(With apologies to Stanley Kubrick.)
What follows is a relatively low-cost way to make the Harmon Kardon audio system sound good.
The original post is in black. My updates are in red. There have been many comments and updates to this thread. I edit this initial post (#1) to keep it current but subscribers to this thread don't get notifications of edits so if you're interested in the audio upgrade solution recommended here I suggest you read all the posts that follow and return to #1 from time to time to keep current.
WORRYING.
I was angry and disappointed with the Harmon Kardon system for 7 reasons:
1. The HK system
sounds awful: it is harsh, especially toward the upper end, fatiguing, and uneven across the audio spectrum. The bass has no solidity.
2. The HK system has a
poor soundstage: instruments and voices lack clear spatial definition.
3. The HK system has very
little capacity to customize the sound: just treble and bass tone controls that, sadly, boost their respective spectrums unevenly. No mid-range adjustment. No EQ.
4. The HK system is
integrated so tightly with the car’s electronics that replacing components is a challenge.
5. The HK system is
noisy: from the factory there’s an annoying upper frequency hiss that apparently comes from the Active Sound Design (ASD) module linked to the HK amp.
The HK sound is also muddied by the fake engine noise that ASD puts through the speakers.
6. The HK system is
expensive, especially for what you get.
Depressing reality checks: The Sony system on the Ford hybrid C-Max SUV (MSRP $24,170) costs $275 less than the HK and has a mid-range adjustment. The Sony sounds better than the HK. I rented a run-of-the-mill Nissan Altima. It had a 3-band equalizer. The $5.99 Neutron music player app on my Galaxy phone has a 4-band equalizer.
I was particularly annoyed that my immediate impression after listening to the system for the first time was that, after springing for the “premium” system, I was facing the proposition of spending even more money to upgrade the “upgraded” system. I expect more of a $50K car. The poor quality of this "premium" option diminishes the luster of the BMW brand.
7. I add a quirk reported by some members that the HK subwoofers may unexpectedly go offline, usually coming back after a car restart. This may be caused by the amp overheating under load, especially prolonged heavy bass draws. This is an annoyance but it happens infrequently and isn't a big deal.
***
NOT WORRYING. LIVING.
I have however arrived at a compromise that doesn’t involve too much more money and that makes the system sound good. I’ve concentrated on reducing noise and making modest equipment improvements, primarily to the speakers, to improve the audio. This solution avoids having to interfere with the complicated computerized electronics of the car. None of the modifications requires any specialized skill or equipment. For the record, I’m a lifelong audiophile with preferences toward natural, clean and dynamic sound. I am not so much interested in high-thud sound but I do appreciate clear, solid, well defined bass. I listen to all kinds of music.
Here’s what I've done, with money and time outlays listed. Thanks to all the people on the forum who made various suggestions about these changes.
1. Disconnected the center channel speakers.
Results: better soundstage and a little cleaner sound. You’ll need a small Torx ratchet set.
Time: Under an hour.
Cost: $0.
This procedure has no effect on the navigation voice, which comes through loud and clear through the rest of the speaker system.
2. Installed the Technic Active Sound removal harness.
Results: (1) eliminates the fake motor/exhaust sound fed through the speakers and (2) reduces if not eliminates the hiss that interferes with the music from the audio system and was giving me headaches. Not only is the sound system improved but the car is noticeably quieter.
Zooks527 has a terrific installation tutorial on the forum: http://www.2addicts.com/forums/showthread.php?t=1202389 .
Time: about 2 hours.
Cost: $65.
[CAUTION: I had a problem with the BMW SOS emergency button after my audio mods. It seemed at first that the harness might be incompatible with the BMW SOS emergency button, rendering the SOS service inoperable. It turned out, however, after investigation that the harness is safe. The SOS problem was due to a defect in the BMW telematics control unit, which operates independently of the ASD and the harness. No need to worry.]
Installation of the original version of the harness results in a reduction in bass response and some other audible issues. Forum member Silver6spd discovered that an incorrect wiring setup in the harness was causing the problem which was itself the result of a mistake in BMW's original OEM schematic regarding the polarity of the left front speaker.
The fix is easy:
1. Among the looping wires in the harness you'll find a white wire and a white/black wire.
2. Cut each of these two wires at the center.
3. Connect the wires crosswise so that each wire consists of a white-connected-to-a-white/black wire.
4. Put a wire connector or a wire nut or electrical tape on each. Make sure you don't over-tighten the wire nut and break one of the connections - or you'll lose sound to a speaker. Test for sound and you're all done.
Thanks to Silver6spd for recognizing the problem and tracking down a solution. Future versions of the Technic harness will have the correct wiring. Thanks also to Technic for working to correct the issue. Pictures of the simple fix at are posts #252 and 253, below.
A cleaner solution involving a little more time and effort changing the pins rather than splicing the wires has been suggested by mdputnam: http://www.2addicts.com/forums/showt...9#post20512019.
Use the approach with which you're more comfortable: there's no difference electronically or sonically. The fix is well worth making since the harness results in a noticeable improvement of the sound of the system.
3. I'll be installing the BMW weather-stripping on the front doors.
Results: reduces- engine and road noise for an even quieter cabin.
Time: 20 minutes.
Cost: $30.
I've now installed the weather-stripping. Quieter as advertised.
For information on ordering the weather-stripping, see posts #171-3, below.
Note that the correct part numbers are 51487300693 and 51487300694.
A thread on installing the weather-stripping is at http://www.2addicts.com/forums/showt...atherstripping .
4. Replaced the HK stock speakers in the front doors with Eton B100W component speakers (mid-range + tweeter for each door).
Results: tighter and cleaner sound with a smooth, more natural sound across the spectrum and a punchier mid-low. The harshness of the mid-upper and upper end of the HK system is gone. Eton speakers are highly regarded in Germany and on the Continent but are not very well known in North America. These are very fine and reasonably-priced speakers. They can be ordered from Germany via Amazon or the
Extreme Audio website. Mine arrived in a week, delivered to the door by FedEx.
Many forum members in the U.S. have ordered the speakers from Germany with no problems.
The speakers are an easy installation, assuming you’re not squeamish about taking the door panels off. The speakers are an exact fit with no additional adapters or connectors needed.
Though you do need to be careful: one member accidentally drilled through a wire connected to the airbag system. Just work slowly and you'll be alright.
Bonus: opportunity to add sound deadening material – I used Dynamat Extreme – to the door frame around the mid-range and to the door panel. Eton makes different versions of the speaker.
It’s important that you order the “B100W” version. Grave has posted an excellent installation tutorial on the forum.
He has good pictures accompanied by instructions in French. See his post at http://bmw-one.com/phpbb3/viewtopic.php?f=21&t=34196 . I've written up a (very poor) English translation of his instructions that I can PM. For further help on the installation see also Solarphil's excellent guide at http://www.2addicts.com/forums/showthread.php?t=1258290 .
Time: about 4 hours but I really took my time, trying not to put a screwdriver through a cone. That includes Dynamatting the doors and panels. A less cautious amateur could probably do the job in a couple of hours, a pro in an hour. If you have a pro do it, you shouldn't have to pay much since no special fittings are required: it's plug and play after the panels come off.
It's well worth it to make this investment since most of the sound comes from the front speakers.
Cost: about $250, including shipping.
***
The total cost to make the HK system sound good (Technics harness, Eton speakers for the front doors, weatherstripping, some Dynamat) was just under $350, which is about as much money as I care to spend on the audio system right now, having already parted with $875 for the HK.
JL Audio speakers for the rear deck add another $75-100. See below.
Is the system all I wanted?
No. But it’s a damned sight better than the factory HK setup. The sound is tighter, cleaner, more natural sounding, and much easier to listen to at volume. The hiss seems to be gone. The cabin is much quieter. The HK woofers are OK.
If I’m overcome with a burning urge to relieve myself of more money on the audio system and I have time on my hands I’d probably, in order,
(5) Replace the rear speakers JL Audio C2-400x coaxes, as per Viffermike’s suggestion.
I broke down, bought, and installed these.
Result: Much more natural sound, huge difference in lower and mid-bass. The treble is also improved. Sure glad I did this.
Time: under an hour.
Cost: $75-$100.
The installation is extremely simple. Two of the three JL screw holes align exactly over two of the holes in the car. You can easily secure the third mounting tab by using a wide washer or similar item and the original BMW screw. Adding speakers to the rear of a convertible takes more work than in the hardtop and might require the help of a pro. See posts #222 & 224 in this thread and the "M235i Vert" thread.
Installation note: the original connectors are locking connectors. Use a very small screwdriver or an awl to release the lock. Don't just pull.
The increased and tighter bass may cause a bit of a rattle from the rear, even if you install the dynamat as recommended in this thread. The rattle comes from the child lock latches. An easy solution suggested by clemsonkev: pack the lock with a few packing foam peanuts and close the latch. Problem solved.
(-) Replace the HK underseat woofers. Time: a few hours. Cost: depends on choice but plan on around $500 for the pair.
Not necessary with the addition of the Eton and JL Audio speakers. Even doing one set of speakers improves the bass, especially the JL's in the back. One or two members have replaced the under-seat woofers with Bavtech and other speakers, leaving the original HK head unit. What change there was was unremarkable.
(-) Install a Bimmertech amp. Time: a few hours. Cost: $849.
Not necessary.
Another speaker option to consider is Bavsound. Their front door package (mid + tweeter) is about $100 more than the Etons. The Bavsound rear shelf speaker set is about $200 more than the JL Audio. They also offer a center channel speaker for $100 and a center channel tweeter for $100.
Bavsound has announced that the package will rise by $100-200 on June 1st. There are other speaker options that are more expensive.
6. I will install more Dynamat as I work on the car.
I added Dynamat Extreme to most of the bare metal in the trunk. You can see a few photos of the Dynamatting in posts #126 & 148, below. My goal was to make the listening environment sepulchral. The car is now like a tomb and the sound is considerably improved, especially with respect to solidity and delineation of musical sources in the soundstage. I should add that road noise is considerably reduced, so adding Dynamat is not just an audio issue.
My choices reflect my prior conviction that it makes sense to improve the speakers before the electronics and my resistance to dumping tons of money on a system that, in the end, is still limited by the capabilities and limitations of the HK headunit/amp. I would much rather have had control of the audio from beginning to end, in which case I might have ordered the base sound unit and put the money in on a good, complete aftermarket system. I realize that there’s room to disagree on these points. But an important question is whether the HK head unit/amp is superior to the base HiFi unit. It probably is, in which case it probably makes sense to spring for the HK system, knowing that further expenditures are in your future.
I'm now done fooling around with the audio. The system is pretty good.
I hope this post is helpful to other HK owners similarly afflicted and to other 2-series potential buyers thinking of what options to include and exclude.
***
Reflections on Eton/JLAudio v. Bavsound/Bimmertech
The current price for Bavsound Stage One package upgrade (front and rear, including center channel, but excluding the subwoofers) is $797, with a possible price increase of $100-200 in summer 2016. Adding the Bimmertech amp ($849) puts the Bavsound/Bimmertech combo at between $1746-$1846. The Eton/JLAudio speaker combination is $350.
Is the nearly $1400-$1500 difference between Bavsound/Bimmertech and Eton/JLAudio worth it?
The Bimmertech amp is tunable (though not through a simple EQ array on the car's display) whereas the Eton/JLAudio fix relies on the HK tone controls. The ability to fine-tune the Bimmertech amp allows for more customization than the HK tone controls. Tuning the Bimmertech involves downloading and installing a tuning file with a laptop and a USB cable. You can then fine-tune the tuning manually with a laptop and cable. Installing and adjusting the tuning on the Bimmertech will be fun for some, a pain for others, since there no such thing as single standard or optimal tune that will satisfy all listeners. See http://www.2addicts.com/forums/showthread.php?t=1232178 for what's involved. In any event, installing a tune is not something that can be done on the fly if you want to alter the sound while driving or in a hurry, as you can do with conventional tone controls.
As for a judgment on the sound itself - which is, after all, the prize - it would be good to have the two systems side by side for an A/B comparison but the likelihood of that happening is very low.
But watch this space: an A/B comparison is coming soon.
After living with the upgrades listed here for quite some time, I personally don't feel the need for extra power or superior electronics in the car: the system sounds good and has all the power I need even at high revs and speed, especially since so much noise has been eliminated from the environment.
To this I would also note some difficulties forum members have had with Bavsound and Bimmertech.
First, several forums members have reported issues with Bavsound distribution, production line delays, missing parts, and speaker quality control.
Second, as reported by Zooks527, there is a potential problem that the Bimmertech 3rd party amp may cause routine dealer ECU flashes to abort and immobilize the car(!). The flash may be looking for a response from the audio that it doesn't get because of the 3rd party amp. Not seeing the response, the flash fails and the car turns into a brick.
When this happens the 3rd party amp has to be uninstalled and the stock amp reinstalled while the car is in the shop. The car can then be reflashed by the dealer. The 3rd party amp can be reinstalled after the flash in the shop or at home. If your car is immobilized in the shop you will have to tell the dealer the probable cause since the dealer may not be aware of the incompatibility of the amp with the flash procedure.
Note: The bricking problem appears to be caused by the 3rd party amp, not the Technics ASD bypass harness.
I am not aware of any dealer who has charged an owner for time and labor on reflashing the car and getting it to start, on the grounds that the owner's installation caused the problem. Nor have I heard of a dealer who has tried to void the warranty because of an amp installation. But these are possibilities. At best the problem is an unpleasant inconvenience - it's not exactly a barrel of fun to rip out the trunk liner and reinstall it, reseating it under the rubber trunk seal. And at worst the uninstallation and reinstallation could result in damage to the components, liner, and/or rubber seal, extra time at the dealer's, and perhaps even repair charges. There are other amps (for example, the JL 600/6) that cost less than the Bimmertech and amps that cost more but until we hear from owners of such amps who have actually had ECU flashes we have to assume the same risk applies. Now it should be pointed out that ECU flashes are only infrequently installed by dealers. That said, in order to be safe, owners with 3rd party amps need either to be sure to uninstall the amp before every visit to the dealership - which may not be possible in the case of unplanned or sudden visits - or ask the dealer not to flash the car - which is not a good policy. Ignoring this issue could leave you with an immobilized BMW on the shop floor. I should point out, though, that some members have reported having an ECU flash on cars with aftermarket amps installed, with no adverse results. So the jury is out on this one.
Forum member djarchow has reported that the Bimmertech amp may cut out when stepping on the brake and turning the headlights on. The culprit may be low level electrical noise in the car that causes the amp to shift to switch to AUX inputs, muting the main inputs.
All this gets back to the problem of the system's close integration with the car's computer systems. For a discussion of the risks of installing after-market electronics in this car, see this thread: http://www.2addicts.com/forums/showt...4#post20053574
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I won't pursue the possibility, made in another thread, of installing a MusicarNW Stage 3 system at upwards of $5,000. This is way beyond what I could personally justify spending on an automotive sound system, especially considering how good the system can sound with the modest changes suggested above. For the record, I understand the irony of someone who has spent $50K on an automobile complaining about the extravagance of spending $5K on a sound upgrade.
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Forum member fancyfl1ght has reported static white noise problems with the JL Audio xd800/8v2 amplifier.
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There is some ongoing discussion about other possible polarity issues with the HK system but at the moment it's not clear that there actually are such problems. Moreover, as djarchow has argued in another thread, what might seem to be a simple issue with the polarity of a speaker can actually involve many other variables in the system. If we get confirmation that there actually is a specific problem with polarity (apart from the driver's side rear speaker), I'll provide an update to this thread. Until then best not to rush into changes.
***
Finally, a gentle reminder. When making electrical connections be sure that the connections stay secure. If you use wire nuts don't over tighten them or the wire may come out of the metal connector inside. Same for electrical tape: be sure as you wrap the tape that you don't undo the connection inside. I know this is Basic Working With Electricity 101 but at least two members (not naming names 
) have inadvertently disconnected wires and have lost sound.
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Conclusion: All in all, the simple speaker swap with sound deadening and noise reduction seems to me the way to go from the standpoints of sound, convenience, price, and risk. People can choose which of the improvements to make on an incremental basis. If you have the inclination, though, I really do recommend carrying out the full installation.
I'd welcome others' views.
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These reflections do not take into account the possibility of replacing the underseat woofers which, for reasons noted (posts #27 & #159, below), I'm not inclined to do at this point. The space limitations for the enclosures make it pretty unlikely that just replacing the speakers will make a significant difference at the lower end. As I said earlier I was trying to keep costs down to what I considered to be reasonable after spending for the "premium" HK upgrade. Philosophical reflections on how much money to spend on the underseat woofers are sprinkled through the discussion but see especially post #537 and following.