Equipment needed for install-Am I on the

Hi All,

First off I apologise for the length, but  the more  I read - the more confused I'm getting. A little knowledge can be a dangerous thing, and I really don't want o fry mys equipment, my car, or me! I am primarily concerned with sound quality but want to obviously be loud.

1. I'm putting in an RF 1000bd for my sub(s). At least one RF Power RFR3112 DVC, 2 if I can get it to fit in my Miata's trunk with everything else. I read that mounting the amps vertically-I assume this means on any side-is the best position-will allow it, although it will be extremely tight. Is there any problem with doing this? The amps would literally be mounted to the sub enclosure. I also have an Alumapro 5F capacitor I'll be putting in with this.

2. I have figured the enclosure dimensions at 32 X 10 X 16 = 2.175 cube. I figure this to account for sub displacement of approximately .1 cube, although I will be under the 1 cube per recommended size by .025 and the cube of the internal chamber separation. Am I actually gaining any great difference in sound quality or volume running one of these subs as opposed to two? If not I'll save myself alot of trouble and just run one.

3. I'm using a RF851X for the fronts-2 sets of RF FNQ3614 components. I'm going to door mount in the original positions one set and mount the second set centered directly behind the seats (2 seat convertible). Should I mount the rear tweeters within the 2" recommended distance from the mid or position them in a different position. The manual says over 7" if not within the 2". I've read where other Miata owners have mounted them on the seat belt tower. I'm interested in the best sound so I can position either way-any advice?

4. From what I've been told with one of these subs I'll be at 4 ohms, with 2 at 2ohms. The fronts are 4 ohm speakers-on 4 channels what will the resistance be? Does it matter in my setup if the fronts and subs have different resistance since they are running from seperate amps?

5. Now the part that really gets me-wiring etc. I figured on buying the RF amp install kits  The 1000bd says 4 AWG with a 100A fuse  and the 851X also says 4AWG with a 60A fuse. I know this is probably a stupid question but I couldn't find anything that explained it-Do I need two complete kits both hooked to the battery, do I run one from the battery to a distribution block  and then to each amp, or do I need to get a larger gauge from the battery to the distribution block and then to each amp? What about from each amp out . What about the fuses?

Any assistance is greatly appreciated

Thanks

Yeovil

Sorry-the would be do it yourselfer again,

 If there is any equipment that you would recommend please do so. I haven't bought any wiring, fuses, distribution blocks etc yet. If there is anything I didn't list that i need or is recommended please let me know

Thanks

First off, don't worry about the length of your post--hell look at how long mine is!!!  I have been known for many a lengthy post and some people probably hate it to death, but I like to be as detailed as possible and always want people to learn something new every time they visit the forum.

When you're working in this vehicle, be VERY careful when removing any of the body panels, especially the dash trim panels/bezels, etc.  This vehicle is known for having extremely brittle dashes that will shatter if you pull just a lil bit the wrong way.  Let me know when you're ready to do your install and i'll send you some instructions on how to properly remove the various panels.  okay now to address your questions.....

1.  The best way to mount an amp is right side up, with the heat sink/fins facing upwards (hot air rises).  You CAN mount them upside down but I would not recommend it unless you have no other choice.  Sideways mounting  (i.e. perpendicular to the car's floor) is not as bad as upside down mounting but again keep in mind that the amps need air.  If you can rig up even just one crossflow cooling fan for each amp it will help tremendously.  You need not worry about cooling the capacitor, though.

Some people say mounting amps directly onto a sub box is a bad thing to do.  I don't want to start a huge debate here but personally I've never had a problem with this type of mounting.  Some people say it makes the box more weak, but honestly I think you only need to worry about that if you are doing competitions and hardcore stuff like that.  I always just try not to use screws that are so long that they go all the way through to the internal chambers, although that's kinda just a little nit picky thing I've always done as a habit--it's probably not even necessary, but it certainly won't do any harm so I guess that's why I do it that way.

2.  Lol the power HX2s are pretty awesome subs.  One will do you just fine I think.  I am still trying to get a mental picture of how you intend to mount the amps and realize that that might affect whether or not you get two subs.  If you've already purchased two subs and can't return one of them then we'll have to figure something out, but otherwise I'd say you only need one sub.

3.  whenever possible I'd recommend following the manufacturer's guidelines with regards to mounting positions of tweeters.  In this case, Rockford is suggesting they be less than 2 inches away from the woofer, or more than 7 inches, and I have to agree with them.  Once you get past 7 inches you can really put the tweeter anywhere (within reason), but try to go for a spot that's at ear level, or at least that's aimed towards your ears.

4.  These subs have two 2-ohm voice coils, and your amp is 2-ohm mono stable.  Usually these subs are intended to be used with Class D amps that are 1-ohm stable (for example the JBL BP1200.1), and in that situation you wire both voice coils in parallel for a 1 ohm total load on the amp.  Unfortunately, your amp is not 1 ohm stable and although you could try hooking it up this way if you have a good cooling fan on it, but I would not recommend it.  This means your only other option is to wire the two voice coils in series, for a 4 ohm total load.  This will only use half of the theoretically available power of your amp, but still that's 500 watts RMS.  Not  exactly mickey mouse numbers here.  It will be very loud I guarantee you that.  Check out these RF diagrams, they show you how to hook you'd hook up a single 2-ohm voice coil DVC sub.

With that being said, this also complicates things because if you had two of these subs, they could be wired in such a way as to present the amp with a single 2 ohm load.  This would effectively mean 500 watts to each of the two subs, all while keeping the amp nice and stable.  This would obviously make it a lot louder but whether or not you're going to want it that loud is kinda hard for me to say.  If it's possible you might consider buying a single sub and box, and seeing what you think.  If you still want more bass, get another single box and another sub (or sell both boxes on ebay and get a dual box)

5.  For simplicity sake, run a single 2-gauge fused power cable directly from the battery, down a side of the vehicle opposite the signal cables, to a spot near both amps, the use a distribution block to send each amp a 4 gauge power cable.  For the grounding wires you do basically the same thing, except instead of hooking up to the battery, you'll connect them first to a distro. block, then run a single 2 gauge wire to a spot of bare metal on the vehicle's chassis, as close as possible (max 4 feet) to the amps.

If you use just one sub, you'll never get anywhere near the 100 amps that it is supposed to be able to draw.  That's assuming you're running it at 2 ohms, and very loudly I might add.  Stil, since you're running one single power cable, you need only have one single fuse.  I'd recommend a 150 amp ANL fuse.  Since you seem to be keen on RF products, you should know that they make a 2-gauge power/ground kit that includes an ANL fuse and fuseholder, in addition to enough 2-gauge power cable to run from your battery back to your distribution block; also it comes with 2-gauge groounding cable.  You'll still have to get about 5-10 feet of 4-gauge power cable, 5 feet or less of 4-gauge grounding cable, a distribution block (2 gauge inputs, 4 gauge outputs) and a 150 amp ANL fuse (fuse included with 2-gauge power kit is only rated for 100 amps.

All of that is just for power distribution--you'll also need to get the signal from the head unit back to the amps.  As I mentioned before, run the signal wires down the side of the car opposite the power cable, to prevent interference and noise problems.  You'll need two cables for the 4-channel amp, and a single cable for the sub amp.

One VERY important thing I forgot to ask you....what kind of head unit do you have?  if possible give us the model number.  I'm assuming you're already running an aftermarket one.

Hi,

Thanks for the detailed answer I appreciate it. I have a Sony WX-4500X head unit and am also installing a Sony CDX 757MX changer

I'm more than happy running one sub. I just wanted to ensure that I would have a clear and loud setup. I'm not concerned with being able to knock buildings over just want to be able to blast out on the open road with the top down. Only using one will actually make the install alot easier-more room to place everything.

Another thing that should simplify my install is that the battery is in the trunk. I will only have to route the signal wires from the frront. To decrease the possibility of interference/noise problems should I place both amps to the far side of the trunk from the battery and run the signal wires to that side?

Is the wiring kit you were talking about this:  Rockford Fosgate RP1802-C SPL Amplifier Wiring Kit

Any recommendations on the Distribution blocks? I would need two -one for the power and one for the ground, both 2 gauge in and 4 gauge out type correct? Also any suggestions on signal wire, and speaker wires for the sub, components. 

That's all I can think of

Thanks Again

Rockford makes a dual-amp kit but the wires are not big enough for your setup.  The 2-gauge kit that I was originally suggesting was the CP2POS.  Now that I remember the location of the battery, you might be better off just getting the items separately because you're gonna need significantly less 2-gauge power cable, but maybe 1 or 2 more feet of 2-gauge ground cable.

Usually the fuse for the main power wire has to be within 20" of the positive battery terminal, but since your battery is in the trunk, if you can locate the amps within a couple feet of the battery, you can use a single fuseholder/distribution block like this one.  Basically it performs both functions.  It has two outputs but only uses a single ANL fuse which is what you want.  Just remember to get a 150 amp ANL fuse, as well as a ring terminal that's big enough to fit 2-gauge wire.

As for the amps, once again since you're so close to the battery your best bet is to just run the grounds to the negative battery terminal.  I couldn't find any distro blocks that would work for your situation that are not fused, so you should just run two 4-gauge ground wires (one from each amp) directly to the negative battery terminal.  You can use an adapter like this one to connect both wires to the single battery post.  Whatever you do, do NOT get a fused distribution block for the ground cables as this totally negates the whole concept of having the ground wire.

If your head unit has separate front/rear/sub preouts then use all three sets of them.  Any RCAs you get from rockford will be fine, just make sure they're run down opposite sides of the car.

Hi again,

1. Will this work for the ground dist block-http://www.sounddomain.com/sku/ROCCPGD2 and I would run this to the negative terminal or ground to the chassis metal? Is there any advantage to either method over the other?

2. This for the Power dist block-http://www.sounddomain.com/sku/ROCCPGFDL2

3. What do I need to use wires (gauge ), dist block etc for the Alumapro cap 5 capacitor?

4. For the speaker wires-what gauge would you recommend for the sub, for the tweeters and mids? There are alot of opinions I've noticed on the subject-does the wire make any difference for speakers-or is wire wire? I see these choices as an example-http://www.sounddomain.com/shoplist~b~Rockford+Fosgate~t~Speaker+Wires

5. As far as the power cables would 6ft of 2awg power, and 8ft of 4awg sound about right? Grounds the same?

Thanks

Wayne

I forgot that you're gonna have a cap hooked up so that changes things....you'll want the main power cable to be fused, so here's what to do:

1) Using 2-gauge power cable and a ring terminal, hook up to the positive battery terminal.  Within 12" of the battery, put one of these inline with the power cable, and use a 150amp ANL fuse.

2)take the fused output from the fuseholder and run it using 2-gauge power cable, to the capacitor's positive terminal, and use a ring terminal to secure it to the post.  Take another 2-gauge power cable with a ring terminal, and secure it to the same positive post, then run it to the distribution block.  You'll notice that this distribution block does not have a fuse--that's because the power cable is already fused inline, before the capacitor.

3)each of the two outputs on the distro block will run an unfused 4-gauge power cable to each amp

4)for the ground wires, use another one of these but in the opposite direction (i.e. 2 4-gauge ground wires IN, 1 2-gauge ground wire OUT to battery's negative terminal)

5)You'll also need to use a 2-gauge ground cable (w/ring terminal) from the capacitor's negative terminal, to the negative battery terminal.  As I mentioned above what you'll probably want for the negative battery post is one of these, as it will let you hook up the two 2-gauge ground cables securely to the battery post.

This is all still assuming your battery is in the trunk and that you're going to be mounting the amps and the cap there.  If not, this setup will be VERY different.

For the wiring for the speakers, I'd say 16 gauge is fine, and for the subs, 12 gauge is fine.

That amount of cable I think will work out fine, but you might need more of the 2-gauge grounding cable since you'll be having two separate 2-gauge grounds running to the negative battery post, whereas with the power cable there's only a single wire coming off the positive post.