Bad sound through aux X5 e70

[Well777]

Hello! I have an acoustic question. I have a 70 with top hi-fi, before that there was a 65th body also with top hi-fi. I listen to music from a portable hi-rez player through aux. In the e65, the amplifier is analog and everything that the player gives out, in an uncompressed form, can be realized through standard acoustics. This resulted in a very good sound. When I took the 70-ku, the sound was terrible compared to the e65. The forums advised to put an amplifier from restyling. I did it and the sound became noticeably better. The CD began to play closer to the seven, but the aux still sounds flat. As I understand it, the problem is that in the 70s everything is implemented differently. The analog sound comes through the aux to the head, and it again translates it into digital through the ADC and feeds it to the amplifier in this form. I think at this stage the quality is lost. So the question is - if the amplifier from restyling partially helped, will the transition to NBT or NBT EVO help? I just think that in 2008 the ADC in my head was clearly antediluvian. I don’t really understand what changes when installing NBT, does the head unit change so that as a result of the installation a newer generation ADC is in the car, maybe it won’t cut the sound like that? Thanks for the possible answer

[argento]

Not sure I have your answer, but I have a setup through the AUX that outputs sound better than a CD in the OEM Individual Audio option (S752A). I use an Android Monitor, playing ALAC files via UAPP, through a dragonfly cobalt DAC, and to the AUX input in the center armrest. I have OEM equalizer set to flat and I have oem surround unchecked/off while UAPP and the DAC do the rest. So it's possible to sound great.

Maybe the oem EQ via the bmw amp doesnt have the capability to cleanly output the Aux audio. I've also done testing and found that some aux cables are much better than others (and yes I've also read the many reports that say they make no difference, but I went with my testing and hearing)...I am using an Audio Quest Big Sur aux cable, but also found the Evergreen series to be equivalent, FWIW. AND a even a tiny piece of lint on the aux cable can cause static, so use compressed air to clean out the socket and clean off the 3.5mm plug.

[Well777]

Originally Posted by argento

Not sure I have your answer, but I have a setup through the AUX that outputs sound better than a CD in the OEM Individual Audio option (S752A). I use an Android Monitor, playing ALAC files via UAPP, through a dragonfly cobalt DAC, and to the AUX input in the center armrest. I have OEM equalizer set to flat and I have oem surround unchecked/off while UAPP and the DAC do the rest. So it's possible to sound great.

Maybe the oem EQ via the bmw amp doesnt have the capability to cleanly output the Aux audio. I've also done testing and found that some aux cables are much better than others (and yes I've also read the many reports that say they make no difference, but I went with my testing and hearing)...I am using an Audio Quest Big Sur aux cable, but also found the Evergreen series to be equivalent, FWIW. AND a even a tiny piece of lint on the aux cable can cause static, so use compressed air to clean out the socket and clean off the 3.5mm plug.

Thanks for the answer. Yes, I'm talking about something else. Although, maybe you are right about the interference, I will try to replace the cable from the AUX to the head unit, on one of the forums they wrote that it was bad and without a metal braid. I actually and so practically use your circuit. I play hi-rez music (24, 32-bit) on an Ibasso dx220 via an expensive quality cable. And it turns out that there can be no problems with sound from the outside, it remains to pick inside ..

[RL18]

So what you’re saying is your using a DAP (digital analog player) with a built in DAC, then playing music through your NBT evo or carplay upgraded headunit through its provided aux which is then hooked to your stock aux?

Why are you hooking it up to the upgraded headunit? Hook your media player directly to the stock aux location. Your just adding the headunit in between to f up your signal.

[Well777]

Originally Posted by RL18

So what you’re saying is your using a DAP (digital analog player) with a built in DAC, then playing music through your NBT evo or carplay upgraded headunit through its provided aux which is then hooked to your stock aux?

Why are you hooking it up to the upgraded headunit? Hook your media player directly to the stock aux location. Your just adding the headunit in between to f up your signal.

No, you misunderstood me. I have a hi res player, it can only be connected via aux. The regular aux in bmw is implemented as follows (I have a circuit) - the sound in analog form is transmitted to the CCC head unit (I have it now), the head unit has an ADC (analogue-to-digital converter), which converts analog sound into digital and sends it via optics signal to the amplifier. It is not possible to bypass the head unit, for this you need to connect directly from the player via optics. So I had a question whether it would be better to digitize the sound with a newer processor in the NBT EVO. If so, then I will order it and install it, I now have CCC.

[RL18]

Originally Posted by Well777

No, you misunderstood me. I have a hi res player, it can only be connected via aux. The regular aux in bmw is implemented as follows (I have a circuit) - the sound in analog form is transmitted to the CCC head unit (I have it now), the head unit has an ADC (analogue-to-digital converter), which converts analog sound into digital and sends it via optics signal to the amplifier. It is not possible to bypass the head unit, for this you need to connect directly from the player via optics. So I had a question whether it would be better to digitize the sound with a newer processor in the NBT EVO. If so, then I will order it and install it, I now have CCC.

I don’t understand why you say the headunit aux has a ADC, it doesn’t. Aux is a direct analog signal. It bypasses the headunit and goes directly to the amp. If you’re playing from any media device then you need a quality DAC if using aux because you need a good analog signal. Usb and Bluetooth are the only connections that are a digital signal through the headunit, which is still converted back to analog for the amplifier via the headunit DAC (which is old tech and not up to date with modern DAC). Amplifiers use analog signals, not digital. So I’m not really sure what you’re asking. Upgrading your headunit will likely make zero difference. It’s either your media player, aux cable, your aux port, or the amp.

[Well777]

Originally Posted by RL18

I don’t understand why you say the headunit aux has a ADC, it doesn’t. Aux is a direct analog signal. It bypasses the headunit and goes directly to the amp. If you’re playing from any media device then you need a quality DAC if using aux because you need a good analog signal. Usb and Bluetooth are the only connections that are a digital signal through the headunit, which is still converted back to analog for the amplifier via the headunit DAC (which is old tech and not up to date with modern DAC). Amplifiers use analog signals, not digital. So I’m not really sure what you’re asking. Upgrading your headunit will likely make zero difference. It’s either your media player, aux cable, your aux port, or the amp.

Unfortunately, that's not the case, that's exactly the problem. Starting from the e70, bmw has implemented a scheme when the head unit sends a digital signal to the amplifier, which has a DAC and the conversion to analog takes place already in the amplifier, unlike, for example, bmw e65. Because of this, AUX goes to the head unit, where there is an ADC converter, which converts the analog into a digital signal, and the digital signal goes to the amplifier. It turns out a double conversion of sound, and I think that because of such an implementation, the sound loses quality. Before that, I also had a bmw e65 with top hifi, as now in the E70, and there my hi res player played much better, since there the signal through the AUX went directly to the amplifier.

[RL18]

Originally Posted by Well777

Unfortunately, that's not the case, that's exactly the problem. Starting from the e70, bmw has implemented a scheme when the head unit sends a digital signal to the amplifier, which has a DAC and the conversion to analog takes place already in the amplifier, unlike, for example, bmw e65. Because of this, AUX goes to the head unit, where there is an ADC converter, which converts the analog into a digital signal, and the digital signal goes to the amplifier. It turns out a double conversion of sound, and I think that because of such an implementation, the sound loses quality. Before that, I also had a bmw e65 with top hifi, as now in the E70, and there my hi res player played much better, since there the signal through the AUX went directly to the amplifier.

Well it doesn’t make sense for bmw to run BT, Usb, and Aux through the same wire (digitally via optical cable) to the amp. That’s stupid. I do see that the music from the headunit goes to the CD player then to the amp amp via the “most” cable but it was my impression that the aux bypasses the headunit and goes straight to the amp to feed it an analog signal… apparently not on the top hifi. Then both the hifi and “stereo” sound systems are analog going to amp for the aux and when using Bluetooth or usb. Very weird that bmw would change that on the top hifi. Really kind of ruins it.

With the factory headunit it would be the CD player that is receiving the signal from the headunit and outputting to the amp via the most cable right? So how would a nbt evo headunit change anything for you?

I have base audio with an aftermarket dsp and amps though so my setup is different.

[argento]

My understanding is the difference between BASIC, HIFI, and TOP HIFI is just the amp and component speakers used. The HIFI Amp (N40a) doesn’t show MOST connections in the wiring schematic (only KCAN), where the TOP HIFI Amp (A18) does show MOST connections.

In ISTA I see what's stated above that CCC/CHAMP (headunit) appears to send the audio signal via MOST through various systems (HUD, CD, SAT, Digital Tuner, BT, Telematics, Video Module, Rear Entertainment, and NAV) in series on its way to the A18 Amp.

For N38b CIC/CHAMP (headunit), it appears to send AUX-IN to the CIC then I assume on to the A18 Amp via MOST, which makes sense to me b/c the CIC/CHAMP allows gain adjustment of the AUX-IN…I assume the CCC/CHAMP allows the same. However, in CIC, I’ve not found diagrams showing the audio signal goes through multiple systems in series like CCC.

So, does the BASIC sound system have an Amp outside of CHAMP (headunit)?

[not trying to jack OP thread, just trying to understand the systems so we can better answer the issue]

[Well777]

As far as I remember, from what I read on the forums, in the basic version, the signal does not go to the amplifier through optics, which means it goes in analog form. But I can’t say for sure, I have never had a bmw without top hifi. The only thing I can say is that when I turn on my hi res player via aux in my friend's hyundai sedan car, the sound resolution is better, more details. Which just says that the sound is cut off in the head, because there is no such situation with CD playback. I have plans to replace CCC with NBT EVO and if there is a difference, then I will put full-fledged crossovers in the front doors and in the dashboard and replace the tweeter.

[RL18]

https://ia801005.us.archive.org/11/i...%20Systems.pdf

Check this out ^. Top hifi is the only system to send a digital signal through the “most” cable from the CD player. All the other systems are getting an analog signal from the headunit. Not sure why BMW would do it this way but they do a lot of silly things.

If you have top hifi, you can’t change the fact that it’s a digital signal. The amp itself gets the signal via the most cable. You have to recode and replace most likely everything that the most cable goes through because it’s two one way wires essentially going through everything. Upgrading to the nbt evo will not change this for you. The only reasonable option I can see for you if you want analog (better sound quality) is to get a dsp that has an “aux” input available, use that for your input signal (which would plug right into your media player), then power the speakers with an aftermarket amp or get a dsp/amp combo, then either splice into the existing speaker output wire or run new wire to each speaker location. By doing this your audio system would be completely seperate from the headunit.

An amp that comes to mind that offers this is a Musway dsp/amp and actually one that I’m looking at currently to get. 12 ch amp with 16 channels dsp, would be plenty to add whatever you want. They have other dsp amps available too.

[argento]

I don't have the same issue using AUX-IN, TOP HIFI, CIC, and active sound design, however I do have some upgrades, including new custom crossovers, B&W speakers, and the equipment I mentioned in the above post going from android monitor to AUX-IN.

To the OP with HIFI, one thing you can check are the diplexers in your front doors. I bought a used set to examine and if your diplexers are old enough the capacitors degrade and change the crossover points. The diplexers are only in the front doors if you have TOP HIFI (aka: Individual, S752A option; not S677A option). You can actually use (plug and play, just have to mount) the oem diplexers in the other locations if your happy with the oem crossover point, fwiw.