cross over help

jnt

I just installed :

Alpine 9835 Head Unit
Polk mmc 6500 components
Polk mm 2104 woofer
(2) mtx 502 amps

on the alpine i personalize web site I have no idea on what or even how to set the crossover at. I am completely new to this and dont have a clue. The crossovers that came with my component set are already set up to limit certain frequencies to the tweeters and mids?

exalted512

i would set your components at ~60Hz high pass and your subs at ~80Hz low pass
-Cody

MacLeod

That sounds about right to me. I doubt thall be the best right off the bat but its a good starting point. From there you can fine tune it til you hit that sweet spot.

For my setup I have my sub crossed at 70 Hz and my fronts crossed at 50 Hz and it seems to work well.

jnt

thank you for the info! Couple more ?'s

how does adjusting the db number from 0 to -12 effect the sound of the woofer and the component set...and also the db/oct set to "off"....On the alpine site, when adjusting the crossover freq it doesnt mention anything about high pass or low pass. So I set my front speakers at 63 hz and my sub at 80 hz.

MacLeod

Db is a unit of measure and it depends on the application.

In this case it means the slope of the crossover. A 24 db cutoff will be steeper than a 12 db. A flatter cutoff will allow more frequencies in other than the specified one whereas a steeper slope will be more restirctive and allow less thru.

Actually, if I were you Id forego the head unit x-over and just use the one on the amp for now. It should supply enough flexibility to tune your system pretty good. If you still feel it needs a little tweaking then get into the h/u. But for now Id suggest setting everything to "flat" or 0 db or whatever and use your amps.

AustinKP

Originally posted by jnt
thank you for the info! Couple more ?'s

how does adjusting the db number from 0 to -12 effect the sound of the woofer and the component set...and also the db/oct set to "off"....On the alpine site, when adjusting the crossover freq it doesnt mention anything about high pass or low pass. So I set my front speakers at 63 hz and my sub at 80 hz.

You actually set the crossover points correctly. The dB/octave slope needs to be something like 12/18/24. If you have it off, you're defeating the purpose of the crossover.

On the Alpine site, because it knows what you're adjusting for the mids and subs, it automatically sets the high pass for the mids and low pass for the sub.

jnt

MacLeod: when I set up my amps, the mtx manual said if I was using a component set then use the FR setting (which I guess means full range???) and for my the amp powering my sub it said to use the LP (low pass filter???) Is that what you mean by using the crossover from the amps?

thanks!

AustinKP

Originally posted by jnt
MacLeod: when I set up my amps, the mtx manual said if I was using a component set then use the FR setting (which I guess means full range???) and for my the amp powering my sub it said to use the LP (low pass filter???) Is that what you mean by using the crossover from the amps?

thanks!

Well, if you're going to use the amp's xover, you'll want the fronts set to HP and the sub to LP. Then set the dials to 60 and 80 Hertz. The FR setting for the fronts is if you want to use the HU's built-in xover.
-Austin

jnt

thanks austin!

neomagus00

Actually, I use the HU xovers, and leave the amps at fullrange. It works very well, because I can pull up the xover point on the fronts if I'm hearing too much bass or if I want to play it louder

AustinKP

Originally posted by neomagus00
Actually, I use the HU xovers, and leave the amps at fullrange. It works very well, because I can pull up the xover point on the fronts if I'm hearing too much bass or if I want to play it louder

Ditto!