System: Boss Riot 635 amp(1200W x 2) which is really doing (200W RMS x2) into 2 Polk GNX124 12" subs, with a RF 1 farrad cap.

Right now I have a fused 4 Guage wire(20feet) running from the battery to the rear of the car. I then have a splitter and run 8 guage from the splitter to a capacitor and the same from the cap to the amp. Is my wiring sufficient? Is there anything I am doing wrong or should watch out for?

 

sounds good to me, especially for only that boss amp.

 

how long are the 8g runs?

 

THe 8 guage runs are no longer than a 1 foot each. Goes from the distribution box to the cap and the cap to the amp all right in a row.

 

then your fine. just made sure you gound the cap not the amp. (I.E. power 8g to the + of the cap then a 2nd wire on the + post goes to the + on the amp. Then the - on the amp goes to the - on the cap then you have a 2nd wire on the - post of the cap to ground it) Most people ground the amp an not the cap like they should when they run a cap. i'm sure you have it done the right way but wanted to make sure

 

I don't have it all wired up yet....but unless there was some instructions on the cap to do it that way I would have done it wrong! Thanks for the insight!

 

your welcome.. also make sure you charge the cap befor you install it.

 

Ok, how do you charge a cap? I assumed it would charge up just by sitting connected for a bit.

 

What size fuse does the Boss amp have? My guess is that 4 AWG is overkill, although it gives you the opportunity to upgrade without rewiring.

 

The boss amp has a 30 amp fuse on it.

 

You have more than sufficient wiring in place should you want to upgrade or add on in the future.

4awg will handle plenty of current draw and those 8awg runs could be much longer and still not have any issues.

 

Then you're fine. You could run 10 AWG and still be completely safe.

 

your "lamp cord" quip comes to mind from a couple weeks ago.. heheheh

 

when you get the cap it will tell you how to do it. most come with a Card that you put on it and then you hook it up to the battory till the little light goes off. its very EZ to do but if you don't do it that way as soo as you put the power cable on the cap you will get some mad sparks if you don't have it charged

 

Here's a link to one of the sites I saw listed on YOUR webpage.

http://www.the12volt.com/info/recwirsz.asp

Not saying it's the "bible", but seems to be a good 'round about' chart.

AJ

 

Now that I look at that page more, I think my RF amp is seriously under rated.

According to the "Current Draw by Power" chart, my Punch 100 puts out ~300 watts bridged.

I know this because I have 8 ga. wire going to it, and it kept blowing 40 amp fuses. So I put an inductive pick-up on it to check the amp draw and it peaked at ~55 amps. I had to use a 60 amp fuse.

That would explain how I hit 135.5dB with only 1 12" MTX 3000. And that was an 8 ohm sub.

Now I have a 4 ohm Pioneer IMPP with a 60 amp fuse, but I have yet to really crank it up because the sensativity of the Pioneer is about 3dB higher than the MTX was, and it hurts my ears.

AJ

 

NTX make 8ohm subs so you can put two in a mono Box and then wire then up so they will become a 4ohm load on the amp. havieng only one 8ohm sub in a car is next to stupid... but you chould take that 8ohm sub and hook it up to a home stero. :lala:

 

Trying to determine what size wire to use based on an amp's advertised power rating is like using a yard stick to measure crank bearing clearances. It's WAY too imprecise. Besides the obvious issue with innacurate power ratings, you still wind up making assumptions about the amp's actual power output, the amp's efficiency and a host of other things. By evaluating your wire size based on the fuse size on the amp, you no longer make assumptions or comprimises. You know that the amp won't draw more current than what the fuse is rated at, so you base your wire size on that value.

 

:lala: :sillylol:

 

That's what the site is there for man. I post good links as I find them in the tech section to help others out. I just put up a ton more yesterday actually.

 

Until you know the whole story, keep those "stupid" comments in you head please.

I did have 2 running parallel (BTW, that's what it's called ) but one of them got too hot and decided the dumpster was where it'd rather be.

Besides, running an 8 ohm sub mono is actually easier on your amp(s). AND the music is usually more accurate because.... if you pay attention to most amps' ratings, when you run them bridged into a 4 ohm load, then the amount of power that they "brag" about is usually at a higher level of THD. Plus it makes for a happier amp. It runs cooler and lasts longer.

I should know, each of my amps is ~10 yrs old.

Oh yea.... Did I mention that I hit 135.5 dB with that ONE 8 ohm sub? WHY... YES, I DID!!!

AJ

 

hey man i'm just trying to help. no need to get all bent out of shape.

 

Actually, regardless of the power, the THD is way too low to be anywhere near audible, so running 1 sub is just making it quieter, not making it sound better. Actually, if you look at a THD curve, except for points beyond clipping, the THD is highest at low power outputs, usually under 1 watt. I never cared enough to find out why, but it must have something to do with a class A/B amp having higher THD in the class A region. Beyond 1 watt, the THD is pretty flat until you approach clipping, but with a higher impedance, you'll approach clipping at a lower wattage, so it basically all becomes a wash.

The only legit claim to better sound quality with a higher impedance comes from the amp's damping factor. Problem is... almost any amp's damping factor is multiple times higher than any sub can respond to anyway. Anything above around, say, a damping factor of 30 is basically not doing any good. Most good amps now have a damping factor or around maybe 200 with an 8 ohm load. With 4 ohms the damping factor will fall to 100... still way higher than you can hear.