Joe X

If your amp does everything right except for overheating is most likely because of installation/operation error, said that if you continue using it like that it will fail without a doubt, common causes of overheating include: - bad grounding / wiring - low impedance loading - low input voltage - clipping - subsonic filter not properly set - poor ventilation, sometimes you can install fans if the amp needs to be in a poorly ventilated location Also is very possible that if those issues are not corrected a new amp will also overheat, so fix or have someone fix the issues and if the system is not playing loud enough then yes get a better amp, more subs or whatever. Since you have a single 1/0 wire it could source up to a 2K or so amp, if you get an amp with multiple 1/0 inputs you will probably need to upgrade your full electrical system too.

The mojo 3000.1 will drive 4 of the mojo pro 12 and you would need to buy electrical upgrades for your car to run that amp which can be very expensive. If you are going to use 1 or 2 subs you probably don't need so much power, you still can use it but you are paying for more capacity than you need.

The good news is that the car cabin gain that bass box pro uses by default (you can enter measured gain data for your vehicle) is for an infinitely stiff car cabin, which is never the case for real vehicles so that big peak you see in reality will not be as big. The other thing is that you can reduce the peak by many means without building the 6th order box, one of them is by using damping materials (poilyfiil, dacron, etc.) inside the box, here is a comparative plot using and not using damping material: As you can see the peak is more reasonable in size and the advantage of this method is that you can use a lot, or little of it and even take it all away as you see fit. Yet another method is by using a parametric equalizer or a flexible DSP to try to customize your frequency response. The disadvantage of these methods and the reason they are almost never used is that they kill output.

Your sub has an incredibly stiff suspension and a brutal motor so is not surprising that it does that, actually is meant to do that, to fix that behavior without losing a lot of output I came up with a "compact" parallel 6th order box: It's about 4 cubic feet net (which defeats the purpose of getting a 12" sub) but you get 28-55 relatively flat. That sub is so SPL oriented that it has dual 1.4 ohm coils clearly aimed at wiring in parallel to 0.7 ohm to suck all the power it possibly can from most amps.

BTW the DATS or similar device are used on a well broken in driver, if you use it in a new sub it is going to give you bad parameters, quite frankly Fi provides reliable parameters, DATS is necessary on reconed/modified subs or those chinese subs where the manufacturer gives fake parameters to boost sales.

To answer your question, if firing against a close surface it best that is a stable (no flexing or rattling) and non absorbent (like the seats) surface, typically in a daily setup you will fire the port to the passenger side and sub up or forward, experimentation is most important as well a doing some research on what works for a particular vehicle, there is no general rule as personal preference is also a factor. To better model with bass box pro activate cabin gain setting and setup to 60Hz, the way you have it output drops fast below tuning which is not the case inside a car cabin, also since rises very fast below tuning, you need to setup your subsonic filter to protect your sub.

Near the middle of a cabin is no great place to put a sub box, I would get some existing box and do some tests to see what you like, in a SUV the ideal place is close to the rear gate, from the corners if it is a not so large box generally those are done firing back, but testing is what will answer your question best.

The ideal box will let your sub fully reach Xmax on the power available, Xmax is the maximum distance the cone move from its resting position while sounding good and avoiding damage to the sub. Box size has to do with how efficiently power will be used and what type of sound you will get, larger box results in higher efficiency and lower notes being playing louder, smaller box is for higher sound quality but less efficiency and lower notes being played less loudly. If your amp has little power compared to what the sub can take you will want a larger box so you get louder on the power you have. To decide your box size, tuning and port area you use modeling software like WinISD, hornresp and others to give you an idea on what needs to be done, there is a thread right next to yours by the name "Need Box/WinISD Advice " where you can see how they work. Also one needs to bear in mind the vehicle you use, among many factors the cabin size will determine how loud lower bass will sound, the smaller the cabin the louder lower bass will sound. I can give you some magic numbers but best is that you better understand what you are doing.

Did my own modeling with bass box pro and a 4th order did work fine, share you the results: Box specs: sealed chamber: 1 cubic feet Ported chamber: 1.25 cubic feet, tuning: 48Hz, Port area: 34 square inches. Frequency response: Cone excursion: Vent airspeed ( 48Hz, 34 square inches): volumes and port area are for one sub, for two subs volumes and port area double. The only issue is low Xmax of the sub, you would need to use your subsonic filter if intending to push the full 800WRMS to protect the sub.

I found that your issues you find with your fourth order bandpass are connected with your WinISD usage, So I install the program and fill the data and here is what I get: Notice they give the CMS parameter in the wrong units, that can cause problems. Frequency response: Cone excursion: Vent airspeed: box specs are in my next post where I use a more professional software but honestly results are very similar, find what is wrong and proceed to build your box.

Your cabin gain simulation seems ok with that linkwitz transform filter set to 60Hz so that seems good. Your box will be good or not depending on your goals, if you are aiming for a not loud flat response box it could likely do the job. If you are aiming for high performance like what is expected in car audio you need to check a lot of things to make sure. Not sure if the box is going to be a blowthrough with the box mounted inside the bed toolbox and therefore a ported design needs to be excluded, if not model the ported box and compare, likely ported will be louder. Next, your port area seems low, for 4th order bandpass designs one needs your peak vent airspeed to be low, like 15-18 meters per second or lower as all your output will go through the port. disable the filter to view this plot correctly. Also the 1:1 chamber ratio is only adequate for flat response, most car audio designs use 2:1 for extra output, you need to model greater ratios to see what can be gained always checking not going over Xmax in your excursion plot at any frequency at the maximum power you intend to deliver. The excursion plot will only work with the filter off. Before you build the box post your design to get feedback on it, bandpass designs need extra care to work correctly.

Actually 2 12s will give similar output as a single 18 on the same power, if you gave twice the power you would get louder than a single 18 and you can go higher than twice the power, likely 5-6 K is possible. A single 15 you can do but due to the significant difference in cone area you would need a lot of power to reach a 18, it would be very expensive not for the amp, amp is cheap but for the electrical, the 15 would likely really need twice the power to rival a 18, about 3dB is what a 18 has on a 15. If you still want a 15 check out steve's videos on the new deaf bonce 15s, looks like those subs are highly efficient due to the gigantic motors, no t/s params for them yet but for sure will be one of the loudest 15s ever out there.

In your situation I would go for 2 12s, say the sundown M12s, total cone area is near a 18 and 4.5 cubes net and 70-80 square inches of port area will be enough for them. You can then upgrade the power later if you want and go louder than the single 18 would be able to. Wanting to have a 15 to sound as loud as a 18 on the same power is rather difficult, you usually need like twice the power on the 15 to reach the output of the 18 and then it can be done but it is more expensive, you need a better electrical, amp and sub.

You should start describing your system first with some pics, maybe you have a bad installation or bad components. As far as amazon reviews go you will find people who sincerely like and recommend boss head units so not much to gather from those opinions unless they are negative opinions, I always pay attention to those. In my experience I would recommend to get something from pioneer or alpine as expensive as you feel comfortable with for sound quality, watch some function demo videos to see how it all works for the units you are interested in, how responsive, etc.

Turning on 2-3 devices from your head unit would never cause any issues, when you are trying to turn on something like 10 amps plus dsp and other stuff you may get that some do not turn on and then you try the relay but this will not result in the head unit turning off. To me it looks like the power lines of your head unit might have a poor connection, your car's turn on switch could have some issue or you could have poor grounding. Although infrequent your head unit could have an issue also. To check you will need a cheap multimeter, make sure you have one.