Harmon Kardon sound system speaker button?

[Gordo_GT]

In my tests:

Button off = only output from front speakers
Button on = output from all speakers

[Go Horns!]

Has anyone upgraded the stock Head Unit (leaving the speakers/subs as is) that can recommend some good units? The stock Harmon Kardon system leaves a lot to be desired especially if you've ever heard Nakamichi or Mark Levinson's in a Lexus.

I did everything, but if you are going to go aftermarket on the headunit, get BMW part # 65900410495. It is a bmw bracket and plastics for aftermarket units. Pics here: http://www.zhpmafia.com/forums/showt...talled-finally

[spoonerDee]

I found this button when I first bought my car a few years ago. Pushed it the first day I had the car, its been on ever since. I only found one CD that it didn't sound good on.

Also, my stereo is barely ever above a whisper so it doesn't make much of a difference.

[zhp43867]

In my experience, it will sound good or not based on your other tone settings. Deviating from totally flat (bass, treble or fader) at all will change how it effects the system. At all speakers flat, I like the button. Bu for HK the way I had it setup I preferred fader to the front 2-3 clicks- which gives a touch more stage- at which point the button made voices and such sound hollow.

[Gordo_GT]

After listening to good quality headphones and listening the HK system, it makes the HK system sound like shit.

My personal preference is to have the button off. The sound is more true and natural. With the button on you hear all these extra noises and echo sounds that muddle the sound.

I keep my bass and treble at the medium (default) setting, fade is 2 notches biased to the rear and the balance is 1 notch biased to the right to get a more centered soundstage. Since my music is coming from my iPhone, I am using the OEM jack with a gain of 1 to have the clearest sound possible.

This is the only way that I have found to get decent sound out of my car.

[RITmusic2k]

To my ear, it sounds like they're applying a comb filter to the output signal. It's the same technique used to create "stereo spreader" effects in mono source material. In essence it slices up the frequency spectrum into regular intervals, and then alternately pans each slice a little bit to the left and the right (i.e., 100-500Hz: left, 500-1kHz: right, 1kHz-5kHz: left, and so on). It is technically a distortion of the source material as originally presented, but it can give a nice impression of greater breadth in the sound stage when not overdone. Personally, I prefer it activated.

[Jlastor]

Is it working through the HK amp or the headunit?

Someone asked if you changed the headunit for a Dynavin what would happen...

[Tnhl1989]

No because the button is tied into the HK amp itself. So as long as you have the HK amp it would still work regardless of whatever head unit that is in the car.

[zhp43867]

No because the button is tied into the HK amp itself. So as long as you have the HK amp it would still work regardless of whatever head unit that is in the car.

This. It still works with an aftermarket head unit. Once you replace the stock amplifier, the effect is gone.

By the way, an aftermarket head unit may increase sound quality a tad (especially if it has its own effects/processing engine) but not by that much. The head unit is not the problem in the stock system.

[WOLFN8TR]

The button activates the HK "Spatializer" signal processing that changes the sound stage of the audio system; instead of sounding like is coming from the fixed speaker locations of the car, this processing takes the sound and "move" it to the center of the car, creating this "space" between the listener and the source.