My bluetooth connected mini amp stereo project

Joined
18 February 2012
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574
Location
SoCal
For this project, I had a couple goals in mind:
1. Be able to connect my iPhone to the stereo.
2. Remove some excess weight.

I never listen to the actual radio or CDs anymore, so I decided I wanted to remove all of the associated parts relating to those two. I removed the CD changer from the trunk and the radio headunit from the cabin, with intentions of wiring a mini amp directly to the speakers.

I now have an NSX-R delete plate covering the hole.
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I purchased a Fiio A1 mini amp and was able to wire it directly to the speakers. I was pleasantly surprised to find that the original owner had installed aftermarket speakers, so I did not have to deal with the amps in the speakers. I spliced the power off of the cigarette lighter power source, as I wanted it to work like OEM, and not have it draw power when the car is off. Due to the fact that the amp is 12v DC, I was able to splice directly into the power line.

This is how I had it for a little while, which is obviously not ideal. My end goal was to put it into the center console armrest.
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I eventually fit it all into the armrest, creating a tunnel for the wires from the center console through to the armrest, and it was great. I was using a Belkin retractable audio cable to plug my phone into, and it worked fine. But, there was just something not ideal about having a cord, and having to plug my phone in every time. So I searched some more for bluetooth adaptors.

I was elated to find the Kinivo BTC450 hands free car kit, and it turned out to be exactly what I was looking for. It's actually an incredibly cool little device because the little module has a microphone built into it (for phone calls), and also remote control buttons, so I can pause and skip the music using the little remote. Another great (and very necessary) feature is, this particular one auto connects to your phone when you turn on the car. Apparently other modules don't auto connect. After I plugged it in, it worked great, but there was static coming through the line. After some quick research, I was able to find this PAC ground loop isolator which stopped all of the static, and now the audio comes in crystal clear! I also ordered a cigarette lighter socket because the BTC450 uses one of those plugs, and it has a usb port on the other side, so I'll be able to charge my phone as well.

Here's everything stuffed into the armrest, the amp is a perfect size to be a snug press fit. I secured the ground loop isolator down with sticky tape.
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I sticky taped the remote module in an out of the way but easily accessible area.
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I'm incredibly happy with the way things turned out, as I ended up with even more functionality than I had originally planned for. The bluetooth connectivity is awesome since I don't have to plug anything in. The stereo gets loud enough for me on the highway. It doesn't get ear bleedingly loud, but who wants that anyway? In the future I'll do a little bit more wire management, but honestly the arm rest will be closed all the time anyway, so I'm not in a rush.
 
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What exactly did you mean by "I purchased a Fiio A1 mini amp and was able to wire it directly to the speakers"? Did you open up the doors and bypass the BOSE amps? If not, I don't understand how you got this to work as you would have been "double-amp'ing" the signal .. once with the Fiio; and then again with the BOSE amps .. which would probably only work with very Fiio low amplification. Or maybe by ripping out the head unit, the BOSE amps in the door are no longer being powered and maybe the signal just flows through .. which would be an interesting development that would also simplify any central amp project. What did you do with the sub?
 
OP: Do you adjust volume just on the iPhone? I also have the Kinivo (for me wired straight to the Bose amps in the doors) and I find the beeps it makes to be annoyingly loud.

Thanks for the link to the ground-loop eliminator. I have a slight bit of alternator whine that is irritating and that I didn't have when connecting my headphone jack straight to the Bose amps, even while charging my phone.
 
What exactly did you mean by "I purchased a Fiio A1 mini amp and was able to wire it directly to the speakers"? Did you open up the doors and bypass the BOSE amps? If not, I don't understand how you got this to work as you would have been "double-amp'ing" the signal .. once with the Fiio; and then again with the BOSE amps .. which would probably only work with very Fiio low amplification. Or maybe by ripping out the head unit, the BOSE amps in the door are no longer being powered and maybe the signal just flows through .. which would be an interesting development that would also simplify any central amp project. What did you do with the sub?

I wired it to the speakers so long ago I forgot to mention when I went into the door panels I was pleasantly surprised to find that the original owner had installed aftermarket speakers. My original plan was to bypass the amps and wire straight into the speakers. Unfortunately since I didn't have to do it, I have no info on what would be required. Sorry for the confusion.

When I went in to remove the sub, the footwell was filled with an aftermarket amp and some crossovers. Which I removed.

- - - Updated - - -

OP: Do you adjust volume just on the iPhone? I also have the Kinivo (for me wired straight to the Bose amps in the doors) and I find the beeps it makes to be annoyingly loud.

Thanks for the link to the ground-loop eliminator. I have a slight bit of alternator whine that is irritating and that I didn't have when connecting my headphone jack straight to the Bose amps, even while charging my phone.

Yes, I adjust using the phone, although the volume knob is accessible. I agree the beeps are very loud and I was wondering if there's a way to disable them.

Yeah ah the ground loop isolator is a magic little box! I was surprised about how well it works.
 
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I wired it to the speakers so long ago I forgot to mention when I went into the door panels I was pleasantly surprised to find that the original owner had installed aftermarket speakers. My original plan was to bypass the amps and wire straight into the speakers. Unfortunately since I didn't have to do it, I have no info on what would be required. Sorry for the confusion.

When I went in to remove the sub, the footwell was filled with an aftermarket amp and some crossovers. Which I removed.
Tks for the clarification. I put in a central amp system and bypassed the door amps so I know what's required. I just wanted to clarify for other readers that central amp solutions also require bypassing the door (and sub) amps.
 
...I agree the beeps are very loud and I was wondering if there's a way to disable them.

Yeah ah the ground loop isolator is a magic little box! I was surprised about how well it works.

You are right about the ground-loop eliminator. I got one and it worked wonders for my Kinivio > Bose-amps setup. And a nice side effect is that it attenuates the signal a little, so the beeps from the Kinivo are no longer fully annoying. I was all set to put a head unit in my car but I'm wondering if I even need it now. I think I may end up there for the better DAC and some improved usability compared to the Kinivo but I'm in no rush. I will probably start with amp & speakers and see how I feel then.
 
I was pleasantly surprised to find that the original owner had installed aftermarket speakers, so I did not have to deal with the amps in the speakers. I spliced the power off of the cigarette lighter power source, as I wanted it to work like OEM, and not have it draw power when the car is off. Due to the fact that the amp is 12v DC, I was able to splice directly into the power line.

May I ask what kind of aftermarket speakers you have?

I am trying to do the same setup but unfortunately the FiiO A1 is no longer available so I have to piece together something else.

I think for the lower powered amps, I need speakers that are at least rated at 4ohm.
 
May I ask what kind of aftermarket speakers you have?

I am trying to do the same setup but unfortunately the FiiO A1 is no longer available so I have to piece together something else.

I think for the lower powered amps, I need speakers that are at least rated at 4ohm.

Wow that is crazy that the amp is no longer available! I wonder what happened...

Unfortunately I do not know what kind the speakers are... Some sort of Eclipse speakers.
 
My only guess is that they are gearing up to release a new version and have discontinued the A1 - maybe there will be an A1+ or A2?

Thanks for the info and for putting together this thread!

Can't wait to rip out the stock system....Have you acquired the block off plate for your stereo yet? If you have, I'm curious as to how it mounts/secures to the center console.
 
I hope that is the case, because this amp is a very cool piece of electronics.

Yes, I have acquired the block off plate from Louis, Advanscpap on Prime. It secures to the center console using screws and washers that friction fit hold it in 4 to 6 places (I forgot how many). It's pretty secure, and you don't have to drill the center console which is always a plus.
 
Just wanted to raise a shout out to Colin for this nice write up and install. He helped me with it and I now have 21st century electronic architecture in my NSX. Very cool and a great guy to deal with. Thanks.
 
Just a quick update, I enjoyed the sound improvement so much with this little device, I bought one for my truck. Just got done installing it and can't believe the quality of sound in Bluetooth over the direct RCA connector. What a nice little upgrade for under $40. Love it. Thanks Colin.
 
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