# Slope Select? 12dB or 24dB?



## BikeBoy24 (Jun 10, 2001)

Can someone explain to me what the slope select on the on-board crossover of my Xtant x603 does?
Right how, I have the high/low pass filters set at 90hz. There is a jumper for 12dB and 24dB. Right now, it's set at 24dB for both. I've tried looking it up, but no clear answer. Thanks.


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## dieselgus (Dec 12, 2003)

*Re: Slope Select? 12dB or 24dB? (BikeBoy24)*

12Db vs 24Db on a crossover slope relates to it's steepness, or rather, it's effectiveness at getting rid of the unwanted frequncies outside of the passband. A 12db sloped crossover is less "steep" or "sharp" than a 24db crossover. Why the db ratings you may wonder?? A 12db crossover applies 12db of reduction per octave(low slope), whereas a 24db applies..... you guessed it.... 24db of reduction per octave. Why you may be asking??? Sharp crossover slopes allow for a more accurate setup and tuning of any system. You will get less overlap between drivers in a system, allowing for more efficient ust of those drivers within a given passband.
to sum up.... high slopes are good! Some of the processing I use in my PA system will allow up to a 60dB slope on any crossover point.... now that is a brick wall filter! Also... good choice on the x603... Xtant make a beautiful product. My old school 3300ic (the x603 of 10 or so years ago) is still overworking away without a whimper at a 2 ohm load on all 3 channels, never a problem, has never shut down, and is currently running in it's third vehicle/3rd different system.
Gus
PS: I'm using a 24db lowpass at 53Hz on my sub, and a 24db highpass at 35Hz on my mids..... the horn/mid cross is courtesy of a big honkin' 18db passive network. 3 channels of whoppin' 300w power... whoot!


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## BikeBoy24 (Jun 10, 2001)

*Re: Slope Select? 12dB or 24dB? (dieselgus)*

Thanks for the info http://****************.com/smile/emthup.gif 
So I guess I should leave it at 24dB right?


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## JEATER (Dec 12, 2003)

depends on what you are running off that amp since that slope is a summation of all the slopes
you should shoot for 24db so if you are running a crossover with a 12db slope then put it the amp on 12 if you are not running a crossover before or after (active/passive) then do 24db
if you are running full pass theres no slope
60............
anything after 24db you will get phase problems


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## BikeBoy24 (Jun 10, 2001)

*Re: (JEATER)*

I'm just using the amp's crossover, at 90hz. Focal 165K2's in the front, and a sub in the rear.


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## JEATER (Dec 12, 2003)

im guessing that the focals K2 have a 12db but it could be 18 i forget havent been into audio much but you can do math
24 - 12 = 12
sub has no XO so 
24 - 0 = 24 <----the number you use on amp
you might wanna stay below 80hz on the XO unless you got a small sub or if thats how you like it to sound then its ok


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## BikeBoy24 (Jun 10, 2001)

*Re: (JEATER)*

I just checked. They have a 18dB/oct crossover. So what should I set it to? 12dB or 24dB?


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## BikeBoy24 (Jun 10, 2001)

*Re: (JEATER)*


_Quote, originally posted by *JEATER* »_
you might wanna stay below 80hz on the XO unless you got a small sub or if thats how you like it to sound then its ok

I might try 80hz. With the x series amps, I think I have to change a whole module of resistors. I don't know why they just didn't go with a variable resistor, which you can change. Cash grab!


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## dieselgus (Dec 12, 2003)

*Re: (BikeBoy24)*

Set resistance value XOver packs are quite accurate. At one time, there was a 'how-to' in the owners manual about roll your own resistor networks. If you like, I could dig around in my toolbox at work and see if I can find the chart somewhere.
Gus
PS: a 60db crossover slope is used when setting up an absolute brickwall filter. Commonly used for a system highpass to prevent the mass destruction of thousands of dollars worth of 18" drivers in a concert PA situation.... infrasonics are a bitch.


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