Vetluver

When my sub starts hit loud and hard it causes the battery voltage to dip below a certain level and causes the auxillary devices to shut off. AC, seat controls, etc are temporarily shut off till you restart the car or a certain amt of time occurs(?). A malfunction warning comes on the speedometer to let you know.

gmdebruyn

see if they can provide it for you. have them call me and i can tell them where to get them if they don't. i have another source to get them since i do some work in the home theater industry.

gmdebruyn

not sure how your amp is wired, but i've never experienced this.

i have the amp triggered by an ignition controlled 12v circuit. even when the music starts as i start the car i've never had this happen. what amp are you using? how efficient is your driver?

vraa

Have you tried using a cap to route power for the amp so your aux devices don't dip below needed voltage?

medici78

Vetluver, what kind of amp do you have? This sounds kind of odd. I know there's several members running decent sized amps with no problems.

ThemisN

I was thinking about doing a freeair setup as well, but am concerned with being able to put BACK the stock sub once Im ready to sell the car. Since you cut that plastic, Can the original sub be put back? Im not so sure.

Vetluver

I have a JLA 500/1 monoblock sub amp with a JLA 10W7. It's wired directly to the battery. I have not put the "1000 watt" cap that I bought on yet. I had the battery checked and it's fine.

I think the 10W7, JLA's best, eats power too.

vraa

Why aren't you using the cap?

Vetluver

Just bought it, Will hook it up this weekend.

I've never had to use a cap before but according to the local shop MBs are very sensitive to voltage changes. Should fix the problem.

vraa

Take pics of install.
I'm curious as I need to do something along these lines for a friends car when I have time.

Vetluver

Ricky, these are pictures of the battery compartment. I took Positive off the lug attached to the post. The Negative is attached to the chassis bolt which has factory grounds attached. These were the easiest and most reversible leads I could find.

The cap is supposed to go as close to the amp as possible but I wanted it out of the trunk below the mat.

As you can see I have dealt with big connectors for these momoo wires previously and decided to do it the easy way. I perforated the plastic of the cable with an awl then stretched it open with a needle nose, then screwed the post through the cable itself. It won't pull apart like standard connectors will and it was way easier IMO.

The bare posts are not covered for illustrative purposes. I taped then up after taking this pic. Obviously if you have a cap of this size and leave them untaped you might short something out, like YOU. I learned this the hard way with a .25 F cap on my Vette. This is a 1 Farad cap and could shock the chit out of you.

Sorry for the lighting and quality of some the pics.

vraa

Pictures look fantastic.
I'm wondering, how do you have it secure where it is?

Vetluver

Cap came with plastic mounting points and you could attach with one set if you wanted to but I just have it wedged between the car and the spare. It's really tight in that area and motion is not possible. I really don't like drilling or altering my E55 any more than is necessary.

If I was to do it again I probably would use a cap designed for 500 watts, it's half the size and could be tucked in a little better. My local shop just didn't have one that small and gave it to me for the cost of the smaller cap. Still it was redicuously over priced.

There is a nice feature on the side tho, has a voltage read out so you can monitor the health of your battery. You could get a smaller capacitor from an electronics store for way less than one from "Rockford Fosgate"

medici78

JL Audio amps draw a lot of current, but i doubt they normally draw enough to cause the problem you are seeing.

Vetluver

I can only surmise that my battery might be weak but I've had it checked twice and each time it was fine.

The only time that the accessories shut off is when the stereo is playign loud and the sub is kickin a$$.

One the MB techs explained that if voltage in battery circuit drops below a certain level, even for a millisecond, that's enough to trigger the protective function.

I guess we'll see if the cap cures the problem. I'll let you all know.

gmdebruyn

vetluver,

i do not have a cap and i have not seen this problem.

cheers,
gareth

Nait Sirhc

So what did you use for input to your JL amp? Did you simply tap what was going to the stock sub originally? (That's how I have my sub box wired... tapping two wires to one of the sub plugs, into a line-out converter, RCAs from LOC to amp.

Not very pleased with the set up and I'm definitely considering doing something like yours. However, my sub is a Kicker L7 1500w and would be quite a bit too loud if I don't get this set up correctly...

rluvsbenz

gmdebruyn
That's a very nice setup. I too was looking for more thumps from my factory sound system. This is a great idea without loosing your trunk space. Do you mind sharing the cost of this modification?

Esh

Remember... this thread is from 2005

rluvsbenz

Sorry wasn't paying attention to the dates. I was reading previous threads.

Adsonic

I wonder now after 5 years if other options are better than this, as I feel it doesn't get any better.

AMGfan

I think the "under the reardeck" subwoofer enclosure is the probably the best of a bad environment (i.e. car interior)...it gives a cleaner look, leaves space in the trunk for storage, and affords very good bass output depending on driver used, power amounts, and quality of construction.

https://mbworld.org/forums/w211-amg/...o-surgery.html

SterlingE55

I did something similar to AMGfan, not nearly as nice and only a single 10. I ripped out the stock sub, cut out the sheet metal where the stock sub fires down through. Built a box that fires up through the stock location that's only 4.5" thick so I have almost all of the usefulness I had with the stock sub. I haven't covered the box yet, but I'll be building another box for the Boston G5 I'll be replacing my Type R with soon. I'll try to remember to take some pics to show what I'm talking about.

Nait Sirhc

How difficult is it to remove that stock sub? It looks like a huge PITA to get to...

SterlingE55

It's not all that bad. Remove the rear seat, headrest (there's a lever that has to be pushed). Some push pins hold the rear deck on, pull those twist the sub, unhook the wires and she's out.