Quick question here to the audiophiles here, ,
when using active crossover do you still set the amp crossovers?

I have an active crossover as part of the in the head unit (alpine CDA 7878).

I am unsure if I need to also set the amps crossovers... It would seem redundant, I was thinking of setting the amps to full and having the head unit to the routing...

Jim

 

I'd say it's really up to you. My HU has the crossovers as well but I figure there's no harm in redundancy. However, an example of what I have....

From the HU, HP set to 50 HZ (to cancel out very lows) and that goes to both the front and rear amp. My focals can take 50hz so that amp is set to full and the rear is set at HP as well. In addition to that, the fronts have their own crossover so i don't really have to worry about them getting damaged

Subs I just set LP to 125 from the HU

 

I have to agree....owner's preference. On my system the EQ high passes the front and rear output at 100 hz while the sub filter is adjustable. First I set the amp filters on the front and rear at 100 to match the EQ but I have since set the all of the amp settings at full and use the EQ to set the high/low pass. I have not noticed any difference.

David

 

In my truck I turn the amp X-overs off so I can change things from the HU without having to fiddle with the amp while I am driving....

Robbie

 

Totally agree with using the HU crossover control in lieu of the amp crossover due to accessibility.
In my case, I have an eq that allows me to change the crossover for all my speakers and also change the slope to 12, 18. or 24. I love having the control at my fingertips for we all know that all cd (or other media) are not created equal.........
If you try to use your HU and amp crossovers together, you nullify the HU crossover as the sound will be contoured by the last crossover the signal goes through.

 

Doubling up on the crossovers like that just increases the rolloff at that frequency. Say you have both your crossovers at 60Hz low-pass, and that they both have a 12DB/Octave rolloff. By using both crossovers at the same time, you are effectivelly doubling the rolloff rate to 24DB/Octave. Basically, you are doubling the crossover(s) effectiveness. It will let less of the upper frequencies through (based on the 60Hz low pas setting, of course). Some people prefer this steep slope on their crossovers, but in reality, speaker frequency ranges (subs, mids and tweets) should overlap slightly to smooth out the response of the whole system. By overlapping your crossover settings correctly, you get a much fuller, richer sound...

Hope I didn't confuse anyone.....darn electrical engineers....

 

Absolutely correct.

As well there are two things to think about.

What most people don't realize, unless their HU is $1000, is that the crossovers in them basically SUCK. Usually they're only 12db/octave cutoff and the quality of the components will be cheap. Any good external cross-over will offer higher quality and BETTER sound.

A simple test is to listen to your favourite music track and disconnect the front/rear speakers and only power the subwoofer. Try this first with your HU subwoofer output, then listen to the sub by itself, no highs!

Now, run full-range to a good external cross-over and play only subwoofer, no front/rear or tweeters.

In most cases the external will sound "clearer".