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Discussion Starter · #1 ·
I just bought a brand new Visonik 300W 10" sub and amp. Now, I am wondering if it's ok to just tap into one of the speakers at the back, or whether it's MUCH better to drag an audio cable from my deck. My deck does have SUB outs, it's an aftermarket Sony Xplod unit..

I'm also wondering what's the best way to get power to the amp.. Is there anything in the trunk that I could hook it up to? Maybe I could let the power go over the old cell phone cables? Where is best to tap into?
 

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Definitely wire it from the head unit. Not only is it the proper way to do it, and other ways may be risky, but you will be able to control sub controls from the head unit, which is a big plus.

As for the power, you can simply buy a kit from any audio shop... don't go cheap, and get a fuse (I think most kits have it already anyway).

Demon
 

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DemonAstroth is 100% correct. Definitely drag an audio cable and a power cable. There are several reasons for this and I'll give a couple of the most important ones.

1. RCA cable: The power level in speaker cables is HUGELY higher than the power level in RCA type leads because the signal has already been "amplified" or made much stronger. It would be like hooking a fire hose to a straw; funny, but your straw is toast.

2. Power cable: Wires have resistance that cause power loss over a distance so the longer the cable, the harder something (in this case your battery) has to work to push the same amount of power through to the other end. Let's go back to our fire hose analogy: Bigger wires (fire hose) are much easier to get power through than small wire. (straw) Generally the larger the diameter of the conductor, the lower the resistance is and the more power is reaching your amplifier.

Since you are talking about a subwoofer amp, which requires the most power as it is pushing the largest, heaviest speaker components over the greatest distance and is pushing the most air, the last thing you want is to have it starved for power.

If you use your existing itty bitty wires for running a cellphone setup (the most powerful of those in the early 90's drew 3 watts) you'll have wimpy impotent bass and before long your car will be home alone on weekends watching late night tv and ordering male enhancement pills to be like Bob.

Do it right. This is a good cheap kit.

Don't have impotent bass. ;)
 

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im not so sure bout 10 gauge power wire for a sub that pumpin out 300w..but it depends on the amp..i'd go with 8 gauge.
 

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You can tap into rear speakers only if your amp has speaker level inputs, but definitely run a seperate power cable (with a fuse) to your battery and ground it to the frame.

You will get better results with the sub-out RCA on your headunit because you can adjust the sub level independent of the volume, and it probably has a built-in crossover (in case your amp does not).
 

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Discussion Starter · #6 ·
Alright, well I've decided to do everything the proper way..

Although my amp does have a built in crossover and speaker-ins, I've decided to run an RCA from the headunit (it's crossover is probably better and it can control the amp). I am running 10-gauge "Monster Cable" fused wire from the battery.

Any suggestions of where to run these cables?
 

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GDub26 said:
im not so sure bout 10 gauge power wire for a sub that pumpin out 300w..but it depends on the amp..i'd go with 8 gauge.
I've just heard Visonik in the economy end of the scale. My experience with those companies is that the wattage ratings tend to be quite generous. 300 WATTS BABY!!!! (at 1kHz with 3% distortion)

And if you do some basic multimeter tests, you'll find that for the amount of current draw vs. power drop due to resistance on a 10 gauge stranded wire over the typical 15-18 ft. run is minimal.

Firehose sized wire is nice, but not as necessary as the marketing companies would have us believe. There is decidedly a law of diminishing returns.
 

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Discussion Starter · #8 ·
Bou_Te said:
I've just heard Visonik in the economy end of the scale. My experience with those companies is that the wattage ratings tend to be quite generous. 300 WATTS BABY!!!! (at 1kHz with 3% distortion)

And if you do some basic multimeter tests, you'll find that for the amount of current draw vs. power drop due to resistance on a 10 gauge stranded wire over the typical 15-18 ft. run is minimal.

Firehose sized wire is nice, but not as necessary as the marketing companies would have us believe. There is decidedly a law of diminishing returns.
I agree with you.

The sub AND amp BRAND NEW cost me ~60$USD!!! The wiring is gonna cost me about 20... I'm sure that it's crappy, but I heard it at the store and it sounded really good to me.. I'm not an audiophile or anything, just want a bit more bass.

I'm not going to dump my money on 8-gauge cable, that is $10 more than the 10-gauge. I also believe that it's all a marketing scheme..
 

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The concept behind it is sound physics. However, when it comes to marketing these days, I was surprised and a little amused to find that they rated these things at "up to 300 watts" and the like. Since wattage is only one part of the electrical equation, that seems quite arbitrary.

For your needs, I'd confidently say that 10 gauge will suit your needs quite well. If at any point in the future, your needs change, then by all means rewire. However, that kit that I pointed you towards should have all the wires (long lead, short ground, long switched AND the RCA cables plus connectors) that you should need for this install.

Just double check that the RCA cables are included. From the description, it looks as though it's an "I" version, but a quick email or phone call wouldn't be a bad idea. They ship stuff out quite quickly once an order is placed.

Good luck with your install man!
 

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Make sure to run your power and signal (RCA cables) seperately! Most RCA cables aren't as well shielded as the manfacturer will lead you to belive and can pick up interferance by running them too close to power cables. I recommend pulling your power cable down the drivers side and your signal cables down the passengers side to emilminate this possibility. Good luck with your install, it should be pretty straight forward as the P10 interior is extremely easy to work with.
 

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XnotedgeanymoreX said:
Make sure to run your power and signal (RCA cables) seperately! Most RCA cables aren't as well shielded as the manfacturer will lead you to belive and can pick up interferance by running them too close to power cables. I recommend pulling your power cable down the drivers side and your signal cables down the passengers side to emilminate this possibility. Good luck with your install, it should be pretty straight forward as the P10 interior is extremely easy to work with.
WHAT HE SAID X 2!!!! Sorry - never even thought about this in the beginner's tutorial.

So very important! You'll pick all kinds of alternator whine if you're not careful with cable routing. Also two other tips: 1) if you do have to cross your power and signal cables, make sure you do it at a 90 degree angle like an X. Running them parallel like II does the whole noise thing again.
2) If you have a whole bunch of extra wire that you don't want to trim (I find this more in home audio than car - but it happens) I used to make a nice looped section, ziptie it and then tuck it away. Turns out that a wire loop makes a GREAT antenna and picks up all kinds of signals and noise. Take that loop and twist it 180 degrees in the middle to make the loop a figure 8. Cancels the antenna effect quite nicely.
 

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Discussion Starter · #12 ·
Thanks for all the advice guys!

Any ideas of how and where to actually run both cables? As in, precise locations of where you guys run them?

I'll try to follow your advice super-closely and hopefully everything will turn out good!
 

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I ran RCA's from the trunk through a little hole in the corner by the PS corner of the rear seat. Pop up the door sills and release the carpet from the body with the little tabs then tuck the wire down there. When you get to the front of the car remove the 3 plastic nuts that hold the carpet down and take off the access panel at the edge of the door jamb and the one at the bottom of the dash (by the passangers feet) Work the RCAs under the carpet and up through the other side by putting your arm down there. pull the RCAs up into the backside of your dash until you have about how much you want there. Pull the rest of the RCA back where it came from, a little at a time and then re-secure your interior. Sounds complicated, bu i did it in about 30 minutes (and i pulled 6 sets of speaker wire for a 4 channel amp setup) Pretty much the same for the power cable on the other side (you'll want to run your 12v switched hot "remote" lead on the other side with the power cables too) except for using a grommet in the firewall to pull the cable through... just fine one you can fit it in and run it! Once you're inside the car it is just like the other side. Have fun!!!
 

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I won't have any suggestions on power wire runs until after this weekend since that's when I'll be doing my first ever G20 stereo install. As far as the run from the sub amp to the subs, again your answers will vary. That distance tends to be very short: anywhere from 1 foot to 4 feet depending on where you've mounted your amp in relation to your sub box.

You won't get much of an impedance loss over this distance, so standard speaker wire won't hurt. However, buying 1-5 feet of heavier (shielded) wire from a car audio store that will sell by the foot isn't a bad idea in a car environment where electrical noise is fairly easy to pick up.
 
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