I have seen a lot of guys gravitating to the nicer Kenwood and Sony head units.
I have some experience with the Kenwoods and wanted to add a little insight here.

If you are setting a cutoff to your front speakers of say 80 Hz in your deck,
There may not be a need to engauge the filter on your amp if it has one. It should be set to full pass

In other words you dont want to filter the front at 80hz on the head unit, and the kick on the High pass filter on the amp for the front channel.

What you get is double compression.
This could be the cause of muddy audio depending on the system.
Weaker systems will hear the hit more then a high end system.

So just be careful where and when you apply a slope or gain cutoff in the head unit.
Maybe Im only pointing out the obvious
If so I apologize.

 

Thanks for sharing.

 

Great topic Makdaddy,

Since the internal radio crossover is a 12dB/octave filter at 80Hz, you *can* actually use the amplifier's crossover too, but it MUST be set to the same frequency. If not, you may encounter those weird anomalies you described...

The most common filters are as follows, with the higher order slopes filtering "faster" than the lower ones:

1st order = 6dB/octave
2nd order = 12dB/octave
3rd order = 18dB/octave
4th order = 24dB/octave

The below graph shows how fast the crossover works at different orders. The crossover frequency in this example is 1kHz, but it works the same for 80Hz. With higher order crossovers, you hear less "bleed through" below the crossover frequency.



So if you use the radio's built-in 80Hz High-Pass (12dB) crossover combined with an amplifier's 80Hz High-Pass (12dB) crossover, the net result will be a 24dB/octave crossover at 80Hz. Pretty simple, right?

The practical side, is if your midrange are bottoming out during high output, use a higher order crossover (24dB) or increase the crossover frequency from 80Hz to say 90Hz or even 100Hz.

 

Very interesting. Thanks.

 

Exactly
Thanks for the more technical explanation
I know a lot of guys are new to this
I can see someone having issues, Im just hoping it may help some

 

Is there any particular reason to choose the crossover settings on the head unit over the one at the amp?
Looks like the one of the advantages of the X998 over the Sony Head Units is that it has separate crossovers for the front and rear. In that case a setup with a Sony HU might be better served with a Full setting at the HU and the use the amps crossovers.

 

With the head unit you have more slope and know exact frequency vs a pot and a 12 db ( Average slope on most amps). You can have much more precision with fine tuning using the head unit vs the amp.

 

^^^^^^ This