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Another subwoofer option - NVX Audio

The RD500/1 is great and a huge upgrade to the VMD1 amp. On paper, there's only 180W delta (2ohm) between the two but the sound is way cleaner at loud volumes (I initially bought the kit from NVX then opted to replace the amp with the RD500/1). My main goal was to maximize the bass but not sacrificing any trunk space - wanted it to be as stealth as possible. Tbh, if you don't care about your system being incognito/stealth, i'd save the bones and reuse your already existing HD1200/1 (great amp btw - had it in my land cruiser). You can wire it at 4ohm, port the box, and be bumping 2-3x more bass than mine, but then again, i dont know what your objectives are, just adding my 2 cents.
Thanks for the info. I had my finger on the order button to get the Audiocontrol LC 1 800 amp but just hesitant about the power draw. The AudioControl is supposed to be really efficient and has an LC2i built in so no need for a separate line level amp, an all in one amp. The unfortunate thing is the that while I love the HD1200/1 it is a little inefficient and will pull a lot of power, plus I will need to find a remote start for it because it needs more than a line level amp will provide. Also just being conservative to keep the power draw low as not to throw error codes. The Tesla audio system is relatively low power so you don’t need much bass volume before you overwhelm the other speakers.
 
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Max223

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Aug 23, 2021
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Hi, is anyone able to tell me which size of Posi-taps to buy for this install and how many? Thanks in advance.
I ordered these ones but they didn’t arrive until afterwards. I just ended up splicing the wires. Posi-tap Connectors, 16-18 Gauge Wire, Bulk Pack of 20 https://www.amazon.com/dp/B004D0C18...abc_91F7QN03TGQDE2W69Y06?_encoding=UTF8&psc=1

I think you’ll only need 5-6, one for each of the four speaker wires, power, and possibly ground.
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Thanks for the reply guys. I ended up buying 6 blue and a 6 mixed pack based on the ground and power being 8 gauge and blue saying 16-18 ga. I’d rather have extra than not enough since I can’t buy them locally where I am, so I’d be leaving the job partly done if I have issues. I was planning on using the wire that comes included in the kit. I have an LR so I think it should be enough. It’ll be a few weeks before I can install though so I won’t know until then.
 
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Thanks for the reply guys. I ended up buying 6 blue and a 6 mixed pack based on the ground and power being 8 gauge and blue saying 16-18 ga. I’d rather have extra than not enough since I can’t buy them locally where I am, so I’d be leaving the job partly done if I have issues. I was planning on using the wire that comes included in the kit. I have an LR so I think it should be enough. It’ll be a few weeks before I can install though so I won’t know until then.
Did you get it installed? Thoughts on the process and result?
 
Part of that was my fault. It isn't a "complete" kit in that if you watch the video, you will see them mention a mounting bracket for the XLCA2 (LOC unit) that goes near the factory amp area. That is something they just fabricated for that install. It is light enough as another user mentioned it can just "float" next to the power amp or add velcro to mount it in the well and out of the way. The VADM1 amplifier will get mounted further up if you mount the same place as the video and there is room in the void below it that you can feel comfortable installing with the self-tapping screws.

It seems they have issues from time-to-time shipping with incomplete boxes though. My amp didn't come with the cables and an Amazon review of the VADM1, a customer was missing the terminal block you screw your speakers into, so take account of what you receive. From what I can gather:

VADM1 should (probably) come with:
1. 4 pin terminal block (mine was already inserted) for screwing in the speaker leads
2. 3.5 mm to RJ11 connector for the remote bass control (mine was absent)
3. Remote bass control (without LED). Mine came with it, but missing the cable and the XLCA2 came with it so I could adjust the bass if I wanted with this.
4. 4 pin white connector to RCA (required to connect to XLCA2) (mine was absent and they had to ship it)
5. Allen wrench to adjust power terminals
6. Mounting screws

XLCA2 should (probably) come with:
1. RJ11 to RJ11 cable for bass control
2. Remote bass control with LED
3. Mounting bracket attachments
4. Mounting screws
5. (2) wiring terminal blocks

The wiring kit includes the expected materials so you can see if you have them. I used the remote wire sense, the speaker cable, the power cable, ground cable, fuse, and RCA plugs from it. The power and ground cable already come with one end having a connector.

IMPORTANT:
Before going to work on the system, find the link to mountain pass performance reset routine and unplug the negative battery terminal and open the contact connector under the seat. Another user pointed out a good idea in removing the fuse in the fuse block before connecting everything and then installing that last. Be sure you have a full 12V battery and/or leave your frunk open.

You don't need to use positaps or t-taps if you get a stripper that spreads the insulation. They sell one at ACE hardware for $17 to $20. You make a miltiary splice by spreading the wire to tap into with this and using a small precision screwdriver or pick to make a hole in the wires and feed your wire to insert in there, close the hole and wrap the inserted wire around the exposed area. Then use electrical tape around it and place a few zip ties over it to keep it firmly in place. One mistake I made was trying to go back and spread one further and accidentally clipped some strands, so ended up grabbing the soldering iron for that one. The cost is going to be roughly the same if you use positaps, but you get a tool you can use for quick stripping down the road if you are working on your car or your house.

The jack nuts are tricky to get to install. I stripped the one that came with it and if the friction wrench that is coming today doesn't hold it in place, I may just have to resort to zip ties with some padding between the frame and the speaker box mount to keep it from rattling.

Tools needed:
1. 10 mm socket and wrench/driver
2. 13 mm socket and wrench/driver
3. wire stripper
4. electrical tape
5. precision flathead screwdriver
6. allen wrench set (I don't think the wire kit came with one for the fuse block)
7. friction wrench (maybe)
8. cheap multimeter is helpful - check continuity between terminals at the plug for the factory amp and test voltages. Placing in VAC and measuring the output of the RCAs from the XLCA2, you will see enough change when music is playing to confirm you are getting output.

Material that helps but probably isn't absolutely needed:
1. Tesa Tape
2. utility knife to trim away factory tesa tape carefully and/or scissors.
3. velcro strips to mount the XLCA2 and/or the VADM1. Both are plenty light enough that industrial velcro are probably ok. Note you will want to avoid covering the factory label like I did. Luckilly the box has the serial number on it.
4. 3.5mm to RCA adapter to plug into your cell phone to test the amp if there is no sound

If you have a factory amp and want to continue using it: Allyn recommended wiring the speakers out of phase to prevent it from cancelling out the factory sub. In their setup they kept both connected and that is what they did for a sound they liked. I have mine wired this way because I listen to a wide range of music and really like getting that drum hit that the smaller sub will do better at.

I think that is about it. HTH

Links for items I ordered:
Strippers: https://www.amazon.com/gp/product/B000OQ21CA/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
(I saw a generic set at Ace when getting the headphone to RCA adapter)
Tesa tape: https://www.amazon.com/gp/product/B00XPDVER2/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
Pick set (in hindsight, the precision flathead screwdriver would've done the job): https://www.amazon.com/gp/product/B002KS1E7I/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
Friction wrench (don't know yet if it works): https://www.amazon.com/gp/product/B00NWJJLXS/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

I saw a specific jack nut insertion tool on there for around $50 but it doesn't come with the mandrel so you would end up spending over $100 just to mount the sub with that.
This is great! Thanks for the write up. Any tricks you learned in hindsight about the jacknut and/or mounting the xlca2 and vdm1 (Ie location)? Thanks again!
 
In another thread someone posted that it is imperative to draw from the battery itself rather than the penthouse so that the battery can be monitored better. But I’ve also read pulling from the battery is how the error codes show up…any thoughts/advice would be appreciated!

Below is the snippet from other thread:

In short - take the extra effort to run both the positive and negative from a VC group (namely VCfront) for both protection from shorts as well as vechicle function as Tesla updates are reading things now on these VC"s that they never have before. Toolbox has many new power parameters on this latest update than they didn't have before.

I would hate to see something not work on your car now that was working before the update and you take it in to tesla and they charge you $500+ for finding a cross ground issue due to your accessory.
 

bo3bdar

Member
Feb 21, 2021
263
336
Silicon Valley
In another thread someone posted that it is imperative to draw from the battery itself rather than the penthouse so that the battery can be monitored better. But I’ve also read pulling from the battery is how the error codes show up…any thoughts/advice would be appreciated!

Below is the snippet from other thread:

In short - take the extra effort to run both the positive and negative from a VC group (namely VCfront) for both protection from shorts as well as vechicle function as Tesla updates are reading things now on these VC"s that they never have before. Toolbox has many new power parameters on this latest update than they didn't have before.

I would hate to see something not work on your car now that was working before the update and you take it in to tesla and they charge you $500+ for finding a cross ground issue due to your accessory.

I've just ordered the NVX boost subwoofer as well, and will be installing it all in the next few weeks. I'll post here if I run across anything. It seems like the conclusion is that the jacknut is trash and you'll want to use something better. Can't beat the look and the installation size though. The 10" woofer should be better than the 8" woofers in the doors and the 8" subwoofer for you LR people. I have SR, so adding this sub should really help.

The VCFront is not what you would connect to for power, that would only be for the an on/off signal to tell the amps to power up. That would be the 18 AWG wire that the kit comes with. Lots of older threads talked about using VCLeft, but I think those no longer work for the on/off purpose and maybe VCFront still does.


In terms of power connections, I had a long discussion with some people here and a Reddit guy who had a failing DC-DC converter. We can't know for certain because we get conflicting info from different Tesla ServiceCenters. However, my conclusion is that you want to use the penthouse connector and not the 12V battery.

I get to that conclusion based on experiments that someone here did when trying to power a 12V->120VAC Inverter to power his house during power failures. He did some great tests and found that the charging circuit for the 12V battery only provides a max of about 5 amps, on the order of 80Watts. That's low enough that if you are running some decent power through your stereo that you might actually be drawing down your 12V battery while simply playing loud music. You won't hit the big plate numbers of 1000W RMS and all that, because those are more transient during music, but you can easily draw 100W from stereos.

There was concern about using the penthouse connector early on, but someone else figured out that the errors the car would throw while using that were caused by inrush current when the amplifiers power up. By limiting that in-rush current, you can avoid having the car throw any errors. The full NVX kit with VADM1 should work fine because the inrush seems to never trigger the car errors for this kit, but if you run something bigger, you need to worry about setting up a relay to avoid the errors.

(Normally I add links to the relevant conversations, but at the moment... I'm too lazy. Sorry about that, but you can search around a bit.)
 
I've just ordered the NVX boost subwoofer as well, and will be installing it all in the next few weeks. I'll post here if I run across anything. It seems like the conclusion is that the jacknut is trash and you'll want to use something better. Can't beat the look and the installation size though. The 10" woofer should be better than the 8" woofers in the doors and the 8" subwoofer for you LR people. I have SR, so adding this sub should really help.

The VCFront is not what you would connect to for power, that would only be for the an on/off signal to tell the amps to power up. That would be the 18 AWG wire that the kit comes with. Lots of older threads talked about using VCLeft, but I think those no longer work for the on/off purpose and maybe VCFront still does.


In terms of power connections, I had a long discussion with some people here and a Reddit guy who had a failing DC-DC converter. We can't know for certain because we get conflicting info from different Tesla ServiceCenters. However, my conclusion is that you want to use the penthouse connector and not the 12V battery.

I get to that conclusion based on experiments that someone here did when trying to power a 12V->120VAC Inverter to power his house during power failures. He did some great tests and found that the charging circuit for the 12V battery only provides a max of about 5 amps, on the order of 80Watts. That's low enough that if you are running some decent power through your stereo that you might actually be drawing down your 12V battery while simply playing loud music. You won't hit the big plate numbers of 1000W RMS and all that, because those are more transient during music, but you can easily draw 100W from stereos.

There was concern about using the penthouse connector early on, but someone else figured out that the errors the car would throw while using that were caused by inrush current when the amplifiers power up. By limiting that in-rush current, you can avoid having the car throw any errors. The full NVX kit with VADM1 should work fine because the inrush seems to never trigger the car errors for this kit, but if you run something bigger, you need to worry about setting up a relay to avoid the errors.

(Normally I add links to the relevant conversations, but at the moment... I'm too lazy. Sorry about that, but you can search around a bit.)
Thank you!!
 
Thank you!!
He replied in the other thread with this, I am getting mixed signals for sure. I did read that most people haven’t had a problem connecting to penthouse. On the nvx YouTube installation video there are some comments saying it’s safer to connect to battery, but I’ve read a couple that say it’s safer to connect to penthouse.

“Yes! It is indeed MUCH safer to use the 12V battery than it is to use the penthouse.

Tapping the penthouse has no protection.

And

I would recommend that you also tap the negative of the battery.

Cross contamination of using the positive from one VC and the negative of another will eventually cause errors as the vehicle also measures/monitors return current.”
 

bo3bdar

Member
Feb 21, 2021
263
336
Silicon Valley
He replied in the other thread with this, I am getting mixed signals for sure. I did read that most people haven’t had a problem connecting to penthouse. On the nvx YouTube installation video there are some comments saying it’s safer to connect to battery, but I’ve read a couple that say it’s safer to connect to penthouse.

“Yes! It is indeed MUCH safer to use the 12V battery than it is to use the penthouse.

Tapping the penthouse has no protection.

And

I would recommend that you also tap the negative of the battery.

Cross contamination of using the positive from one VC and the negative of another will eventually cause errors as the vehicle also measures/monitors return current.”

Can you point me to that thread? I've been unable to dig it up via searches. I like to review everything, especially stuff that contradicts what I think I know.

The penthouse errors are pretty well understood at this point, and he's definitely wrong in stating that it doesn't have protection. That's what those errors are about- the DC-DC converter thinking it has a short and putting up errors, and disconnecting the circuit. I would call that... protection. The only real questions about the penthouse nowadays is what is the best protection circuit to use, and how paranoid to be. Some people refuse to use a solid-state relay, others have added a thermal reset for any possible overheat conditions. One guy did set his wiring on fire using a badly sized SSRelay.

Another reason I believe that using the front 12V battery is the wrong approach, is because we already know that's a weak spot for the Model 3. Lots of people stranded when it fails, lots of people with no warnings given, lots of people have them fail in 2 years. Given that it's a weak link for the car, I think it doesn't make sense to stress it further and possibly shorten it's lifespan further.

Here is Marc's blog where he talks about how much power he can get out of the 12V penthouse. He's powering a 3000W Inverter without getting any faults from the car, so that's a good indication we can power a 1000W peak stereo without any problems.


His earlier post, where he talks about testing the 12V battery up front for the inverter. Would be much easier to use, if we had the full power of the car there, but alas its limited. How many amps can you get from the 12V system for emergency situations?

Everything works great, except I cannot get more than maybe 5A from the car to its 12V system. It's not even what the cigarette lighter adapter is rated for (15A peak). In other words, it charges my batteries slower than they discharge if I plug just a 100W light in my inverter.
I've tried putting the car in drive and even that way, it still doesn't recharge the 12V system faster than it discharges.
Is there a better 12V bus I should tap into that gets more amps from the DC-DC converter than what is being sent to the battery?
 

bo3bdar

Member
Feb 21, 2021
263
336
Silicon Valley
don't use the power from the under the seat battery. I got error message after few days and I took off the amp. I took the car to the dealers and they couldn't figure out why. They reset the system and the error code. I'm using the battery in the frunk.

Interesting, thanks for posting. You are the first person I've heard of who had the NVX setup throw errors. Anything unique about your setup, like a different amp than the VADM1? Also what is the exact error? A fellow on Reddit had some errors that he originally thought was caused by his Hansshow type F amp, but actually wound up being that his DC-DC converter failed and was replaced by Tesla.

People using the penthouse connector for really monster amps, like 3000W of power are using a relay protection circuit to keep the amps from having a huge in-rush current draw and triggering the Model 3 DC-DC converter protection circuits. Should be unnecessary for an amp as small as the VADM1. Here is a good writeup with some background:

 
Can you point me to that thread? I've been unable to dig it up via searches. I like to review everything, especially stuff that contradicts what I think I know.

The penthouse errors are pretty well understood at this point, and he's definitely wrong in stating that it doesn't have protection. That's what those errors are about- the DC-DC converter thinking it has a short and putting up errors, and disconnecting the circuit. I would call that... protection. The only real questions about the penthouse nowadays is what is the best protection circuit to use, and how paranoid to be. Some people refuse to use a solid-state relay, others have added a thermal reset for any possible overheat conditions. One guy did set his wiring on fire using a badly sized SSRelay.

Another reason I believe that using the front 12V battery is the wrong approach, is because we already know that's a weak spot for the Model 3. Lots of people stranded when it fails, lots of people with no warnings given, lots of people have them fail in 2 years. Given that it's a weak link for the car, I think it doesn't make sense to stress it further and possibly shorten it's lifespan further.

Here is Marc's blog where he talks about how much power he can get out of the 12V penthouse. He's powering a 3000W Inverter without getting any faults from the car, so that's a good indication we can power a 1000W peak stereo without any problems.


His earlier post, where he talks about testing the 12V battery up front for the inverter. Would be much easier to use, if we had the full power of the car there, but alas its limited. How many amps can you get from the 12V system for emergency situations?

This is the other thread
 

bo3bdar

Member
Feb 21, 2021
263
336
Silicon Valley

This is the other thread

Thanks for the link, it's interesting. I didn't realize it was today's info, so google searches didn't find it.

Just my informed opinion based on reading everything I could find, but I don't think he is right. The penthouse is unquestionably protected, the car looks for short circuits there and will trip a software breaker and refuse to boot the car until it is corrected. It can provide 200 amps, which is 200*12=2400 watts of power, so you better believe Tesla didn't overlook that. The penthouse is not fused, it's a circuit breaker.

I also do not believe his anecdote about 'a guy' whose car was bricked because of a short in the subwoofer. This is not a believable story because no one is stupid enough to install a stereo with a tap on 12V without having a fuse in the power line. Not from the penthouse and not from the 12V battery. It's just not done. You can set your car on fire if you don't have a fuse. This is stereo installation 101, and I just don't believe anyone would be stupid enough to skip adding a fuse. A 60 amp fuse would have blown long before the car would have cared. If he gave a source for that story, or if I'd run across even a second instance of this, I'd give it more credence.


His suggestion to keep track of ground is also questionable. The entire car also uses a chassis ground like any other car. The Tesla schematics show a simple chassis ground, not extra wires. Running an extra wire for the ground is OK, but really odd. It is possible to get weird ground problems if people are not careful, like if they mount an amp to a metal plate that is not grounded, you can have a floating ground for the amp case.

Don't know. I might have to join there and see if I can get better details from him. He sounds like he knows what he's talking about, but none of the other hardware modders here like Ingeener or Travis have spoken about any sort of ground problems or worrying about the VCFront controller.


I think it's also worth noting that NVX does not have any other recommendation other than using the penthouse. If they were getting customer complaints, I would expect them to revise their setup and installation recommendations.
 
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Thanks for the link, it's interesting. I didn't realize it was today's info, so google searches didn't find it.

Just my informed opinion based on reading everything I could find, but I don't think he is right. The penthouse is unquestionably protected, the car looks for short circuits there and will trip a software breaker and refuse to boot the car until it is corrected. It can provide 200 amps, which is 200*12=2400 watts of power, so you better believe Tesla didn't overlook that. The penthouse is not fused, it's a circuit breaker.

I also do not believe his anecdote about 'a guy' whose car was bricked because of a short in the subwoofer. This is not a believable story because no one is stupid enough to install a stereo with a tap on 12V without having a fuse in the power line. Not from the penthouse and not from the 12V battery. It's just not done. You can set your car on fire if you don't have a fuse. This is stereo installation 101, and I just don't believe anyone would be stupid enough to skip adding a fuse. A 60 amp fuse would have blown long before the car would have cared. If he gave a source for that story, or if I'd run across even a second instance of this, I'd give it more credence.


His suggestion to keep track of ground is also questionable. The entire car also uses a chassis ground like any other car. The Tesla schematics show a simple chassis ground, not extra wires. Running an extra wire for the ground is OK, but really odd. It is possible to get weird ground problems if people are not careful, like if they mount an amp to a metal plate that is not grounded, you can have a floating ground for the amp case.

Don't know. I might have to join there and see if I can get better details from him. He sounds like he knows what he's talking about, but none of the other hardware modders here like Ingeener or Travis have spoken about any sort of ground problems or worrying about the VCFront controller.


I think it's also worth noting that NVX does not have any other recommendation other than using the penthouse. If they were getting customer complaints, I would expect them to revise their setup and installation recommendations.
Thank you. I commented on the YouTube installation video and nvx said:

“If you feel more comfortable hooking it up to the front battery go with that. Some have reported errors when hooking it up to the point under the seat. One the ones we've installed we haven't gotten any errors even after a year of having it installed.”


So it seems safe to install to penthouse. I wonder if the error people were getting is from installing a bigger amp or sub.

Thanks again!!
 

bo3bdar

Member
Feb 21, 2021
263
336
Silicon Valley
Thank you. I commented on the YouTube installation video and nvx said:

“If you feel more comfortable hooking it up to the front battery go with that. Some have reported errors when hooking it up to the point under the seat. One the ones we've installed we haven't gotten any errors even after a year of having it installed.”


So it seems safe to install to penthouse. I wonder if the error people were getting is from installing a bigger amp or sub.

Thanks again!!

Good idea to post on the Youtube and ask about it. That's good info that they have had some customers report problems. Hard for them to know what was happening and whether it was installed similar to their setup. The VADM1 amp is pretty small and D-class so it's efficient. I'd actually be quite surprised if anyone ever got errors when using that amp.

As another data point, there is a giant thread here regarding the Hansshow upgrade. They also tap the penthouse connector and reportedly do not generate any errors. That's a DSP based amp, a little bigger than the NVX setup. I think that the nature of the internet is that you can often find errors and complaints, but rarely successes- so I think that the lack of people complaining about the Hansshow causing errors is suggestive that it is OK. Similarly with NVX, no one who has gotten errors has bothered to post that I can find.

Lastly there is guy here todd2fast4u who does an aftermarket setup as well, using a rockford amp and subwoofer and an alpine 4 channel amp for the tweeters. He taps the penthouse and has said that he's not gotten any reports of the errors.


For what it's worth, I think my plan will be to run off the penthouse without a relay to start, and only add the relay if I ever get errors from the car. I'm adding two d-class amps for about 1000W of RMS power. I don't think it's particularly risky to the car, but am still studying.
 

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