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Choosing crossover: 12, 18, or 24db slope

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43K views 22 replies 9 participants last post by  Arezump  
#1 ·
I'm trying to pick a good crossover setup for the following system:

Fronts: 6.5"/1" components, amp does not have a built-in crossover
Center: DIN-sized center speaker kit, amp has 12db slope crossover, will probably use 400Hz
Rears: 6.5" coaxials, amp has 12db slope crossover, will probably use 100Hz
Sub: 6.5" CVT654, amp has 12db slope crossover, will probably use 100Hz

So the easiest solution would be to just use the head unit crossover setting or a pair of Fmods to hi-pass the front components, 12db slope at either 80, 100, or 120Hz. Does the passive crossover included with most components already hi-pass for the mid-bass or not?

Alternatively, I had thought about going with either the Planet Audio EC20B or the Clarion MCD360 3-way crossover. Those crossovers would let me use an 18db slope over three pairs of speakers, including much more control over the sub. I could use it on the Fronts, Center, and Sub, while letting the Rears remain 12db amp crossover'd.

I have read here that I may have phase issues with a 12 db or an 18db slope. The Planet Audio and Clarion include phase switches for the sub only. My head unit allows time alignment. Not too keen on reversing speaking polarity.

Thoughts and recommendations are much appreciated!
 
#3 ·
I would disagree with the "always better" statement. It all depends on your install, so experiment.

In my experience, with closely mounted drivers that are capable of playing a wide range, 12db slopes with phase inversion sound more natural to me than steeper slopes. If you're playing near your speaker's limits, then yes, steeper slopes are better always.
 
#8 ·
Thanks for the responses.

Neither the head unit or the amp list their crossover type, other than being 12db/octave. Upon further reading though, I see that the head unit crossover is deactived when playing SACD, which will be one of the primary uses. So the head unit crossover is off the table.

Here are a few choices which differ by slope (and price!):

1a. Pair of 12db/octave Fmods on the non-crossover'd amp. $25
1b. Plus an 18db/octave PFmod on the sub. $40

2. Six channels of 18db/octave crossovers for the fronts, center, and sub. $60

3. Six channels of 24db/octave Linkwitz-Riley crossovers for the fronts, center, and sub (AudioControl 6XS), plus the pleasure (sic) of dealing with the replaceable crossover modules :(. $200+

Further thoughts?
 
#10 ·
ahh..c'mon man, dont pave the thread by forcing its subjectivity to be debated again..& again....how in the hell u think that passive wouldnt be the best method?

am nodding my head when it comes to those "time consuming" part..but for certain people out there, the climax are just right at the peak of "doing the right thing" by giving all your commitments on choosing various names, values, type of capacitors/coils/resistors as they think that those efforts could be much more rewarding rather than doing it "plug n play..!!" :D
 
#12 ·
wow..you're too emotional man.. take it easy..
no one will take the podium today!
btw, watch your words as no one like to be a "screen dumb" or an emotional biatch socializing on her menstrual pain day! ouchh..!! :D
 
#13 ·
Um, so if I can interject, I understand a 12 db slope changes the phase 180 degrees and an 18db slope changes it 270 degrees. And the 180 can be fixed by reversing polarity. Can the 270 be fixed, or do 18db slope/270 degree crossovers always sound off?

18db and 24db seems to be relatively popular for the subwoofer, while 12db and 24db seem more common for the components. What is the reason?
 
#22 ·
I think it's because people like to have their sub not play high, so they try and keep it at a steep slope, and for the components I'm pretty sure those are the most common simply because they are the easiest to integrate for most people. Eg. flipping polarity with a 12db x/o.

I'm not sure an 18db (for example) crossover is "fixable" in the sense of phase inversion or similar, but I do know that slopes of 6db, 18db, etc, can be very helpful if you want to get more out of your system. MiniVanMan said once that he is a fan of the odd order slopes for several reasons, most of which I cannot recall. But one was; in a car if a driver has a natural rolloff of 6db per octave, then wouldn't it make more sense to use a 6db crossover so that the actual real world rolloff is 12 db? I thought it was a good idea, so I went out and played with my crossovers for ages..

Food for thought ;)
 
#23 ·
But it would be even more sad if one's judgment was actually derived from his own pigheaded behavior & assuming options to be fairly suggested in his own preference - only?
you may have your own reason to say whats the the "best" but preferences are just made of personal taste, views, likings & opinions and could be differ from what you have or experienced!
you may not have the intention to force someone for having similar interest or opinions like what you have, but your phrase on stating that "Goin passive on car is not the best method" is like-wow! this man knows everything! & oh..plead me to understand u..will ya? :D
 
#19 ·
I just realized something as well....which turns out to be my fault for not asking more questions about the situations certain statements were made in.

I have always found it quite disturbing that many people here have claimed to run Midbass hipass crossover points of 70hz etc......when in fact I should have confirmed that most were likely running a Linkwitz alignment, which is already -6db down at the crossover point......rather than doubt them entirely.

For some reason, when someone rattles off a crossover value in conversation, My brain is programmed to think Chebychev first, by default (even though it's an alignment that I would never use).....looking at the crossover point itself as the actuall beginning of the slope with no attenuation beforehand.....then onto Butterworth as my secondary, which is only -3db down at the crossover point.

EUREKA ! My brain actually does work on occasion......lol