I have never done any kind of car audio installation of any kind and I have a bunch of questions about what I need to do. I have no problem removing panels from my car, stripping/soldering or working with wires, I just need a place to start. I currently have an aftermarket headunit that already has 4 RCA outputs (FL, FR, RL, RR) running to 2 low wattage junker amps that I am replacing (one 4 ch., one 2 ch.). I have three 10's in a box already. With that said, here are my questions:
1.There is only one L/R speaker input on the box (does this mean they're parallel or in a series? I'm clueless to wiring/electrical terms.)
2. I don't know if the subs are 8 ohm or 4 ohm. If they're 8 and I get an amp that's 4, bridgeable to 2, am I going to screw something up?
3. Right now the 4 channel amp gets the inputs from the FL/FR RCA's and the 2 channel (sub) amp gets the inputs from the RL/RR RCA's. Is this correct?
4. When installing the new amps do I need to install a crossover, and if so, should it be a 2 way or 3 way? (Again, I don't know the dirrerence.)
5. I know that there is a fuse already installed on the power cable a few inches from the battery, and most all amps have fuses in them, so do I need to install new fuses going to the new amps? The amps I have now don't have any fuses on the wire.
6. The amps I have now have power from one red, one black running to the 4ch amp from the car battery. Then the 2 ch amp has the red and black wires just running from the first amp to it. Should they be like that, or does each amp need it's own power feed from a distribution box?
7. Do I need to install a capacitor? If so, what size (1 farad 2 farad etc...) I have seen something called a BattCap which looks like one of those great big boxy flashlight batteries, and claims to be equal to a 30 farad capacitor. Are these a good idea, or should I stick to a regular one? I know part of this has to do with my next question.
8. I have quite a big budget to spend on amps, so they will most likley be 1600-2000 watts each. (I realise my current speakers can't handle this and will be upgraded at a later time) Do I have to run a new power cable from the battery that's 0 awg?
There are a few more questions I have, but I'll wait until after some of these are answered to see if it answers some of the other ones, or changes them. Thanks for any help.
Replies (5)
Swez on 09/8/2003 23:51:15
OK, we can help out but I am not up too all the details noted right now as it's late... time for beddy-bye and I gota take my Geritol.
Will review your details tomorrow and make some comments to lead you along.
At least you understand some of the basics... but we will cover the details in depth too. If I use words/terms that you are not familiar with... ask and I will 'splain them to ya.
Welcome to the forum!
Swez
Swez on 09/9/2003 07:58:55
OK, morning now and well rested... let's get on with the show...
1. These tri-sub boxes are generally wired to net a 4 ohm load to the sub amp. If you have an ohm meter, check the ohms load off the sub box terminals. If you see something different that ~3.2 ohms, please advise.
2. Most likely, these are 12 ohm subs in parallel. This is most common in MTX tri-sub boxes. A 2 channel amp, bridged MONO will do fine with a 4 ohm net load. If a different wiring scheme is used and say 8 ohm subs... they can be wired in parallel for a 2.67 ohm net load. Here, a Class D MONO sub amp that is 2 ohms stable, makes the most sense.
3. That will work in most cases. Do you have rear speakers running off the 4 channel amp as well? If you do, a set of "Y" splitter patch cords can be used feed HU rear channel signals to rear channel inputs on 4 channel amp & sub amps.
4. About amp crossovers... better amps have built in crossovers already. For Mid/Highs, the crossover to use is a HP filter, set to around 80 Hz. For the sub, set the LP filter to same... 80 Hz and subs will get only lows... below 80 Hz.
5. The battery fuse is there to protect the electrical system. You will need a large enough fuse and wire gage to handle the current drawn from both amps. The more output the amp is capable of, the larger the gage wire needed and fuse values as well. Most newer amps have fuses either inside the case or externally mounted to the chassis on the power input side.
6. When using 2 amps, is best to used a power distribution block. You take one larger power wire from the battery/fuse block... run it back to the amp locations and split the power at the D-block to each amp. The wire gage to use for each amp is determined by the power consumption of eah amp. The main power feed wire gage is determined by the total power draw from both amps added together.
7. Caps are really not a great way to go. Btter to invest in a high output ALT and a larger capacity battery set. (800 CCA rating or more) The bigger the battery CCA #, the more current storage buffer you will have for the amps.
8. It would be good to pick out a few amps you wish to buy, then get a wiring kit that matches your power draw needs for these amps. In most cases... #2 or #0 gage power feed will handle larger amplifiers.
I have a few questions for you...
a. What is the ALT capacity on this model car?
b. Battery... what is the CCA rating on that?
c. What gage power feed and fuse are installed to date?
d. Have you pulled 1 sub out of the box to see what make and model # these are? Usually stamped on the magnet back plate.
Having these details handy before you start will net a clean install later. So far, very good detail of questions and you are on the right track.... just want to keep you moving forward as you swap out old gear for new.
Swez
seant7326 on 09/9/2003 10:28:51
Thanks for all the great info. I will need to call Nissan to find out about the alternator capacity, and I'll check out the battery and speakers today. I'm sure the power feed and fuse will need replacing, looks to be 4 awg or smaller.
seant7326 on 09/9/2003 21:23:00
OK, I found that my alternator is 80 amps, and the battery I currently have is 460 CCA. I'm not sure about the fuse or power feed, but I am replacing them anyway as I'm sure they're not adequate for what I plan on doing. About how much is a battery with a higher CCA rating (like 800 as you suggested)? And if I need to replace the alternator what are my options, pricewise? Are alternators interchangeable, or do I need to get one that's made for my specific make and model?
Swez on 09/9/2003 21:54:15
Well, asking good questions... we need to define your goals. If you want a very potent system, of Mids/Highs and Subs, looking at some pretty notable upgrades for your electrical system.
An 80 amp ALT and that battery will not do well in a large amping system. But seeing that you have a very small vehicle, a huge system is not needed or very easy to do. What do you want to do in terms of your sound system? SQ, high SPL or a bit of both?
Yes, you can beef up the battery and maybe... have the ALT tweaked for more output... but is that needed? Tell me where you want to go.
Once that is defined, then we can move forward with intelligent choices OK.
Swez
1.There is only one L/R speaker input on the box (does this mean they're parallel or in a series? I'm clueless to wiring/electrical terms.)
2. I don't know if the subs are 8 ohm or 4 ohm. If they're 8 and I get an amp that's 4, bridgeable to 2, am I going to screw something up?
3. Right now the 4 channel amp gets the inputs from the FL/FR RCA's and the 2 channel (sub) amp gets the inputs from the RL/RR RCA's. Is this correct?
4. When installing the new amps do I need to install a crossover, and if so, should it be a 2 way or 3 way? (Again, I don't know the dirrerence.)
5. I know that there is a fuse already installed on the power cable a few inches from the battery, and most all amps have fuses in them, so do I need to install new fuses going to the new amps? The amps I have now don't have any fuses on the wire.
6. The amps I have now have power from one red, one black running to the 4ch amp from the car battery. Then the 2 ch amp has the red and black wires just running from the first amp to it. Should they be like that, or does each amp need it's own power feed from a distribution box?
7. Do I need to install a capacitor? If so, what size (1 farad 2 farad etc...) I have seen something called a BattCap which looks like one of those great big boxy flashlight batteries, and claims to be equal to a 30 farad capacitor. Are these a good idea, or should I stick to a regular one? I know part of this has to do with my next question.
8. I have quite a big budget to spend on amps, so they will most likley be 1600-2000 watts each. (I realise my current speakers can't handle this and will be upgraded at a later time) Do I have to run a new power cable from the battery that's 0 awg?
There are a few more questions I have, but I'll wait until after some of these are answered to see if it answers some of the other ones, or changes them. Thanks for any help.
Replies (5)
Swez on 09/8/2003 23:51:15
OK, we can help out but I am not up too all the details noted right now as it's late... time for beddy-bye and I gota take my Geritol.
Will review your details tomorrow and make some comments to lead you along.
At least you understand some of the basics... but we will cover the details in depth too. If I use words/terms that you are not familiar with... ask and I will 'splain them to ya.
Welcome to the forum!
Swez
Swez on 09/9/2003 07:58:55
OK, morning now and well rested... let's get on with the show...
1. These tri-sub boxes are generally wired to net a 4 ohm load to the sub amp. If you have an ohm meter, check the ohms load off the sub box terminals. If you see something different that ~3.2 ohms, please advise.
2. Most likely, these are 12 ohm subs in parallel. This is most common in MTX tri-sub boxes. A 2 channel amp, bridged MONO will do fine with a 4 ohm net load. If a different wiring scheme is used and say 8 ohm subs... they can be wired in parallel for a 2.67 ohm net load. Here, a Class D MONO sub amp that is 2 ohms stable, makes the most sense.
3. That will work in most cases. Do you have rear speakers running off the 4 channel amp as well? If you do, a set of "Y" splitter patch cords can be used feed HU rear channel signals to rear channel inputs on 4 channel amp & sub amps.
4. About amp crossovers... better amps have built in crossovers already. For Mid/Highs, the crossover to use is a HP filter, set to around 80 Hz. For the sub, set the LP filter to same... 80 Hz and subs will get only lows... below 80 Hz.
5. The battery fuse is there to protect the electrical system. You will need a large enough fuse and wire gage to handle the current drawn from both amps. The more output the amp is capable of, the larger the gage wire needed and fuse values as well. Most newer amps have fuses either inside the case or externally mounted to the chassis on the power input side.
6. When using 2 amps, is best to used a power distribution block. You take one larger power wire from the battery/fuse block... run it back to the amp locations and split the power at the D-block to each amp. The wire gage to use for each amp is determined by the power consumption of eah amp. The main power feed wire gage is determined by the total power draw from both amps added together.
7. Caps are really not a great way to go. Btter to invest in a high output ALT and a larger capacity battery set. (800 CCA rating or more) The bigger the battery CCA #, the more current storage buffer you will have for the amps.
8. It would be good to pick out a few amps you wish to buy, then get a wiring kit that matches your power draw needs for these amps. In most cases... #2 or #0 gage power feed will handle larger amplifiers.
I have a few questions for you...
a. What is the ALT capacity on this model car?
b. Battery... what is the CCA rating on that?
c. What gage power feed and fuse are installed to date?
d. Have you pulled 1 sub out of the box to see what make and model # these are? Usually stamped on the magnet back plate.
Having these details handy before you start will net a clean install later. So far, very good detail of questions and you are on the right track.... just want to keep you moving forward as you swap out old gear for new.
Swez
seant7326 on 09/9/2003 10:28:51
Thanks for all the great info. I will need to call Nissan to find out about the alternator capacity, and I'll check out the battery and speakers today. I'm sure the power feed and fuse will need replacing, looks to be 4 awg or smaller.
seant7326 on 09/9/2003 21:23:00
OK, I found that my alternator is 80 amps, and the battery I currently have is 460 CCA. I'm not sure about the fuse or power feed, but I am replacing them anyway as I'm sure they're not adequate for what I plan on doing. About how much is a battery with a higher CCA rating (like 800 as you suggested)? And if I need to replace the alternator what are my options, pricewise? Are alternators interchangeable, or do I need to get one that's made for my specific make and model?
Swez on 09/9/2003 21:54:15
Well, asking good questions... we need to define your goals. If you want a very potent system, of Mids/Highs and Subs, looking at some pretty notable upgrades for your electrical system.
An 80 amp ALT and that battery will not do well in a large amping system. But seeing that you have a very small vehicle, a huge system is not needed or very easy to do. What do you want to do in terms of your sound system? SQ, high SPL or a bit of both?
Yes, you can beef up the battery and maybe... have the ALT tweaked for more output... but is that needed? Tell me where you want to go.
Once that is defined, then we can move forward with intelligent choices OK.
Swez
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