How to use the OEM amp Wiring

[alexand3r]

This information is awesome, thanks guys!

I figured that I would share my experience:

I tried the 445u amp without thinking about it's specs too much. I believe that it worked so well for the first guy that used it because perhaps his 6.5 speakers are two-way and have a crossover of some sort.

I tried using this amp on the stock speakers and, while way louder and cleaner, this amp only has a high-pass filter - which is not good for our stock woofers. My plan is to use this info and hook up an amp with a low-pass filter to the stock speakers, specifically this one:

Kicker 11DX125.2 (It will also work with the stock wiring - 15A)
***Only $67.99 at Best Buy***

I like the highs that the stock system offers and figure that by using this amp I can flatten low frequency EQ settings on the head unit, which should clean up the highs for the dash speakers even more, and then use the gain and bass boost on the amp to enhance those signals going to the door woofers for a fuller, more crisp sound.

Any which way, I have this amp being shipped to store and it should be there by this weekend. I'll give this a shot and report back with my findings.

[B-R-Z]

In my BRZ the door speakers rattle and sound terrible. Once I installed a sub in the trunk I just disconnected the factory amp to eliminate the door speakers. I can now turn my volume up to 100% and the highs are loud and clear and it all together sounds great.

[alexand3r]

Originally Posted by B-R-Z

In my BRZ the door speakers rattle and sound terrible. Once I installed a sub in the trunk I just disconnected the factory amp to eliminate the door speakers. I can now turn my volume up to 100% and the highs are loud and clear and it all together sounds great.

I've already 'matted my door skins, cards and foamed all switches to take care of the rattles. I've actually never tried pushing a pair of 6.5 speakers and am curious to see how much bass I can get and if it will be acceptable (as I do not want to take up trunk space with a sub).

If not, I may try switching out one of the door speakers with a 4-ohm woofer, hooking up a 4-ohm 8" or 10" speaker in the trunk and running both of those off of one channel (Amp is stable at 2-ohms). Or perhaps I could replace the doors with 8-ohm speakers and put in a 4-ohm sub, bridged to both channels.

[alexand3r]

Update:

Just installed the amp and went ahead with door speaker upgrades. Sounds great, IMO much better than the Alpine amp. However, there are only two channels - but the sound stage is very nice with the factory dash speakers (Being powered off of the headunit). It really just fills in the sound all around you with more frequency, not just highs/lows, but better mid-range imaging.

I did some tests bridging the two channels to a 4-ohm speaker and it seems to handle it just fine. Therefore my next step is making a 80 Hz passive crossover (I want to leave the fronts set to full-range) and testing that with a 10" sub, bridged to the L/R channels. For the crossover I'll be testing 330-350uF caps and 10-12mH inductors to see what sounds best.

This amp is much bigger than the Alpine unit, but still fits nicely in the stock amp location. I'll take some pictures once I'm done with the whole thing for those who are interested. I'm just going for a nice, clean install that is easily put back to stock. Again, I would like to thank the OP for the wiring schematic, it is much appreciated and has been very useful.

[B-R-Z]

I have been running on everything except the door speakers and I am missing the mid bass. I need to fix my window switches to not rattle and get better speakers that will allow me to max out my volume.

[alexand3r]

Originally Posted by B-R-Z

I have been running on everything except the door speakers and I am missing the mid bass. I need to fix my window switches to not rattle and get better speakers that will allow me to max out my volume.

Oh yeah, that'll do the trick.

In case you haven't done it before:

Just take your door cards off, pop open the window switch case with a flat head and cut a piece of dense foam to go in there under the circuit board (I re-purposed some foam from packing material that came inside of a sound card box). Just don't get it too tight (ie - cut the foam too thick) or your switches will be overly sensitive.

[OneMic]

I didn't change a thing as far as speakers and deck. I kept the factory system. I just added amp and sub. If you plan on doing the same thing I recommend the AC LC2i. I love it!

[Cockatoo]

Just ordered some new goodies, gonna use this thread to help me re-pin the line level inputs:

http://www.polkaudio.com/products/mm1040
http://www.polkaudio.com/products/pad4000_4
http://www.polkaudio.com/products/mm6501

[Cockatoo]

Just put my speakers and amp in! Lightyears better than the stock setup with just a component set up front and a 10 inch sub in the trunk.

*I took the stock dash speakers out and its the perfect place to stuff the crossover!

[Cockatoo]

Also for those that need speaker adapters but don't want to buy those expensive ones, these worked perfect!:

[ame="http://www.amazon.com/gp/product/B007ZQGZWO/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1"]Amazon.com : Toyota Aftermarket 6.5-Inch Plastic Speaker Adapter (Black) : Vehicle Audio Auxiliary Adapters : Car Electronics[/ame]

[Chimera]

any plans for rear speakers?

Originally Posted by Cockatoo

Just put my speakers and amp in! Lightyears better than the stock setup with just a component set up front and a 10 inch sub in the trunk.

*I took the stock dash speakers out and its the perfect place to stuff the crossover!

[Cockatoo]

Originally Posted by Chimera

any plans for rear speakers?

I don't like rear fill.... so pointless. Especially since there will be no back seat passengers in this car.

[SubieNubie]

How much juice can the stock wiring to the door speaker and handle? I'm looking at purchasing an Alpine MRV-F300 (75RMS @ 2ohms) to power the OE door speakers before I purchase some upgraded ones. Also I have yet to dig around the trunk, would anyone happen to know if that Alpine amplifier would fit in the stock amplifier location?

UPDATE

I got around to taking some measurements yesterday after I was done washing the BRZ. From the measurements on Crutchfield, the MRV-F300 won't fit without some modification to the foam piece surrounding it. It looks like I'd need to take at least 1/2" off the inside and chamfered corner. Adding to that bad news, it looks as if you need to disassemble the rear seat just to remove that foam piece (reference). In addition to that, it is not flat where the OEM amplifier is mounted. The bottom slops down towards the rear seats. Also the rear seats taper toward the front as well.

[Chimera]

Idk about size but if you run the 445u bridged it pushes 90 w. I did that for quite a bit with no issues.

Originally Posted by SubieNubie

How much juice can the stock wiring to the door speaker and handle? I'm looking at purchasing an Alpine MRV-F300 (75RMS @ 2ohms) to power the OE door speakers before I purchase some upgraded ones. Also I have yet to dig around the trunk, would anyone happen to know if that Alpine amplifier would fit in the stock amplifier location?