My car came with the Harman/Kardon stereo as stock; & whilst it sounded OK, I felt the mid & low bass were definitely lacking. Harman/Kardon claims their system is 480W, I believe that's peak-to-peak power. A much more realistic number is the RMS power — the same number that Crutchfield uses to rate all the products they carry. By that metric, the Harman/Kardon is about 160 RMS, with more power going to the dual voice coil rear 6x9s (52W RMS per channel) than the front 6.5s (26W RMS per channel). Now that we've established a standard by which to measure, we can compare apples to apples (so to speak).

My car had the factory aux port, but as Bluetooth for the H/K is either prohibitively expensive, or not available, I decided to go aftermarket & completely revamp the system.

I must warn you ahead of time, the way I configured my system may seem a bit unorthodox, but stick with me, I'll explain why I did what I did. I am an Electro-Mechanical Engineer, so I might know a thing or two about wave propagation . To that end, I have set up many car stereos, all pretty much the same way, & everyone who has listened to my stereo setups has commented how great it sounds!

I went with a Pioneer DEH-X8800BHS. It has six 4v preamp outputs (2 front, 2 rear, & 2 for the subwoofer). It commands my Android phone via Bluetooth, & it is Pandora, Spotify, HD radio, & Sirius/XM capable. Installation of the head unit was very straightforward, a mounting plate (p/n 99-9302) & wire harness adapter (p/n 71-9003) from Metra & it goes right in.

Yes, Sonic rides with me everywhere I go. He is my daughter's favorite character ever since she was little, & now that she's gone on a mission, it reminds me of her. The subwoofer remote gain control **** can be seen just to the left of the head unit.


Night view.

An Axxess ASWC-1 makes ALL the steering wheel buttons work!

Axxess ASWC-1


The kit Axxess wants to sell you (If you tell them you have the Harman/Kardon) has two boxes (ASWC-1 plus another larger box) & a maze of wires.
Axxess AXDIS-BW (Doesn't work).

I hooked it all up according to their instructions, but couldn't ever make anything but the volume buttons work; & even then only intermittently. I called their tech support, but to no avail. Their tech even said — after conversing with him for about 5 minutes — he thought I knew more than him. Perhaps all of that rubbish is needed if you were keeping the stock H/K amp, but I'm not. So, in sheer desperation, I tore the whole mess out, & made my own harness. I just used the ASWC-1 box, not the other thing, & connected the black wire to ground, the red wire to switched (ignition) power, the pink wire to the steering wheel buttons bus (White/red/yellow in pin 9 of the factory harness) & the 3.5mm plug into the Pioneer head unit; for a grand total of 4 wires to connect, and...Viola! Volume up & down works, track previous & next works (including controlling my Samsung Android phone!) The phone button answers my phone when there's a call, otherwise it attenuates the volume by 20 numbers. The R/T button cycles through the different modes (CD, Bluetooth audio, Pandora, Sirius/XM, etc. It's programable with an app; you can set each button to perform a second function with a long (2 second) press, or remap the existing buttons to perform other functions.

I put a JL Audio 4-channel 75W RMS/channel amp in the same exact position as the Harman/Kardon amp, & ran 6g wire directly from the battery through a home-built power filter (basically a couple of caps & a choke) then used the stock trigger (white wire) to turn the amp on/off.

JL Audio amp in stock position.

My car originally came with the factory navigation system. I have long since replaced that with the Chrono Pack, so I put a Sound Ordinance B-8PTD 125W RMS 8" powered subwoofer under the passenger seat in the place where the navigation control unit used to be. The sub has a remote gain control that I installed in the lower dash, just to the left of the radio. I had to raise the passenger seat 10mm via spacers under each of the 4 seat bolts, so far no one has complained that it's too tall.

Subwoofer fits nicely under the passenger seat.

I put Stinger X-mat sound damping in the doors & in the rear quarter panels. I highly recommend this stuff! I think it's better than Dynamat. My doors always sounded hollow when I closed them. After I installed the mat, my wife got in the car, closed the door, looked at me very surprised, got out, closed the door, opened it, got back in, closed it again, & said "It sounds like a Mercedes or a Jaguar; not cheap like it used to." (For the record, I hadn't told her I had installed the sound damping material; she wouldn't have understood/cared anyway. The point I'm making is, she noticed the difference not having been told anything was changed.)

Anyway, back to the stereo. For speakers, I installed Infinity Primus 6510cs 6-1/2". They come with a separate tweeter & a crossover box. The fronts mounted right up with an adapter by Metra (p/n 82-9302) & the tweeters mounted in the stock position — angled 30° back toward the listener's ear (because high frequencies are very unidirectional) — with just a little bit of fabrication using the mounts that came in the kit. For the rears, I used the same Infinity speakers as the front (because I now have a subwoofer doing the work of reproducing the low frequencies) via a Scosche 6x9 to 6.5 adapter plate (p/n SA-69) & I put the tweeters in the adapter plate; angling them up about 30° (again, because high frequencies are very unidirectional). I didn't take a picture when I was installing them, but you can see how nicely they fit behind the stock speaker grills.

Speakers fit beautifully underneath the stock grills.


Looks very factory.


Trim piece removed to show tweeter mounting.


I need to make a domed grill for the tweeter.

I put speaker cups (baffles, see picture below) behind all 4 speakers. The purpose for this is two-fold: 1) It protects the speakers from getting water damaged, &, 2) It further helps attenuate the secondary waves from bouncing back at the speakers; thereby distorting the original sound wave. (The X-mat also contributes in this regard.) I would exhort you to do the same; they're cheap, & they definitely improve the sound quality. Just make sure you poke the hole for the speaker wire in the BOTTOM of the cup, to prevent water from getting in.

Speaker cups (baffles).

Now on to the configuration: First I set my gain with my digital oscilloscope & 0db sine wave test tones of 40Hz, 200Hz, 1KHz, & 2KHz. I increase the gain until I see the signal just barely start to clip, then back it off just a touch. I set both the preamp & speaker level gain according to this procedure; this way I know I have no distortion in the signal. If there is any distortion, it's in the speaker itself. (Though I carefully matched the speaker power ratings with the output capabilities of the amp, to avoid this condition).

As the frequency goes up, the power required to produce the same volume is reduced; because the speaker cone has to travel less distance, so it takes less power to overcome the magnet. The subwoofer is rated from 40-200Hz, so, I set my LPF to 200Hz (with a 24db/octave slope). This makes the subwoofer reproduce sounds like the bass guitar, not just the kick drum. I set my HPF to 125Hz (also with a 24db/octave slope) so I get a bit of overlap. For reference, 125Hz is low B#, about halfway between the 2nd & 3rd string on a bass guitar. The sub has 125W RMS, so I figure I may as well use all that power to produce all the frequencies it is capable of doing.

To recap: The stock system had a total of 160W RMS (at best). I now have 425W RMS, & the division of labor is much better because I have an 8" sub to produce the low frequencies. How does it sound? Awesome! Much cleaner, no distortion at all, with much tighter, punchier bass!

Did I mention no distortion?

Now that I've seen some of you clever blokes have installed a double DIN touch screen head unit, I think that will be my next upgrade.

 

Nicely done. The complete redo is a considerable effort, but looks like it all worked out. Curious, did you look at other headunits? I'm leaning towards the Kenwood KMM-X704. No CDs nowadays so one less thing to worry about and the Kenwood is less $$$

I mounted the tweeters in the same pod using Polk components, I find that the tweeter is pretty muffled under the stock non-HK grill surround. Will be curious to see what you do to cover the tweeter.

 

Geeze, Tom- overkill much?

 

You're just jealous!

 

100%!

 

I'm somewhat partial to Pioneers; I've used them in the past with great success. I'm actually thinking about converting to a double DIN unit. If I do, it will be without a disc player for a couple of reasons:
1) My phone has a 512 GB memory chip full of FLAC audio; enough music to last me several months without playing the same song twice.
2) No disc player means the head unit is shallower, so I don't have to trim the HVAC box.

 

Let me know, I'll build a system for you.

 

I'm confident you will!

Let me check with my accountant, CFP and the bank and I'll get back to you!

 

 

Yeah, I have a Pioneer double din in another car and the sound quality is noticeably better than a Sony I have in a different car. Apples and Oranges perhaps, but I think it's better, so I'll go with that.

Long ago, I had a Kenwood and it sounded warm and pretty nice, so that's why I had that in mind. Overall, most of these single din HUs are cheap compared to decades ago. Since this is a noisy little car, I'm not going to go super crazy with a big audio investment, but the Pioneer HU you have and the Kenwood were the top candidates.