ttomczak

Here is the question... Looking for opinions / facts / etc... on the following.

For those of you that have the option of setting cross overs via the head unit and the amp, which did you choose and why?

For information purposes - I have a DNX7100 HU and 500/5 JL Audio amp...

Thanks in advance!

Sorry, somehow I double posted...

0TheRadioFlyer97

IMO I would use the head unit to set the Xovers. A Head unit will usually give you better tuning options such as slope of the Xover. In addition, when using the head unit, you can adjust your setting from your seat which will allow you to hear the difference in staging without having to get up and fiddle with the amp, then sit back down and see how it sounds.

Kale

Aside from being active, the HU allows me to high pass my front speakers as low as 40hz... and with a slope as steep as 24db/ocatave. Where my amp is only 12db...

pentavolvo

when its an option i always use the headunit

robvuk

I'll go along with that. If you truly have 24db/oct. that's the best.

ttomczak

Ok, I am hearing the HU, however would it change anything to point out the JL gives the option of

12db (Butterworth alignment) and 24db (linkwitz riley alignment)

Also...

Front Crossover: Fully-variable (50 Hz - 5 kHz), selectable-slope (12 or 24 dB per octave) BP or HP

Rear Crossover: Fully-variable (50 Hz - 5 kHz), selectable-slope (12 or 24 dB per octave) HP

Subwoofer Crossover: Fully-variable (40-200 Hz), selectable-slope (12 or 24 dB per octave) LP

For what it's worth, I would rather have the HU do it as well however I can't seem to find out what the slopes are...

Shangreer

The DNX7100 does not allow you to modify the slopes on the crossovers. This is the only area where I am dissappointed with this unit. It is Kenwoods most expensive 2-DIN nav and it has the audio management capabilities that rival their lowest end single-DIN units. My 25th Anniversary deck simply kills this one in that regard. But, I will live with it for the Garmin Nav.

I believe the slope is 24dB/octave.

Shan

Spkrboy

Unless we assume all other things are equal, this question can't be answered that simply. It's entirely possible for a high-quality shallow-slope XO to be better than a lower-quality steep-slope XO. It's also common for a system to sound better with mixed slopes or shallow slopes simply because of the speaker setup or the acoustical environment. Slope isn't everything.

ttomczak

Nice, so your opinion is what exactly? (specific to my question)

I am looking for feedback, so far it's running to the HU for control rather than the AMPs setup...

To all other's, thanks so very much! I will reset to the HU's x-over and see how that works out!

Spkrboy

Since I wasn't very clear, apparently...

There's no way to say one is better than the other without connecting things in each possible combination to see what sounds better. A blanket statement that one should be used over the other can't really be made in this situation. You may find that using a combination of the two sounds better than each independently.

fej

Generally speaking, most HU's that have built in crossovers offer more options for tuning your specific setup. Most are 6-12-18-24db variable. Most amplifier crossovers are only offered with 12db slopes, some offer 18db options, and a few like the JL that you have offer 24db rolloffs.

Like spkr said, steeper slopes does not always mean better. I have tuned with both a 6db slope, and as high as a 48db slope in various systems. The most important portion is the blending of frequency response between midrange and tweeter, and where the overlap, or underlap occurs. (at least IMO)

Example would be the passive units that come with my Pioneer 720prs set have 12db slopes at 2khz for the midrange lowpass and the tweet highpass. My current tune has those speakers at 18db 2.5k midrange lowpass and 3.15k 18db highpass on the tweet and the sound difference is quite dramatic.

I have had cars with a 1.6k midrange rolloff at 6db, and a 4khz tweeter highpass at 6db that blended beautifully. This is very driver, install, and power specific.

As for which is better, IMO I rely on the HU processing more than I have on amp processing. I usually only rely on amp crossovers for the sub low pass point as most sub amps include 18db slopes and that is generally sufficient. However, you can occasionally use both an amp and a HU crossover to gain additional slope options, although 12 HU + 12 amp does not necessarily equal a 24db slope, I have found you generally lose 2-3db rolloff when stacking them from 2 different sources. I of course do not have the level of testing equipment that spkr has

Fej

Sm0ke

After reading some of the cooments on the equipment you have (I have been out of this for a few years so model numbers mean nothing to me) I would personally use the crossover in your amp. A JL crossover will out perform your Kenwood crossover. As far as playing with the slope you can change the slope/order of the crossover and it will move around the imaging/soundstaging in the car. Try setting the front of the car at 24db/octave and set the back at 12db/octave have a listen and the switch it around. You will amazed at how the voices etc will move around in the car. It all has to do with time delays between the different orders of crossovers and you will be able to fine tune things pretty nice. It does work alot better if you are adjusting slopes between the left and right channels due to the fact that our ears on on the side of our head (LOL), but it will still work. You will get much cleaner and better bass out of the JL crossover also.

robvuk

I agree, this is why I suggest 24db. What you're hearing is phase shift. No phase shift on a decent crossover at 24.

fej

Smoke I have to disagree with a few things, first the statement that the JL crossover will work better than the Kenwood crossover is purely opinion, even if based in experience from other products. Have you tested both? Have you compared 24db Kenwood vs 24db JL? Maybe you have, but I have to lean towards the you have not option. If you have, I retract my remarks.

Secondly the "cleaner and better bass" from the JL crossover is just flat out incorrect. Unless for some reason the kenwood unit's crossover does not work correctly, the performance should be the same given the same settings (or slopes in this case). In fact the Kenwood unit is going to dictate to the JL amp how it performs based on the quality of signal that the JL amp has to work with. Remember, you could have a million dollar amp, but if the signal that is it amplifying is of poor quality, that million dollar amp will still sound like shyt.

I by no means am a Kenwood fan, in fact I have never purchased anything from them as I have OLD experience with their product line, and have never cared for their HU designs or features. That being said, saying X will work better than Y is like saying a JL 10w7 is better than an ID IDQ 10. You need to clarify available power, enclosure space, and frequency range needed before any sort of opinion could be made about those 2 subs.

You could also be hearing multiple point sources for the same frequency range, IE too much overlap at the midrange to tweeter crossover point, which would add 3db to that specific range causing a peak in your response.

Fej

Spkrboy

I agree with fej to a large extent there. While robvuk is absolutely correct in a technical sense, that word decent is a serious qualifier. In fact, it eliminates most built-in crossovers, and actually makes this discussion pointless.

There are other considerations than slope. Group delay can be a serious problem. Phase errors between non-coincident drivers (which is always the case in a car) can't be overcome by electrical slope. There is also the distinct possibility that a mixture of slopes or staggered points can be more effective than simply employing a 24. The family of crossover employed also makes a difference, and can make two very similar crossovers sound quite different (Linkwitz-Riley vs. Bessel vs. Butterworth, etc.).

Ultimately, unless you're using an outboard crossover from someone like Audio Control or Rane, the issue is really moot.

robvuk

You and fej are both correct about point sources and group delays. The way most car sound systems are installed, it's really an excercise in futility.