Been a while, components and amplifier hookup question

kenstewart

Been a long time since I've posted, but you guys have been the most reliable car audio buffs I've come across. Hope you don't mind me asking this question.

I had the momo 5250s in my truck, but recently got a deal on some Image Dynamics Chameleons (CXS54s) to match my two Image Dynamics subs. The crossovers for the momos had two amplifier channel connections each so I utilized all four channels of my MTX Thunder 684 amp. Now, the Image Dynamics crossovers only utilize one amplifier channel each. So, now I have these awesome speakers that sound like crap because I'm not feeding them enough power. Here are the specs for the amp and the speakers:

Speakers:
100watt RMS @ 4 ohms

Amp: at 4 ohms
@12.5 volts:
60wattsx4 ... 240wattsx2 bridged

@14.4 volts:
85wattsx4 ... 340wattsx2 bridged

Ok, so it's too powerful bridged (or is it?), so my question is can I dump the ID crossovers and run directly from amp to speakers? Do I lose any fidelity by dumping the ID crossovers and utilizing the MTX amp crossovers?

BTW, still keeping the Momos and putting them in my son's Mustang

1996blackmax

You will not lose fidelity.... the only thing is the MTX's crossover will not give you high enough crossover points as they only go up to 200HZ. You will run in to the same thing with your HU. Your tweeter will get fried.

Those MTX amps give you more power than those specs, so that amp is probably giving somewhere around 80 solid watts or so. I woul think that this would be enough power to make them sound good. I am running 90 watts RMS to my Rainbows, and i think they sound very nice with that power. They are also rated for 100 watts. I had the amplifier model below yours and the birth sheet said it gave me a little over 30% more power than the posted ratings. If you bridge the amp you will be getting around 300 watts per channel. You may need to move another amp.... You could try bridging the amp and setting the gains to their minimum rating and see how that goes, but be very careful with the volume knob.


Seeing that you have a CD8445, I would get the microphone if you do not already have one to help you tune your system. This feature comes in very handy. Sounddomain has it for $20 dollars.... http://www.cardomain.com/item/ECLMEI100

kenstewart

Actually, I remembered I had another new MTX amp, MXA3002 2-channel amp. It's 75x2 @ 4ohms. Looks like my solution, then I can pull the Thunder 684 and put it in my son's stang running the Momos. Not the full 100RMS, but I know the MTXs underrate their amps, so it should be kicking out at least 80/85 RMS so I should be good to go right?

Oh, forgot ... my HU has 8V preouts, any prob since the MXA3002 says it takes 5V preouts max input signal? Must not have been since my sub amp says the same, but my previous comp amp (Thunder 684) said it took up to 8V signal.

1996blackmax

That rating is an RMS rating, you'll be fine. I actually contacted Arc Audio about this before. My CD7000 has 5V preouts, and my two previous Eclipse units had 8v preouts. I was running them with my Arc amps which have a rating of 250mV - 2.5V with no problems.

kenstewart

Thanks for the info

1996blackmax

no problem

2002tahoe

my HU has a 2.5 volt pre-out. is that horrific? when i switched from my stock HU to a Pioner DEH3800 i lost a lot of bass. is this because i am running it from the HU instead of a Hi to Lo converter from a speaker?

MacLeod

2002tahoe wrote:

my HU has a 2.5 volt pre-out. is that horrific? when i switched from my stock HU to a Pioner DEH3800 i lost a lot of bass. is this because i am running it from the HU instead of a Hi to Lo converter from a speaker?

That doesnt sound right unless your stock HU had a pre-set EQ to ramp up the bass.

2002tahoe

its a stock AC delco unit from GM for a 2002 Tahoe. would it be because i have crappy rca cables?

kenstewart

BTW, congrats Mac on your win. You gave me tons of good advice when I first set up my system, glad to see you win