FlexIS350

Loving my new (to me) 2007 IS 350.

The Mark Levinson system is crisp but, as others have mentioned It's missing a distinct phatness of bass at low frequencies which I've just gotta have. My only listening experience has been satellite radio.

I had an unused 1200W kicker amp laying around and 2 Kicker 12"s in a closed box which recently came out of a buddy's car so I took them down to local audio professional to have it installed. I have done these kinds of installs before myself but wanted to leave this one to the professionals because this is the nicest vehicle I have ever owned. The guy charged me $160 to run the wires from hood to trunk, connect the RCAs to the stock head unit and set up the amp/sub.

The only problem is that the new sub, which should totally bang, really just doesn't. It gets completely drowned out by the factory sub. Sound is (hardly) coming out of the subs, they are hardly moving at all and are basically inaudible.

The sound guy acknowledged the weakness of the bass but claimed I just needed to spend more money ($200) with him for the purchase and installation of a line driver which he thinks may help. Call me crazy, but I get the sneaking suspicion that this guy has done something to limit the output of the audio as punishment for bringing in my own gear and not buying from his shop. I need a few questions answered and would appreciate any info you guys may have on this sort of thing.


1) Is this a common issue for people who add an additional sub and amp to the stock head unit?
2) Is the line drive a potential/best solution?
3) Could he have missed something in the install which would cause this kind of issue? How should I begin to check his work?

Thanks guys

jw669

iTrader: (8)

First off, either remove the stock sub or at least pull the plug to it so that you do not have two drivers powered by different things, trying to do the same thing.

Did he tune the amp at all?

02Legend

iTrader: (3)

How did he connect RCA's to the factory head unit for the signal going to the amp? As far as I know, you would normally disconnect the factory sub and use the wires to go to a line out converter (LOC) to get the signal for the amplifier and then go from there.

eknine9

iTrader: (8)

You're running two subs, if they are DVC make sure he set up the voice coils correctly to run the right resistance. If they are SVC then you don't have a choice and it's possible your sub-amp pairing isn't good. Also check the gain on the amplifier and make sure it's set properly to the output voltage on the RCA's.

Line-drive is not a good solution, it just boosts the voltage on the RCA's while diminishing audio quality. It's a temporary solution thats kind of like slapping a band-aid on a gushing head-wound. It definitely sounds like the amp isn't tuned at all, and it's also very possible he hooked the RCA's up to a filtered output for speakers and not a subwoofer output.

I don't know much about the stock head-unit but I imagine it doesn't have RCA outputs so he probably tapped in to one of your audio lines, if he tapped into a speaker line and your head unit filtered the audio signal to that speaker already then the subwoofers would also be receiving this filtered audio signal.

There's no choice here, you're gonna have to check and re-do his work. If you're familiar with car audio then I suggest digging in or finding a more reputable shop that you trust to do so because his explanation soudns suspect.

tknx

Your guy didn't know what he was doing. (1) you need to disconnect the main sub - you are probably getting cancellation everywhere. (2) did he do any EQ on top of that?

lexus997

Someone is going to have to check that shop's work:

1. Audio signal input to amp
a. Line level
b. Speaker level
c. Full bandwidth
d. Filtered: high passed or low passed

2. Amplifier settings
a. Gain
b. Filter settings to match the bandwidth of the input signal

3. All audio signal connections polarity
a. Correct polarity at amp
b. Correct polarity at subs

4. I would disconnect the OEM sub


I added a sub/amp combo to an Acura that I used to own as I just did not want to go with a full blown upgrade. I simply tapped into the rear speaker wires, sent those two signals to the amplifier, and installed a dual voice coil subwoofer. It did what I wanted it to do (added bass to the stock system) for the amount of effort & cost that I was willing to put forth.


If you add two subwoofers to a vehicle, it should be noticeable.

Shibumi1

Unfortunately disconnecting the ML sub may cause its own set of problems you'll need a 12ohm 100w resistor connected across the speaker leads so the factory amp still sees a load then you can connect your line out converter to those leads and run them to your amplifier. what the problem is as you get into the higher volume levels of subsignal will cut out as not to blow the sub. To avert this try getting a full range signal from the front door mids at the ML amp itself.

LexRuger

I had this problem when I first got my sub installed. They had the amp gain nearly all the way up but the sub would just not get loud. The sub barely moved. So, I had the LC2i installed and it made a night and day difference.

MikeFoxx

iTrader: (8)

^^^^^ This is your answer... and i'm buying one as well

Also... disconnect that factory sub and/or remove it all together. Keep it somewhere so when a WTB in the classifieds pops up you'll be ready.

darkgt23

kickers aren't that great any more though, but they should be better than what you are describing

Slammer1

I know this is a little old and the OP hasn't responded but thought I would put my .02 in. First off, I want to say that $160 to run power and ground as well as connect with a Hi/Lo converter is definitely a fair price. With that said, he did NOT connect your interconnects (RCAs) to your factory HU as there are no RCA outputs. He essentially wire tapped speaker level signals from the factory output in order to get a signal for the amp that you've added. This is quite common, so no worries. Being that this is a sub install, my initial concern is that he tapped speaker wires that are for mids or highs, not bass. When this is done on these cars, most will wire tap the outputs to the factory sub, to ensure that they have a "bass" signal to send through the HL converter and to the amplifier. No need for a line driver by any means. Ask him to double check what he has tapped into and take a look at the amp's settings. I did the HL converter as well as OE interfaces prior to doing my custom dash install and ditching the factory system completely. While I wasn't pleased with the results of the first two, they were certainly better than what you are dealing with. I had plenty of bass but not the sound quality from the door speakers that I was looking for. Best of luck.