iphone 6(64gb) latency

[anfirmor]

Phone contract on my iphone 5 ended and I treated myself to a shiny iphone 6 64gb thinking of how much nicer a slightly bigger screen would be, plus the extra speed/power/grunt.

I did a latency test on the old iphone 5 a while back by simply recording a click track to another track using the apple earphones/mic with the earpiece next to the mic.
According to the time axis in Multitrack DAW the delay seemed to correlate with the buffer settings ie. I was seeing 2 ish mS of delay.

Now with the iphone 6 I did the same trick and saw 4 ish mS of delay. Just to be pedantic i then recorded 11 tracks, cascading to track 11. This gives me 10 delay steps from the transient edge on track 1 to the transient edge on track 11. MT DAW is telling me 46mS delay, ie 10/0.046 = 4.6mS

Any idea why my faster iphone 6 is worse than my iphone 5? and where the extra 2mS is coming from. I'm a bit dissapointed.

ps. the project was 41.1kHz, 16bit and the phone was in aircraft mode with no other apps running.

[anfirmor]

Ok. I set up my old iPhone 5 this evening and installed MT DAW. Repeated the 11 cascaded click tracks test and the latency works out at 2.8mS.

I transferred zip files to and from each iPhone and so verified it's not a display issue. The exact same timing differences show for the projects on each phone.

The iPhone 6 has 2mS added latency. Nearly double. So my faster phone is, in fact, slower.

What's going on?

[pwnified]

In general usually latency is calculated as the roundtrip time from microphone input to speaker output by external test. But what you mention sounds like there is something off about the compensation by a bit. I'll look into that, there really should be zero milliseconds latency after compensation. Thanks for examining this, it might mean that the different ios devices are reporting invalid latency compensation values.

[anfirmor]

Not sure how that impacts on things but the latency is real. Listening to the first and last tracks (1&11) played together the iPhone 6 is audibly much much worse

I hope this is a fixable software issue because if it's hardware I will be very disappointed.

Bye the way, I did this test as I'm trying to decide on a mobile audio interface. IK HD or Sonic Port VX. I fancied the smaller IK HD but no direct monitoring. Seems like that will be an invaluable feature if apples stuff is going backwards.

[anfirmor]

Oh yes. I'll do the same test with my iPad mini retina tomorrow and report back.

[anfirmor]

Just did a rough verification in Garageband on the iphone 6. Two tracks mixed to a wav as iTunes was being a pain. Used Wavosaur on the PC to find transients.

Looks like the round trip is 4.8ms approx. Same as MT DAW.

Also did a quick check on the ipad mini retina (2). Approx 4.8ms again and maybe even 5ms.

When the input pop up appears in MT DAW it states (128), presumably 128 samples, so at 44100Hz thats about 2.8ms as the buffer setting claims. Works out fine on iphone 5 but not iphone6 or ipad mini retina.

Something to do with 64bit hardware maybe?

If it is hardware issue it's not good. The only real advantage Apple stuff has over Android is the superior audio capabilities. It can't be MT DAW so it's either the hardware or ios; hopefully ios cos there's no fix for hardware.

There's a lot of audio adapters out there for ios that have no direct monitoring, especially if you want a mobile option. If lectric geetars are your thing (using jamup, bias, pod etc) then nearly doubling the latency will do no good for the old blood pressure.

I'm a string player in the main and so use to having the sound source near my ear. I know the latency discrepancies only mean the difference between about about 3ft and 4.5ft from the sound source but when the instrument you play is so close to the ear and you've got cans on then you get funny phasing/time effects which bugger up your intonation. Slightly less painful with acoustic guitars as the instrument to ear distance is roughly 2ft.

Hope pwnified can supply an answer to this, even if it only confirms that somebody in Cupertino needs a.................well you get the rest.

[pwnified]

Actually the iPhone 6 seems to be the worst of the iOS devices, sometimes testing much higher latencies than other iPads. You can do a click test if you download an app here: http://superpowered.com/latency/

[anfirmor]

Thanks for that. I tried that app but it won't install at present.

As a developer do you get any insight into hardware specs and iOS issues. Just trying to determine if it's iOS routines for a particular device or its chipset. Is a fix is possible by submitting a bug report or if its down on the silicon?

Amazing how good MT DAW is on the iPhone 5. Also great on my other devices. Seems to give the least latency of all the apps I've tried including Auria and Cubasis.

Grrrrr

[pwnified]

It's always worth filing a bug report, Apple uses bug redundancy as a gauge of importance, or what to fix next. So if enough people complain they'll look into it. As a developer, I don't get any inside information on hardware. In fact anyone can become a developer. Really all we get is access to beta builds of new iOS versions. We're not supposed to talk about anything due to the NDA, however, anything given to developers will surely be leaked to the public anyway.

You'll find more information on hardware specs at wikipedia than at apple.

The MFi program is a different story, since that's a hardware membership, they must have access to all the technical details. It's impossible to get on that program though, so I've heard.

[anfirmor]

Thanks for the help. Apple are a closed bunch aren't they.

I'll try a "measured by external means" test as soon as my disappointment has worn off but I suspect I'd be better off looking for an audio interface with direct monitoring. Works beautifully with my Focusrite 2i2 (powered hub, cck etc.) but i would like a mobile solution for the phone. Irig Pro is close except for the direct monitoring.

I do hope that Apple don't continue lowering their standards with regard to audio capabilities.

Thanks again