Trunk Monkey

iTrader: (1)

Hey guys, I'm about to run my setup active and was wondering if I could get some help with setting this up. I'm still learning about the correct x-over points, slopes to use, etc in active setups so you might need to spoon feed me lol

Questions:
1. What do the different slopes mean? 6db, 12db, 18db, 24db, etc...
2. I will be running a 2-way setup, so what happens by lowering/raising the x-over point for tweeter and the mid?


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OK....so now onto what I have and where to set it up. I will be running:

Amp:
MB Quart Q4.150

• 4 ohms: 150 watts x 4 chan.
• 2 ohms: 220 watts x 4 chan.
• Bridged, 4 ohms: 440 watts x 2 chan

Components:
1. Massive RK6
2. Image Dynamics CXS62 (2-ohm!!)


Vehicle is an '04 Acura TL. Tweeters in stock location on dash at bottom on a-pillar, firing up into windshield. Doors are fully deadened and sealed. Stock navigation unit is being used so no Time Alignment, processing, etc....yet. Sub stage is 2 JL 12w6's sealed (not sure if that's needed)

I was wondering if you all can help me with what x-over points and slopes should be used with each setup (Massives and ID's). Thanks a ton guys!:beerchug:

geekybiker

1) Its how steep the roll over curve is. That's Db per octave. So say you have a highpass @300hz -6db. That means starting at 300hz, it will roll off 6 bd per octave. So 150hz will be -6bd, 75hz -12db 37.5hz -18db. Etc, etc.

2) Well, you're just going to be transferring the audio between the tweeter and mid for certain frequencies. Be careful about going too low on the tweeter, you can blow them fairly easily by asking them to play too low. If you can get the TS parameters and frequency response graphs for both the tweeter and mid it will probably help you figure out where you need to cross. However the correct way to do it is probably with a Realtime spectrum analyzer. Otherwise you're just guessing at your response. On axis and off axis response are different and you have to deal with cabin gain. <<--- all book knowledge though.

jda123

Start with the lows at 80 and the highs at 3K. Use -12db. I am assuming that the subs will/do play up to 80.

Play with it from there. There are graphs of the CXS 2 ohm online - they are different from the 4 ohm slightly.

Remember with the bandpass filter (I assume with the BP filter option), when you raise the tweeter frequency, you also raise the midbass frequency as well, so those two roll together.

Trunk Monkey

iTrader: (1)

so bandpass means when you raise the freq. of the tweeter is raises the mid of "equal" value??

jda123

This is way too simple, but you are effectively setting a lower and upper limit and taking the in between.

High pass, as well as low pass, restrict on one side of the line, but allow anything to pass on the other side of the line. Bandpass has 2 lines.

You can read more about this for hours if you want.

jda123

Most amps take the low part of the bandpass from one channel and the high part of the bandpass from another. They then use the high part of the bandpass as the starting point for the high pass filter.

...so that one knob controls both.

geekybiker

Band pass is a high pass and low pass filter together. If you have a sub, it will mostly likely be low pass(100hz and lower), the mid will be band pass (100hz-3khz) and highpass for the tweets (3khz+)

Trunk Monkey

iTrader: (1)

Ah! Gotcha. Less knobs/crap to deal with. Thanks for the info