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Wow, this thread has been great! It answered almost all my questions, but I have a few left:
Do I run the powered signal (from the amp to the fronts) with the 12V power or with the unpowered RCAs? It seems like I'd get interference no matter which side I put them on.
How do I affix all the hardware like the xovers, DCI, terminal blocks, etc? Will double-stick tape be good enough or do I need to screw them down? How do I keep them from rattling?
How do I keep the wires themselves from rattling? I'll ziptie them to existing harnesses when I can, but I assume I won't have that everywhere.
I'm going to be running the fronts and rears from my new head unit until I buy an amp (I'm going to run all the wires now in anticipation, don't worry). The HU is 4x45W; do I need to upgrade the power wire going to it? It doesn't make sense to me to run an 8ga wire from the battery to the HU when the HU only has a little pin for 12V in anyway, so I was going to use the stock wiring.
I'm planning to run the following wires:
* power from battery to trunk
* F/R/Sub RCAs from HU to trunk
* F/R powered outs from HU to trunk
* Amp remote from HU to trunk
* speaker wires from trunk to each door and each headrest
Is there anything I'm forgetting? Even though I won't have an amp and sub for a while, I want to run everything now so I only have to tear apart the car once.
Run the remote wire down the diver's side along with the power cable.
The wires won't rattle once they are under the carpet. I only ziptied cables in the areas where after I was done I could undo the zipties. If I ever have to replace a cable I don't want to have to pull out all of the other cables that it may be tied to.
As for how to attach the x-overs, etc. I just screwed them down to the amp rack once everything was done and tuned. By waiting to the end it saved me time when I was switching out parts try to find the source of my alt whine.
It sounds like you have all of the correct wires. Just remember that you will need to have the speaker cables run to where you will be mounting the amp if you don't want to go back and re-run the cables later. I would honestly advise you just to put off the project until you can install the amp. It's one less time you have to yank out the HU and have to pull speaker cables through the doors.
As for how to attach the x-overs, etc. I just screwed them down to the amp rack once everything was done and tuned.
I was planning to put them in the doors so I wouldn't have to run two sets of wires to every speaker location. Is it better to do that or to put the xovers in the trunk and run doubles of every wire?
By waiting to the end it saved me time when I was switching out parts try to find the source of my alt whine.
You're not the first person to mention alt whine. What causes it (induction, fluctuating power, etc)? What do I need to do to avoid it?
It sounds like you have all of the correct wires. Just remember that you will need to have the speaker cables run to where you will be mounting the amp if you don't want to go back and re-run the cables later. I would honestly advise you just to put off the project until you can install the amp. It's one less time you have to yank out the HU and have to pull speaker cables through the doors.
No worries about installing the amp later...I'm going to run all the wires for it to the trunk so I can just plug it in when I get it. The extra wires will just be dead until then.
While I can't give you a well defined reason why, the general concensus is to not put the crossovers in the door. There has been some talk about moisture issues and the fact that you just can't get to them easily enough.
Generally speaking, our cars have a good track record of being alt-whine free, that is compared to other models. Most of the time alt whine is cause by inproper grounding - either the ground location is no good, the connection isn't solid enough (forget to scrape off paint), or the ground wire gauge is to small when compared with the power cable. Odds are if you use the same size cable AND make solid connections AND run power seperate from your RCAs, you won't have an issue.
My problem at the end was due to a bad amp. It took forever to issolate the issue because it was a bit intermittent. Once I swapped the amp, it's been smooth sailing.
While I can't give you a well defined reason why, the general concensus is to not put the crossovers in the door. There has been some talk about moisture issues and the fact that you just can't get to them easily enough.
Okay, that shouldn't be a problem. I'm going to run 4-conductor wires to the speakers, so I'll just use half for low and half for high.
4-conductor wire can be run through into the doors with no trouble what so ever. I did it, its a piece of cake. The reasons Cathan mentioned for not placing the xovers in the door are all correct and I would agree with them totally.
I second the comment that the ground wire should be the same size as the power wire, under the conditions that they both run the same distance to the battery. They carry the same current, so having them the same makes the voltage drops symmetric. Making the ground wire smaller increases its resistance and makes the ground less stable than the +12V supply.
However, if you are grounding to the frame right next to the head unit, your ground wire does not need to be as big as the power wire. The resistance of a wire is proportional to length, so if you have a short run you can get away with a smaller diameter (higher resistance per unit length).
Originally Posted by 05S2KinClovis_CA,Sep 7 2005, 08:00 PM
Aftermarket head units does not require a 10 gauge lead. In this instance more is not better. It is just harder to run a 10 gauge lead for this source. The 12V hot lead for all head units is just to provide power for the memory for the clock, presets...etc. The fuse size is usually 1 amp or less for this lead.
This comment about the +12V unswitched yellow wire on aftermarket head units is not generally true. As one counterexample, my Alpine head unit has a 10 or 15 Amp fuse and a filter module on that line. All of its power is drawn through that wire. The +12V switched red wire is there just as a control signal to tell the unit when the car is on. Odds are that if the manufacturer recommends 10 gauge wire for a given connection, that is the primary power wire. They don't just make up arbitrary suggestions like that.
On the other hand, in my Miata I just used the factory wiring harness for my Alpine CDA-9833 and did not run any new power wiring, and never had any trouble. I plan to do the same in my S2000. The factory wiring has fuses chosen to be safe for the wire gauge in the car -- if I start blowing those fuses, then I will string heavier gauge wires.
You can of course use heavier gauge wire than is necessary, if you want to ensure that you have minimum voltage drop between the battery and stereo power input, or between the stereo ground and chassis ground. But I sure hope that the head unit has internal voltage regulators and/or uses circuitry with high power supply rejection ratio, if it's designed to work in an automotive environment.
Grounding the head unit locally to the chassis is not really necessary if you are just operating the head unit by itself with no external amps or inputs. However, once you add other devices, you should pick one single ground point and ground everything to that. The car's chassis is probably low enough in impedance that the whole thing could be considered a single grounding point.
Originally Posted by Orthonormal,Oct 14 2005, 01:11 PM
I second the comment that the ground wire should be the same size as the power wire, under the conditions that they both run the same distance to the battery. They carry the same current, so having them the same makes the voltage drops symmetric. Making the ground wire smaller increases its resistance and makes the ground less stable than the +12V supply.
However, if you are grounding to the frame right next to the head unit, your ground wire does not need to be as big as the power wire. The resistance of a wire is proportional to length, so if you have a short run you can get away with a smaller diameter (higher resistance per unit length).
This comment about the +12V unswitched yellow wire on aftermarket head units is not generally true. As one counterexample, my Alpine head unit has a 10 or 15 Amp fuse and a filter module on that line. All of its power is drawn through that wire. The +12V switched red wire is there just as a control signal to tell the unit when the car is on. Odds are that if the manufacturer recommends 10 gauge wire for a given connection, that is the primary power wire. They don't just make up arbitrary suggestions like that.
On the other hand, in my Miata I just used the factory wiring harness for my Alpine CDA-9833 and did not run any new power wiring, and never had any trouble. I plan to do the same in my S2000. The factory wiring has fuses chosen to be safe for the wire gauge in the car -- if I start blowing those fuses, then I will string heavier gauge wires.
You can of course use heavier gauge wire than is necessary, if you want to ensure that you have minimum voltage drop between the battery and stereo power input, or between the stereo ground and chassis ground. But I sure hope that the head unit has internal voltage regulators and/or uses circuitry with high power supply rejection ratio, if it's designed to work in an automotive environment.
Grounding the head unit locally to the chassis is not really necessary if you are just operating the head unit by itself with no external amps or inputs. However, once you add other devices, you should pick one single ground point and ground everything to that. The car's chassis is probably low enough in impedance that the whole thing could be considered a single grounding point.
Your comments are kinda confusing... and you somewhat contradict yourself.
Anyway I don't know anyone that runs the grounds all the way back to the battery... nor do I do I think anyone here is going to do 'that' kind of an install in an S2000 that would require it.
