2021 Sierra, Best SQ Src - Carplay vs DAP/Apple Camera Connection USB Dongle

[RickWilson]

Hi there,

Think this is probably my last post before I embark on my build and it is about my source input and streaming services. Looking to get some insight from folks on their experiences.

Build:

2021 GMC Sierra Sierra AT4
Helix P6 Amp for Audiofrog GB60/15 Active (Front), GS62 (Rear)
JL HD750.1 for 2 x JL 12TW3 (Stealthbox)
Factory Head Unit (Non-Bose) w/ LLJ Customs Loopback Harness
iPhone 11 Pro Max

Question #1: Input Selection

Looking at the following options:

• #1 - Carplay, wired, USB-C - Max quality out of HU is 24 Bit/48kHz (confirmed via AmazonMusic HD)
  
  • Very convenient obviously and retains all HU, volume and steering wheel functions
  
  
• #2 - Apple Camera Connection Kit
  
  • This would allow me to charge my phone (lighting port) and stream hi-res to my Helix (up to 24bit/96kHz) (USB port)
  • I am unsure of the correct wire/adapter I need to get from the USB out (on Apple dongle) to the SPDIF in (on Helix).
  • I lose Carplay, volume and steering wheel controls but have true hi-res audio going to the DSP. Also not sure if I would run into issues with auto-turn on of the amp from the high level inputs if the Helix is prioritizing the SPDIF input (I would still keep my high level inputs for radio/xm/stranger who uses Carplay usb inputs)
  • Is 24 bit/96 kHz truly worth it? Also feel I need a Director or Conductor for volume adjustments or I'd drive myself crazy.
  
  
• #3 - DAP
  
  • Same as #2, just unfamiliar in this market. Seems like the FiiO M11 Plus is the play but again runs into the same issues at #2 from a functional standpoint.

The further I research into getting a digital connection while maintaining factory HU and steering wheel controls is causing more of a headache than it will be worth. Just trying to get opinions of folks who have similar audiophile/SQ builds as above who have heard the differences of analog high level inputs vs. DAP/Digital signals.

Question #2 -

I am still deliberating what streaming service to use. I was an Apple iTunes person who converted to Spotify a couple years ago but Amazon, Tidal and Apple Music now all far exceed Spotify (I feel) in quality capabilities. But if I remain on 24bit/48 kHz high-level analog inputs to my Helix P Six, I am not sure I am going fully recognize the quality differences. I just don't know whether Spotify premium streams at 16 bit or 24 bit.

Thanks for any advice!

[Jdunk54nl]

To me this is worrying about things that aren't going to make much of a sonic difference compared to learning how to properly tune, unless your factory stuff has crazy EQ / all pass filters.

I would only worry about this if you have issues using the factory HU and carplay. I like the convenience of having all of the factory stuff still functional to navigate menus and change volumes.

Same with streaming services as long as they aren't doing weird things with the conversions. I doubt, in a double blind test (especially moving in a vehicle), you would notice any sonic difference between the max spotify currently offers and others. I use spotify because it has the best gui for me out of all the ones I have used. I hate apple's. Tidal was a close second but it's suggested music wasn't as good as spotify. Amazon music was a third place. Nothing really spectacular besides the free HD streaming.

You also have to think about cell phone signal quality when using HD streaming services. I know I would get way more pauses in Tidal/amazon hd streaming lossless quality if my cell signal dropped much at all. I never get pauses with spotify. This is with them locked into the top streaming quality.

[RickWilson]

Thanks again for a quality response. After all the reading I have done in the past couple days, I'm settling on the same conclusion as you provided. I'm sure adding a Topping D10S would add a little sprinkle to the system but just add a whole other layer on controlling the system and integrating it. Think my time is better served spending a little time cleaning up the input EQ and leaving the all the HU functions in tact. Especially since this is a company vehicle. If PAC or NAV-TV come up with a digital integration solution, I may re-consider but looks like it will be a while before they get a product out for this generation of HUs.

I am currently on Spotify so it makes me happy to ready this. I only had marginal interest in Apple because I have my previous library saved in the Apple cloud still.

Overall, like you said, I doubt I could tell the difference in a blind test and should focus on a quality tune/set up.

[nadams5755]

i find minimal value in high-res content/equipment. it seems all the streaming/download services have their own masters and you'll find mastering differences in content vs CDs.

hurling a two-ton death machine down the road, i'd lean strongly at #1, especially if you can get a clean+flat signal from the factory radio.

screens on phones are larger than daps, so then #2 second. it's a pain to live with daily. you'll likely get a message on your iphone saying "accessory not supported," however it still works correctly. i did this for a couple years and eventually went to a carplay radio. a usb->spdif bridge like a topping d10/d10s works as well. i did this for a while as apple/af figured out the charging issues w/ the usb-hec.

#3 meh, i generally don't like the UI/UX on DAPs. plus you'll probably have a coax cable and power cable coming out of opposite ends of the dap.

#2 and #3 have to figure out a mount or whatever as well.

#2 and #3 will probably want something sane for volume control, like director, urc3, or conductor. have to figure out that as well.

you know what they say: if it's not difficult to use, it's not sq.

having a good source is important. nailing the install+deadening and tuning are much larger pieces of the sq puzzle.

[RickWilson]

i find minimal value in high-res content/equipment. it seems all the streaming/download services have their own masters and you'll find mastering differences in content vs CDs.

hurling a two-ton death machine down the road, i'd lean strongly at #1, especially if you can get a clean+flat signal from the factory radio.

screens on phones are larger than daps, so then #2 second. it's a pain to live with daily. you'll likely get a message on your iphone saying "accessory not supported," however it still works correctly. i did this for a couple years and eventually went to a carplay radio. a usb->spdif bridge like a topping d10/d10s works as well. i did this for a while as apple/af figured out the charging issues w/ the usb-hec.

#3 meh, i generally don't like the UI/UX on DAPs. plus you'll probably have a coax cable and power cable coming out of opposite ends of the dap.

#2 and #3 have to figure out a mount or whatever as well.

#2 and #3 will probably want something sane for volume control, like director, urc3, or conductor. have to figure out that as well.

you know what they say: if it's not difficult to use, it's not sq.

having a good source is important. nailing the install+deadening and tuning are much larger pieces of the sq puzzle.

I share your exact same logic. Been talking about this a lot more on the DIYMA cross post I have off this. Sadly the P Six doesn’t support the Conductor (like only current in the fleet it seems) which is really the only remote I’d be able to accommodate reasonable in the build and aesthetic I’m going for.

I hear you can retain the functions of song change and play pause from the head unit via BT while using D10S set up. Just need volume control. I have a JL knob for my 750 already installed but would have put the conductor there instead it is was supported. Going to peak around potential mounts for a Director tho.

I started on deadening really before anything haha, after doing two doors I was blown away. Exterior shells of the doors have full dynamat xtreme and a layer of CCF. Interior panels have full sound skins prefab kits and interior of plastic door panels is done selectively with Dynamat CCF. Plus some ABS speaker mounts. I’m hoping that holds up to what the GB60s are gonna put out lol

[nadams5755]

you can find diy instructions for a urc.3 on diyma if you want a different aesthetic. with the two knobs of the urc.3 you could skip the jl bass knob and control the dsp's sub-out levels.

https://www.audiotec-fischer.de/en/b...essories/urc.3

https://www.diymobileaudio.com/threa...x-dsps.141022/

[Cutaway]

• #2 - Apple Camera Connection Kit
  
  • This would allow me to charge my phone (lighting port) and stream hi-res to my Helix (up to 24bit/96kHz) (USB port)
  • I am unsure of the correct wire/adapter I need to get from the USB out (on Apple dongle) to the SPDIF in (on Helix).
  • I lose Carplay, volume and steering wheel controls but have true hi-res audio going to the DSP. Also not sure if I would run into issues with auto-turn on of the amp from the high level inputs if the Helix is prioritizing the SPDIF input (I would still keep my high level inputs for radio/xm/stranger who uses Carplay usb inputs)
  • Is 24 bit/96 kHz truly worth it? Also feel I need a Director or Conductor for volume adjustments or I'd drive myself crazy.

This is a pretty solid option IMHO for a few reasons
Like you mentioned in another post, you still retain your CarPlay functions, Handsfree calling and any signals/prompts from your Stock Head unit running analog into the P6. While simultaneously streaming bit-perfect signal from your iPhone via a Topping D10s to the P6 which would allow you to leverage the BurrBrown DAC in the HELIX which is probably better than the DAC of the factory Headunit. Both the URC.3 or the Director are great options for Master Volume and separate Sub Volume control.
Setting up the Helix software to automatically toggle between Analog & Digital Input Signals from the Headunit for Phone Calls/Nav prompts & Signal from your iPhone is pretty simple and straight forward and SUPPER reliable.

The downsides of this is are:
1) the addition of a digital bridge that converts signal from your phone to SPDIF (Topping D10s or similar) and the use of the Apple Camera Kit (converts from Thunderbolt to USB and allows simultaneous charging).
2) the need for an external volume control (URC.3 or director)

there is a notable difference in sound in the options you laid out, however like Jdunk54nlmentioned you might not hear the difference driving but you definitely can when sitting still, at least that has been my experience. I personally like to keep the conversions from D/A - A/D to a minimum and this way you only have one D/A of the music which is handled in the P6

[Cathul]

If you would go Mosconi for DSP and you had volume information et. al. on the CAN bus, you could use the RC CAN open to retain full control from the headunit while feeding a digital signal to the DSP from your phone.

[RickWilson]

This is a pretty solid option IMHO for a few reasons
Like you mentioned in another post, you still retain your CarPlay functions, Handsfree calling and any signals/prompts from your Stock Head unit running analog into the P6. While simultaneously streaming bit-perfect signal from your iPhone via a Topping D10s to the P6 which would allow you to leverage the BurrBrown DAC in the HELIX which is probably better than the DAC of the factory Headunit. Both the URC.3 or the Director are great options for Master Volume and separate Sub Volume control.
Setting up the Helix software to automatically toggle between Analog & Digital Input Signals from the Headunit for Phone Calls/Nav prompts & Signal from your iPhone is pretty simple and straight forward and SUPPER reliable.

The downsides of this is are:
1) the addition of a digital bridge that converts signal from your phone to SPDIF (Topping D10s or similar) and the use of the Apple Camera Kit (converts from Thunderbolt to USB and allows simultaneous charging).
2) the need for an external volume control (URC.3 or director)

there is a notable difference in sound in the options you laid out, however like Jdunk54nlmentioned you might not hear the difference driving but you definitely can when sitting still, at least that has been my experience. I personally like to keep the conversions from D/A - A/D to a minimum and this way you only have one D/A of the music which is handled in the P6

Thanks a ton for the advice. Currently in a debacle of keeping my P Six or not because of the conductor vs Director because I do have a desire to use a digital signal either now or later. Just working through what I feel is the best amp and DSP set up is for my build.