Audio System Upgrade Information

The Do It Yourself section is used provide assistance with mods and fixes. Whenever you are making a change to your car please take pictures and notes. Let others know what to watch out for and any useful tricks you learn. If you are starting a post in this section from scratch please hold it to a higher standard than you would for other forum posts. i.e. technical detail and even grammar.
Please post about issues or problems in the Technical Support & Problem Troubleshooting forum.
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ms_enj
Posts: 14
Joined: Fri Jan 10, 2014 4:01 pm

SamirD wrote:Lovely progress!

I wonder how hard it would be to just make a clear sticker that would go over the factory camera iris to give it guide lines?
You'd have guide lines, but I don't think you'd have much else. Even a "clear" sticker suck over a wide-angle lens will turn the picture into a cloudy blur.
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cocos3
Posts: 122
Joined: Thu Jan 17, 2013 7:11 am
Location: Mid-North Coast, NSW, Australia

Thanks for your reply ms_enj, you make it sound so simple...haha.
It probably isn't worth messing around with, you're right!
I just know when the beep is constant, there's about a foot to go...I can live with that....
Red 2013 Prestige w/ sat-nav
SamirD
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Location: HSV and SFO
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ms_enj wrote:You'd have guide lines, but I don't think you'd have much else. Even a "clear" sticker suck over a wide-angle lens will turn the picture into a cloudy blur.
I was thinking that might be the case between the plastic of the sticker and the adhesive.

But still if some super-expensive stuff could do the job, even at $20 it would be cheaper and easier than replacing the camera.
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ms_enj
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cocos3 wrote:Thanks for your reply ms_enj, you make it sound so simple...haha.
It probably isn't worth messing around with, you're right!
I just know when the beep is constant, there's about a foot to go...I can live with that....
No problems,

Sometimes the simple option is the most convenient one! ;)

Another update. Yesterday my SOT-071 harness and Scosche line level converter arrived, and they've been cut up and wired into the socket I have to suit the exisiting plug on the car's wiring loom.

Had a play this morning, and there's plenty of scope for adjustment in the Scosche unit, and feeding it into my headphone amplifier and cans, it doesn't seem to affect the sound quality at all.

My plan for optimum level matching is to burn a CD with a 5 minute long track that is nothing but a 1kHz sine wave at 0dB.

Put it in the RF headunit, turn the volume all the way up, put a 47k resistor across the speaker outputs one at a time (to simulate the input loading of having the the amplifier connected), and measure the amplitude of the sine wave peak-to-peak.

Put the CD in the Garmin unit, do the same, and this time adjust the LOC to match the output of the RF unit.

That should just about get me the ideal output level from the Garmin unit to suit the input of the RF amplifer, without running the risk of clipping the input signal, or raising the noise floor too much.
SamirD
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Holy crap that sounds impressive! I wonder how much different the factory navi+Rf would have sounded if they would have done this to tune the settings?
~tc~
Posts: 999
Joined: Tue Mar 29, 2011 3:33 am
Location: Houston, TX USA

But that assumes the RF unit is correctly optimized ... I can tell you in the case of the Kenwood navi unit, that does not appear to be true.

I would do it the "old fashioned" way - hook it up for real, set the HU volume for 3/4 max, and adjust so it's barely clipping coming out of the amplifier.

Also, ideally, you would use either white noise or at least a variety of frequencies to account for any non-linearity in the output.
2011 Sport SLS with nav Black Pearl Metallic
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ms_enj
Posts: 14
Joined: Fri Jan 10, 2014 4:01 pm

Ok folks, I return with more interesting news from the world of Kizashi Factory audio... 8-)
~tc~ wrote:But that assumes the RF unit is correctly optimized ... I can tell you in the case of the Kenwood navi unit, that does not appear to be true.

I would do it the "old fashioned" way - hook it up for real, set the HU volume for 3/4 max, and adjust so it's barely clipping coming out of the amplifier.

Also, ideally, you would use either white noise or at least a variety of frequencies to account for any non-linearity in the output.
I would expect that the RF headunit would be optimized *perfectly* for the RF amp - After all, they were designed from the outset to work exclusively as a pair, so why wouldn't the headunit be outputting the exact signal level the amp requires.

The Kenwood, on the other hand, was most likely chosen by Suzuki because it ticked all of their desired feature boxes at the lowest price point, could be easily rebranded, and installed without having to change the car's wiring loom... Just a short extension on the end. I expect there would have been very little consideration to sound quality beyond making sure that it actually had sound... After all, if the nav unit is there, and the fancy badges are on the speaker grilles, then John. Q. Public will be safe in the knowledge that he's getting premium sound system, and can be charged accordingly.

Anyway, I digress.

Given my CRO is out of order at the moment, I can't see clipping using white noise, but I can measure it's output using a multimeter to get a peak-to-peak level as a guideline at least.

Either way, after simulating the input loading of the amp, and testing at 10 frequencies across the spectrum, and white noise for good measure, I think I may have found the answer to the lack of bass people commonly complain about with the Kenwood headunit or when swapping the RF headunit for an aftermarket one.

The Rockford Fosgate/Panasonic headunit has 4V preouts. The Kenwood DNX6160 only has 2V preouts, according to the specs.

When I initally set up my line converter while playing with the new HU yesterday, I worked around the amp expecting 1 to 1.5V p-p, as you would get from a headunit that has standard line outputs. I had the same issues that others were reporting when using line converters or the Kenwood nav unit, not much output from the sub, poor imaging, and a pretty average sound.

This morning, I got the RF on to the bench, plugged it in, did some measuring, and found the HU has 4V preamp outputs... Delivers 4V p-p up to around 1.5kHz, drops to 3V around 5.5kHz, 2V around 9kHz, and 1.5V from 15kHz onwards.

Grabbed the Garmin unit, turned the line output converter up to maximum (which only netted me 2.75V p-p at full volume with the same tones as the RF head unit, so I'm ultimately going to have to change the voltage divider in it), then balanced the channels until I had them within 10mV of each other.

Plugged it in, and behold, the Rockford Fosgate "sound" is back, at least once it gets over a third on the volume scale, which I suspect is caused by the line converter's output being too low initially.

While it sounds like there is a conservative EQ curve applied at the RF headunit too, most of the audio processing is done in the amplifier itself. There's also no variance in the RF headunit's output voltage front to rear or left to right with the balance and fader controls centred, so that's something else to keep in mind when changing to an aftermarket one.
murcod
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Location: Australia

ms_enj wrote: Either way, after simulating the input loading of the amp, and testing at 10 frequencies across the spectrum, and white noise for good measure, I think I may have found the answer to the lack of bass people commonly complain about with the Kenwood headunit or when swapping the RF headunit for an aftermarket one.

The Rockford Fosgate/Panasonic headunit has 4V preouts. The Kenwood DNX6160 only has 2V preouts, according to the specs.
Don't forget the Kenwood is installed using a line level converter - so the RCA output levels don't come into the equation. You'd need to check what the Suzuki supplied line level converter outputs are before drawing any conclusions.
David
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ms_enj
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Joined: Fri Jan 10, 2014 4:01 pm

murcod wrote:
ms_enj wrote: Either way, after simulating the input loading of the amp, and testing at 10 frequencies across the spectrum, and white noise for good measure, I think I may have found the answer to the lack of bass people commonly complain about with the Kenwood headunit or when swapping the RF headunit for an aftermarket one.

The Rockford Fosgate/Panasonic headunit has 4V preouts. The Kenwood DNX6160 only has 2V preouts, according to the specs.
Don't forget the Kenwood is installed using a line level converter - so the RCA output levels don't come into the equation. You'd need to check what the Suzuki supplied line level converter outputs are before drawing any conclusions.
Sorry, I should have clarified that. In saying that, I meant that the difference is why switching from the Suzuki LOC to the preouts on the Kenwood makes no difference (as others have already tried.)

I'd be willing to bet that the Suzuki LOC outputs at normal line level too...
~tc~
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Joined: Tue Mar 29, 2011 3:33 am
Location: Houston, TX USA

The RF head unit is Panasonic if I'm not mistaken, but I agree it was probably more designed to work together than the nav unit.

Interesting observation about the line levels. Something like an AudioControl overdrive might be required then when switching to RCA ...


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2011 Sport SLS with nav Black Pearl Metallic
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