Alpine X701D-A4

[captain_video]

I'm curious (3 years later, just installing a x703d now) - why did you connect anything to the DAB on the stereo? I skipped all the DAB-related steps on the assumption that none of it functioned in North America. Curiously, the label for the antenna connection on the x703d says "sxm/dab" as if Sirius could be supported, but maybe that's something that they'd planned to do at some point and never finished.

Sirius/XM is not available in Europe so it is highly unlikely that they would provide support for that. There is no reason to connect anything related to DAB for the reasons you cited.

[afrancke]

@captain_video, do you know if it's possible to disable DAB as a source on the x703d user interface such that it stays hidden away/doesn't appear when scrolling through sources?

[captain_video]

@captain_video, do you know if it's possible to disable DAB as a source on the x703d user interface such that it stays hidden away/doesn't appear when scrolling through sources?

Not that I'm aware of. I have the older X701D-A4 and I am not aware of that being an option.

[captain_video]

I'm trying to determine if I can tap into the wiring harness at the amplifier to feed an external crossover for aftermarket 2-way component speakers for the front doors in a 2014 A4 with the Concert system. I have the X701D-A4 and I never got around to installing external amps using the RCA output adapter from the head unit. I still plan to do that at some point as my budget allows so hopefully this is just a temporary setup. I believe the Alpine has internal 4-ch amps but I'm not sure how they're connected to the factory wiring via the harnesses supplied with the unit. Are they powering any of the speakers directly and bypassing the factory amp? I have never been able to locate any info about the internal amp configuration in this unit. I need to know where I can tap into the speaker wires to insert the crossovers. According to the wiring diagram for the Alpine it appears that the speaker outputs are connected to the Quad connector that interfaces with the factory wiring. I just don't know how the internal amps in the Alpine are wired to the car's speakers such that they bypass the factory amp.

I have the KWE-BO1AU adapter installed in the signal path so I'm wondering if that is attenuating the signal such that it acts as a line level adapter to drop the output to a line level input at the amp and then the speakers are fed from the factory amp. If I remove the adapter and tap into the connector from the Alpine will that be able to drive the speakers from the internal amps?

[Smac770]

Concert always has an external amp in the US, where all the cars are standard or B&O, no basic or basic plus. If the Alpine was just a direct swap with the Concert head unit, then the Alpine is sending low level signals over 4 pairs to the amp in the back, which is processing that into the 6 channel amplified output. I suspect the Concert head unit is always running it's output through the 4-ch amp in it, just a matter of the coding switch between higher voltage (to speakers) or lower voltage (to feed the J525). The Alpine could be emulating the same configuration, as it has to produce output that the J525 amp is expecting.

Not sure the wiring question. The J525 produces six output wire pairs. One to each "corner", one to the dash center, one to the subwoofer (assuming standard sound system; "Concert" refers to the front end infotainment system, it says nothing about the back end sound system). So those speaker output wires at the J525 (left rear) is what you'd want to work from. Unless you're wanting to ax the entire factory 6-ch speaker config and start from the wires from the Concert to the J525. But those are not speaker ready amplified signals. You'll need to run those into something to do the crossovers and eq and time delay and all that.

[Smac770]

So we see the connection on the power cable harness 18 with the quad-lock connection to the car harness, same as how the Concert was connected. The 4 wire pairs to the J525 are here. Disconnect the 32-pin on the J525 and you'll stop hearing the audio.

But we also see there's an optional pre-out cable harness 3, producing 6 RCA jacks you can just run to normal aftermarket electronics. So rather than have to mess with the Concert to J525 wire pairs, you can just use normal RCAs on the Alpine. But, the factory wiring is already there in the left rear to work with as well.

[Smac770]

Ok, so that's what's going on: https://www.alpine.co.uk/p/Products/...View/KWE-BO1AU

I presume the Alpine does not have a configuration setting like the Concert for high voltage vs low voltage output on the four "speaker output wire pairs". Thus you have to add that thing or smoke your J525, which any US B8 with Concert is going to have (ie, standard 9VD or B&O 9VK; we don't get basic 8RE or basic plus 8RX)

The Alpine would appear to be producing 4x50w (peak), which gets dropped down to J525 input levels by the in-line device (I assume it inserts at the "ISO loud speakers" junction in the diagram), and then run down the factory wiring to the J525. The J525 is producing 3x40w (rms?) and 3x20w (rms?), so you're probably getting better power with the J525, unless you plan on running to aftermarket amplification.

Lots of options, just have to decide what's actually getting wired up to what.

[captain_video]

Lots of options, just have to decide what's actually getting wired up to what.

I have everything connected with the KWE-BO1AU. It sounds like it's attenuating the speaker level output from the Alpine internal amps which is then fed into the factory amp and then to the speakers. I am assuming that if I remove the KWE-BO1-AU between the Alpine and the quadlock connector I can use the output of the Alpine harness connector that mates with the 8-pin tan connector to power the speakers directly. I am assuming the each of the four amp channels are powering the left and right front pairs as well as the left and right rear pairs. I'm not as concerned about the rear speakers as much as the front 2-way component speakers I want to install. I suppose I could just remove the KWE-BO1AU attenuator and connect the two front tweeters and door mid-bass woofers directly to the Alpine and use the internal crossovers to configure the 2-way component speakers.

Would you happen to know the part number of the 8-pin tan connector that's part of the factory QuadLock connector? It would be nice if I could just wire everything into a replacement connector and not disturb the factory wiring.

It just occurred to me that if I use the four powered channel outputs from the Alpine directly and bypass the factory amp I will lose the subwoofer output. Gotta think about this some more.

[Smac770]

I'll make some pictures. But offhand, if you're replacing the factory front woofer/tweeter pairs with new front woofer/tweeter pairs, why are you needing to do anything with the electronics?

[captain_video]

I'll make some pictures. But offhand, if you're replacing the factory front woofer/tweeter pairs with new front woofer/tweeter pairs, why are you needing to do anything with the electronics?

More electronics in the signal path = more noise and distortion. I don't like the fact that the Alpine is using internal amps to power speakers and then the output is converted to a low level input only to be amplified again using the factory amp. I hate using line converters for this very reason. That design makes absolutely no sense to me, but I understand why it appeals to anyone wanting an easy upgrade to a factory stereo. Alpine should have provided separate speaker outputs for the four amplified channels along with a dongle for the preamp outputs that would have the 8-pin connector to mate with the QuadLock connector as well as a set of RCA outputs so you could use an external amp. There was absolutely no point in including an internal amp the way it's designed if all you're going to do is send the signal to the factory amp. The internal amp is completely unnecessary in this setup. I can only assume it's designed this way to be used with the upgrade kits for the dash speakers and the door speakers. There is no mention of having to install the KWE-BO1AU attenuator in the manual or the Alpine website if all you're doing is replacing the head unit.

My current plan was to use the internal amp and crossover in the head unit so I can use the four amplified channels for the left and right front woofer/tweeter pairs. I will probably end up using an external amp so I can use an actual crossover instead of the Mickey Mouse high pass filter setup using the 10 uF capacitor. I already have the RCA preamp output adapter for the head unit so that would be the easiest solution. I'll have to settle for a lower quality amp for now since I can't afford the amp I really want.

[Smac770]

You're forgetting about 8RX which is common in Europe, but was never offered in the US. That's the scenario where there's no separate J525, and where you don't use the KWE-BO1AU. As the Alpine website points out, for 9VD or 9VK, you have to add in the KWE-BO1AU.

The reason I ask is "are you adding third-party amplification for these aftermarket speakers" or not? If not, then the electronics should be left as is and you should make use of the amp channels from the J525 as is. If you are, then plug in the RCA output jacks to the Alpine and run those.

If this is a matched component set (woofer, tweeter, and matched passive 2-way crossover unit), then you only want the one amp channel anyway.

[captain_video]

I have no idea what 8RX is. I don't recall seeing the need for the KWE-BO1AU on the Alpine website, but it's been quite some time since I looked up any info on the X701D-A4 so chances are I had read about it there at some point. I think I learned about the need to use KWE-BO1AU somewhere in this forum. I bought the unit used on ebay and it included everything including the KWE-BO1AU and the backup camera kit so I didn't have to purchase anything extra.

I do plan to use an aftermarket amp using the preamp outputs from the Alpine. I just picked up a 4-channel Rockford Fosgate amp that has RCA pass-through outputs so I can connect a separate subwoofer amp. I have an older Zapco monoblock amp that I used for that in my previous car so I will use that along with my 12" IDMax subwoofer and custom enclosure I bought on ebay. I'm curious to know if the internal amps in the Alpine are still outputting a signal if the preamp outputs are used. I assume they are so I can still power the rear speakers using the factory amp and use the Rockford Fosgate amp for the left and right 2-way components using the crossovers in the RF amp. I know that the low frequencies are rolled off for the front speakers and they're fed mostly to the rear door woofers and subwoofer in the factory setup. I wonder if the Alpine has any effect on that or if it sends the full range signal to all four preamp outputs. I had assumed that the factory amp rolled off the front speaker low frequencies so bypassing that should give me better bass in the front.

[Smac770]

Audi Concert to Alpine 8RX from PDF.png

This is the basic sound system config with the Concert and Symphony head units (the Chorus is similar, but has only a 2x 20w amp and is only paired with the 8RE sound system without the rear speakers). This is what the Alpine directly slots into, with the Alpine 4-ch internal amp driving the same speaker configuration as the Concert 4-ch internal amp.

Audi Concert to Alpine 9VD from PDF.png

This is the standard sound system config with the radio head units (not supported with Chorus). In this config, the radio units are coded to low output power, probably just skips the voltage gain stage. But regardless of how it was implemented, you still get four "speaker" outputs. I assume the fade and balance is still processed by the Concert, and would be seen in the different voltage levels of the four outputs. The processing of the center and sub signals from these, and the removal of the sub bass from the four main inputs, would be done at the J525.

For the Alpine, it could have directly slotted in for the Concert, but it appears the Alpine has no switch to drop the output voltage for the amplified outputs. Which isn't surprising, that would be a very abnormal scenario for an aftermarket radio unit. If one wanted to use low level signals, one would just use RCAs. But this is integration into a factory configuration. Though I have to wonder, what if one ran the RCA outputs to the J525 input pins. It's all just "voltage". Still, for whatever reason, the Alpine solution is to run a resistor block on the speaker outputs before it joins the factory harness on way to the J525 inputs.


Beyond that, I can't really say since I'm not sure exactly what it is you're trying to remove and trying to add. The tweeters in the factory config have a cap for some basic bass blocking, but that's it. If you're replacing the factory 2-way speaker pair with an aftermarket set, I assume you'd source or implement some quality 2-way crossover config matching the two drivers well. But none of that requires doing anything with the electronics. The Alpine amp channels are 50w peak into 4Ω 9(iirc); the standard sound system is 40w rms to the fronts, which I believe is a 2Ω woofer and 8Ω tweeter. I'd probably stick to the J525 amp channel, until you're ready to add aftermarket amps.

At which point, the Alpine probably runs the RCAs and speaker outputs at the same time. So run the RCAs to a 2-ch amp to drive the front pairs and leave the speaker config as is to run the rears, sub, and center. Then just disconnect the front speaker wires from the J525.

[Smac770]

As for the 8-pin brown, appears it is 3B7035447 : https://www.ecstuning.com/b-genuine-...tor/3b7035447/

[Smac770]

I have no idea what 8RX is. I don't recall seeing the need for the KWE-BO1AU on the Alpine website, but it's been quite some time since I looked up any info on the X701D-A4 so chances are I had read about it there at some point. I think I learned about the need to use KWE-BO1AU somewhere in this forum. I bought the unit used on ebay and it included everything including the KWE-BO1AU and the backup camera kit so I didn't have to purchase anything extra.

I do plan to use an aftermarket amp using the preamp outputs from the Alpine. I just picked up a 4-channel Rockford Fosgate amp that has RCA pass-through outputs so I can connect a separate subwoofer amp. I have an older Zapco monoblock amp that I used for that in my previous car so I will use that along with my 12" IDMax subwoofer and custom enclosure I bought on ebay. I'm curious to know if the internal amps in the Alpine are still outputting a signal if the preamp outputs are used. I assume they are so I can still power the rear speakers using the factory amp and use the Rockford Fosgate amp for the left and right 2-way components using the crossovers in the RF amp. I know that the low frequencies are rolled off for the front speakers and they're fed mostly to the rear door woofers and subwoofer in the factory setup. I wonder if the Alpine has any effect on that or if it sends the full range signal to all four preamp outputs. I had assumed that the factory amp rolled off the front speaker low frequencies so bypassing that should give me better bass in the front.

I was already making the diagrams post when you posted this.

The Alpine unit is likely just like any normal aftermarket receiver unit. I don't see why the amp out and pre out wouldn't be active at the same time.

The Alpine likely emulates the Concert in that there's no crossovers on the output signal. There could well be some kind of subsonic filter, but I doubt Audi bothered. The RF amp might have a subsonic along with the 2-way.

I would have expected the J525 to 2-way all four inputs, summing the low pass from all four to create the sub signal. Sending sub range to the rear doors makes no sense. Probably why people are always posting about blown rear door woofers.

You might have to wonder whether to leave the dash center in play as well. It's unlikely to be timbre matched to the new fronts, unless you're changing it as well. If eliminating that, you might also consider letting the Alpine amp outs run the rears, throwing in a passive bass blocker to remove the sub range. Then you could remove the J525 altogether.

[captain_video]

Thanks for the info and the diagrams. I was already aware of the amplifier configuration for each system in the Audi. Info on the Alpine was a bit sketchy regarding the internal amps so that's what I've been trying to clarify so I greatly appreciate your input on that. I always dedicate a single amplifier channel to each driver I install when upgrading a car sound system using external crossovers, whether the passive units that come with the speakers (but only if it can be configured for bi-amplification) or the internal configurable crossovers in either the amp or the head unit. That will guarantee you the best possible sound from your system. The 4-channel amp that I will be installing will drive the two tweeters and woofers in the front doors. I picked up a pair of used blank upper panels for the door pillars on ebay and already mounted my tweeters there. I'll disconnect the ones in the dash when I get everything else set up. I'll configure the crossover in the amp for the 2-way component speakers in the front doors and just run the rear door speakers off the factory amp for the time being.

I have a separate monoblock amp to drive my aftermarket subwoofer. The 4-channel amp has a pair of RCA passthrough outputs that will feed the sub amp. I'll see how it sounds with the center dash speaker in or out of the setup to see which sounds best. I will probably end up disconnecting it altogether. I may also end up disconnecting the factory amp and just run the front 2-way components and the sub using my own amps. I have some sound deadening material that I want to install in the front doors plus I have to run the speaker wires through the kick panels from the trunk and into the front doors. I already have my power distribution panel installed in the left rear of the trunk so I just need to finish wiring it up to the installed components and connect the positive lead to the battery. I use a relay to send the 12V turn-on signal to a small distribution block and then to each of the amps. That wire still has to be run from the head unit to the relay. The panel is mounted over top of the factory amp and will be hidden behind the upholstered panel when I reinstall it. I still have to decide how I want to mount the amps, but I will most likely install a panel under the rear shelf and mount the amps there. I hate losing the utility of my trunk just to install amps so I like to mount them out of the way as best I can.

I just have to find the time to get everything installed and configured. My wife has me tasked with other things so it's not as high on her priority list as it is on mine.

[Smac770]

She permits you to have a priority list?

Brings back memories of my large board in the back of the Probe with all the 4ga and the big 1F.

[captain_video]

She permits you to have a priority list?

Brings back memories of my large board in the back of the Probe with all the 4ga and the big 1F.

LOL, not really. I just have to do things for myself when she's not paying attention. If I do things she wants me to do then she might cut me some slack.