[PLUR]

So, here we go. The $64,000 question: can the rear 4-inch drivers be replaced and swapped out for Infinity reference 4022?

Yes they can.....

Could you provide the difference in sound with your replacement of the two speakers at the doors? I'm not sure if this upgrade is more for the passengers in back to enjoy or can you tell a noticeable difference from driver seating position? Thanks

 

[Dfwatt]

Could you provide the difference in sound with your replacement of the two speakers at the doors? I'm not sure if this upgrade is more for the passengers in back to enjoy or can you tell a noticeable difference from driver seating position? Thanks

For sure most of the difference which I experienced as better treble output and much more clarity on vocal material and an overall slightly brighter sound is coming from the three front drivers that are swapped out for the Infinity reference 4022. The back two drivers swapped out also seem to contribute to a somewhat brighter spectral balance. For that reason I am not going to replace the two on the package shelf because think I'm already tilting a bit towards the treble which of course can be adjusted with tone controls to taste but still I don't want a super bright sounding system.

The best bang-for-the-buck for sure in terms of any modification of the system is swapping out the 3 4 inch drivers in the dash. Most of your sound is actually coming from those, especially for the driver and any front seat passenger.

If you spend a boatload of money on putting in a high powered subwoofer to increase your low end and you do nothing with the front dash speakers - unless you're really a bass junkie and you like having your internal organs vibrate in harmony with the music - I think you've potentially misallocated your funds. The three front drivers cost a whopping 75 bucks. It has to be the best 75 bucks from a stereo standpoint I've ever spent and I've spent a lot of money on stereo gear. Too much in fact. Hope that's helpful.

 

[Johnston]

For sure most of the difference which I experienced as better treble output and much more clarity on vocal material and an overall slightly brighter sound is coming from the three front drivers that are swapped out for the Infinity reference 4022. The back two drivers swapped out also seem to contribute to a somewhat brighter spectral balance. For that reason I am not going to replace the two on the package shelf because think I'm already tilting a bit towards the treble which of course can be adjusted with tone controls to taste but still I don't want a super bright sounding system.

The best bang-for-the-buck for sure in terms of any modification of the system is swapping out the 3/4 inch drivers in the dash. Most of your sound is actually coming from those, especially for the driver and any front seat passenger.

If you spend a boatload of money on putting in a high powered subwoofer to increase your low end and you do nothing with the front dash speakers - unless you're really a bass junkie and you like having your internal organs vibrate in harmony with the music - I think you've potentially misallocated your funds. The three front drivers cost a whopping 75 bucks. It has to be the best 75 bucks from a stereo standpoint I've ever spent and I spent a lot of money on stereo gear. Too much in fact. Hope that's helpful.

Any comment on sound quality improvement through the tweeters and woofers in the door? The traditionally located speakers I mean. Are you saying the front 3 in the dash will have much more impact than the tweeters and woofers in the doors?

 

[Dfwatt]

Any comment on sound quality improvement through the tweeters and woofers in the door? The traditionally located speakers I mean. Are you saying the front 3 in the dash will have much more impact than the tweeters and woofers in the doors?

Yes at least as long as you're sitting in the front. If you're sitting in the rear the output from the door speakers becomes significant obviously for rear passengers and more significant depending of course on how you set your front aft balance control. For folks who like a bit more omnidirectional sound and who move the balance control back a bit, then those rear door speakers contribute more significantly to perceived spectral balance and the sound field.

 

[Johnston]

Yes at least as long as you're sitting in the front. If you're sitting in the rear the output from the door speakers becomes significant obviously for rear passengers and more significant depending of course on how you set your front aft balance control. For folks who like a bit more omnidirectional sound and who move the balance control back a bit, then those rear door speakers contribute more significantly to perceived spectral balance and the sound field.

I'm actually strictly speaking the door speakers for the front. In my previous vehicles I actually either fade audio to front or disconnect the rear speakers entirely. I ran a x channel amp for the front component speakers plus a mono amp for sub in trunk. This was a system w/o any speakers in the dash. I prefer a well defined front stage (vocals coming from straight ahead instead of 'around') vs the immersion.

 

[Dfwatt]

I'm actually strictly speaking the door speakers for the front. In my previous vehicles I actually either fade audio to front or disconnect the rear speakers entirely. I ran a x channel amp for the front component speakers plus a mono amp for sub in trunk. This was a system w/o any speakers in the dash. I prefer a well defined front stage (vocals coming from straight ahead instead of 'around') vs the immersion.

sorry I misunderstood your question. The front door woofers have no output above 200 cycles. In that sense they provide a foundation and definition of bass for the front passengers who are a good distance away from the subwoofer. Even though bass below about 60 to 80 Cycles is generally perceived as non-directional if they had no bass drivers in the front compartment you'd have an imbalanced sound field. But the front door 8-inch drivers only provide low end. They don't even have really any contribution to low mid-range or at least minimally. In other words the bottom part of the male vocal range appears only minimally in those drivers. Almost all the mid-range is coming from the 4-inch drivers, and as the cliche goes "mid-range is where the music is". Although the low end and high frequencies contribute significantly to the perception of music as realistic and as accurate - obviously - it's the mid-range drivers that are doing the bulk of the real heavy lifting in relationship to musical reproduction. If you would adjust your fader balance towards the front you'll have a pretty well-defined sound field in front

 

[Dfwatt]

sorry I misunderstood your question. The front door woofers have no output above 200 cycles. In that sense they provide a foundation and definition of bass for the front passengers who are a good distance away from the subwoofer. Even though bass below about 60 to 80 Cycles is generally perceived as non-directional if they had no bass drivers in the front compartment you'd have an imbalanced sound field. But the front door 8-inch drivers only provide low end. They don't even have really any contribution to low mid-range or at least minimally. In other words the bottom part of the male vocal range appears only minimally in those drivers. Almost all the mid-range is coming from the 4-inch drivers, and as the cliche goes "mid-range is where the music is". Although the low end and high frequencies contribute significantly to the perception of music as realistic and as accurate - obviously - it's the mid-range drivers that are doing the bulk of the real heavy lifting in relationship to musical reproduction. If you would adjust your fader balance towards the front you'll have a pretty well-defined sound field in front

and I forgot to add that even in their stock configuration the 7 4-inch drivers put out significant treble, probably more than the door pillar tweeters do and the immersion speakers in the front A pillars. I suspect they start rolling off somewhere around 8 K but in any case a lot of the vocal range is there including for the female voice. I think the immersion speakers and the door tweeters really provide not a whole lot. I don't know what their contribution is to over all loudness at high frequencies but I bet it's pretty modest compared to the 4-inch drivers.

 

[JazminSidley]

Hey, I have some news. It's not as conclusive as I would like, but it's still good news. I started getting the "Cannot Maintain Vehicle Power" errors again, and the penthouse 12V tripped again. I still haven't figured out what causes the trip, but I have found a catch-all solution.

I did some experiments to try to determine exactly what's causing the trip, and I haven't found an answer. My car has given me the CMVP error at least a dozen times now. It always appears first thing in the morning after my car has been sitting overnight with the stereo installed. I know I can pull 5-6A out of the penthouse 12V (P12V) while the car is running, no problems at all. And every time I've measured the current on my stereo while the car/stereo are shutdown, it's pulling 2-3mA. That's for three amplifiers and two DSPs. So I disconnected my stereo, connected some resistors to the P12V, and left those sitting overnight. I tested 3mA, 5mA, and 10mA. It never tripped. So as I said before, I'm guessing some electronics are pulling larger bursts of current intermittently. I honestly don't know. But, I have found a solution.

I installed a solid state relay in between the P12V and my stereo. It's controlled by the VC_LEFT trailer turn-on signal (the empty pin identified by Ingineer). So when the car is shutdown, my stereo is effectively isolated from the P12V. The relay allows <<1mA through while shutdown. I've had it installed this way for about a week now with no more problems. I was worried that the startup current might cause problems when I completely isolate the system like this, but that hasn't been the case. The relay I recommend is this one from Crydon. It costs $68 and it's designed for high reliability, industrial use. You could use a traditional mechanical relay for $5, but you'll need to be very careful selecting the right one. Those can pull significant current, produce significant heat, and might or might not be susceptible to vibration.

I am fairly confident that I have identified the cause of the "Cannot Maintain Vehicle Power" error. The cause is the DC-DC converter tripping when first powering on and trying to charge up the large input capacitors present inside the sub-woofer amplifiers. The large capacitance causes a high current spike on the converter , preventing it from powering on. Since the dc-dc converter turns on a few times over night to keep the 12v battery maintained, if it is unable to start up, the 12v battery discharges, giving the "Cannot Maintain Vehicle Power" error. I was able to trigger this error much more often by using an aftermarket 1F capacitor in parallel with my amplifier, giving weight to the argument that the capacitance is the cause of the error. Using a cheap amplifier with a small input capacitor will probably avoid tripping the dc-dc converter, but any high-quality amplifiers, or stiffening capacitors will likely cause a lot of problems.

I would like to provide a word of caution on the use of a solid state relay to isolate the amplifiers from the 12 supply. When the SSR turns on, it must handle the huge inrush current of charging the amplifiers input filtering capacitors. This momentary input current may be very far in excess of the rated pulse current of the SSR. The inrush current will be higher if multiple amplifiers are used. This repeated high-current pulse may shorten the life of the SSR. Using a conventional 30A automotive mechanical relay would be much worse, as the contacts would burn out quickly under those conditions. An external starter solenoid would be more likely to be up to the task.

I hope someone finds this information useful.

 

[Feathermerchant]

I wonder if the solid state relay has a soft start that would mitigate the inrush somewhat.

 

[_Travis_]

I am fairly confident that I have identified the cause of the "Cannot Maintain Vehicle Power" error. The cause is the DC-DC converter tripping when first powering on and trying to charge up the large input capacitors present inside the sub-woofer amplifiers. The large capacitance causes a high current spike on the converter , preventing it from powering on. Since the dc-dc converter turns on a few times over night to keep the 12v battery maintained, if it is unable to start up, the 12v battery discharges, giving the "Cannot Maintain Vehicle Power" error. I was able to trigger this error much more often by using an aftermarket 1F capacitor in parallel with my amplifier, giving weight to the argument that the capacitance is the cause of the error. Using a cheap amplifier with a small input capacitor will probably avoid tripping the dc-dc converter, but any high-quality amplifiers, or stiffening capacitors will likely cause a lot of problems.

I would like to provide a word of caution on the use of a solid state relay to isolate the amplifiers from the 12 supply. When the SSR turns on, it must handle the huge inrush current of charging the amplifiers input filtering capacitors. This momentary input current may be very far in excess of the rated pulse current of the SSR. The inrush current will be higher if multiple amplifiers are used. This repeated high-current pulse may shorten the life of the SSR. Using a conventional 30A automotive mechanical relay would be much worse, as the contacts would burn out quickly under those conditions. An external starter solenoid would be more likely to be up to the task.

I hope someone finds this information useful.

So the HV battery's DC-DC converter actually turns off when the car goes into some deeper mode of sleep? That would explain everything. I thought it stayed on 24/7 unless faulted.

I don't want to use an inrush limiter in series because a limiter rated for 20+ amps is going to produce a lot of heat and I don't want to deal with that. What about a current limiter in parallel with the relay? A resistor rated for a few watts, or an inductor, or an inrush limiter (since it's parallel and only used for periodic charging)?

 

[Feathermerchant]

You could use two relays. One with a limiter then one on a time delay with no limiter. The limiter relay closes first to charge the capacitors then the other relay a second or so later to bypass the limiter.

 

[JWardell]

I am fairly confident that I have identified the cause of the "Cannot Maintain Vehicle Power" error. The cause is the DC-DC converter tripping when first powering on and trying to charge up the large input capacitors present inside the sub-woofer amplifiers. The large capacitance causes a high current spike on the converter , preventing it from powering on. Since the dc-dc converter turns on a few times over night to keep the 12v battery maintained, if it is unable to start up, the 12v battery discharges, giving the "Cannot Maintain Vehicle Power" error. I was able to trigger this error much more often by using an aftermarket 1F capacitor in parallel with my amplifier, giving weight to the argument that the capacitance is the cause of the error. Using a cheap amplifier with a small input capacitor will probably avoid tripping the dc-dc converter, but any high-quality amplifiers, or stiffening capacitors will likely cause a lot of problems.

I would like to provide a word of caution on the use of a solid state relay to isolate the amplifiers from the 12 supply. When the SSR turns on, it must handle the huge inrush current of charging the amplifiers input filtering capacitors. This momentary input current may be very far in excess of the rated pulse current of the SSR. The inrush current will be higher if multiple amplifiers are used. This repeated high-current pulse may shorten the life of the SSR. Using a conventional 30A automotive mechanical relay would be much worse, as the contacts would burn out quickly under those conditions. An external starter solenoid would be more likely to be up to the task.

I hope someone finds this information useful.

I would agree with your conclusions.
I think a precharge circuit is what you need then, as we previously discussed.
It would be helpful to know what your inrush and max operational currents are, but we can maybe ballpark. Say your inrush is 50A for a half second (of course it's really a curve).
Connect the amp through a large resistor. Using a 5 ohm resistor will limit to 2.8A @14v which is perfectly reasonable. You would need a 40+W resistor for continuous use but it should only be on for a half second so probably fine with a 10W.
Or use a 10ohm for half the current/power.
5 ohm 20W resistor
10R 20W
5R 50W
Then use a delayed turn on relay..a half second should be plenty...to make the hard connection to the amp. I would guess a 30Amp.

...OK I spent 15 minutes searching for a 0.5 to 1 second delay start relay that would work and couldn't find one...so that means you need to use a normal relay and delay the signal with a circuit or controller.

So the HV battery's DC-DC converter actually turns off when the car goes into some deeper mode of sleep? That would explain everything. I thought it stayed on 24/7 unless faulted.

I don't want to use an inrush limiter in series because a limiter rated for 20+ amps is going to produce a lot of heat and I don't want to deal with that. What about a current limiter in parallel with the relay? A resistor rated for a few watts, or an inductor, or an inrush limiter (since it's parallel and only used for periodic charging)?

You could use an NTC to slow the inrush, but you will have to spend a bit of time sizing it. You should NOT have to worry about the heat...heating up is how they function, adding a heatsink to an NTC will defeat its purpose. I'm not so sure it will work well enough unless there is a huge difference between your inrush and your peak operational currents. A precharge circuit is preferable.

 

[oripaamoni]

I would agree with your conclusions.
I think a precharge circuit is what you need then, as we previously discussed.
It would be helpful to know what your inrush and max operational currents are, but we can maybe ballpark. Say your inrush is 50A for a half second (of course it's really a curve).
Connect the amp through a large resistor. Using a 5 ohm resistor will limit to 2.8A @14v which is perfectly reasonable. You would need a 40+W resistor for continuous use but it should only be on for a half second so probably fine with a 10W.
Or use a 10ohm for half the current/power.
5 ohm 20W resistor
10R 20W
5R 50W
Then use a delayed turn on relay..a half second should be plenty...to make the hard connection to the amp. I would guess a 30Amp.

...OK I spent 15 minutes searching for a 0.5 to 1 second delay start relay that would work and couldn't find one...so that means you need to use a normal relay and delay the signal with a circuit or controller.

You could use an NTC to slow the inrush, but you will have to spend a bit of time sizing it. You should NOT have to worry about the heat...heating up is how they function, adding a heatsink to an NTC will defeat its purpose. I'm not so sure it will work well enough unless there is a huge difference between your inrush and your peak operational currents. A precharge circuit is preferable.

Check out these programable time delay boards, I used a TRM-2 on one of my old audi projects. https://www.curioustech.net/timers.html

 

[Feathermerchant]

The digital delay solution is complex and unnecessary. An RC (resister, capacitor) circuit is all you need to delay the turn on.

 

[_Travis_]

The digital delay solution is complex and unnecessary. An RC (resister, capacitor) circuit is all you need to delay the turn on.

I'm considering that. Not only does it provide a turn-on delay, but it also provides a turn-off delay, which is something I need. If you cut main power and turn-on signal to the amps at the same time, you sometimes get a loud pop out of the speakers, which isn't good for anyone. So I'm going to try a resistor in parallel with the relay and a 5-second RC circuit for turn-on signal delay.

 

[JazminSidley]

I spent a few hours designing and modeling the attached circuit. I believe it will meet our requirements.
It provides the functionality of both the pre-charge resistor and the paralleling relay mentioned above. Additionally, it provides a 2 second delay before pre-charging to allow the vehicles DC-DC converter to come online , stabilize and connect to the 12v battery. It also limits pre-charging current to around 14 amps.
I have the parts on order and should be able to have it built and tested within a few days.

** EDIT **: I have posted instructions for an easier to build at home circuit that accomplishes the same goals. See this post below ( HERE )

Circuit Diagram Link

 

[Feathermerchant]

Is that 30A MOSFET supposed to power the amplifier?

 

[JazminSidley]

Yes it is. It could be up-spec'ed if a large amplifier was being used, or 2 ran in parallel. The listed one has a 30A cont/ 100A intermittent rating, that should be sufficient for most amplifiers. Almost any P-channel mosfet with a low RDS on could be used with this circuit.

 

[JazminSidley]

I have identified the cause of the "Cannot Maintain Vehicle Power" error when installing aftermarket amplifiers and drawing power from the CD-CD terminal under the rear seat. The cause is the DC-DC converter tripping when first powering on and trying to charge up the large input capacitors present inside the amplifiers. The large capacitance causes a high current spike on the converter, immediately tripping a current fault= and preventing it from powering on. Since the dc-dc converter turns on a few times over night to keep the 12v battery maintained, if it is unable to start up, the 12v battery discharges, giving the "Cannot Maintain Vehicle Power" error. I was able to trigger this error much more often by using an aftermarket 1 farad capacitor in parallel with my amplifier, vs without the capacitor, giving weight to the argument that the capacitance is the cause of the error. Using a cheap amplifier with a small input capacitor will probably avoid tripping the dc-dc converter, but any high-quality amplifiers, or stiffening capacitors will likely cause a lot of problems.

The solution to this is to use the attached simple circuit when drawing power from the DC-DC converter. The circuit works by limiting the inrush current to 12 amps when the DC-DC converter comes online by placing a 1 ohm resistor inline with the amplifier. However, this resistor would quickly overheat when the amplifier was in use, so a bypass relay is powered from the accessory 12V line coming from VC-Left. The car turns on the acc signal about 3 seconds after powering up the DC-DC converter, giving the amplifiers plenty of time to charge the input capacitors.

The only items needed are a 12v 30A automotive relay (amazon-link), and an approximately 1 ohm ignition resistor (amazon-link). If you are running a very high powered amplifier(s) , you may want to use 2 x 30A relays in parallel to avoid damaging a single relay.

I have am currently using this circuit in my Model 3, with a 800w Kenwood amplifier and a 1 farad stiffening capacitor. I have verified that it does allow the DC-DC converter to power-up without any error messages.

(Image-Link)

 

[Stach]

I know that the SR+ is missing the amp and sub, but are the necessary wires (Power, Left, etc...) back at the location of the Tesla sub? If so, what are all of the wires that can connected to back there?