I have a Kenwood KDC-MP828 and under the adjustment menu it has where you can set the frequency for the Front, Rear, and low pass (subwoofer). The ranges are : Through/40/60/80/100/120/150/180/220hz for the front and rear hi pass. The Low pass ranges are also the same. My question is that do I just set these to through since my amp is controlling the frequency? I figured you would use the actual frequency when running without an amp. Also where should the slope be or is there a specific place? The hi pass filter slope and low pass filter slope ranges from -12/-18db/oct.

Thanks

 

You can use just the amp crossovers if you want, I do not know what you are running and what slope they have, but you can sort of boost your slope by using both the HU crossover setting and the amp crossover at the same (or as close as you can make it) settings. Might be worth looking into for your mid high pass point.

Fej

 

Hey Fej, thanks for the quick reply! I am using Alpine SWS 6.5 components in the front and Kenwood 605ie components in the rear. Both have a -12db slope. What controls the slope on the amp(s). I am using the Hifonics ZX4400 for the components. I have the slope set currently at -12db on the HU.

Thanks

 

I am pretty sure the 12db slope you are referring to are in the passive crossovers that come with the components, and generally speaking (90% of the time) that 12db will only low pass your midbass (say at 3.5k hz) and high pass your tweets (same 3.5k hz) for you. It will not however high pass your midbass/range you need your HU or your amp to do this. Occasionally depending upon the quality of the component the midbass/range is not even low passed at all they just let it play all the way through to when it just trails off on its own (usually leads to a decrease in sound quality/accuracy).

So you need to high pass your midbass/range in both of those sets of components. You can do it via your amp or your HU. Depends on if you ran 2 sets of RCA's to your amp or not.

2 sets of RCA's to the amp should allow you to set the high pass crossover point differently for the front than the back at the HU. Because it is so difficult to get good midbass in the front I usually recommend that people cross the rear drivers in the 160-200hz range to not pull the midbass rearward.

If you ran only one set of RCA's you are probably going to have to pick a spot for both, probably 80hz or 100hz if you use the HU or 80-90hz on the amp. As I mentioned earlier you could try that 80hz point on BOTH the amp and the HU and see what happens. Also you can choose to use ONLY the crossovers on the amps to handle the individual channels and leave the HU at full range.

Fej

 

Hey Fej, I do have two sets of rca's going to the amp for each set of components. So what you are saying is to set the rear components in the 160-200hz using the HU or the amp? what about the fronts? I do have alot of bass/midbass coming through the rears and I would like more highs. right now on the amp for the front and rears the frequency is set around 80hz.

Thanks
-Jason

 

I would do the rears in the 160-200hz range on BOTH the HU and the amp, start with the 160 and move it up to see how you like the sound and how it affects the midbass. (You could actually go a fair amount higher if you chose to, say 800hz to really clean up the midrange in the rear component and keep the midbass up front as best you can) This should give you about a 20db rolloff or so, I do not know the formula for how the 2 12db's stack exactly. You could do the same for the 80hz in the front which IMO should help a fair amount. Worst case scenario is you like the sound of only one 12db slope for your system and then you have the option of choosing what I believe is a little bit more fine tuning of the amp or the predetermined settings on the HU.

Fej

 

Thanks Fej! I adjusted the rears to around 180hz and they sound alot better. The fronts are still @ 80 along with the sub. Both are still set on -12db on the HU.