Joe X

As before, in your situation I would get 4 sundown audio X8 v.4 and make sure your box tuning is 32-33Hz (I think that box is tuned high) that is the best you can do as far as I know.

Looks like you won't be gaining a lot with your new setup, you lose cone area and gain RMS, the result is for sure not a compelling upgrade. As far as getting lower I would have gone for the XL Elite instead of the SPL version, and also gately don't give you the box specs. I would have gone for 4 X8 on say 5K and make sure the box specs are right.

With the stereo channels you just need to use one of them, left or right, say you check front left and rear left. Then the sub channel since is a mono channel you have only one output to check. Notice that the test tracks are not the same for the mids and highs channels than the one for the sub channel. Check the manual to know which audio tracks you need to use. You need to connect the DD-1 to the amp as if you were connecting a speaker or a sub. Please read the manual a couple of times and make sure you understand everything before starting your tests.

A box that is 14H x 29W x 19D sealed would have an internal airspace of 3.5 cubic feet enough for two 12s in sealed, how re you saying that you don't have space, that's plenty of space. 8' subs are very inefficient and those subs seem not to work well in sealed (EBP = fs/qes = 74) , my recommendation is doing the two subs in ported and you will still be left with plenty of free space in that trunk.

If your battery is well charged and you play the songs as long as your voltage does not drop significantly you know your electrical is holding, the real question to answer is how much time your weak alternator will need to recover the lost charge to the battery. In practice it's the wrong approach because you will want to play that extra song or you won't be willing to wait the recharge period, typically you keep doing mistakes and sooner rather than later you end up with a damaged alternator and battery.

Big 3 is such a cheap and effective upgrade that I would recommend to anyone running 1000W or more.

OP batteries do not make power just store power so at the end of the day you can only spend as much energy as your alternator can produce.. that is it... you can for sure get excellent wiring and a good battery and a healthy alt but all that is going to help only to a point. If you don't want to spend on electrical your only option is spend the available energy more efficiently and that is made possible by using more efficient high diameter woofers and efficient box designs, you can easily have a system that is spending 1000W that will be just a loud as a standard system spending 2500W.

Your question belongs to the subs/enclosures forum you put your question in a junk section.

What to do next depends on what you want, if you want louder but still low a sundown X 10 would work just fine in that enclosure. If you want a 12" it would need to be one that works well in relatively small enclosures, for example a DC Audio 12" will work just fine in that box, if you want better sound quality an image dynamics IdMAX 12 would work there. You need to be clear about what you want that you are not getting.

The sub parameters don't mean much alone, they are meant to be used by software along with the specs of your box and the listening environment. The following is your sub with the box specs given and inside an average sized sedan car at 30 Hz in red and 34Hz in yellow. That box design is made to maximize the deeper bass output as possible even when the sub cannot be great at the low end bass due to it's low Xmax of 12mm. That big peak at tuning is due to the too large net volume of 1.7 cubes. There is no difference in output in this case just different peaking frequency. Still higher tuned boxes (with otherwise same specs) tend to seem louder to the ear because of human hearing.

Strictly you need software modeling for the sub specs, box specs and car to make your mind on what is the situation but generally speaking tuning lower makes you less loud, more so if the vehicle is large, but also a box design too tight can kill your lows, to people trying to reach down low I recommend larger subs, they are just louder for the watt.

Odd system, midbass centric it looks like, anyways here is a detailed power analysis, hopefully you can make your mind on what to do: Assumptions: Total nominal amp power(RMS) = 2180W, class AB = 1280W, class D = 900W Usage: full power in all amps playing MUSIC ONLY. Car services = all active (air conditioning, motor, lights, etc): Battery Voltage = 13 V Alt Capacity = 132 A Usage Factor = 50 % (see above) Total Input Power Services = 686.4 W Total Input Current Services = 52.8 A Total Input Power Audio = 1880 W Total Input Current Audio = 144.615384615385 A Total Required Power = 2566.4 W Total Required Current = 197.415384615385 A Battery Current draw (A) = 65.4153846153846 A So on these extreme conditions your battery will need to provide 65A to the system to keep your system playing at rated power. At this point you have two options, play your system loud at times, not loud or off at other times to let your battery recharge. OR get an alternator that can supply those extra 65A or more and play loud all the time. Most people do not play their systems at full power all the time and the battery usually has a chance to recharge and you don't need to upgrade your alternator. To me my original advise stays, do the big 3 upgrade to a deep cycle battery and have your electrical thoroughly checked to make sure you have that current available. As someone told you above it is a good practice to install a cheap voltmeter so that you know your average voltage stays the same as days pass and that you don't have voltage dips below 12.5V, if you have either you can think of upgrading battery and/or alternator.

If you open and close the ski hole and it sounds the same probably making the holes will not help.

The power going to the sub or subs is usually 70% or more of the total power of a system so your numbers do not make sense to me. Also bear in mind that the actual power a bass stage will take is about half of RMS when playing music or 450W playing at full power. So the real power your system will take will be far below your estimate. Assuming you have a 900W RMS amp for the sub and an amp for mids and highs I would just get a deep cycle battery, do the big 3 and have your electrical system checked to be in perfect condition, specially making sure your alternator is healthy. Nothing more to start. You can always list your car model and all your audio system components models (amps, sub, etc.) for a more detailed power analysis.

The enclosure suggestion that sundown offers is actually larger than their suggested specs by a quarter of a cube, if you oversize the box too much it will perform poorly on the fast "punchy" bass that musics like metal need to sound good. So Sundown's box would be my suggestion for you.

A high pass filter will pass HIGHS not lows, set the switch to LPF and it will work as expected. Drive a sub from a 4 channel mids/highs amp is not a great idea, there is no subsonic filter included which helps save energy and protects the sub. Also make sure your sub is wired to 4 ohm which is the minimum stable for bridged mode with that amp, otherwise the amp may get damaged.

Use accessories that specifically state "for car use" and you don't have to worry while you are in the 9-15V region.

All those chargers you mention exist as car accessories which will directly take 14.4V, you just need a small distribution block to have one input and multiple outputs to the devices you want to power, for the noctua fan it will depend on the input voltage, those usually take 12v and likely can be directly powered with 14,4V and if not you could then add a small regulator board for it. Designing a custom central DC/DC step down is totally unnecessary, inconvenient and would take space, also would prevent future expansion. Also premade accessories individually include over current /short circuit protection that is absolutely necessary.

It is honestly a mystery to me why would you be asking about a raw calculation basically useless for setting gains when you have a DD-1. But anyways of course do use it, it works perfect and it is very easy to use.

You use per channel RMS OR 500W Assuming a 4 ohm impedance i get 44.7 Volt, in either left or right channels. If the rear and front speakers impedance are the same then the calculation is valid for all channels. Remember not to use those numbers for actually setting the gains, the only valid methods to set your gains are using a scope or a DD-1. The DSO152 mini scope can be had for less than $20 maybe if you know where to look.

if you measure the voltage from the front battery negative terminal to the negative terminal of the amp while playing hard and you get more than say 0.1 volts then your ground connection is bad.

You use per channel RMS, in the case of that amp is 500W. The knob will change the gain of both left and right channels, it would be impractical to have a gain knob for left and right separately when you want the same gain for both in a stereo amp.

In the amp the two positive terminals are connected together, same goes for the negative terminals, they do it for ease of wiring, the amp is still just one channel. The only thing you have to bear in mind that the total impedance at the amp don't go below the amp minimum stable. Since at least one person had problems wiring this amp at 0.5 ohm I would recommend to wire no lower than one ohm if possible.

If you go for that solution you may have to isolate the head unit and other audio components that you may have as well, all wiring power and signal should be isolated. Many times one of these components will be responsible for the issue. Knowing that you have a pioneer head unit, the PICOFUSE issue comes to mind, I don't know if pioneer found a better solution for that but there is a way to test with a multimeter, if the negative power terminal of the head unit and the negative of the RCA output terminals do not read a ZERO (0) you have blown the internal picofuse, that causes terrible and uncontrollable noise. Each and every ground loop issue can be solved as long as you go through each and every known test, also it is not worth to buy anything to fix it unless you have a known proven cause. If you still want to go for battery isloation get a battery isolation that can be setup for manual use as these solutions normally connect your rear battery as long as the car is on and that is not what you want to do.

Yes you can, it's a high current relay that you can engage or disengage with a manual switch. It is a terrible way to deal with a ground loop issue.