NOTE: I am not sure where to post this in order for it to serve the most good.
This is an alternative to replacing the stock head unit and messing up the stock audio capabilities. I am specifically referring to/addressing HK systems. And it is a CHEAP solution.
I bought this thing that's called/referred to as a "DVR". It provides AUX output. While doing research I learned that using AUX input of the HK system allows for full control of all stock speakers. Other solutions require replacing the stock head unit and losing fader control and compromises the response of the subwoofer (it's treated like any speaker). The idea of trying to track down something that can output direct LINE OUT came from this guy:
I searched everywhere and could not find an actual head unit that had LINE OUT. But while digging around I eventually ran across this solution:
I bought this unit, but that video should provide a clear enough overview of what these kinds of units can do.
Here's my installation (any other placement just didn't sit well with me). I hadn't peeled off the protective film on the display yet! (screen would normally show maps on the right side [as I have configured] but as I was sitting in my garage I didn't want to advertise where I live! also, the music was a random pick by my music player/phone)
![Image]()
Mounting location only made sense! Now, HOW to mount?
![Image]()
WTH? OK, it's an 18 year-old car and that head unit is WAY outdated. Further, there's zero need to see this display. Anyway, that's half of a dual-lock fastener; these are essentially Velcro on steroids.
Here's the other half of that dual-lock (I say other half but they're both the same, unlike Velcro which has two different pieces):
![Image]()
I created a mounting plate [aluminum] that the DVR attaches to using... you guessed it, dual-lock fasteners: didn't think a picture of that was necessary- you should get the idea by now. The mounting plate has a lip that inserts into the CD slot. In order to keep that lip in the slot (one could build up more material closer to the slot and put additional dual-lock fasteners there) I slightly bent the lip up so that it results in binding pressure as you press everything back to lock into the dual-lock fastener affixed on the lower part of the HU's screen. Have only a little time with this install but it seems like it's pretty secure. The DVR unit doesn't weigh very much.
Initially I was hoping to affix the DVR unit directly to the screen face of the stock HU. Turned out the that the deeper back part of the DVR is a little wider than the HU's screen area (recessed area). So... the mounting plate is Plan B!
(I had to scramble for material for the plate; had an old aluminum clipboard in my scrap metal bin- yea!)
My other concern was that of what to do with all the wiring/cables. I managed to stuff all the excess stuff inside the ashtray: what good is the ashtray for? Had to sacrifice the lighter outlet. I actually removed it in order to route the AUX cable (goes into the glove box- MB's factory placement of AUX port), the wires to connect up a separate lighter socket (I'll address this in a bit), a USB cable going back into the center console (for connecting my phone) and video cable for the backup camera (this ended up a failure due to incompatibility of devices). The unit I got, and I suspect it's likely the case with other similar units, has a multi-function cable which has a cigarette plug power adapter, aux cable and plug, and a USB port. It's pretty bulky. Suffice it to say, I managed to cram everything into the ashtray bin/enclosure AND am able to (much like jumping on the top of a suitcase lid to get it to close) close it!
I am not sure I came up with the best solution on how to get the main cable from inside the ashtray area TO the unit. As I have parts from a parts car I decide to hack up the ashtray. I notched the ashtray door's faceplate: you can detach it from the black plastic piece that does all the hinge work. In the first pic you can see the notch. It's a little oversized in order to feed out a video cable for the backup camera (I had to punt on the backup camera- I'll explain in a bit).
One could, and I pondered this, use the approach that the Amazing Road guy used and move the stock HU to the trunk. Doing this would be a heck of a lot easier to deal with all the cables. Would require solving the mounting issue, though: keep in mind "dual-lock fasteners"!
So, what did all this work get me? Oh, the unit cost about $100: I said "cheap solution" right? I have Android Auto via my Android phone. Verified that Apple CarPlay works for the wife's phone. All functions work: music of course; phone; messaging; maps (google or whatever it is that Apple uses). The stock HK system's sound is ALL there- fader, subwoofer continues to be driven as it should. Just set the HU to Aux and that's it. Volume control buttons on steering wheel continues to work and that's what you really only can/should use: I believe this is the only such control that is possible from the steering wheel. I have NOT attempted to see how "FM" works; the DVR is supposed to do FM but I have not checked it out; at this point I can't say that I care one way or the other.
My mounting location interferes with the CD changer door opening: well, I think it does; I haven't tried it; why would I used this anyway? (nothing against CDs; if you want to retain that quality record/copy using FLAC).
The DVR does NOT DO apps. Whatever you have via Android Auto or Apple CarPlay is what you get.
The camera support is crap. I pre-installed a NATIKA camera (in the trunk- drilling and all that) but the DVR would not recognize the camera. I'd bought a couple of RCA to 2.5mm jack adapters (camera cable end is RCA) but neither worked: I checked these adapters and found they were configured differently- WARNING, there isn't any industry standard so be careful not just with say this DVR but with anything. DVR vendor says you have to use their [cheap] camera. I bought their camera just to hack the cable -no way was I going to install the actual, cheap camera!- but was unsuccessful. NATIKA's support assisted me in trying to make this all work: these folks are worth buying from as they have real support! This is but a small part of my 5-month long restoration project and I just flat out ran out of time and patience in which case I'll just have to back the car up using old-school means: eyeballs in mirrors! If there's any techno-heads out there that think they can help me figure out how to get the NATIKA camera to work with the DVR unit I'd be forever grateful.
Don't expect to get any support from a vendor such as this: I'm sure that there might be some in China but no idea how you'd find out. I suspect that's why the Carpuride offering is a lot more expensive: it's basically a support wrapper (US) around the same Chinese products; I did reach out to them to inquire about the configuration of their 2.5mm jack and got a response but if I recall it was that they didn't know
If you're happy with the sound from the stock HK system then you'll be happy with this because that's exactly what you get- you're still using the stock system, just feeding it via AUX.
I am still in the "testing" mode. From time to time things glitch. Bluetooth drops out. The unit thrashes through its BT connection sequence DINGING all over the place: music turned up load = LOUD DINGS! I'm not sure what is to blame here. I suspect it's my phone; it may be just standard BT timeouts I don't know: it shouldn't drop BT if BT is active; this kind of leads me to suspect that the DVR might be dropping and then the phone thinks that BT isn't needed so it puts it to sleep (or whatever; I just noted that I check the connection settings on my phone and see that BT gets turned off). The manufacturer appears to offer/provide updates from time to time in which case it's possible that any fix could be coming along. There's also the possibility that the processing power is a bit weak and that running maps and music together can sometimes stress the unit. Again, I am not sure as I don't yet have much time with this setup.
Apple CarPlay is only supported in wireless mode. A quick test by my wife resulted in an initial thumbs up.
I'll look to provide a followup on how it's all working. As of this point in time I'm fairly happy with this solution.
This is an alternative to replacing the stock head unit and messing up the stock audio capabilities. I am specifically referring to/addressing HK systems. And it is a CHEAP solution.
I bought this thing that's called/referred to as a "DVR". It provides AUX output. While doing research I learned that using AUX input of the HK system allows for full control of all stock speakers. Other solutions require replacing the stock head unit and losing fader control and compromises the response of the subwoofer (it's treated like any speaker). The idea of trying to track down something that can output direct LINE OUT came from this guy:
I searched everywhere and could not find an actual head unit that had LINE OUT. But while digging around I eventually ran across this solution:
I bought this unit, but that video should provide a clear enough overview of what these kinds of units can do.
Here's my installation (any other placement just didn't sit well with me). I hadn't peeled off the protective film on the display yet! (screen would normally show maps on the right side [as I have configured] but as I was sitting in my garage I didn't want to advertise where I live! also, the music was a random pick by my music player/phone)
Mounting location only made sense! Now, HOW to mount?
WTH? OK, it's an 18 year-old car and that head unit is WAY outdated. Further, there's zero need to see this display. Anyway, that's half of a dual-lock fastener; these are essentially Velcro on steroids.
Here's the other half of that dual-lock (I say other half but they're both the same, unlike Velcro which has two different pieces):
I created a mounting plate [aluminum] that the DVR attaches to using... you guessed it, dual-lock fasteners: didn't think a picture of that was necessary- you should get the idea by now. The mounting plate has a lip that inserts into the CD slot. In order to keep that lip in the slot (one could build up more material closer to the slot and put additional dual-lock fasteners there) I slightly bent the lip up so that it results in binding pressure as you press everything back to lock into the dual-lock fastener affixed on the lower part of the HU's screen. Have only a little time with this install but it seems like it's pretty secure. The DVR unit doesn't weigh very much.
Initially I was hoping to affix the DVR unit directly to the screen face of the stock HU. Turned out the that the deeper back part of the DVR is a little wider than the HU's screen area (recessed area). So... the mounting plate is Plan B!
(I had to scramble for material for the plate; had an old aluminum clipboard in my scrap metal bin- yea!)My other concern was that of what to do with all the wiring/cables. I managed to stuff all the excess stuff inside the ashtray: what good is the ashtray for? Had to sacrifice the lighter outlet. I actually removed it in order to route the AUX cable (goes into the glove box- MB's factory placement of AUX port), the wires to connect up a separate lighter socket (I'll address this in a bit), a USB cable going back into the center console (for connecting my phone) and video cable for the backup camera (this ended up a failure due to incompatibility of devices). The unit I got, and I suspect it's likely the case with other similar units, has a multi-function cable which has a cigarette plug power adapter, aux cable and plug, and a USB port. It's pretty bulky. Suffice it to say, I managed to cram everything into the ashtray bin/enclosure AND am able to (much like jumping on the top of a suitcase lid to get it to close) close it!
I am not sure I came up with the best solution on how to get the main cable from inside the ashtray area TO the unit. As I have parts from a parts car I decide to hack up the ashtray. I notched the ashtray door's faceplate: you can detach it from the black plastic piece that does all the hinge work. In the first pic you can see the notch. It's a little oversized in order to feed out a video cable for the backup camera (I had to punt on the backup camera- I'll explain in a bit).
One could, and I pondered this, use the approach that the Amazing Road guy used and move the stock HU to the trunk. Doing this would be a heck of a lot easier to deal with all the cables. Would require solving the mounting issue, though: keep in mind "dual-lock fasteners"!
So, what did all this work get me? Oh, the unit cost about $100: I said "cheap solution" right? I have Android Auto via my Android phone. Verified that Apple CarPlay works for the wife's phone. All functions work: music of course; phone; messaging; maps (google or whatever it is that Apple uses). The stock HK system's sound is ALL there- fader, subwoofer continues to be driven as it should. Just set the HU to Aux and that's it. Volume control buttons on steering wheel continues to work and that's what you really only can/should use: I believe this is the only such control that is possible from the steering wheel. I have NOT attempted to see how "FM" works; the DVR is supposed to do FM but I have not checked it out; at this point I can't say that I care one way or the other.
My mounting location interferes with the CD changer door opening: well, I think it does; I haven't tried it; why would I used this anyway? (nothing against CDs; if you want to retain that quality record/copy using FLAC).
The DVR does NOT DO apps. Whatever you have via Android Auto or Apple CarPlay is what you get.
The camera support is crap. I pre-installed a NATIKA camera (in the trunk- drilling and all that) but the DVR would not recognize the camera. I'd bought a couple of RCA to 2.5mm jack adapters (camera cable end is RCA) but neither worked: I checked these adapters and found they were configured differently- WARNING, there isn't any industry standard so be careful not just with say this DVR but with anything. DVR vendor says you have to use their [cheap] camera. I bought their camera just to hack the cable -no way was I going to install the actual, cheap camera!- but was unsuccessful. NATIKA's support assisted me in trying to make this all work: these folks are worth buying from as they have real support! This is but a small part of my 5-month long restoration project and I just flat out ran out of time and patience in which case I'll just have to back the car up using old-school means: eyeballs in mirrors! If there's any techno-heads out there that think they can help me figure out how to get the NATIKA camera to work with the DVR unit I'd be forever grateful.
Don't expect to get any support from a vendor such as this: I'm sure that there might be some in China but no idea how you'd find out. I suspect that's why the Carpuride offering is a lot more expensive: it's basically a support wrapper (US) around the same Chinese products; I did reach out to them to inquire about the configuration of their 2.5mm jack and got a response but if I recall it was that they didn't know
If you're happy with the sound from the stock HK system then you'll be happy with this because that's exactly what you get- you're still using the stock system, just feeding it via AUX.
I am still in the "testing" mode. From time to time things glitch. Bluetooth drops out. The unit thrashes through its BT connection sequence DINGING all over the place: music turned up load = LOUD DINGS! I'm not sure what is to blame here. I suspect it's my phone; it may be just standard BT timeouts I don't know: it shouldn't drop BT if BT is active; this kind of leads me to suspect that the DVR might be dropping and then the phone thinks that BT isn't needed so it puts it to sleep (or whatever; I just noted that I check the connection settings on my phone and see that BT gets turned off). The manufacturer appears to offer/provide updates from time to time in which case it's possible that any fix could be coming along. There's also the possibility that the processing power is a bit weak and that running maps and music together can sometimes stress the unit. Again, I am not sure as I don't yet have much time with this setup.
Apple CarPlay is only supported in wireless mode. A quick test by my wife resulted in an initial thumbs up.
I'll look to provide a followup on how it's all working. As of this point in time I'm fairly happy with this solution.
