head unit adjustments vs amps

[Sesamecreep]

Hi all! I been confused for a while now please help. Now the adjustments through the head unit like LPF, HPF the crossovers i understand but the amps for speakers and sub usually have the same adjustments. My question is what do i adjust first the amps or the head unit? Do they confilt with each other?

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[LosIsATool 5,000+ posts]

Only use one or the other. If you use the HU make sure the filter on the amp is open. Opposite if you use the amp.

 

[blazian87 10+ year member]

Welcome @Sesamecreep

yea they will conflict with each other.. What headunit do you have? Sometimes it's just easier to do it off the headunit since it's more accurate than turning the knob on the amp.. You can also just do it by ear with the amp if you know what to listen for.. otherwise, just use HU to get a good feel for it. Make sure the filters are indeed on before you crank it up loud because it can lead to a blown speaker if you're not careful.

 

[Sesamecreep]

Ok thanx that makes sense. I have a Kenwood DNX891HD.

 

[gckless 5,000+ posts]

Could use both.

 

[n2audio 5,000+ posts]

using both would just steepen the slope.

Just think about it logically...if you have the hu set at 80hz for example, and it's a 12db lp filter, you've clearly reduced a lot of the signal above 80hz. Then if the amp is set at 80hz as well, and also is a 12db filter, you've reduced signal strength again - in the same range. I don't know exactly how the math works out, but you're basically just "stacking" the filtering effect. That may sound better, or it may sound worse.

Personally, if I had x/o's at my fingertips (as opposed to only in the trunk) I would definitely want to be able to toy with them. So i say either use the HU or use them both.

 

[jstone2020]

so if i have my frequency on my headunit set to 60hz for the subwoofer then on the actual amp i should have it turned all the way up? is that what you mean by all the way open? i have a jvc20bt..