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Discussion Starter #1
I bought a rather nice 300+ watt RMS amp with high level inputs, built-in low-pass xover. It was not very expensive, under $100 with shipping but looks extremely well made with big power transistors and lots of heat sinking. It looks pretty nice too, since it is a big 15+ pound chunk of black-anodized aluminum with no kiddie styling whatsoever. It is more than a foot long and 3/4 of a foot wide, so I'm pretty sure I am going to get as much output as my woofer can handle.

I will make the box tomorrow in my shop. I have lots of MDF, glue and screws already.

I was planning on disconnecting the rear door speakers, and using that for the high level inputs. However, from reading the install instructions with the amp, it looks like I should also attach a "turn on" wire from the stock head unit to the amp, so that the amp isn't running when I am not listening to the stereo.

The manual suggested the connection for an automatic antenna would be ideal. Is there any such thing? I suppose I could otherwise find a cheap relay at Radio Shack and connect to the panel lights on the LCD to provide this function.

I have tried searching for "wiring diagram", but I got lots of links but no answers. I swear that somebody has posted a link to this more than once, but there are too many bad matches to find it.

Is the cigarette lighter power sufficiently robust for a 300 watt rms amp? I know the lighter is pretty high current but it doesn't have to do 200 watts continuously like it would do under load from the amp. It would certainly be easy to connect to, and it is already fused, and rather conveniently turns off with the ignition switch. Again, I could also use a relay to turn on a more direct connection to the fuse block.

The only thing I ever use the lighter for is to charge my cell phone, so I don't care if the amp+cig lighter are too much. I won't be doing that.

Is good quality zip cord sufficient to power the amp? I have some vey high quality low-oxygen zip cord about 2x as thick (or more) and much finer wire braid than the usual lamp-style zip cord. I know that you have to go a lot thicker wire than I am used to with home wire because 12V wires need to run a lot of amps. I suppose I could just double it up to make sure.
 

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Discussion Starter #2
I have already determined that the cig lighter is probably not enough. Searching on the web indicates that it is probably fused to 20 amps. So I am going to have to connect to the fuse block I suppose.
 

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Take it from ACC and you should be fine - it's just needs 12V and I think the wires is yellow with silver dots. Has worked perfectly fine for me. I assume you do not have a Bose, because there should already be a "turn-on" wire in the harness as well as the automatic antenna (if you have that also). It's just a turn on lead so ACC will be the best option because it won't be on unless the car is on.

If you are worried about the 300W thing - don't worry cuz the V_in should be coming directly from your battery terminal.

Most likely your amp has 12V, turn-on (remote) and Ground. 12V is from the battery, turn-on is from ACC and ground to the chassis.

Here is something I found from the endless "shitty" forum search -
This is probably the most helpful thing I found while searching...

This is back of HU pinout:

.-----------|...............|-----------.
|..X V U S | ##### | F D C A |
|............................................ |
|..W...T.......P N L J H..........B. |
|.............R Q O M K I G E....... |
L------------------------------------J

A Left front door speaker (+)
B B+ (Power back up)
C Left front door speaker (-)
D Right front door speaker (+)
E Illumination (+)
F Right front door speaker (-)
G Illumination (-)
H - pwr ant
I - speed pulse
J - amp remote
K - nav: parking brake
L - telephone mute
M UART 1
N Audio control switch 1
O CAN (+)
P Audio control switch 2
Q CAN (-)
R ACC
S Left rear door speaker (+)
T Signal ground
U Left rear door speaker (-)
V Right rear door speaker (+)
W Power ground
X Right rear door speaker (-)

I will make a more user friendly version, but for now it's quite helpful!!

credit: http://www.mazda3forums.com/index.php?topic=15294.0 "celo" --> *edited - to include this in the main body, not the quote*
 

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Discussion Starter #4
Thanks for finding that. I knew I'd seen it before. Perhaps we could make this sticky after I redraw the diagram in CorelDraw.
 

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Just Curious, what amp and sub did you end up getting?
 

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Discussion Starter #6
Profile HA1000M



Power handling: 400 watts RMS/700 watts max *VCdia: 2-1/2" *Le: .95 mH *Impedance: 4 ohms *Re: 3.3 ohms *Frequency range: 23 - 1,000 Hz *Fs: 23 Hz *SPL: 89 dB 2.83 V/1m *Vas: 3.00 cu. ft. *Qms: 3.00 *Qes: .52 *Qts: .44 *Xmax: 14mm *Dimensions: A: 12-3/8", B: 11-1/8", C: 5-3/8".

http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=295-464

BTW I don't work for parts express, but I get a lot of my audio parts from them and Madisound.

Ths sub has less xMax (14 mm vs > 20 mm) than most sub drivers. The emphasis is on accuracy. It is designed with very low noise suspension, has shorting coils in the gap to provide magnetic damping. The smaller xMax makes it easier to design a driver with good magnetic control and efficiency as well. I had this one in my home, but it was sometimes inadequate, so I bought its 15" sibling for my house, which is not inadequate at all. The movie soundtracks that were causing over excursions with the 12" driver are no longer a problem.

Since the car is so much smaller than my house I am hoping that this will be adequate. I don't listen to movie soundtracks in my car either and very rarely listen to hip hop. I am not interested - as someone posted here - in "hurting" my ears.

From his rather strange point of view that was (ahem) a good thing. My sub is going to be adequate in output. I don't need to produce 120 db sounds. Ever.

BTW I have the box assembled and I am just making it look pretty this morning. Hopefully, I can begin the new year with a big bang.
 

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Yes you don't need 120db, but you have a higher floor sound base to get your sound from. In other words your car stereo has to play above road noise and what not, while your home stereo has very little noise to play above (maybe fan noise and a/c noise). So you'll probably use more juice from your amp than you think.

And as for wiring your amp up, get an 8 AWG wiring kit (run the wire from your battery to your amp, and ground the amp near the amp), and don't ever think to use you're cig lighter as a place to wire up your amp. That would be a great way to start a car fire, if the fuse didn't blow first.
 

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Discussion Starter #8
The system is capable of at least 95 db down to 25hz. I expect to hear road noise, not drown it out. That is the unfortunate part of listening to a stereo in a car. However, since I have a 45 minute to 1.5 hour total commute each day, I figure I can make it less stressful listening to some good music. I don't mind hearing road noise, it is important feedback for driving the car properly.

Yes, I am going to connect to the fuse block, not the lighter. It is only about 1/3rd as much amperage as my booster requires. Someone posted elsewhere that there is a free 40-amp position on the fuse block, and I am going to hook to that if it still there on my car model. If I had three 300-watt amps, I would run a wire from the battery, but the fuse block is already distributing at least a few hundred amps of power, so another 40 more for my single amp won't be that big of a deal.

It will be nice when cars switch to the new-fangled 44 volt system scheduled in a couple of years. You won't have to carry such huge amounts of current to get 300 watts to an amp.
 

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I really wouldn't suggest the fuseblock method you describe, 1 being if something goes wrong, and you take it to the dealer, you're going to get royally screwed. 2 being if it's not under warranty and something goes nuts in the fuseblock, you're going to get royally screwed. If you wire it to the battery on the other hand, you can pull out the amp and sub, and fool the dealer (maybe). Otherwise they're going to blame the mishap on you're 'shoddy' workmanship, no matter how good it is.

That's just me, if you want to go that route, go ahead, it's not my car.
 

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I second that - I wouln't touch the fuse panel at all. Battery would be the best option and isn't that hard to do - and your amp can take what power you need from there. There is always that possibility your amp can draw a little too much and you end up replacing more than just an inline fuse.
 

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Discussion Starter #11
I hadn't looked at the fuse block yet, but as soon as I did, I could see that it was something way different than what I had on my much older cars. The fuse block is one huge glued-together mass. On older cars, the fuse block was much more accessible, and it was really easy to tap off the hot side and add additional circuits.

Modern computer design makes it possible for them to engineer this much more elaborately. None of the wires are as oversized as they were on my '72 Beetle. It doesn't look like there is a single input wire either, there are lots of smaller ones instead, so you can't just piggyback onto the large input wire the way I used to do.

So I just took the car to Car Toys. I wasn't exactly looking forward to doing the hard work of running the wires around anyway. I did way too much of that when I was a kid and I still find it to be just work rather than fun.

So it cost me $85 bucks, plus $50 for the harness that I didn't have yet.

In the meantime I can do the much more fun stuff of working on the box.
 

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Discussion Starter #12
Happy New Year everyone and thanks for the help with my sub. It works fine. I will post some pictures when I get my new cell phone. My current phone takes pictures, but they are worthless.

I need to tweak it quite a bit, but it sounds good already. I think the bass boost is set a bit high, and it may need to cross out about 10-20 hz sooner.

I was listening to a very bass heavy electronic music (Goldfrappe) for 20 minutes and the amp isn't even warm. This is part of the reason why I bought a class D amp as they are extremely efficient. I also never heard any indication of over excursion like I did when playing the same material at home on this woofer.
 
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