cross over settings

[Falko]

I have component speakers in the front of the truck. On the crossovers there is an adjustment switch which reads -3, 0, +3. Can you guys let this audio novice know what these are for? Thanks.

[jk13]

Tweeter output level in relationship to the woofer.

 

[Falko]

So if I wanted to reduce the tweeter output, I'd drop to the -3?

[David]

Yes.

For example, if the larger midrange/midbass is mounted very low in the door, and the tweeter is mounted very high in the door, then the tweeter will have a large positional advantage. That means the tweeter will play louder. Not entirely bad to have some extra emphasis on upper harmonics or upper percussion, especially to contend with high noise levels at higher driving speeds, but an abrupt change in sound level favoring the tweeter at the knee of the crossover can ruin a lot of music, particularly vocals. So the flat (0dB), accentuated (+3dB), and attenuated (-3dB) tweeter levels will allow you to compensate for various car to car tweeter positions. To determine which setting is correct to your ear, I would use a female vocalist as my test. It's very different than a boat system where the only crossover you can control is typically at the sub/satellite junction.

Keep this part in mind. The crossover (frequency dividing network between the midbass and tweeter) can only be designed to work at optimum at one tweeter level, which is flat (0dB). A well-designed crossover uses both highpass and lowpass filters that are combined in such a way that the overlapping region is minimized, and hopefully audibly seamless. As you accentuate or attenuate the tweeter level you also re-bias the crossover somewhat and compromise some of that seamless quality. So the 'flat' setting is usually best unless there is something about the installation positioning that would have an overriding priority.    

Edited June 21, 2016 by David

[Falko]

Funny you say that about female vocalists, that is pretty much where I notice it, well, that and Maroon 5.

My mids are in the stock door positions, and at the time of install the best place I felt for the tweeters was in the window pillars near the windshield. But I am noticing they are a bit overpowering in that spot in some music. I can separate the components from the sub with the HU crossover and balance that, but obviously the HU can't really control the external crossovers of the components. The best I could do is tune them down with the equalizer or cut the top out, which obviously doesn't sound great. I will drop it to the -3 and see where that lands me. In reality, I don't hear very well so it must be really annoying to others.

 

Thanks all for the help.

[shawndoggy]

that's the big compromise with pillar mounted tweeters, especially metal tweeters that usually sound "bright" to begin with.  Best is to mount tweet with/near the mid driver.  I have my comps mounted in kick panels in my excursion and they sound really good that way.  of course that's a compromise too, because as soon as my wife sits in the passenger seat and puts her big arse purse right in front of the passenger kick, all stereo imaging is totally blown.  

Going with the minus 3 setting seems like a no brainer in your case.  Ultimately you are the one who listens to it so let your own ears decide.

[David]

As you have already discovered, tweeters that are too prominent cause problems with sound quality. Not only do you end up with a real uncomfortable edge to vocals and other broad midrange instruments that are rich with upper harmonics, but the tweeters become so localized it becomes a distraction. Also, the higher the tweeter locations the greater the distance differential is between left and right tweeters and your point of perception, compounding the SQ problems.  

-3dB is definitely enough to make a difference in the close quarters of a vehicle cabin. As you are changing the tweeter output, you are simultaneously making some moderate changes to the passive crossover function. So when making these changes it never hurts to experiment with reversing the polarity of the tweeters in respect to the mids. It can also help to aim the closest tweeter slightly off-axis and the more distant tweeter on-axis.        

[Falko]

by reversing polarity, I assume you mean switching the +/- wires?

[David]

Yes, switch the +/- on the tweeters only, just as a trial. Sometimes changing the distances between the mid and tweet plus a change to the passive crossover will have just enough impact through the mid & tweeter overlapping region that reversing the polarity can sound better. Once again, go back to the vocals where the small change is more likely to be heard.    

[Falko]

Flipped the switches last night, since it is easy to do. Made a big difference, no more directional tones from the tweeters, much smoother sound. I'll experiment with the polarity when I get a chance.

Thanks all.