Help me Design my Car audio system?

Question

I was looking for somone to help me design my car audio. I have a basic design i belive, but i need help modifying it to the best i can get. I will have the names of everything in here, they can be found on Crutchfield.com under these names.
Subs - Infinity Kappa Perfect 12.1 = I want these to play 18-200
Midbass - Kicker SSMB8 - Want these in kick pannels play 180 - 500
Door Speakers - Polk Audio db6500 - High end 480- 8000 for the woofer, and then 7980 - 20k for tweets.
Back Speakers - Don't matter.

Now i need Idea's for amps and cross-overs to get for the gear above, or any other suggestions on what to get for gear.

I have the Infinity Ref. 611a for the subs.
MTX Thunder 3404 - can't be found on crutchfield - for the 2 doors and 2 back speakers

and i was thinking kicker ZX 300.1 for the midbass in the kick pannels. will this gear be able to meet my goals? or how to some of you people have your systems set up?

Answer 1

Yeah, you seem to have a good understanding about how to accomplish good sound. But first, I want to address your crossover points. They shouldn't overlap like you have expressed. There should be somewhat of a gap between each xover point. Most xover slopes are between 12-24dB per octave. With your design, the frequency respones is going to spike at these xover points, which you will just have to reduce with an eq.

Try to keep a span of about 1/4 to 1/3 octave, dictated by the slope of the xover. Here would be a "normal" seperation point for the equipment you have listed; Sub 18-80hz 18dB slope, MB 125-350hz 12db slope, mids 400-4k hz 12db slope, tweets 4.6-20khz 12db slope.

The higher the slope the closer the xover points should be. 200hz lowpass for the sub is way too high. It will be bass in the rear only, with no sense of frontal imaging.. Bass notes are omnidirectional, but anything past 100 hz is not.

Crossover and EQs, Make sure they are versitle!!! Adjustable slope and infintiely varible on the x over points. Multiple inputs and outputs are going to be neccessary for your set-up. Look for a good signal to noise ratio. Parametric EQ are the most versitle, but are often hard to tune correctly. 31 band EQs allow it to be highly adjustable and are quite easy to tune.

FYI, I would rethink the Infinity amp for the subs. The are not a real powerhouse of an amp. MTX or Kicker would be better amps for the subs. Excellent job on the selection of speakers. Those Kicker MBs are wonderful!

Email me if you have any more Q's or just need some advice. You seem to design like I do.

Answer 2

well, i dont think you really need a "midbass" speaker. i think that by cuting this out, you can get a really good set of comps that will do the same, and probaby cost about the same as the mid-bass speakers, and amp your going ot need to push them.

i'd recomend comps from Boston Acoustics, Kenwood Excelon, Diamond Audio, and MB Quart. any of these will really really sound good up front.

as far as the rears your right, who really cares? unless people ride in your back seat a lot, there really not going to matter too much.

i'd ditch the idea of MTX though. IMO there speakers dont sound all that great.

Those Infinity subs are awesome. Kappa's are some of the best sounding subs on the market today.

also i'd stear clear of the kicker amps. i ordered 4, two years ago, and 2 have them have taken a dump on me already. niether was abused, they just stopped working. not to mention the SQ isnt all that great.

i'd look into the Kenwood Excelon amps at www.woofersect.com. there pretty cheap for the price and give you really excellent SQ.

so lets review.

Fronts: good set of comps
Rear: doesnt matter much
Subs: great choice
amps: stear clear of kicker and look into Excelon

good luck dude, and you've got the right idea. just make sure you listen to everything you can before you buy anything. stay away from BEst Buy and Circut city, and go to some private shops. if you've never been to a private shop, you'll be amazed at what you hear when you get there.

Answer 3

Sounds to me like you have it all figured out. I can tell you that not enough people know enough about custom ausio to give you any real help here.

Continue to use the resources you currently are using. Sounds like you are well on your way to needing a hearing aid in about 10 years.