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Discussion Starter · #1 ·
I have been absolutely everywhere looking for basic information on crossover settings. I have searched here, searched caraudio.com, wikipedia - you name it i have searched. I have read the tutorials here and elsewhere but I am still confused.

Here is my setup...
Alpine 9887 HU
(4) Infinity Reference 6822cf Coaxials
- Soon to be replaced w/ 720prs
(1) Crunch P900.4 Amp
(1) Stock Sub & Amp for 2007 Ford Explorer

I want to get the most out of what I currently have but I cant figure out the crossovers. I have taken suggestions from some of the threads here but I cant get it to sound good.

Currently they are set at stock settings

Low 80hz Flat
Mid 80hz Flat
High 125khz Flat

I understand that the settings are set by the users taste and everyone sets them different so should i just leave them alone or what do you suggest i do?

Thanks for any help.
 

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I have been absolutely everywhere looking for basic information on crossover settings. I have searched here, searched caraudio.com, wikipedia - you name it i have searched. I have read the tutorials here and elsewhere but I am still confused.

Here is my setup...
Alpine 9887 HU
(4) Infinity Reference 6822cf Coaxials
- Soon to be replaced w/ 720prs
(1) Crunch P900.4 Amp
(1) Stock Sub & Amp for 2007 Ford Explorer

I want to get the most out of what I currently have but I cant figure out the crossovers. I have taken suggestions from some of the threads here but I cant get it to sound good.

Currently they are set at stock settings

Low 80hz Flat
Mid 80hz Flat
High 125khz Flat

I understand that the settings are set by the users taste and everyone sets them different so should i just leave them alone or what do you suggest i do?

Thanks for any help.
Crossovers are simply the point at which the frequency response rolls off. Big subs can't play high frequencies, and little tweeters can't play bass. So, you create a crossover point for the subs and tweeters and mids to play their range.

There is highpass, there is bandpass and there is lowpass. They do precisely what you think they do. A highpass crossover PASSES higher frequencies than the one selected, and ones below that point fade away to lower and lower volume levels. Crossover points are actually at the -3dB down point.

A crossover point is also defined by its slope. This means, how fast the frequency response drops off, once it starts to cut off. Slopes as low as 6dB/octave or as steep as 24dB/oct are certainly possible, and beyond. The steeper the slope, the more your response will stick to that crossover point. Think of a soft rolling hill vs a steep cliff. A soft hill will gently take you down in elevation. A steep cliff does it rather aggressively. The advantage of a steep rolloff is that you can set up a relatively low or high cross point and keep the speaker well within its operating abilities. This applies especially with tweeters, which will FAIL and die if you give them bass frequencies beyond their abilities.


Where are you fuzzy? What's unclear about crossovers?

BTW, there are little boxes called crossovers as well, these are simply electrical components that separate a signal out so the tweeters get their high frequencies, and woofers get their low frequencies. These are just like your active crossovers, but they do it with capacitors, resistors, inductors, etc. to make it work without electronics.
 

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I have been absolutely everywhere looking for basic information on crossover settings. I have searched here, searched caraudio.com, wikipedia - you name it i have searched. I have read the tutorials here and elsewhere but I am still confused.

Here is my setup...
Alpine 9887 HU
(4) Infinity Reference 6822cf Coaxials
- Soon to be replaced w/ 720prs
(1) Crunch P900.4 Amp
(1) Stock Sub & Amp for 2007 Ford Explorer

I want to get the most out of what I currently have but I cant figure out the crossovers. I have taken suggestions from some of the threads here but I cant get it to sound good.

Currently they are set at stock settings

Low 80hz Flat
Mid 80hz Flat
High 125khz Flat

I understand that the settings are set by the users taste and everyone sets them different so should i just leave them alone or what do you suggest i do?

Thanks for any help.
go to a local car audio store, talk to a couple people in there, if you meet someone you TRUST, offer them a 6 pack to tune your system, should only take em 10 minutes.
 

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BTW it sounds like you have a similar Alpine to what I used to have. Low means Sub. Mid means Rear, and High means Front to this head unit. That's because this unit is probably in the wrong mode. Some have little switches on their top or bottom chassis to turn it from high-mid-low to front-rear-sub. It really does the same thing though. The first two are high-pass, and the rear is low-pass.

Now, I own a 2008 Tribute, which has a lot in common with your Explorer when it comes to that integrated amp and sub that comes with it. I ripped mine out, BTW. With your head unit, did you hook up a set of RCA outputs to your factory amp somehow? Does the factory sub actually play still?
 

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Discussion Starter · #8 ·
Crossovers are simply the point at which the frequency response rolls off. Big subs can't play high frequencies, and little tweeters can't play bass. So, you create a crossover point for the subs and tweeters and mids to play their range.

There is highpass, there is bandpass and there is lowpass. They do precisely what you think they do. A highpass crossover PASSES higher frequencies than the one selected, and ones below that point fade away to lower and lower volume levels. Crossover points are actually at the -3dB down point.

A crossover point is also defined by its slope. This means, how fast the frequency response drops off, once it starts to cut off. Slopes as low as 6dB/octave or as steep as 24dB/oct are certainly possible, and beyond. The steeper the slope, the more your response will stick to that crossover point. Think of a soft rolling hill vs a steep cliff. A soft hill will gently take you down in elevation. A steep cliff does it rather aggressively. The advantage of a steep rolloff is that you can set up a relatively low or high cross point and keep the speaker well within its operating abilities. This applies especially with tweeters, which will FAIL and die if you give them bass frequencies beyond their abilities.


Where are you fuzzy? What's unclear about crossovers?
That helps - but what is still fuzzy is wouldnt you always want the steepest slope because you would want to just get rid of those frequencies that the speakers cant play?

BTW it sounds like you have a similar Alpine to what I used to have. Low means Sub. Mid means Rear, and High means Front to this head unit. That's because this unit is probably in the wrong mode. Some have little switches on their top or bottom chassis to turn it from high-mid-low to front-rear-sub. It really does the same thing though. The first two are high-pass, and the rear is low-pass.

Now, I own a 2008 Tribute, which has a lot in common with your Explorer when it comes to that integrated amp and sub that comes with it. I ripped mine out, BTW. With your head unit, did you hook up a set of RCA outputs to your factory amp somehow? Does the factory sub actually play still?
(1) Now this really helps me out - I thought "mid" meant mid bass - WOW! I am an idiot. - but, how would i cut out the "high" and "low" frequencies on the mid and front channel?

(2) But isnt the other mode for the dead unit (on the switch) for running active?

(3) I did hook up the RCA outputs on my factory amp with a PAC and it is running out of the "sub" preouts. Yes - the factory sub still plays.

did you install the stuff yourself or did a shop do it?
I did do the installation and it was quite clean tbh. Used a Stinger amp kit, butt connectors etc. I have installed maybe 7 head units in my time - its the technical stuff that throws me off not the mechanical.
 

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That helps - but what is still fuzzy is wouldnt you always want the steepest slope because you would want to just get rid of those frequencies that the speakers cant play?
That's a logical conclusion to draw. However, in the real world it wouldn't sound natural. It just sounds better if there's some transition ("rolloff") between the drivers.

(1) Now this really helps me out - I thought "mid" meant mid bass - WOW! I am an idiot. - but, how would i cut out the "high" and "low" frequencies on the mid and front channel?
I reviewed the owner's manual for your HU. The crossover has two modes controlled by the switch. For your coaxials it needs to be in 2-way mode, what Alpine calls 4.2ch or F/R/Sub-W mode. Refer to instructions on page 16. If you don't have the manual, you can download it here:
http://vault.alpine-usa.com/products/documents/OM_CDA-9887.PDF

Once you get it in the right mode, try setting all three - Front, Rear and Sub - all to the same frequency. I'd start around 80hz and go from there.

(2) But isnt the other mode for the dead unit (on the switch) for running active?
Well, either way you're running active because your HU is acting as an active crossover. The difference is whether it splits it into 3 bands - hi/mid/low - or just 2 - hi/low. It sounds like it's currently set for the 3-way mode. Since you have coaxials handling everything above the sub, you want 2-way mode. You'd only want 3-way if you had separate components running on dedicated amp channels.

If you flip the switch, the display should say Front/Rear instead of Hi/Mid when you go through the settings.

(3) I did hook up the RCA outputs on my factory amp with a PAC and it is running out of the "sub" preouts. Yes - the factory sub still plays.
Doesn't sound like there's a problem here.
 

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Discussion Starter · #10 ·
That's a logical conclusion to draw. However, in the real world it wouldn't sound natural. It just sounds better if there's some transition ("rolloff") between the drivers.


I reviewed the owner's manual for your HU. The crossover has two modes controlled by the switch. For your coaxials it needs to be in 2-way mode, what Alpine calls 4.2ch or F/R/Sub-W mode. Refer to instructions on page 16. If you don't have the manual, you can download it here:
http://vault.alpine-usa.com/products/documents/OM_CDA-9887.PDF

Once you get it in the right mode, try setting all three - Front, Rear and Sub - all to the same frequency. I'd start around 80hz and go from there.


Well, either way you're running active because your HU is acting as an active crossover. The difference is whether it splits it into 3 bands - hi/mid/low - or just 2 - hi/low. It sounds like it's currently set for the 3-way mode. Since you have coaxials handling everything above the sub, you want 2-way mode. You'd only want 3-way if you had separate components running on dedicated amp channels.

If you flip the switch, the display should say Front/Rear instead of Hi/Mid when you go through the settings.


Doesn't sound like there's a problem here.

Awesome - i feel much better and I again am excitited instead of aggravated to play with my system.

Thanks for all the help - you guys have been great!!!
 

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Excellent! Now that namby-pamby approach of "Maybe this crap isn't for me" will never be heard again, right? :)

Because you CAN do it.
 
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