BernieB I use Bluetooth on my iPhone ST3 for background music and it seems very reliable , a bit more use and I will possibly make use of this on my iPad main backing track program feed once I am convinced it is as reliable as cable.
This then allows me to choose more up to date iPads without a headphone Jack.
But I need to be absolutely convinced and that takes time.
Stage Traxx will detect the output delay and adjust scrolling and midi commands by the output delay so from that side you should be fine. Of course each command (start, stop, seek, crossfade, ...) in Stage Traxx will be delayed by about 100ms (or whatever your actual latency is) in case of bluetooth. That might or might not be a dealbreaker for you.
Nevertheless I would not rely on bluetooth audio for gigs with larger crowds.
So my recommendation would be to get the last gen iPad. That is the last iPad with a headphone output.
DaveT I don’t see a delay in Bluetooth being a problem as you are syncing to it , it’s not syncing to you or anything else I actually use a settings delay of 1 second on purpose to give me time to move my hand on to my guitar when I use my AirTurn digit 3 hand control that’s Velcroed on top of my acoustic.
So an extra few milliseconds of delay is no issue to me.
Just an Update
I purchased an Ipad Pro with USB C . I am using a long cable which goes to the mixer case and an adapter that allows usb charging and audio out into the mixer channel
I use an air Midi pedal to start the playback. It works well
Ipad pro any of that model runs perfect with stagetraxx and runs much faster than an ipad air .i use the bluetooth for stage traxx audio files into an a stand-alone bluetooth DCA and from there to my mixing desk this leaves the usb port free to use for my vocaliser or anything else midi
davedroug Thanks for your tip earlier! I tried to get hold of an audiolab mdac mini, but couldn't get it here in Norway. I was told they had some issues, don't know what. But I bought the Fiio BTR5, works fantastic.
Bluetooth audio will always compress the audio with a certain codec. The problem with iOS is that it does not support the aptX codec which most bluetooth devices use. Instead it has its own AAC codec. So if you want high audio quality you need to make sure your bluetooth device supports the AAC codec. Without AAC support the communication will fall back to the old SBC codec which sound audibly worse but works on any bluetooth device.
jaytrax https://www.fiio.com/btr5
The sound is great to my ears. Fulfills all of Peter's recommendations.
jaytrax you have got back to front the external DAC Is far higher quality than the internal DAC on the ipad .light years better plus i don't use poxy mp3 .i only use 48hrz 32bit floating files i've tried with and without Bluetooth, and i just can't tell any difference thats live or with my studio headphones if there is a difference i can't hear it . and have never had so much as a glitch using my setup and Bluetooth it just works perfect and sounds fantastic ,I've been playing since the late 60s and can honestly say now is the best sound I've ever had 
davedroug but it’s still Bluetooth
And there is compression happening during the conversion from the receiver to the inputs of your mixer
All I asked was there any measured comparisons as this is usually a compromise in audio detail
Whether that’s lows, mids, highs or a combination of all.
48k and 32bit is great if your making quality recordings from scratch but it all comes down to the source of recording also
You could have 48k 32bit file, it doesn’t necessarily mean it was well recorded or played from a musical point of view
jaytrax correct, if its not good what goes in its not good what comes out ,most of my backing tracks are done on a Genos through my daw using just live sample instruments. top quality . so they are pretty good. but still i suppose its what people get use to ,but a good DAC will still improve the sound no matter what backing tracks you use . and thats the point,
davedroug
So if I understand correctly you’re working off an arranger/entertainer style keyboard with styles and a combination of samples and synthesised sounds make up these parts ?
That then is edited in a DAW where you have your project set up as 48k and you export 32bit ?
The audio is then added to Stage Traxx and then is sent to your DAC on playback via Bluetooth?
This then has outputs into a mixer of some sort I presume ?
If your mixer is digital it would have a sample rate such as 48k
Is that pretty much your flow ?
jaytrax thats pretty much it ,but also use some live instruments vocal backing on some of the tracks plus a vocaliser run from midi on the backing tracks etc the mixer is a QSC touch mix 8 which is basically a full studio which is first class, best mixer I've ever had what it can't do is not worth bothering about and for me i love the sound i get now. and thats what counts
see if you can tell which is the live guitars and which are the sampled ones https://www.bandlab.com/user7088264374062931/peaceful-easy-feeling-d37a67bf?revId=05882b80-ac93-ea11-96d2-0003ffd1fc09
davedroug
Ok so firstly to my ear this just sounds like an SMF which is then using the internal synthesised sounds of the keyboard/arranger
In all honesty it doesn’t sound authentic
The bends on the guitar parts is obtained using the pitch bend wheel and unfortunately doesn’t sound authentic or natural like a guitarist would phrase it.
There doesn’t appear to be any difference in the sound regardless of the velocity of the sequenced notes, making me wonder if there’s any multi samples or round robin approach used at all.
I mean no disrespect with this reply,
if your happy to use these sounds that’s all that matters.
jaytrax what ever floats your boat man .but your wrong it started life as a style file and was added to live acoustic guitar live bass guitar. and some live lead . main lead midi its a cocktail done to suit me and nobody else . so lets hear one of yours then
