just to clarify, I do have HK "Premium Sound System" but since I have a facelift (2009) SLK r171, I don't need to purchase a fiber optic decoder box? SO will I have to buy a separate amp or anything?
No,let me clarify.
You say you have a HK amp. This amp is located in the passenger footwell. Speakers are wired to that amp in the footwell.
You now have 2 options.
Rewire the speakers to your new radio HU in the dashboard. Pro: simple straight forward setup. Con: possible worse soundquality (HK makes pretty good amps) and more work for your installer.
Use the RCA outputs of your new radio,connect them to a converterbox and connect that converterbox to the HK amp. That converterbox is the fiber optic thingy your installer mentions. Pro: probably better sound quality,allthough only stereo,no DTS or surround. Con:more complicated setup and an extra money for the converterbox.
For this option you need e.g. this device (the converterbox):
XTRONS Optical Fiber Decoder Box for Mercedes-Benz E / CLS / SLK / SL / CLK Series Only Decode Most Bus Based Systems •Description:*This adaptor is a plug-and-play adapter required in vehicles which have original COMAND APS NTG (Most Bus Based Systems) 2 or COMAND APS NTG 2.5 system, it provides...
Replace the HK amp with a new amplifier with DSP and equalizer stuff etc. But then you are talking major $$$$
Hope this clarifies things. If not,just ask.
And for the record I have no hands-on experience with the converterbox (I am an OEM guy
) but others may have. What I heard is that these Xtrons converters work pretty good.
But if your installer suggests another converterbox I would follow his advice. Makes the discussion a lot easier if it does not work as expected.😉