[bubbletea]

I'm currently installing a Nexus 7 tablet (USB audio out) into my car, to use as a head-unit.

Given that DAC technology seems to be constantly changing, I feel overwhelmed when selecting a USB DAC to input into my signal processor / amps.

-Audio files will be 24 bit, 192khz.
-Drivers will need to be compatible with Linux (Andriod tablet.)
-My signal processor has stereo RCA inputs.

Can you recommend a suitable DAC for this environment?

Previous threads have recommended the ES9023 DAC:Hifimediy Sabre USB DAC 2 External PSU 96kHz 24bit ES9023 SA9023 Coaxial OUT | eBay

However, I like this DIY DAC solution (DAC SABRE 9023 + XMOS2):
Building my reference dac (xmos2 to i2s dac sabre 9023) - RaspyFi

Thanks

 

[ProtegeManiac]

I don't understand, why do people keep using USB DACs (or even headphone amps as preamps) in their cars? First, where will the tablet be mounted that you can easily see the display, choose the next track, and have the traffic light in your peripheral vision? Even cops nowadays depending on the regulations in your area can consider that a driving hazard.

Second, how do equipment made strictly for two channel, equidistant listening help make the sound in a car "better"? All the better DACs and output stages in the world won't help much if you're still closest to the driver's side tweeter, the driver's side midwoofer next, then the passenger side tweeter, then the passenger side midwoofer, then finally the subwoofer? Plus all the reflections of the tweeter's sound due to its dispersion pattern being the least of the car manufacturer's concerns when they mounted it near the windshield as in most cars. None of these devices have the 3-way crossover (and matching car audio amplifiers capable of driving your upgraded 4-ohm speakers) with 3-way time alignment that you can find in a $349 Pioneer 80PRS receiver which, compared to the previous models, now has USB. Even //////Alpine has a dedicated media receiver (no transport) that used to support only iPods, but now supports other storage options, and a $149 processor that hooks up to its Ai-Net port (which used to be for their CD changers) so no need to blow money on a PXA-H701 and its dedicated control panel.

Why blow $150 or so on a DAC when the Pioneer 80PRS can work on its own, sending the same processed signal through the speaker amp built into it? You're not "reshaping" or "EQ-ing" the signal, you're introducing time delays to minimize harsh treble and make for a coherent soundstage. If not messing around with the factory-installed dash is a must, there are are two ways around it. First, the factory sound canm with the proper adapters, be routed through the new receiver, which can be mounted on a spare 1-DIN slot. Second option, but this will cost more, is to get one those newer "integration processors" which have basically the same features as other processors, except instead of SPDIF or Ai-Net digital inputs, it has high-level (amplified speaker inputs) to take a signal from the factory receiver, then through an ADC so you can apply the crossovers and time alignment in the digital domain (doing it analog will make the processor too large using whole circuits vs a few microchips), then through quality DACs. Sure, G.I.G.O. applies, but most factory receivers aren't that bad compared to the real acoustic issues in a car that can only be worked around through time alignment in the processor as well as proper installation of the drivers. As much as the 80PRS can be great with just the factory 2-way speakers, I still kind of think of jsut adding a DAC to a car seems like using the same DAC and an amp to use with stock earbuds.

http://www.pioneerelectronics.com/PUSA/Car/CD-Receivers/DEH-80PRS

 

[bubbletea]

ProtegeManiac - thanks for your response.

I realised in my post below I hadn't outlined the system that I'm piecing together.
 
Nexus 7 (android tablet) --> DAC ---> JBL MS-8 (signal processor) --> amplifiers ---> speakers / crossovers etc.
 
 
Why use an external DAC in your vehicle?
To obtain a better conversion to an analogue signal. Why USB? This is the output of my tablet.
 
Concerns around the installation of the tablet.
The tablet will replace the existing head-unit. It will be mounted in place of the regular dual DIN display. I'm currently looking into controlling it via steering wheel controls, to address concerns of driver safety.
 
Why replace a regular head-unit designed for a car?
I view the majority as out-dated and insufficient for my needs in a modern vehicle. I require access to a computer for other tasks.
 
Concerns around time-alignment / signal processing etc.
These will be addressed by utilising a dedicated signal processor (JBL MS-8.)

 

[ProtegeManiac]

  ProtegeManiac - thanks for your response.

I realised in my post below I hadn't outlined the system that I'm piecing together.
 
Nexus 7 (android tablet) --> DAC ---> JBL MS-8 (signal processor) --> amplifiers ---> speakers / crossovers etc.
 
 
Why use an external DAC in your vehicle?
To obtain a better conversion to an analogue signal. Why USB? This is the output of my tablet.
 
 
Concerns around time-alignment / signal processing etc.
These will be addressed by utilising a dedicated signal processor (JBL MS-8.)

 
Ah, that settles it - I thought it's going to be like all those other set-ups before where an iBasso or some other DAC-Amp decodes and feeds a line-out signal into a 3.5mm aux-in. In that case, I suggest the ODAC - if you're going to go custom as much as you plan to you could mount it creatively out of the way and protected (maybe even a copper chassis). I had a brilliant plan a few years ago to use Tripath kits mounted in my glovebox, with a computer fan* to cool them, but then all these fullrange Class D amps came out and I might move soon for my PhD. If and when I do move for a few years, and I get a car there, I'm just getting one of these finished amps with an integration processor. I wouldn't mind the decoding quality too much though - I'll just settle for EQ-ing peaks and dips if any. Traffic anywhere in North America can't be as bad as over here in Manila - not to mention I've spent a few nights in downtown mall/hotel parking lots while Zeus tries to drown the entire city, and I'm just cautious enough to drive up parking building instead of gambling I'd get home without submerging my car (and the audio system in it).
 
 
 
*specs for home use don't require it but since it's in the dash, it'll be blowing on heatsinks on the chips themselves, and a custom copper enclosure which wouldn't be too big considering the size of those things
 
 

  Concerns around the installation of the tablet.
The tablet will replace the existing head-unit. It will be mounted in place of the regular dual DIN display. I'm currently looking into controlling it via steering wheel controls, to address concerns of driver safety.
 
Why replace a regular head-unit designed for a car?
I view the majority as out-dated and insufficient for my needs in a modern vehicle. I require access to a computer for other tasks.

 
My workaround though for newer cars is to jsut hook up the regular GPS unit to the Aux-in, and use a spare 1-DIN slot for the Pioneer P80RS. Or, for simplicity's sake, I'll just not stress over GIGO as much, use an integration processor, then EQ out dips and peaks. I'm thinking of the Alpine H660 (did I even get the model number right? Can't find it on the website). If I could customize the entire dash like what you plan on doing, a tablet and ODAC would be a great idea though - it can have the GPS capability, plus a touchscreen interface for the music player and internet radio.

 

[BusyBoxSt7]

Sorry to resurrect an old thread, but what is the point of converting to analog before hitting a DSP ??? You're going digital > analog > digital > analog. No matter how great that first DAC is, it's not as pure as just sending digital signal into the DSP. I'm not super familiar w/ the JBL, but if it doesn't take digital in, there are plenty of DSPs that do... Just saying this for anyone else reading this thread.

 

[ProtegeManiac]

Sorry to resurrect an old thread, but what is the point of converting to analog before hitting a DSP ??? You're going digital > analog > digital > analog. No matter how great that first DAC is, it's not as pure as just sending digital signal into the DSP. I'm not super familiar w/ the JBL, but if it doesn't take digital in, there are plenty of DSPs that do... Just saying this for anyone else reading this thread.

A stock integrated audio headunit that does not come in a standard DIN size and is integrated into the dash by the manufacturer that does not have a digital output that is a total PITA to remove to maintain all other functions like climate control.

Also in car audio GIGO is a lot less of a problem than "HAHA peasant doesn't have a Maclaren F1." Spotify running through an integrated HU that has to go through an ADC to go into a DSP that will implement time delays to each transducer so that the signal from the driver side tweeter, driver side midwoofer, passenger side tweeter, and passenger side midwoofer will all arrive at the driver's head at the same time as the subwoofer in the rear will make for a soundstage spread on the dashboard and up-front bass that no fanatical adherence to the GIGO principle can fix. Audyssey autoEQ on ///////ALPINES using test tones or manual USB mic measurements to an RTA for referencing manual EQ adjustements will do the rest that the first DAC in the chain might have screwed up.

You can test the problem for yourself at home. Take two chairs and put them down near the back sliding glass door to the patio, then take two bookshelf speakers. Remove the tweeters and double sided tape them to the glass at head level, then run longer wires to the speaker cabinets, and put those on the floor. Put a subwoofer behind you and hook these up to the most expensive Wadia and Meridian CDPs or DACs you can get your hands on. Now sit on one of the seats, play music, and try to fix that without a DSP, regardless of whether it takes optical or analogue. You can't? Welcome to car audio. You can't find a DSP to work with that system by taking an analogue signal from the Wadia? Welcome to car audio post-2005.

That's the reason why, whether an ADC is involved or not, you're still a lot more likely to find a car with a DSP than one of those fancy Nakamichis or Denons or a stock Bentley or Jaguar with a B&W sound system competing for an EMMA or IASCA trophy.

 

[BusyBoxSt7]

I get that if you had to choose between a $3000 DAC and a $300 car DSP, the DSP would make a bigger dent in the audio quality issue in a car. Not arguing that at all... However, there's no reason to pose this as an either/or situation. Do both to a **reasonable** degree. Get any cheap DAP, plug it digitally to a HU if install's easy OR directly to a DSP (located out of sight) and skip the head unit thing altogether so your factory AC controls etc all still work, get a little controller for the DSP (like a $70 URC.3 for a Helix, or the little $30 volume knob for a Mosconi) and/or a steering wheel controller for a DAP like a Fiio (it's a whopping $25 and is sleek). Voila, you can skip all the D to A to D to A to D to A conversions.

Just another option. Do what works for your own priorities.

 

[ProtegeManiac]

I get that if you had to choose between a $3000 DAC and a $300 car DSP, the DSP would make a bigger dent in the audio quality issue in a car. Not arguing that at all... However, there's no reason to pose this as an either/or situation.

There are just too many people these days who think that explaining something is the same as "arguing."

FYI...I didn't think you were arguing. I was telling you to experiment so you can hear for yourself what the problem can be without a DSP.

Get any cheap DAP, plug it digitally to a HU if install's easy...

This scenario is already a problem. Integrated HU's no longer have digital inputs because they're not like ///////ALPINE receivers that have AiNet interfaces for CD changers. Speaking of AiNet...at some point Alpine released the PXA-H100 DSP that works through AiNet, that way they didn't have to ditch AiNet on newer receivers, they just installed as part of the firmware the software needed for the HU to recognize that the PXA-H100 is connected and can control its functions without hooking up a laptop.

There is no if as to the easy installation, you literally can't do digital inputs other than USB storage, and in some cases, they only work with Apple devices. Not everyone can or will buy a car based on the stock headunit even if it did have digital inputs either.

Oh wait no lolz. With the exception of the old iRivers, I can't immediately recall one that uses SPDIF Optical, which is what non-AiNet receivers used to use and will likely use if they still had digital inputs. DAPs use SPDIF Coaxial 75ohm, and at minimum, will require a converter that needs DC power...and they tend to come with an AC to DC adapter that takes 110V or 220V, not 12VDC.

...OR directly to a DSP (located out of sight) and skip the head unit thing altogether so your factory AC controls etc all still work, get a little controller for the DSP (like a $70 URC.3 for a Helix, or the little $30 volume knob for a Mosconi) and/or a steering wheel controller for a DAP like a Fiio

Because some might prefer using the interface on a smartphone, which easily connects to the stock headunit to charge the unit as well as interrupt playback when needed. A DAP bypassing the HU will result in having to manually tone down the master audio volume control (which isn't the master anymore, since, well, it only controls music playback) in order to hear a phone's speaker try to go, "exit right to Interstate 5, then stay on the right." And sometimes there's already an effective lag depending on your speed, so now there's even more of a lag as you manually lower the volume and whoops no Waze isn't going to repeat that so you have to take your eyes off the road and look at the phone screen and compare that to what's outside the windshield.

Oh and speaking of I-5...in California distracted driver laws are really, really, really strict, assuming a cop sees you. You can't even touch just fiddle with playback on the stereo while at a stoplight, and using the digital output on a DAP direct to the DSP doesn't give the DAP control over the preamp volume control the same way an AiNet receiver can command the preamp on a PXA-H100 or PXA-H701 or how your phone or built in nav can cut through the audio if the audio goes through the receiver.

Some people got around this by installing a tablet to retain navigation while sending a USB signal to a DSP or a USB to SPDIF converter (that then connects to a DSP), but that comes with its own problems:

1. The tablet conversion kit that maintains knobs for the climate control can still be costly to install even for those that can otherwise replace an old standard DIN size receiver on an older car or still be able to do some speaker mounting fabrication on any car since manufacturers also tend to tie a lot of the electrical system warranties to not removing the stock receiver or rewiring all the other stuff on the dash.

2. You now have a battery on the dashboard baking in the sun in places where it can get really hot and heavy tint isn't allowed, like California, where you can't even put clear reactive, UV-rejection tint on the windshield, while other places/countries are clamping down on these for one reason or another (in the Philippines, that would be crime).

(it's a whopping $25 and is sleek).

It's sleek on the steering wheel but it's not so sleek if it can't cut through the audio or you have to have several devices out, like a phone on the dash plus a DAP in the glovebox or the seat (if not on the dash too).

You're basically ignoring a lot of other ways one thing can be practical while another can be impractical to other people. I'm prioritizing driving and less invasive installations.

I agree that Spotify would sound better through at tuned system than FLAC through a stock stereo. But I don't see a reason to run Spotify either - using CD quality files is not going to break anyone's bank unless they won't pay for the music they "love"

It was just an example contrasting it to FLAC.

On top of which, if someone was using a smartphone for all the practical reasons above:
1. It only has one SDcard slot (assuming they don't use an iPhone), and not all typically recognize more than 256gb. Some don't even recognize as much as 256gb, assuming they don't beat up their phones and can make do with a battery replacement instead of a whole phone replacement like people lining up outside an Apple or Samsung store.
2. Not even those who actually still spend money on hard copies or FLAC downloads of their music buy all the music they listen to in those formats. If I did I'd spend 10X the money I already spent on my gear, so my focus is mostly on having the CDs and FLAC of metal bands. If I bought all the 100 albums on my Spotify account that I don't have on FLAC or (SA)CD, that's about $1,500, assuming each disc is $15...but good luck with that when I have to pay for shipping. other people can have more on their streaming services than I do, even if they also have hard copies of the rest.

Again, you're too focused on your use case, without thinking of other things that people might need out of a car system where it's fairly easy to avoid having a completely effed up soundstage without necessarily having it run as a reference rig.

Voila, you skip all the D to A to D to A to D to A junk.

(which would be a bit pathetic for anyone aficionado enough to spend time on this forum, but I digress...).

I'm not sure why this is an either/or conversation - perhaps because we're on headfi and your reaction is toward others (not me) who like to miss the forest for the trees. I'm just saying deal with the overall issues instead of honing in on one item, and in that we're in agreement. You know, keep a reasonably clean signal chain, decent source, and tune the system as well.

You can't claim "I'm not arguing!" and people in this forum are "missing the forest for the trees!" when you:

1. Use terms like "junk" and "pathetic"...

2. ...while ignoring the impracticalities to other people of what you thinks is extremely practical...

3. ....and being an adherent of the GIGO principle in a situation where it is not just the soundstage but also the freaking tone and resolution being affected by not having a Maclaren F1. Just hearing the output of one tweeter out of sync with the other tweeter if not also the midwoofers can result in sibilance, thereby affecting resolution.

Just to be clear, all parts above this, I'm explaining. Explaining that there are flaws in your logic, and all I'm doing is making you aware of these.

 

[BusyBoxSt7]

You’re right, some of what I wrote was argumentative. I’ve edited my post. My goal was to present another way to do things. That way is much more convenient for me both in terms of install complications and in terms of use while driving. I prefer separate devices for things. My hearing is good enough (yeah, personal usage varies, not saying this works for everyone) that I don’t need Waze, or anything else from the phone, playing through the car system. And it’s simpler to me to have a dedicated DAP to control music so I don’t have to shuffle back and forth between apps on a phone. If I need to pause the music, the DAP. If I need to make a call, the phone and the volume knob. There’s 3 components out, a dap, a phone (which is 100% not linked to the system) and an installed volume knob/controller. It can be fairly minimal install in some cars and pretty no frills operation. Quality over quantity/features - my preference.

When you talk about flaws in my logic, I think it’s more a matter of just two people with different goals. My logic isn’t flawed for my goals for a system, and yours isn’t for your goals. It only becomes flawed if either of us attempts to separate everything into two completely separate “camps” and assigns more to the other camp than what the other person said (in this case you seem to be pointing out the flaws/illogic of certain methods/setups that I wasn’t even proposing).

I get it, I’m one guy with a specific set of priorities. We both are. Some people will resonate with yours, and some with mine. I think I’ve said all I’ve got to say on the topic. No ill will at all. Peace.

 

[BusyBoxSt7]

Hmm, re-reading your response I see where I maybe could have been clearer. When I said if a HU install is easy I don’t mean the stock unit, I meant if it’s easy to install a head unit (in some cars it is), for example an 80PRS is basic, has usb in (iPod), relatively simple system/install...

As for other details, when I mentioned plugging straight DAP to DSP, I didn’t mean to toslink. Some DSPs have coax and/or usb. Some DAPs can do coax ‘natively’... And many DAP’s charge via USB or similar just like iPod, no need for a 110/220. I in no way was ever trying to claim that every DAP/DSP would be a simple setup. Some aren’t. There are options that are straightforward for those who want to look into it. I was just saying it’s possible.

Again, no I’ll will. Peace.

 

[Tidalizer]

ok I'm not sure I'm following exactly what you peeps are saying apart from doing some sort of lash up of DACs, amps and wires.

Here's my problem, I want stream Tidal which is 24bit / 96Khz to a head unit, I don't want DACs, external amps, modules, wires, I want a head unit that will give me digitally bit perfect audio and ideally upsampling to 192Khz or beyond.

What I currently have is a Pioneer DEH-80PRS, I stream over bluetooth from my Andriod phone, it sounds good but as usual I want more / better quality,, bluetooth SBC is lossy - I don't want that in my audio chain.

Andriod auto from what I understand is CD quality, so 16bit 44Khz, so that's no good.

What are my options i.e. what car audio manufacturer provides a means of streaming 24/32bit at 96Khz or above from an Andriod phone ? from what I can see there are no options.

 

[BusyBoxSt7]

Tidalizer, I'm having trouble making sense of what you're trying to do or why you're trying to do it without addressing bigger system issues (perhaps you already have but it sounds like the 80PRS is the sole thing in your system besides speakers).

1) Your 80PRS can't play 24 bit files. Pioneer said so (quoted in car audio forums)... So you'll need to get a different HU (that has DSP) and/or get a DSP (and possibly plug straight to it).

2) You do need DSP whether in the HU or a standalone. The difference you'd possibly hear from listening in 24 bit (I say that because it's a bigger difference than sample rate - at least that's consensus with the people who are recording the music far as I know), would require
a) that your speakers are time aligned so the transients, reverb trails, etc aren't happening out of sync with each other and
b) an amp (and speakers) that can reproduce those transients clearly.

3) The amp in the 80PRS is 14w RMS per channel IIRC - and those aren't "underrated" watts. And if you aren't using it in "network mode", then you're sharing 14 watts between your left tweeter and left midbass (woofer), for example. So your transients are probably getting splatted somewhat by any HU's onboard amp. Thus any car audio fanatics using external amps instead of amps smaller than your android phone.

....
By the way, if you have a link to 32 bit music recordings I would be curious. I have yet to see a recording studio that has 32 bit conversion (AD or DA). Perhaps some guys are mastering at that (mixed in 32, yes, I always do). I'm curious how much of the "32 bit" recordings floating around are real or whether blank data is being added to 24 bit files. I get that that could make some diminishing returns difference if the idea is feeding 32 bit into a 32 bit DSP (not just a DAC but a DSP that processes the audio) to avoid any possible timing errors in the bit depth conversion happening in real time... I would be shocked if anyone's car is accurate enough to hear that though. Perhaps a *very* high end SQ competition car.

PS. Sorry to "not answer" your question. Like I said though I don't think it would really help you at least until the other kinks are worked out... If you need help with setting up a bare bones (least number of boxes) hifi car system, just ask. It doesn't have to be super complicated. Mine's only going to have 1 box (dsp) and 1 amp and a DAP and leave the stock stereo in place.

 

[Tidalizer]

ok I'm not sure I agree entirely with what you're saying, DSPs are horrid things if you want quality audio, they either distort your audio and / or reduce your sample rate. Passing analogue via your HU is also a complete nightmare, most HU's if not all will do a A to D conversion, route through a DSP then another D to A step, the initial A to D is likely to be 16 bit 44Khz, so again you lose quality.

The only solution I have is a Android phone to a USB DAC and the DAC line outputs into a pure analogue amp, ideally class A, perhaps including another box for a sub pre-out / crossover, again an analogue box not digital / DSP. To me though this is a complete mess and not as usable as a HU that should be able to do this job.

The DEH-80PRS has 3 burr brown DACs which are 24bit, not sure what sample rate it does, but still the DEH-80PRS has no options for hires input it just has a quality DAC and internals. I've tried all the time alignment junk and all the options many times, I always end up switching it off and going back to a simple crossover setup, it sounds better every time without a doubt.

Yes a 4 speaker amp and better speakers would probably give me a good quality and enjoyment boost but my source would still be passing through a lossy / horrid bluetooth SBC codec.

And sample rate definitely makes a audible difference, yes I know it shouldn't but it does, for example check out audirvana.com this does upsampling to 768Khz for my DAC and wow the sound detail is mind blowing and that's via some medium level hifi gear - not high end stuff.

Sony produce a HU for hires audio but it's an insane price plus I have no idea if you can stream hires music to it (probably not), I want a something sensibly priced that will simply expose a decent DAC to my phone over USB.

Car audio manufacturers seem more concerned about displaying your phone contacts and such like than audio quality.

I don't know of any 32 bit audio sources but to my mind this does give headroom to reduce clipping and is future proofomg, most modern DACs are 32 bit, so yeah I want the latest tech, not 5 year old tech.

 

[BusyBoxSt7]

If you're judging all DSPs based on 80PRS, that's not even an intro DSP. It's a good HU, not a good DSP. 16 bands that aren't adjustable?

-almost every car amp is "pure analogue"
-most mono amps have analog crossovers built in (for subs) and most multi-channel amps have them too. No need for another box.
-again, 80PRS is 16 bit when it comes in. The signal path is 16 bit. The processing is 28 bit float. The music is 16 bits (naturally or downsampled) and the EQ you apply is processed at 28.

I'm a little confused whether you're saying it needs to be wireless from the phone to the headunit/dsp or whether by "streaming" you only meant Tidal is streaming music to your cell.

Yes, Sony's HU is $$$$$$. Tech costs money. If you know any people that develop that stuff, you'll know why... "car audio manufacturers seem more concerned about displaying your phone contacts"... It's always more profitable to sell a lower priced (lower cost) item to tons of people than an expensive item to a few people. Smaller markets = higher prices due to lack of economy of scale (partly).

Honestly, just my incomplete perspective here, it sounds like you have unrealistic goals, wanting something very specific but with no inconvenience. I found two 24/96 wireless streaming DSP options (already knew of them actually). You won't like these solutions because they involve inconvenience and aren't cheap... For the moment, no one can help you because nothing exists on the market that will meet all your wants. Half of your wants are super high end and the other half are pretty low end - thus the product doesn't exist because there aren't enough people demanding that.

Lastly, as a guy who runs a recording studio and is hearing the conversion etc during the actual making of the product (the music), just a reminder that quality isn't summarized well in specs. The best mics often have bad noise floor. Some of the most favored converters are "outdated" and their specs are as well (noise, crosstalk, dynamic range, all of it). Still, a great converter will sound drastically better at 16/44 than an average one at 24/192. The flattest frequency response speakers don't always sound the best. Some of the best sounding speakers don't have great bass specs on paper. Etc, etc.

 

[Tidalizer]

Yes no doubt there are good DSPs that cost money but I don't see the need for one, i want pure audio, not messed with audio, I don't have any EQ in my home setup and no DSP and it sounds awesome, a simple PC->32bit 768K DAC->amp->speakers = audio bliss.

I'm streaming audio from my mobile to the 80PRS over bluetooth, the frustration is simple, my source is 24bit/96Khz but I have no way to get that quality passed to my speakers without installing amps, DACs, loads of time installing and so on, i want a simple HU setup. No that won't sound as good as some class A dedicated amps and better speakers and so on but I want it to out perform the 80PRS sound quality wise aka a HU upgrade and it needs to do at least 24/96.

I don't want anything high end, I want a HU that will allow me to stream 24/96KHz to my speakers, most HUs have a reasonable DAC and to my mind it's only software that would allow my phone to connect to the HU most likely over USB or even wifi and pass the digital audio data ideally in a pure form (not via a DSP) to the DAC.in the HU, I don't see the problem, it shouldn't be that difficult or expensive, all the hardware is already there - even inside the 80PRS - it has 24bit DACs that I'm sure could do 96KHz, just Pioneer took the decision to if you're correct down sample to 16 bit and not provide any means to get 24/96 into the HU.

Bluetooth is no good for hires, even Sony LDAC isn't that good, bluetooth is convenient but useless for proper audio quality, probably the only other option would be aptx or aptx HD, even then all these details are rarely advertised by car audio manufacturers, so a compromise might be a HU with bluetooth aptx.

So yeah I've no idea what products there are that would do the above, most likely none, obviously I was hoping someone could say buy a Alpine (or whatever) blah blah HU and that'll do 24/96, just hook your phone up and you're done, then later upgrade my speakers and add an amp for more of the same but louder.