NEX4000 Audiophile observation

[tickerguy]

Bits are bits if you're feeding the head unit a bitstream.  A lossless bitstream that the head unit supports (e.g. FLAC) is even better.  Whether that bitstream comes off a SD card or something on the USB connector does not matter so long as the data comes off at the rate required to feed the DAC in the head unit.

 

If you're feeding it analog (via the phone's DAC) then you're at the phone DAC's mercy plus the front-end noise in the head unit.  While the latter shouldn't be material the DAC quality is often questionable at best, and what's worse is that you're probably feeding the head unit "headphone out" rather than line out so you're not only getting the DAC quality in the phone you're also getting the phone's headphone amp quality (or lack thereof) before the car head unit gets ahold of it.

 

Note that Bluetooth streaming is also a problem as the Pioneer head units do not support aptX, which is of very good quality.  The standard AD2P codec is only so-so; it beats two stages of analog (your phone's DAC and then headphone amp) most of the time but that's not saying a lot.

[Backenst]

Good input, I guess the question is this?  What is actually happening when you transfer a file using yur iphones lightning adaptor into the USB1 of the Pioneer unit.  is that what you mean by "bits are bits"   And Is that bypassing your phones DAC altogehter and only using the superior DAC on the headunit?

 

Here is what I noticed which is what got this entire string going.  Up until yesterday, I was using a iphone 4s and it connected to the Pioneer using a ligntning cable with a 30pin adaptor so it would fit my iphone.  When I compared the audio quality by playing the same song (file) via the SD card, the SD card version sounded considerable better.  Yesterday, I got the Iphone 6, got rid of the 30 pin adaptor, and now the sound quality between the two sound nearly identical (still need to test a bit more).  So that tells something in the phone or perhaps the cable/adaptor was having an impact on the sound quality.

[Free]

Good input, I guess the question is this?  What is actually happening when you transfer a file using yur iphones lightning adaptor into the USB1 of the Pioneer unit.  is that what you mean by "bits are bits"   And Is that bypassing your phones DAC altogehter and only using the superior DAC on the headunit?

 

Here is what I noticed which is what got this entire string going.  Up until yesterday, I was using a iphone 4s and it connected to the Pioneer using a ligntning cable with a 30pin adaptor so it would fit my iphone.  When I compared the audio quality by playing the same song (file) via the SD card, the SD card version sounded considerable better.  Yesterday, I got the Iphone 6, got rid of the 30 pin adaptor, and now the sound quality between the two sound nearly identical (still need to test a bit more).  So that tells something in the phone or perhaps the cable/adaptor was having an impact on the sound quality.

Great post.

 

Based on your observations, it would seem (my guess) that the connector you used (not the connector quality) with your 4S is not bypassing the iphone's dac.

 

I found this on Crutchfield's website.

 

iPod/iPhone Control

iPod Connectivity w/ DAC Bypass: The Pioneer AVH-4000NEX supports direct connection of your 30-pin or Lightning-connector iPod/iPhone through its rear-panel USB port, HDMI input, RGB port, and 3.5mm jack. The AVH-4000NEX offers audio/video playback, music navigation, information display, and charging of select Apple iPod/iPhone models. It also provides a special AppRadio mode for iPhone 4/4S and iPhone 5/5C/5S users which allows you to access a variety of online music, navigation, and other helpful apps. The AVH-4000NEX allows your iPod/iPhone's music library to be loaded instantly to the head unit and sound quality to be maximized through the head unit's 24-bit D/A converter (bypassing iPod/iPhone DAC), allowing for a Signal to Noise ratio up to 96dB.

• Lightning Dock Connector: If you have a newer iPhone with the Lightning-connector; you can use Pioneer's CD-IH202 HDMI cable and CD-IU52 Lightning-to-USB cable, plus the Apple Lightning-to-Digital AV Adapter (all sold separately) to access stored music and videos, music and video apps, plus AppRadio Mode for playback of advance applications on the Pioneer AVH-4000NEX. This setup also requires your iPhone be paired via Bluetooth to the head unit. You can substitute the CD-IH202 HDMI cable for another manufacturer's mobile-grade HDMI cable and the CD-IU52 cable with the Lightning cable that came with your iPhone. If you desire only music playback from your Lightning-connector Apple device, simply use Pioneer's Lightning-to-USB cable (130CDIU52, sold separately) or the Lightning-to-USB cable that came with your Apple device to connect your iPod/iPhone to the AVH-4000NEX.
• 30-Pin Dock Connector: If you have an older iPhone 4/4S with a 30-pin dock connector, use the Pioneer CD-IU201S RGB/USB cable (130IU201S, sold separately) to enjoy playback of stored music and videos, music and video apps, plus access to AppRadio Mode for playback of advance applications on the Pioneer AVH-4000NEX. If you do not own and iPhone 4/4S, but do have another older 30-pin dock connector iPod/iPhone, use the Pioneer CD-IU201V iPod Video cable (130IU201V, sold separately) for playback of music and movies files stored on your device, as well as music apps. Simply use Pioneer's dock connector-to-USB cable (130CDIU51, sold separately) or the dock connector-to-USB cable that comes with your Apple device if you desire stored music and music app playback only.