSR radio and it works in AptX mode with my macbook pro without having to do anything special. I wonder if the AptX mode on the Sprout radio is enabled or not. It’s not really easy for consumers to tell that AptX mode is being used.
I also tried a windows laptop with an Azio BTD-V400 apt-x capable bluetooth adapter but wasn’t able to verify what mode it was operating in. However it seemed to sound even worse than the iPhone (supposedly SBC) stream so maybe it was just lower bitrate SBC being sent over. I need to try to find a way to verify what codec is being used.
Ben. I too am frustrated a bit by this. I have a phone that is supposedly AptX enabled and is subjectively sounds reasonably good through the Sprout but I can’t figure how to tell what codec is selected when it is streaming. So far no one on this forum by my count has successfully connected any Mac OS X device to Sprout and verified AptX. This is killing me just because I hate not knowing.
Apple IOS (in iPhones and iPads) doesn’t support AptX but OS X (in Mac laptops) absolutely has the codec. They’ve had it in there for a while and it works with most AptX enabled headphones if you turn off multipoint support in the headphones themselves. Occasionally some devices (such as the Sprout it would appear) refuse to play nice with Mac Laptops and AptX. No good answer why. That’s the frustrating part.
If you hold down the option key on your Mac keyboard and click on the bluetooth icon in the menubar, assuming you have Sprout connected and are streaming music, it will show you the codec being used. With Sprout it is consistently SBC. With other AptX devices it will show up as AptX.
I want to get an initial hypothesis out there on why Sprout and OS-X don’t play well with AptX and how to (maybe) fix this. Please not that I haven’t validated any of the assertions I am making here but I intend to do so once some time frees up.
We have learned that OS-X will refuse to use the AptX codec if the A2DP audio SNK has multipoint enabled as a feature. Multipoint is typically useful in headsets to allow you to groove to music but be interrupted if the phone rings. Great if you are a help desk worker, for instance.
It is plausible that multipoint is enabled on the Sprout. It wouldn’t be particularly useful but (excepting the Mac OS-X issue we are trying to solve) would probably be regarded by the engineers at PS Audio as likely innocuous.
Lots of headphones use the same CSR bluetooth radio that Sprout uses. These headphones frequently have a switch to enable or disable multipoint functionality. This means that somewhere on the radio board there are probably some jumper pins that the switch connects to.
The Sprout bluetooth radio will, therefore, also have these pins but with a static jumper to configure them.
So…
To prove or disprove this hypothesis I need to:
Pull the CSR spec sheet on the radio.
(assuming there is a jumper) Find the jumpers on the radio board inside my Sprout and
(assuming multipoint is enabled) reconfigure the jumpers to disable multipoint.
I'm not a betting man so I won't lay odds on whether any of this will bear fruit. I also claim no dibs on this exploration if someone wants to beat me to it (or explain why it's fruitless).
I must say, AptX or SBC, Spotify sounds pretty damn good using 320K mp3 over bluetooth from my iPhone. Very nice to test music out to see if I want to buy.
I’d like for iOS to get AptX and hopefully it works with Sprout, but that’s not a deal breaker for me. And having AptX working from a Mac certainly isn’t. I’m using my Mac Mini with USB and love it
I’m happy to wait and see how this plays out.
And just curious, Andrew, do you have any other first impressions besides the bluetooth? How’s the Sprout sound with your speakers? Been looking for your and other’s take in the first impressions thread.
Well, it’s embarrassing but we found the answer. Yes, Sprout has Bluetooth. No, it does not work. . Turns out we have to secure a license and pay a royalty for each unit to turn it on. Sorry, guys, we totally did not understand that and had no easy way to test the functionality of the device. We’re kind of new to the whole thing. Our engineering director is gathering the details and we’ll see where that leads us.
Fritz: “First Impressions” posted to the appropriate thread. Thanks for the poke!
Paul: Your honest and public acknowledgement of an understandable mistake will cement PS Audio as a company I will always endeavor to do business with in the future. I can name on one hand the number of companies I have dealt with who were willing to so quickly share this with the user community. Naturally I look forward for the field upgrade and want to thank you publicly for your honesty and business ethics. I love my Sprout even w/o AptX. I’ll love it more sometime next calendar year.
I’m glad to find out that information Paul. Now I don’t have to spend any more effort trying to get it to work when obviously it is impossible currently. I look forward to the update to gain Apt-X, hopefully something that can be handled ourselves through USB or something.
When we first did the work on Sprout we were all quite amazed at the Bluetooth performance. All we’d read about Bluetooth suggested the quality sucked and would not be something used by Audiophiles for anything other than a convenience or a novelty. “Look, I can stream from my phone.” But truth is, at least with Sprout, it sounds pretty damned good.
It is interesting how a well designed DAC, properly implemented, can take what should be a ‘meh’ digital signal and make it sound great.
Paul McGowan said
It is interesting how a well designed DAC, properly implemented, can take what should be a 'meh' digital signal and make it sound great.
Agreed. I've been impressed with the sound via bluetooth streaming as I said earlier. I wasn't expecting AptX since I'm using an iOS device and knew it wasn't implemented in iOS for now.
Sprout is a great product, this is just a minor bump in the road that you all are addressing. No worries on my part at all.
While SBC can operate at bitrates up to 345 kilobits per second, according to McClintock manufacturers don’t implement it that way.
If you set the initial and minimum bitpool for SBC to 53 on a Mac using Bluetooth Explorer, the Mac will communicate with Sprout using the SBC codec at 345 kb/s consistently (I'll post graphs if people are interested). This means the SBC bitrate is essentially equivalent to AptX's 354 kb/s when a Mac streams to the Sprout. This is about as good as SBC gets and even CSR admits the AptX vs. SBC "bakeoff" doesn't have an unambiguously clear winner. The great thing about AptX is that the bitrate ISN'T variable it's always 354 kb/s in every case. AptX uses a fixed 4:1 compression algorithm for PCM data.
If you set the initial and minimum bitpool for SBC to 53 on a Mac using Bluetooth Explorer, the Mac will communicate with Sprout using the SBC codec at 345 kb/s consistently (I’ll post graphs if people are interested). This means the SBC bitrate is essentially equivalent to AptX’s 354 kb/s when a Mac streams to the Sprout.
You may have answered this before, but what do we know about the SBC implementation on iOS? How do we control the bit rate there or how is it controlled by iOS?
If you set the initial and minimum bitpool for SBC to 53 on a Mac using Bluetooth Explorer, the Mac will communicate with Sprout using the SBC codec at 345 kb/s consistently.
Indeed- under Yosemite my BT connection defaults to a bitpool of 40 and works its way up from there. It seems to have settled on about 53. I’m seeing 325 Kb/s without any Bluetooth Explorer twiddling (e.g. I just started everything up and checked what the system had adaptively set itself to.)
So- pretty good bitrate ‘out of the box’ with no twiddling.
The Bluetooth of the Sprout is Just Awesome, I don’t listen my Cd’s anymore is so amazing that I put my CDP on sale. I have all my Cd’s Collection on my iPhone 6 on “Apple lossless” and is so great lol
. Turns out we have to secure a license and pay a royalty for each unit to turn it on. Sorry, guys, we totally did not understand that and had no easy way to test the functionality of the device. We’re kind of new to the whole thing. Our engineering director is gathering the details and we’ll see where that leads us.