Stinger Harman Kardon speakers simple mod to improve sound

andrew tay

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Many have complaint about the HK sound system sounded muffled. High frequency was unclear and teary. Bass was loud but not punchy and defined. One of the forum member has suggested that one of the woofer is wired in reverse phase.
When I was changing all the car woofers I made 2 shocking discoveries:

1) one of the 4 woofers are wired out of phase with the other 3. For me it was the front L door woofer. I did not think its possible to do that in modern car these days. Took an subwoofer install and replacing all 4 woofers in each doors and over au $2000 poorer to find that out. Curse KIA. :mad:
- to check the phase of the woofer I use a phase checking app on my android phone call 'polarity checker'.
- Open all car doors outdoor to reduce inteference. Best doing it at night when is quiet.
- turn off any equaliser and surround sound mode.
- run the app at 80 hz which will play a popping noise through the speaker via bluetooth. Hold the mic of you phone next to the woofer that you want to check. I actually cut the wires which feed to the underseat woofer but you may be able to get away with just covering it with blanket while testing the door speaker and vice versa.
- it will tell you either negative or positive. I found that the front left door was reading differently from the others.
- you can then remove the door card, cut the 2 wires that run to the woofer and joint the wire in reverse.


2) the tweeters and midrange speakers are covered in felt-like material behind the metal grill and plastic cage. By removing the covering felt like material and put some black double sided tape in between the metal grill and the underlying plastic around the edges to stop it from rattling, it opens out the music like lifting a curtain. The vocals sounded so much clearer. No more tearing distortions. You can now set the midrange of the EQ to zero instead of +3. I still don't know why Kia do it in the first place. You don't expect you speakers to sound good if you covered them in blankets. Enclosed a photo of the metal grill with the felt material. You remove them by bending the little tags at the side IMG_20181118_135847.webp
 
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So you’re saying kia made a mistake wiring the subwoofers?
 
If one or more of the subs isn't wired like the others, that is a mistake for sure. But, if your ears don't pick up what others' ears hear, and your system sounds fine to you, then pass on by; there isn't any reason to stop and talk about what you know nothing about.

Felt covering: I think it is a dust catcher for the long haul, intended to keep the speakers clean. Just a guess. Turning up the volume should eliminate any perceived interference. The covering isn't going to distort anything; not with the "white noise" of the operating of the car continuously, already interfering.
 
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From interior to exterior to high performance - everything you need for your Stinger awaits you...
Interesting. I just did a phase test (several available on line) and no troubles - these are sound tests to ensure that the speakers are both pushing at the same time. I therefore assume that the polarity is OK on my speakers (also found some great tests for bass and sub-bass. The HK system went down to 20Hz no problem, even sub-20 you could hear something!).

The dust covers are just one of those things. I run my home speakers without covers but in a car I think the benefit of keeping the cones dirt free will outweigh any loss in sound.

Hope the new system works well for you.
 
good to hear
 
______________________________
From interior to exterior to high performance - everything you need for your Stinger awaits you...
Phase is a tricky thing to measure...

Just to explain a bit more... Home theater system that use a mic for speaker optimization will often report speakers to be out of phase incorrectly. I don't know how the mobile app mentioned here works and if it suffers from the same potential issue or not. Perhaps there's less echo in a car to confuse it, I don't know. What I do know is the only thing I trust is looking at the wires and making sure the polarity is correct. Easier said than done on a factory install! I do find it a bit hard to believe they would wire one speaker wrong though... It's possible, certainly!
 
I also use the dB meter test with tone generator, I use 80 hz. If two speakers are in phase it will show increase of 3 dB. If out of phase it will drop dB between 3 to 6 dB.
Just to explain a bit more... Home theater system that use a mic for speaker optimization will often report speakers to be out of phase incorrectly. I don't know how the mobile app mentioned here works and if it suffers from the same potential issue or not. Perhaps there's less echo in a car to confuse it, I don't know. What I do know is the only thing I trust is looking at the wires and making sure the polarity is correct. Easier said than done on a factory install! I do find it a bit hard to believe they would wire one speaker wrong though... It's possible, certainly!
 
Has anyone else tested the phase in their Stingers lately? I wonder if Kia fixed the issue?
 
From interior to exterior to high performance - everything you need for your Stinger awaits you...
Has anyone else tested the phase in their Stingers lately? I wonder if Kia fixed the issue?
I know what out of phase subs should sound like, and I don't think this is an issue in my '21. There's plenty of punch and range, just not an endless supply of volume due to amp and sub size (7") limitations.
 
I know what out of phase subs should sound like, and I don't think this is an issue in my '21. There's plenty of punch and range, just not an endless supply of volume due to amp and sub size (7") limitations.
A plug and play amp upgrade would be freaking ideal! I came from a factory 1600W Bang & Olufsen with a JL 10W6 to the stinger. I put the sub and 1000W amp in, but the highs need 200-300 more watts.
 
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