Making my own crossover - need suggestions

[dell30rb]

Hi,

I recently bought a car (Highlander) and am in the process of replacing the stock speakers with something decent. I was tempted to just throw in a component set with woofer and tweeters for the front however the in-dash speaker locations (which point straight up at the windshield) had lots of room so I opted to put in 3.5" 2way infinity 3022cfx reference speakers here.

The front doors I replaced with 2way Infinity reference 6x9" 9622ix speakers. The front door speakers and dash speakers are wired together in parallel. I know I don't need the 2way capability but I got these cheap.

The reference 3.5" dash speakers came with a 270uF capacitor so I wired those in-line and I also put a 2.0mH coil in-line with the door speakers, giving me something close to a 1st Order Butterworth around 210-220Hz.

The system is worlds better however I think there is some room for improvement. I feel I am missing something in the low-mid range as my current setup is relying on the dash speakers for sound in this range, yet my dash speakers either can't produce enough in these ranges or can't get it to my ears efficiently.

So, given my setup what would you do? Stick with 1st order butterworth (easiest) and just move the crossover point up? To what point? 500hz... 1500hz? Should I get out the soldiering iron and make a 2nd order crossover of some kind? Just say F it and buy a pre-canned component system?

Thanks, Suggestions appreciated.

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[Louisiana_CRX 5,000+ posts]

Hi,
I recently bought a car (Highlander) and am in the process of replacing the stock speakers with something decent. I was tempted to just throw in a component set with woofer and tweeters for the front however the in-dash speaker locations (which point straight up at the windshield) had lots of room so I opted to put in 3.5" 2way infinity 3022cfx reference speakers here.

The front doors I replaced with 2way Infinity reference 6x9" 9622ix speakers. The front door speakers and dash speakers are wired together in parallel. I know I don't need the 2way capability but I got these cheap.

The reference 3.5" dash speakers came with a 270uF capacitor so I wired those in-line and I also put a 2.0mH coil in-line with the door speakers, giving me something close to a 1st Order Butterworth around 210-220Hz.

The system is worlds better however I think there is some room for improvement. I feel I am missing something in the low-mid range as my current setup is relying on the dash speakers for sound in this range, yet my dash speakers either can't produce enough in these ranges or can't get it to my ears efficiently.

So, given my setup what would you do? Stick with 1st order butterworth (easiest) and just move the crossover point up? To what point? 500hz... 1500hz? Should I get out the soldiering iron and make a 2nd order crossover of some kind? Just say F it and buy a pre-canned component system?

Thanks, Suggestions appreciated.

I use to build my own passive crossovers back in the early days especially when competing with a single amp in the 0-100 watt class ..I still have a bunch of caps and coils ..I may try and put something together again myself in one of my older vehicles

 

[shredder2]

I would think that the doors need some treatment to increase output in the "low mid range" if that is what you feel you're lacking... 200hz?

 

[Jeffdachef 5,000+ posts]

get an active head unit or a dsp. Passive crossovers is not the way

 

[dell30rb]

While I completely agree that a new head unit and an active crossover would make things so much easier - I just got this brand new car (first new car I have ever bought) and I am trying to keep everything looking stock at the moment. So I have added noico sound deadening to the door panels, replaced the speakers and I am trying to get an easy 1st order crossover setup. It had paper speakers and no crossover at all (save for a bass-blocking cap on the tiny dash speaker) so it can be improved significantly.

My question - with the speakers I have in the positions I have mentioned, where do I start with setting the crossover? 500hz? 1000hz? There are calculators online that will give me a cap and coil value and I can go from there.

 

[ciaonzo 5,000+ posts]

While using a single inductor may produce a theoretical electrical 6dB slope, if it comes close to matching up with the driver's natural rolloff characteristics on the high end, you'll actually have something more along the lines of a 12dB or 18dB acoustic. This can cause real phase issues with the other "6dB" filter for the tweeter that you're mating up with. I can appreciate what you're attempting to accomplish but flying in the dark is going to waste a lot of your time for what will likely be mediocre results. I mean, at least get some rudimentary frequency response measurements of the drivers in the environment as well as their actual DCR values, and use a decent modeling software. I use the Jeff Bagby stuff for all my home DIY projects, it's pretty powerful and provides excellent results. Compile your .FRD and .ZMA files and go to town.

Link --> Jeff Bagby's Software Page

2.0mH is pretty decent for addressing baffle step issues for narrow cabinets in home, so in the car it is overly aggressive and robbing you of the range you're describing as missing or lacking. If you want to fly blind, measure the true DCR of the woofer and find the value of inductor that corresponds with something more along the lines of 800Hz-1000Hz. This will keeps things on the warm side but should allow more midrange to shine through.

Keep in mind, that woofer may very well have a break-up peak somewhere on the top end (anywhere between 2.5k and 8k) and that will always come through as annoying unless you build in a resonance trap, but you'll likely need a Zobel circuit at that point as well.

You can do this by ear but it will take a while. Doing things by ear is usually the final step in refinement of the total crossover network, after proper modeling, and mainly for suiting the room or one's tastes. It's rarely the first step.

Best of luck!