crossover done, and i'm pleased.

PoweredByDodge

trial tested it in the truck - what a world of difference with only about 5 minutes of tuning... i'm going to spend an hour or so listening to various things tomorrow and getting it "just right".

but what i finally ended up going with - after realizing that the xover point isn't X db down at half the octave but rather the point is the -3db point (ya, minor brain **** - bigggg difference in what i values) - is this...

tweeters - 4 k Hz high pass @ 24 db / octave
mids - 4 k Hz low pass @ 12 db / octave -- 500 Hz high pass @ 24 db / octave
midbass - 500 Hz low pass @ 12 db / octave -- 80 Hz high pass @ 12 db / octave

fit it all into a nice little box... used ferrite core inductors since air core ones are so damn expensive and so damn BIG ... parts cost me 120 bucks as it is (all the pieces and the box and mini circuit boards)... metal polyester caps for the mids and tweets ... electrolytic cans for the woofers. tolerances between 5 and 10% depending on the part. Went together pretty good - took about 2 hours to solder everything and make it fit right.

Here's some pics... one next to my ugly head to give you perspective - the other is the "front" of it.

the left rail is inputs as labeled and the right is outputs.

oh and tweets / mids / and woofers are all tri-amped now. the 4 6x9's in the bed are going to run off woofer channel and i'll just relay them in and out or some **** -- not too sure how i wanna do that yet. but i dont really care since i dont use them at all in the winter... they stay off

new-yorker

very nice job! I like your solution...my setup is similar.

i have elevation audio concert650 components
focal 8" Midbass
tweeters- 5k hz high pass @ 24db octave
mids- 5k hz low pass @ 12 db octave, 400 hz high pass @ 24 db octave
midbass- 400 hz low pass @ 12 db octave, 70 hz high pass @ 12 db octave


what kind of components are u using?

PoweredByDodge

Audiobahn ACX 352 3.5" coupled components (tweeter is screwed into the mid but can be separated) - mounted in the dash.

Audiobahn AS 96Q 6x9 midbass (another coupled component set but i removed the tweeter permanently and used just the 6x9 as a midbass driver) in the doors.

sad thing is this...

for about 10 minutes today, it sounded exactly perfect, just how i wanted it - after i juiced it up real good... and then -- the magic smoke came out of hte crossover.

son of a bitchin thing burned up on me.

i'm glad i did individual boards for each driver so i know what went bad and where more easily.

the problem was my choice of inductors in series with speakers. i needed higher current inductors -- damn things just couldn't take it. makes sense. I've got to buy 4 high current inductors and replace the smaller ones, but out of 87 parts, to only have 4 that i chose wrong or were bad... i think i'm doin ok.

bad part is - no audio for like a week till this **** comes in the mail!.

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*grunt*... grr...

whole thing is going to have to come apart.

i'm worried that it'll go to hell in a handbasket over time if i dont do it with all high current inductors. which means... more money and a larger case. half of me just wants to go active... i have the amplifiers for it - but i would need two crossovers. and more cables and blah blah blah...

*lots of swearing*.

1996blackmax

Looks like you have been very busy . I say give it another shot.

neomagus00

i'll steer clear till you're happy with it...

1996blackmax

That sounds like a good idear .

new-yorker

PBD, after you get ur hands dirty in making it work, and hearing the end result, you will feel better then you do after sex LOL.

audiobliss

Hmm. So, are you still pleased?

:D

hellohello

how much juice are you running that the coils would cook, and what mhy of coils are you using... I know you had a schem somewhere, but im lazy and you probably changed it around since you posted it anyway... just curious if maybe i could provide assistance, or at least some more f##king pancakes!

PoweredByDodge

lol...

well the last schematic was right (design wise) but wrong (value or parts wise) ... I was trying to match crossing points at half octaves... ya -- what was I thinking? I dunno... But I got it right in the 2nd design.

The values aren't all that bad... I think the ones that smoked were 1.8 mH low pass @ 12db/octave to the mid-bass's. The rest are getting VERY VERY hot, so I try not to play it loud until I get the damn thing built properly. Right now I just jumpered out the smoked inductors, so sound is all wacked out anyway. Better than singing in the car though.

Problem is I looked and most of the inductors I chose that were "high current" aren't really high current at all... then again "high" is a subjective term. I should have looked more closely at the data sheets. But they're rated about 1.5 to 2 amps. I'm running about 75 - 80 wrms to those speakers... so to be on the safe side you would want inductors rated at 5 amps (100 watt friendly). The ones that are shunted to ground (high pass filters) don't really suffer from the same problem, but I figure if I have to replace some I might as well replace all.

It's all butterworth design... several people have told me bessel crossovers are more true, but honestly, I don't think it really matters.

neomagus00

well... according to this summary, butterworths are probably not a bad idea in a car... while bessels have low group delay (rane), the butterworth radiates a constant amount of power across the whole spectrum... in a car, that's probably a better thing, since our group delay and phase is awful anyways, and we're in a closed environment, so a lot of our sound is reflected... hmm... it'd be interesting to build both and see which sounds better...

PoweredByDodge

i'd be happy if i can just get ONE to work, let alone both. for what it's worth though - the few minutes that it worked before it smoked, it did really sound like what i wanted. after **** with this setup since the day i installed it, it's nice to finally be where i want to be with it. stage was right on the dash, not as centralized as i'd like, but i wasn't about the complain, and i did truly feel "enveloped" by the music, where it just wraps around you in a good way, rather than "comin right at you". everything seemed to blend just right.