SL/R231: SL550 back speakers PROBLEM SOLVED!

Last edited by JK417; Sep 16, 2017 at 12:32 AM.
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I ordered last week the air intake filter kit from Ultimate. I asked them, to sell me just the hardware since I was going to use some K&M filters and they responded by saying that their filkters fgave them 6 more HP in a dyno than any others and they would lower the price from $450 to $400. I took it.
The kit arrived today and after I instyalled it, I have to say that the accelaration response is much quicker. It won't blow you away but you can ddefinitley feel the difference. Thanks to all in this thread for your ideas. It's been great.
Now I am just waiting for my rear spoiler from Carid. I think it'll give it a more sporty look. Later, I'll do they Weistec tune and maybe some rims....We'll see
This is the case unfortunately more often than not with premium sound systems. They lack the definition we desire and even more importantly lack the flexibility to make adjustments.
Alpine makes a small 4 channel digital amplifier that works great in almost any scenario when a simple power boost is required.
For this vehicle (2015 sl 550 with h/k system) I simply interrupted the rear speaker lines, wired them to the inputs on the ktp-445u and then connected its outputs back to the speakers. The rear half of the vehicle does need to be removed to access the wires needed for install. There is a plenty of space behind the fuse box to mount the powerpack and since it is a digital amplifier it does not create much heat. Power, ground, and acc power can all be grabbed at this fuse box location rear passenger side too.
For this client, I also added 2 under the seat JBL BassPro 150watt 8" powered subwoofers. (one under each seat) They were a tight fit, but from the options I've seen these were the best ones to go with.
To ensure they were receiving a solid bass input, we installed an Audiocontrol LC2i sound processor. This system ties into the factory subwoofer lines and then corrects any imperfections or limitations in the signal. It also uses a signal-sensing turn-on to tell the JBL amps when to activate. I tied this into the alpine unit as well to eliminate any turn on pops from the rear speakers or subwoofers.
It is a high-level install but very do-able for an Advanced or Master MECP certified technician and the results are worth the time and money for sure!
Install for the powerpack itself would normally be around $400 plus tax. Install for the 2 JBL under seat powered subwoofer would normally be around $1100 plus tax. Price will vary depending on parts chosen but I can email estimates and parts lists if requested.
Let me know if you guys have any questions, sorry I don't have more pictures.
Last edited by G33ksquad; Sep 22, 2017 at 04:56 PM. Reason: pictures were broken
I was still unable to isolate speaker wires running to the rear speakers. I don't think the rear speakers are running off the same amplifier as the rest. I believe the amplifier that I found in the trunk is the 4 channel ICEpower Amplifier. I know that there is also an 8-channel DSP Amplifier somewhere in the car. I wonder if the rear speakers are running off that second amplifier? I also can not find the location of that second amplifier. Any thought?
Now on to Weistec tuning and some black rims....
Also, by doing this, how big of a change does one notice?
Will playing music from an iPhone or radio sound anything close to how it does when the dvd-audio disc that came with the car is played??
Btw - has anyone found a way to mirror their iPhone on the command system so we can play google maps on it?
thanks
Last edited by texasplayer; Jan 17, 2018 at 12:23 AM.
Also, by doing this, how big of a change does one notice?
Will playing music from an iPhone or radio sound anything close to how it does when the dvd-audio disc that came with the car is played??
Btw - has anyone found a way to mirror their iPhone on the command system so we can play google maps on it?
thanks
Re mirror the phone, see this post https://mbworld.org/forums/sl-class-...g-hd-link.html
Last edited by genolan; Feb 18, 2018 at 03:03 PM. Reason: added more




