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Ingenious... looks nice and all tucked away and out of sight....that's what I like about DIY...we can be resourceful and creative....and scavenge.... mine didn't have an internal amp... I would have maybe put it there too...however, I'm always adjusting and tuning the amp and LOC so I guess my location is good for that....
Thanks - even though I'm not doing this exactly as you are, your posts have been helpful. I had about two hours to work on the car today. Ninety minutes of that time was spent test-fitting parts.
I considered mounting my amp in the trunk "ceiling" like you did but I use the trunk to transport bulky items at least once a month. (I stuffed a load of recycling in the car this morning.) I think it is inevitable that I would get careless at some point in the future and push something against the exposed amp or wiring. You have a pickup for your heavy hauling so an overloaded trunk probably isn't a significant consideration for you.
If I have an overheating problem with the amp location I'm using, your installation will be my model for "Plan B."
Yea.. I try to keep my trunk clear of stuff... what car do you have and where is your spare tire? It must be off to the side.... mine is directly in the middle of the trunk..
Yea.. I try to keep my trunk clear of stuff... what car do you have and where is your spare tire? It must be off to the side.... mine is directly in the middle of the trunk..
I have a 2005 C230 Sport Sedan. The spare tire is under the floor of the trunk.
I decided not to put the fuse holder in the engine bay
As Norteno discussed, the engine bay does not have a convenient place to mount fuse holder. I understand that the fuse should be mounted as close to the battery as possible. (Minimizing the cable length that is not protected by a fuse reduces the amount of cable that has the potential to be damaged.) I think Norteno's use of the battery cover is likely the best location in that context. I decided to take a slightly different approach and I hope my decision to put the fuse a few feet farther from the power connection doesn't come back to haunt me.
After about 30 minutes of experimenting in the engine compartment with different locations, I began to consider a location inside the car. I eventually settled on a location in the passenger footwell adjacent to the spot where the cable emerges from the firewall.
Fuse holder in the passenger footwell area
The fuse holder is held on by double-sided tape designed for automotive use.
In order to protect the unfused portion of the cable in the engine compartment, I wrapped it in wire protector and used a shrink tube to seal the end with the ring connector.
Wrapping wire protector around the power cable Shrink wrap protects the end of the cable
In order to avoid disconnecting the amp cable when I need to remove the battery, I'm planning to attach it to the positive power terminal used for jump-starting the car. The ring terminal fits on it and using that location for a power point allows for routing the cable away from anything that could potentially damage it. The is the auxiliary positive power terminal used for jump starting the car.
I didn't measure the unfused portion of the power cable, but it is about 3 feet long, possibly less. I hope that my use of the cable protector mitigates the risk that is the result of using a slightly longer run of unfused wire.
After I finished solving my power cable and fuse holder puzzle, I removed the door-sill covers and ran the power cable, amp turn-on wire and RCA cables to the trunk. My plan was to run the RCA and power cables on opposite sides of the car in order to minimize the risk that the speakers would pick up electrical noise from the power cable. However, due to my decision to mount the amp in the rear fender on the passenger side, I didn't think the cables would be long enough to run down the driver's side and cross through the trunk to the passenger side. So, the RCA's and the power cable are on the same side of the car. I took care to avoid having the RCA's touch the power cable, but time will tell whether I have an issue.
Here's a photo of the amp mount with the power, ground, amp turn on and RCA cables ready to connect to the amp. The ground is attached to a ground point on the side of the car.
Red = Power, Brown Wire = Ground, Blue (thin) = Amp turn on
My next step (when I have about 4 hours free) is to disassemble part of the dash and connect the RCA's and the amp power line. Once I've verified the speakers work, I'll permanently install them.
Last edited by KevinH2000; 10-12-2019 at 09:04 AM.
Looks good.... You puttin in work... it pays off... I love how my system sounds already and I'm only using stock head unit and stock door speakers...I will replace speakers next. my subwoofer is an alphasonik 12 inch shallow mount which sounds fine, and I can use the head unit bass adjustment knob to increase or decrease the bass level according to the type of music I'm listening to....I think your cable wire length should be fine.... of course the shorter the better but that fuse protects the cable itself, not the amplifier which has its own fuse.... and unless you're running crazy amps and pushing your system to the extreme and all other connections are tight and properly installed and grounded which they certainly appear to be, and your speakers are matched well to your amplifier and your power cable is 100% copper, which will prevent heat buildup, and your fuse is matched correctly to your amplifier's power rating, I think it should be fine....I have even used CCA (copper clad aluminum) power cable on moderately powered systems and have never blown a fuse or had it over heat (but I'm not running a high powered competition system though)....l think you have minimized the risk of damage to your system and should not worry about that 3 foot unfused section of cable... I know I have not heard of very many cases where fuses blow and car components are damaged or in the worst case, cars catch fire... I have installed some powerful systems in the past and have experienced alternator failure due the excessive load being placed on the alternator and have installed high output alternators which are excellent but costly....but you seemed to have put together a very well thought out system and taken the necessary precautions to protect your vehicle....I wish some others would chime in and share their knowledge with you and me...
.I wish some others would chime in and share their knowledge with you and me...
The W203's are getting a bit older (mine is 15-years old) so it may be that fewer people are investing in upgrading the electronics. It looks like some of the folks who did a lot of work on their cars 5 or 6 years ago may have moved on.
I'm finding that a few dollars spent on upgraded systems has a significant return in terms of my satisfaction with the car. I've added a double-DIN head unit with navigation, blue tooth and a back up camera to mine. Those additions haven't made it the equivalent of the current models in terms of electronic wizardry, but it has closed the gap. I bought most of my upgrades used, so the price hasn't been outrageous. (The head unit cost $100 out of a wreck and the amp I'm using is a "scratch and dent" from Crutchfield.)
Even though we may not receive any tips, we are "paying it forward." If anyone needs to do this in the future, they will be able to consider two viable options for adding a sub and rear speakers.
I have other plans for this weekend, so I won't be doing any more work for about a week. I plan to have this wrapped up by next weekend provided the speakers aren't damaged.
Again, I appreciate the feedback and the benefit of reviewing your work.
I had some time on Saturday and Sunday and finished my project.
Ground, amp turn on, power and speaker cables - the blue masking tape is for labeling the polarity of each cable. The sub is bridged...
The actual wiring of the amp is fairly easy, taking the dashboard and rear deck apart and putting it back together was time consuming.
Amp installed and connected. Note the RCA cables connected to the top and the heavy duty cable ties holding it firmly to the bracket.
This is the rubber pad that lays on top of the rear deck. I had to remove some of it in order to install the rear-deck speakers.
Removing the rear deck is a the least pleasant task. Fortunately, I recently installed a folding rear seat and that saved some time. The rubber padding had to be cut to accommodate the speakers. I may go back to the donor car and scavenge the padding that accommodated the speakers. It may be a little neater than the pad I cut.
Speakers installed. Note the speaker cables running in the channel in the forward part of the foam.
I found some existing holes to route the speakers into the trunk. I don't like to drill unless I absolutely have to.
Speaker cables entering the trunk
Here's the amplifier with the side trim installed. I can access the amp controls through the access port for the rear light.
Controls are accessible, but a little more room would be nice.
Here are some pictures showing the results. Only a small length of speaker wire at the top right of the trunk betrays the existence of the upgraded sound system. I remain concerned about heat dissipation capacity of this location.
Nice and tidy
The subwoofer circuit control on the amp is set to low pass and the circuit for the 3-inch rear deck speaker is on full range. I may switch to a hi-pass filter for the 3-inch speakers.
I'm in the process of fine-tuning the sound using the head unit controls. There are quite a few options and it may take a 2-3 week period of trial and error to arrive at the sound I like. My initial verdict is that the sub woofer is adding a richer sound and the rear deck speakers provide a more spacious feel to the music. I didn't want or expect booming base from a 10-inch sub.
I did run into one glitch with the sub. The edge of the cone had become detached and it was rattling. I glued it in place using this video as a guide:
The original poster on this thread is more experienced than I am with auto audio. Since I'm in learning mode, I am adding some more information in case another novice needs it.
Specifically, if you add an amp you will receive more return on your investment in terms of better sound quality if you take a few extra steps and adjust your new components for your car. For example, I used this video to learn now to adjust the gain on my amplifier:
Another source of information is your equipment's manufacturer. In my case, I sent an email to the tech support team at Kicker (the manufacturer of my amp.) The Kicker web site had the test signals I used to adjust the amp. A third source is this and other MB forums. I found this information about the stock and upgraded systems on another thread.
Speaker information - Basic System Speaker information - Harmom Kardan Upgrade
Although these documents seem to indicate that the HK subwoofer is rated at 2 ohm, I checked the subwoofer with my multimeter and it turned out to be 4 ohm. I plugged that value into the equation shown in the YouTube video along with my amp rating of 30 watts per channel. (The subwoofer is bridged so the power going to the amp is 60 watts.) This suggested that I set the output voltage at 15.5 volts for the subwoofer. The full-range rear deck speakers showed about 5 ohms, and I set the output for them at 11 volts.
To reach the output voltages required me to turn the gain controls down from the level I set them "by ear." It wasn't practical to perform an A/B test to compare the "by ear" settings to the one I'm using based on the volt meter. My subjective assessment is that the new settings (with the gain turned down) sound better.
Using the original set up with the higher gain level made it sound like the bass was coming from the rear of the car. Now, it sounds more balanced and it is more difficult to identify the location of the subwoofer by sound. Also, with the gain set higher, I had to adjust the fader all the way forward or the sound from the rear dominated. With the gain set lower, the fader control more accurately reflects the sound I hear. That is, if I set the fader for the middle of the car, neither the front nor the rear dominate.
I am planning to see whether adjusting the cross over settings on the amp have an impact on sound quality. If I learn anything I will share it.
Last edited by KevinH2000; 11-02-2019 at 09:39 PM.
Excellent post!!!.. I have a line Out converter in my system to factor into the mix.... which adds another level of adjustment to try and figure out.... I have been using a mini oscilloscope and my ears to attempt to gain the best sound without distortion. In some ways for me, it's almost like a dog chasing his own tail or a horse chasing the proverbial carrot on a stick....might be unattainable.... and each of us have our own desires and expectations from our stereo systems so there are no one size fits all setting. the common goal would be to protect our equipment and investment.... but sometimes I just like to push it to, and past, the limit and blast the speakers beyond their specifications and see what happens...lol ...I think most people who install big subs want big booming sound and may be irrational regarding the capabilities of their audio systems when cranking it up... I know I am sometimes....whoa!!! Good luck and good work...
About 15 years ago I bought a used Miata. The previous owner had installed an aftermarket head unit and amplifier. The aftermarket head unit looked awkward in the dash. (The stock head unit on first generation Miatas is bigger than single DIN, but smaller than 2 DIN. There was a kit available that included a storage bin to make up the gap between a single DIN unit and the larger opening, but it looked cobbled together. The head unit wasn't flush with the rest of the dash.) I wanted to use the amp and the high-end speakers the previous owner installed, so I needed to use a line out or line level converter with the stock head unit. (The seller included the stock unit with the car.) I have forgotten whether the amp had any adjustment controls on it. It didn't make a huge difference in a Miata because they are noisy inside whether you have the top up or down.
With the Mercedes, I am going beyond just installing the equipment. The car is relatively quiet and improvements from my previous set up and the present one with the subwoofer and rear deck speakers is obvious. I briefly disconnected the speakers from the amp yesterday when I set the gains and the system sounded flat without them. I can make additional adjustments on both the amp and the head unit, and I hope I'm able to hear additional improvement.
I was fortunate that you were tackling your project at the same time. As I said earlier, we had different goals (I'm not looking to break windows with my bass), but all the ideas I borrowed from you made this project go smoothly.
Could you send me the link to the stereo graph you posted? I like to see it but it is blurry. Thanks... so your subwoofer is mounted underneath the rear deck along with the other deck speakers also? Maybe I missed something somewhere in your description.... thanks bro...
Thanks... so your subwoofer is mounted underneath the rear deck along with the other deck speakers also? Maybe I missed something somewhere in your description...
Take a look at the 4th picture in post #32. The subwoofer and the speakers sit on top of a foam pad that fits above the rear deck. The cover with speaker grills fit on top of the speakers and the foam pad. The plastic speaker mounts have tabs that clip into slots in the rear deck.
I had to take everything apart again in order to make another attempt to repair the rear sunshade and take care of a couple of other issues related to my folding seat installation. In case anyone ever needs the information, I took photos showing the size of the factory HK sub.
Depth - About 3 inches Diameter - Approximately 8 inches Another shot showing diameter
It fits into a mounting bracket that clips into attachment points on the passenger side of the rear deck.
If you look up in the trunk on the passenger side you can see a round opening that roughly corresponds to the location. For some mysterious reason, the subwoofer is not centered on the opening into the trunk.
You can also see the location of the slots for the mounting tabs.
Rear deck speakers showing their mounting brackets
Last edited by KevinH2000; 11-24-2019 at 10:21 AM.
My decision to use the speakers scavenged from a "part-out" proved short-sighted. I had to repair the subwoofer prior to installation. I heard a rattling noise a couple of weeks ago and I decided to replace the speakers. I bought the replacements from Parts Express. They were relatively inexpensive. The effort I expended removing and reinstalling the rear deck was the major cost.
The 2.5 inch replacement speakers have substantially larger magnets. Replacement Speaker installed in passenger side rear deck mount Clearance is tight in the driver's side mount
The small, full-range speakers are 2.5 inches across. I wanted to use the OEM speaker mounts and the shallow mounting depth on the driver's side mount (the one with the subwoofer) made for a tight fit. Speaker wires soldered to passenger side rear deck speaker. Very good fit in the passenger side mount
Mounting the full-range speakers in the driver's side mount proved a challenge and I'm not 100% satisfied with the fit. Full-range speaker is slighty off center. I rounded two of the square corners with metal snips to make it fit this well.
To attach the subwoofer, I had to repurpose the hardware from the OEM mount to sandwich it into the mount. I used insulating foam strips from Home Depot to ensure a tight fit. You can see glue residue on the top of the speaker mount that is leftover from my repair of the OEM sug. Subwoofer mounted in the trunk. I'm not 100% happy with my metal work. Fortunately, it is difficult to see unless I place my head in the trunk and look up.
It may be wishful thinking on my part, but I think the replacement speakers sound slightly better than the OEM HK speakers.
Hey, what been up? How's the Benz stereo project been going. I stored my Benzo in the garage last November and getting ready to bring it out next month. Just checking with you; hope things are well.
David Perez
2006 C280 4Matic
Thanks for checking in. I hope your project is progressing.
As you can see in my last post, it turned out to be a mistake to re-use the Harman Kardon subwoofer. I decided to replace the sub with an 8-inch Dayton Audio subwoofer from Parts Express. I was able to re-use the Harman Kardon mounting bracket, but I had to cut a hole in the rear shelf to accommodate the larger magnet of the replacement sub. I also replaced the other rear-deck speakers as a precaution. (Removing the rear deck is an irritating job and I would like to avoid doing it again.) The good news is that the system sounds better with the new speakers.
You may recall that my system upgrade goals were to increase the spaciousness of the sound by adding rear deck speakers and improve the bass response with the subwoofer. The amp in my system is adequate for these purposes, but if someone wanted more bass response they would need a larger sub and a more powerful amp than I used. The current setting for my subwoofer on the equalizer in my head unit is 3. When I turned it up to 5 and tested the system at a high volume level, the amp overload circuitry cut in and shut off the amp. I briefly thought of adding a second amp to power the sub, but I am trying to protect my hearing and I normally don't listen to the system at high bass and volume levels. Unless I start to experience frequent amplifier shut downs, I will stay with the current set up.
I haven't done much experimenting with the equalizer settings in my head unit. If I ever have some spare time, I will work on that.
Yea.. me and dude shared tips and pics for the 06 W203 amp install... Mine is doing well..now I'm gonna do the same on this 2010 c350...I will tap into this site again for any help.. 2010 c350 sedan
has anyone been able to run 0 gauge wire instead of 4 gauge. i got two 12s on 4 gauge wire and was told i need to use 0 gauge wire instead due to the amp and subs i have.
10-05-2019, 11:55 PM
