Formatting USB for car audio surround. (Using JRiver Formatting). Questions.

[marpow]

Oh man, loading my 5TB SSD with stereo only music. What a chore, copying files from the NAS to the SSD. There is so much music, and I am only picking the albums that I would like in the car, some music is best left to never listen to again and some in the car and some in the home rig.
When doing this I sure do appreciate regular CD's, I dread all the stereo SACD's I will have to re-format.

 

[jimfisheye]

Random comments from the peanut gallery:

I think all audio device drivers use a 24 bit data stream regardless for a long time now. 16 bit would get delivered in a 24 bit stream zero padded. There are some devices that use 32 bit floating point too. Basing that on observations that dropping to 16 bit vs 24 bit has no effect on latency. Playing with DAW system and audio interface latency and taking measurements. You see the expected timing with different sample rates but no difference between 16 bit and 24 bit. There's a 3rd byte of zeros tagging along for 16 bit.

AVR processing:
Look through the settings to find the 1:1 output that bypasses any and all DSP. Don't be surprised to find a default that alters things and don't be surprised to have to really dig through menus to find the 1:1 setting.

Conversions and downsampling:
Converting DSD to PCM can be a transcode when converted to 88.2k PCM. Choosing a different target throws that option out and you get a lossy conversion. One of those situations where the software goes "malicious compliance" if you don't know the exact right commands. You could do the proper transcode first and then downsample that to 44.1k and be none the wiser. Go straight to 44.1k with the software and the results come out stepped on.

Amazon:
It will be bootleg garbage. You will get ripped off and be sad.

Use a DAW to batch convert!
Reaper, for example, has a batch converter. Click once and walk away.

 

[LuvMyQuad]

AVR processing:
Look through the settings to find the 1:1 output that bypasses any and all DSP. Don't be surprised to find a default that alters things and don't be surprised to have to really dig through menus to find the 1:1 setting.

The problem is, there is no way to know this. AVRs and Prepros always indicate what is being input, but they seldom tell you what is being output. You can test for it, but without doing so you can't tell if the stream is being downsampled. You can try to listen for it, but its pretty hard to hear the difference between 96kHz and a 48kHz downsample (for me anyway). I know what my gear does only because it has been tested in the audio press.

Conversions and downsampling:
Converting DSD to PCM can be a transcode when converted to 88.2k PCM. Choosing a different target throws that option out and you get a lossy conversion. One of those situations where the software goes "malicious compliance" if you don't know the exact right commands. You could do the proper transcode first and then downsample that to 44.1k and be none the wiser. Go straight to 44.1k with the software and the results come out stepped on.

Even 88.2kHz is technically a lossy conversion.

But if you wanted 44.1 from DSD, why wouldn't the initial conversion work just as well? You are saying that there is a major difference in the downsampled data from the initial conversion vs a conversion to 88.2kHz and then to 44.1kHz. ??? Isnt it the same downsample routine?

 

[marpow]

The problem is, there is no way to know this. AVRs and Prepros always indicate what is being input, but they seldom tell you what is being output. You can test for it, but without doing so you can't tell if the stream is being downsampled. You can try to listen for it, but its pretty hard to hear the difference between 96kHz and a 48kHz downsample (for me anyway). I know what my gear does only because it has been tested in the audio press.

This is probably the single biggest problem I have now with the car audio. I am so used to my home rig, all my McIntosh products tell me anything I want to know at any given time, outputs are just a push of a button, not to mention the VU meters on the amps.
Now that I am trying to tune the car it's a lot of manual. They do sell a thing like an Audessy set up for cars LIKE THIS, but I guarantee you at $3500.00 there is no way I will buy this.
But I did get this FREE APP along with this $130.00 Microphone.
My experience is if I want something I really have to work for it, nothing is easy.

On the other subject my plan for all my 5.1 and 4.0 re-formats is to go USB drive Fat32, format as zero compression, 24bit, 48Hz, I do this all in one shot, to do twice does not seem like a viable option for me, time wise.

 

[LuvMyQuad]

On the other subject my plan for all my 5.1 and 4.0 re-formats is to go USB drive Fat32, format as zero compression, 24bit, 48Hz, I do this all in one shot, to do twice does not seem like a viable option for me, time wise.

Maybe rethink the 48kHz for the DSD conversions. My understanding is, those are best left as 176.4kHz, 132.3kHz, 88.2kHz, 44.1 kHz, etc. Always being some multiple of 44.1kHz. Else you will have aliasing, which would need to be run through an anti-aliasing filter, which your conversion software will certainly do, but I believe it makes the conversion more lossy than it has to be.

 

[marpow]

Maybe rethink the 48kHz for the DSD conversions. My understanding is, those are best left as 176.4kHz, 132.3kHz, 88.2kHz, 44.1 kHz, etc. Always being some multiple of 44.1kHz. Else you will have aliasing, which would need to be run through an anti-aliasing filter, which your conversion software will certainly do, but I believe it makes the conversion more lossy than it has to be.

OK, so that formula for SACD only? I just re-formatted a 5.1 SACD to my specs above and noticed the bit rate cuts by 2/3. As a DSD file every song is Bitrate 16934, at the conversion to 48KHz it converts a little different every song, but average is probably around 4100 bitrate.
Now re-formatted the same SACD to 88.2KHz. The Bitrates, go up to around 6900 average.

This formula for SACD only?
I think DVD Audio have no change in sample rate?
In Blu Ray go lower that the standard 96?

 

[LuvMyQuad]

OK, so that formula for SACD only? I just re-formatted a 5.1 SACD to my specs above and noticed the bit rate cuts by 2/3. As a DSD file every song is Bitrate 16934, at the conversion to 48KHz it converts a little different every song, but average is probably around 4100 bitrate.
Now re-formatted the same SACD to 88.2KHz. The Bitrates, go up to around 6900 average.

This formula for SACD only?
I think DVD Audio have no change in sample rate?
In Blu Ray go lower that the standard 96?

If we are comfortable with the idea that the car system is going to downsample everything to 48kHz (which we don't actually know, but it is likely, it may even be a lower rate), it makes no sense to go beyond a 48 kHz sample rate for any of the stored tracks. So 24/96 and higher res from any PCM source (DVD, DVDA, Blueray, etc) should be converted to 24/48 kHz. DSD would go to 44.1kHz to avoid any downsample in the car, while still being a multiple of 44.1. The difference between 44.1kHz and 48kHz is not vast. With the aliasing issues, 44.1 may well give a better result than 48kHz. You can always copy the same tracks sampled to 48kHz, 88.2kHz and 44.1kHz and have a listen. If you notice any difference, then that is your guide. In general, most recommendations call for DSD to be downsampled as a multiple of 44.1kHz and for PCM to be downsampled as a multiple of 48kHz.

 

[Marplot]

OK, so that formula for SACD only? I just re-formatted a 5.1 SACD to my specs above and noticed the bit rate cuts by 2/3. As a DSD file every song is Bitrate 16934, at the conversion to 48KHz it converts a little different every song, but average is probably around 4100 bitrate.
Now re-formatted the same SACD to 88.2KHz. The Bitrates, go up to around 6900 average.

This formula for SACD only?
I think DVD Audio have no change in sample rate?
In Blu Ray go lower that the standard 96?

Yes, that 88.2/44.1 is for DSD64 conversion only. When you rip a SACD you should use 88.2; probably 44.1 for your car.

For your BR audio, there is almost always a 48k version you can use so no need reduce that since it sounds like your car is cool with 48k flac 0 on fat32.

 

[marpow]

@LuvMyQuad and @Marplot
OK, I understand the formula. but sounds like a little trial first.
This is what I know to be true so far.
STEREO-FLAC-PCM: The USB that goes into the stock center console and plays through the UConnect (Dodge) formatted to NTSF plays any and all FLAC PCM files, no matter what the bit rate and KHz sample rate, which is fantastic. I am not interested in re-formatting any albums for stereo that is already FLAC.
STEREO-DSD64 to FLAC: I believe that your formula above re-formatting to FLAC either 88.2 or 44.1 will work well.

5.1 going through the 5.1 decoder: The USB has to be FAT32. This is where it gets tricky. For DSD64 re-formatting the 5.1 and 4.0, I will use the same formula as above 88.2 or 44.1 for trial.
The already PCM FLAC files (BLU RAY or DVD) in 5.1 or 4.0 sounds like what is best is to re-format to 48KHz, if not already there.

Thanks for your help.

 

[Marplot]

looks like you are on it.
that is liberating that you can play stereo however you like.
bummer you have to jump through such odd hoops to get the multi, but once you nail it recreating it will be simple and not only will that car look bad ass, but it will sound it as well.

Some mch Ride of the Valkyrie as you roll seems in order.

 

[LuvMyQuad]

I have an Alpine badged Uconnect system in my Jeep. Keep in mind, just because the Uconnect system will accept stereo 24/96 and 24/192 PCM files, it doesn't mean it will truly decode the tracks at that sample rate. It may well downsample to 48kHz as well. I haven't read anything yet saying it does or doesn't. The good thing is it does not have the restrictive storage requirement that @marpow s 5.1 decoder does. So no harm no foul.

 

[marpow]

@Marplot, thank you, I agree, once the correct formula is acquired, all this back and forth from PC to car will be done.
Today I will experiment with the stereo DSD conversion to FlAC. God knows I have a what seems like a million SACD stereo only discs.

@LuvMyQuad, thank you, yes, I figured that the UConnect will down sample to something, but what I don't know won't hurt me, right? I don't think it is a good use of time converting all the HiRes stereo PCM's, especially when they play with ease, and I don't hear anything necessarily wrong.
BTW: I talked to dealer about turning in my Ford Escape for a Jeep, 5-9 months ordering, and none that meet my specs on the lot, oh well that is another obsession I will save for later.

5.1 QUESTION: In regard to reformatting the 5.1 or 4.0 PCM files. I know probably another trial-and-error process, but do either of you think it would be a needed thing to re-format the already 24/48's to zero compression, even if no need to re-format the sample rate? These files will end up in the FAT32 USB drive to the 5.1 decoder.

 

[Marplot]

It sounds like you need to have flac with 0 compression so I expect that yes, you will have to convert them.
Keep in mind there are tons of tools out there to convert them on the fly so you won't need to rerip. They outcome will be slightly larger file sizes.

If it were me, an opinion you can kick to the curb without a moment's hesitation, if you have to convert, I wouldn't bother with any intermediary compression ratios. Just go from 6 to 0; strorage is way cheaper than my time.

 

[marpow]

Understood, oh God no, I am not re-ripping, that would take forever. I use my JRiver which is tied directly into my NAS and CONVERT.
I would say one conversion takes approximately 1minute 30 seconds to convert, than slide the conversion out of NAS into USB, 30 seconds.
Once I get comfortable with all the different conversions, when I convert, I will just convert to the folder (USB Drive) than I will save 30 seconds per conversion.

 

[LuvMyQuad]

BTW: I talked to dealer about turning in my Ford Escape for a Jeep, 5-9 months ordering, and none that meet my specs on the lot, oh well that is another obsession I will save for later.

I know that's the way it is for a lot of dealers here too. Just out of curiosity, what do you need that they don't have in stock?

 

[marpow]

I know that's the way it is for a lot of dealers here too. Just out of curiosity, what do you need that they don't have in stock?

I wanted a two row, 4x4, 5.7 with the McIntosh

 

[LuvMyQuad]

I wanted a two row, 4x4, 5.7 with the McIntosh

Nice. So what kind of upcharge does that McIntosh carry?

 

[marpow]

All right @Marplot and @LuvMyQuad,
I think I have finally got it.
STEREO: the DSD conversion (24bit, zero compression) either 88.2 or 44.1 sample rate, both played well through the UConnect but the 88.2 had a little tiny hiss that the 44.1 did not have. I am referencing in the quiet of my garage, probably would not notice the difference while driving.
The winner of the Stereo is any format they come as, no conversion, except DSD to FLAC that conversion will be zero compression, 24 bit, 44.1 sample rate. USB SSD 5TB Format NTSF.

5.1 playing through decoder: Tried a 24/96 file as it comes and the decoder sounded like a little lag, like too big but played in surround, clearly.
Tried 24/48 with 6 compression, again played well but something not quite right.
Tried 24/48 with 0 compression, perfect, the winner. USB FAT32. 32 Gig.

All right, thanks for all the help, I feel pretty comfortable with the plan, and not thinking my Chinese decoder that came from who knows where is no good, maybe it is perfect if you play the way it wants to play.

You cannot be an audiophile if you do not have the help of others on QQ, thanks much.
Will keep you posted after DSP tuning, which is the last step, probably this Thursday, I still have to work.

 

[Mr. Afternoon]

I have an Alpine badged Uconnect system in my Jeep. Keep in mind, just because the Uconnect system will accept stereo 24/96 and 24/192 PCM files, it doesn't mean it will truly decode the tracks at that sample rate. It may well downsample to 48kHz as well. I haven't read anything yet saying it does or doesn't. The good thing is it does not have the restrictive storage requirement that @marpow s 5.1 decoder does. So no harm no foul.

You can actually get UConnect to output discrete surround by a backhanded method of using Android Auto. Painful but it works.

 

[LuvMyQuad]

You can actually get UConnect to output discrete surround by a backhanded method of using Android Auto. Painful but it works.

Really. You got a link or anything?