Alternate tweeter location / stereo install synopsis (PICS!)

[ToddG]

The tear out of oem equipment
Write ups about this procedure already exist but I wanted to note a few things.
All four oem door speakers are labeled 2 ohm for the record. I would have to assume the oem HU was running at 2 ohm also. The fronts are labeled as “Nissan” while the rears are labeled “Blaupunkt” (go figure, in a Jap truck?). The oem tweeters I left installed but disconnected from my current system in favor of an alternate tweeter position, more on that below. Not much to say about the oem HU, it removed easily, no surprises there just remember to remove any CD before disconnecting it (*cough* . . bungyfish).

New gear

Kenwood KDC-MP438U
Polk Audio MMC6500 (front)
Polk Audio DB651 (rear)
KCA-SR50 (interface between Sirius receiver and HU)
SiriusConnect SC-C1 (universal Sirius tuner)

I purchased the Kenwood for the following reasons. My requirements were something with decent power to try to avoid amping the door speakers if possible (This unit is rated at 22 watts RMS and 50 peak, more on that in a bit). Other requirements were: MP3 capable, USB input (for tunes on a thumb drive), an auxiliary input (MP3 player, etc.) Sirius radio capable, three sets of pre-amp outs (including sub), and a remote. Also I didn’t want to break the bank on a HU. Simplicity has it’s advantages too.
As I stated in another thread I am a Polk fanatic. My home theater is all Polks accept for my Velodyne sub (Velodyne is the grandfather of subs). So when it came time to chose vehicle speakers that was easy (I’ve had Polks in my last four rides).

As a note, I soldered every connection possible. I’m not a big fan of tapping wires or wire nuts. This will obviously help eliminate a loose wire condition. I didn’t want to cut any factory wires but that ended up being unavoidable. I used all factory wiring for the HU (Nissan adapter from Crutchfield) and factory wires for the rear speakers. Although all four door speakers did require me to cut the factory plugs off at the speaker connection and replace with the shortened Polk leads (no big deal, and yes soldered).

The HU had no big surprises. The only pain involved there was the Crutchfield “Nissan” install kit which consisted of a new HU bracket (plastic, not metal like the oem), a din filler (takes up the extra room left from the double din oem HU) and the trim plates. The trim plate did not fit without modification, hello dremel tool. The Sirius receiver and Kenwood control module plugged directly into the deck, NO extra power leads required (thank you very much). I bundled up the extra wire from them and basically just stuffed them down into the cavity under the radio, it was a snug fit.

The rear speakers went right into the oem plastic speaker “stand-offs”. I did have to drill these stand-offs for extra screws to hold the speakers in place but they fit well and it was easy. The stand-offs provided plenty of clearance for the bigger Polk magnets. I can’t imagine any speaker not having enough magnet room if using the stand-offs. The oem rears were 6-1/2” and the Polk rears were 6-1/2”, easy right?

The fronts, not so easy. First the oem fronts were 6x9 and the Polks are 6-1/2”. This required an adapter plate which you can generally get at any local car stereo install place (I got mine off Ebay). The adapters had to be trimmed (inner diameter) to fit the Polks, hello scroll saw. I mounted the adapters to the doors and then the speakers to the adapters, added extra screw holes as with the fronts to secure them in place. You can’t use too many screws when installing speakers, something I found out many years ago after rattling speakers in one of my first installs had to be redone. The fronts had one other issue that was easily remedied. The factory wiring was on the outside of the speaker hole/stand-off not on the inside as was the case with the rear speakers. After cutting off the factory speaker plug I then drilled a small hole, just big enough for the wires to pull through, and routed the wires inside to make connections to the Polks, a dab of silicone on the wire holes I drilled and I was ready to go. Next the tweeters. I opted to mount them to the “A” pillar. As far as my decision to mount them there, it puts them on a parallel plane with my door woofers and removes the windshield bounce required in the oem locations, plus the wife’s Altima SE-R has them stock in that location. Treble is particularly directional as most know. My tweeters pivot slightly and of course I have them aimed back as far as they go (towards the occupants). I would have preferred to mount them flush, but by my calculations they just wouldn’t have fit. So, I surface mounted them by drilling small holes in the pillar cover and bolting thru with an 8-32 machine screw and lock nut to secure them. They look great and accent the interior nicely. The only downside is now I am advertising to the world that I have aftermarket goodies in the truck (there goes my stealth approach).

Installing the x-overs wasn’t bad except for having to lay on the truck floor (for about 40 mins) to get to the kick panels and under the dash (I know wha wha wha). I cut the factory speaker wire at the kick panels (thank you shop manual) and connected the out (part going to door woofer) to the crossovers. I ran extra wiring from the wire harness at the head unit to the crossover to get the signal there. Of course I then connected the tweeters. The crossover on the driver side went in behind the kick panel no problem. It sticks out the top a bit, but you’d have to be laying down in there to even see it. The passenger side was a little more cramped behind the kick panel so the x-over wouldn’t fit. The passenger side x-over now resides up in the dash behind the glove box.

Lastly I routed my RCA cables and remote turn on lead under the center console and out to under the front seats. These are there for the subwoofer amp and possibly an amp for the door speakers.

Conclusion

So, how’s it sound you’re asking. Well, it sounds probably ten times better than the basic oem Nissan stock set-up. The high end is now present and accounted for, the mids are much much better, and the low end stayed about the same, in other words in need of a subwoofer. From the small amount of time I've listened to the system the tweeters sound almost perfect in that location. They are slightly "bright". Fortunately should I decide to tone the tweeters down a bit, my cross-overs have built in attenuators selectable at, 0,-3db,-6db (currently set at 0). I'm going to leave them this way until I install my sub and give another listen then possibly adjust them. For those of you wondering, the door speakers are running off the HU. They are clean sounding from top to bottom, and when I say top I mean volume all the way up to 35 (top limit on the Kenwood). Why would I do that to brand new speakers . . . what was I thinking!?!? Well quite frankly, the 22 watts RMS the Kenwood is supposedly pushing is a little over rated in my opinion. A decent listening level requires a volume setting of about 20. So as you can imagine 35 is not quite as loud as I would like and most likely I will be adding an amp to the door speakers. I want to wait until the sub is in to determine that. Bass fills a small area like a truck cab quite efficiently since it’s not directional at all. That might be all the fill I need to experience a “louder” listening level. Plus with the low pass and high pass cut-offs properly adjusted to rout the appropriate frequencies to the appropriate speakers, the door speakers will have the same amount of wattage, to produce a smaller range of frequencies. Simply put they won’t be working to produce much bass and that should help the mid and upper ranges.

I have a Polk Audio DB104 10” sub on the way. It’s top mount depth is 5-1/2” and cu. ft. requirements are .66 which should be do-able with a custom enclosure. I’m planning on putting that under the passenger side rear and sacrificing my large storage bin. I’m a little concerned about it fitting, due to magnet diameter. We’ll see. If necessary I’ll use fiberglass for enclosure construction. (I hope I don’t have to, I think working with fiberglass is a pain in the a$$) I’ll follow this up after I fabricate the enclosure and drop the sub in.

Well, I know some people don’t like to read this much and I apologize to them. But, if I help even one person or save somebody some time on their install then this was worth every minute I spent on it.






Pretty pictures attached. My Polk tweeter locations, the wife's SE-R, her tweeter location and my Hella DE Micro driving lights that I've spoken to a few of you about. Enjoy!

[WeeHooker]

Nice write-up Todd, I'm glad it turned out to your satisfaction. Just helped a friend put a set of those polk components in his truck last week. I like them allot. Keep us posted on the sub install too. Never too many approaches /data points IMHO. ( I feel your pain with Glass work too!)

I have my sub amp under the drivers seat and my main amp in the rear bulkhead on the drivers side. The front seat install is easier and has more breathing room but limits you to 17" +/-length. The rear wall has more flexibility but if you don't want to move the jack, limits you to 18-19" or so. I just replaced the "main" amp on the back wall and can tell you that if you mount it low/near the floor, and keep the amp thickness and height down, there is no interference or heat issues. Also FWIW, I ran a Sony XM-4S (50Wx4) and now an Alpine PDX 4.100. (100Wx4) Both are relatively tiny, digital and very efficient. I mounted them right over the raised panel where the vent is. Fits good/clean and makes it easy to tweak settings. Both are cool as a cucumber even after hours of use. FWIW, The Sony can be had for less than $150 and the Alpine runs about 2x that. I'd recommend either for clean power in a small package.

[ToddG]

I'm now leaning towards the 5 channel amp approach. One amp to do it all and be done with it. I don't know. I'll be busy with the sub enclosure this weekend and that should give me time to think it over more. Thanks for the amp input WeeHooker.

[gti16vman]

Wow, great writeup. Looks like when the sub is in there, it should really round out a nice system. And I see what you meant with the gap around the DE's. Will let you know if I come across anything that might work to fill that in.

[ToddG]

I just ordered the PDX-5. Door speakers will need amped to get the volume level I'm looking for. The sub needed amped either way. Small foot print on this amp too, so under the seat it will go. I can't wait! More to come after install.

[tegrady]

Looks good so far!

BTW - My name is Todd G too.

[ToddG]

Originally Posted by tegrady

Looks good so far!

BTW - My name is Todd G too.

From one Todd G to another . . thanks!
(Middle initial is "W" . . . . not yours too is it?) . . edit: never mind, it's probably "E" judging by your nick.

On a side note, it appears my sub enclosure will have to be made of fiberglass to keep wall thickness under control and maximize space. Should be starting that project this weekend. I will of course take loads of pics and document everything.

[05cc4x4]

You know this is how it starts right? I was perfectly happy with my truck and my wife goes and buys me an alpine deck so I can listen to my ipod in the truck. "You know the speakers just don't sound as good as they could". In goes the components. "You know the deck just doesn't have enough power." In goes the amp. "You know there just isn't enough bottom end." In goes the sub and another amp. You'll be happy with it for awhile and then. "You know, those nav systems are on sale". "As long as I'm putting this in, all these accessories, that's only a couple hundred more." In goes that stuff. But by this point you'll run out of stuff to put in the truck. Then you'll be depressed for a few days because you dont have anything to lust over. Then you start looking at suspension systems and tires. That's about as far as I've gotten. It's an addiction, an expensive one. I'm messing around of course, although I bet in a few years all that stuff is in your truck. Looks good though. You should add the audio controls. It's only another hundred or so all together, use my how-to thread. Just think how great it will be not to have to lift your arm up and touch the HU.

[ToddG]

Well, you may be right. For now, all I know is I want my mobile jam sanctuary back. The truck I just sold was hooked up, by me off course. I dearly miss being able to crank up the tunes and drown out the world. I have a really nice home system but the trouble there is the wife and kid are usually home, and occupying my home stereo/theater by watching a movie or TV in surround or playing Xbox360 or Wii. Plus they don't always appreciate my musical tastes.

One thing at a time Justin, one thing!
(the Nav systems are sweet though, damn you!)

[WeeHooker]

I have a really nice home system but the trouble there is the wife and kid are usually home, and occupying my home stereo/theater by watching a movie or TV in surround or playing Xbox360 or Wii. Plus they don't always appreciate my musical tastes.

AH-MEN Brother!
Since I put in the 1000W surround and the 42" Plasma, I've been pretty much pushed out of the living room. When I do manage to get in there, I have to deal with 3 remotes and the Wii to reconfigure everything from Gaming mode to "Can't Dad just relax mode?". Even with an engineering degree, it can be a PITA
My truck has become my sanctuary for listening to what I want ,for as long as i want, when I want and as loud as I want it. Much better investment than that friggen "family" entertainment system !