Building my own Cross-overs. NOW WITH WRITE-UP!!!

[KenC]

This is kind of an esoteric thread, but here goes...
A friend of mine sold me a pair of 6.5" MB Quart midranges. They didn't come with any xovers, and I though that they were playing too high in freq. range. So he's going to help me build my own crossovers for them. They're going to be 12 db/oct ones (I was going to do 24, but they'd cost probably $75 for materials to make). Also, most companies including MB use 12 db/oct xovers for their factory ones (not sure about the QM series though, I'd suspect a 24 db/oct).
I'm going to build both of them on one board, it's going to be massive. And they're going to be totally bi-amplifiable.
Here is a picture of the air-core inductors and capacitors that I'm going to use. They're fucking huge. The inductor weighs over a pound. They're going to be able to handle a TON of wattage. I put them next to a AA battery so you could gauge the size of these beasts.

[Mystikal]

Interesting stuff. Wish I knew how to do such things.

I'd just wimp out and buy a damn Alpine 9813/9815 with the electronic crossovers and call it a day.

[Spaz]

what in hell do crossovers do, sorry i am a noob at steros, i am just getting into them.

[KenC]

what in hell do crossovers do, sorry i am a noob at steros, i am just getting into them.

the human ear can discern frequencies between 20Hz and 20,000Hz. 20 is the lowest frequency (bass) and 20,000 is really high freq (a cymbal crash).
Different sized speakers are better at playing different ranges of frequencies. A subwoofer will play 20-120Hz very well, a 5.25" will play from 100Hz to 3500 Hz well and a tweeter will be from there up in the range.
A crossover prohibits certain speakers from crossing a set frequency. For example, the crossovers I'm building for my 6.5" MB Quarts have a 3,000Hz crossover value. Thus, the woofer will not be allowed to play over 3,000Hz and the tweeter will not be allowed to play below 3,000Hz.

[Spaz]

well shit that makes so much sense, allows your speakers to stay in the area that performs the best. does it help sound quality alot?

[KenC]

well shit that makes so much sense, allows your speakers to stay in the area that performs the best. does it help sound quality alot?

Exactly. Yes, it helps sound quality a lot.

[ColdAccord]

hmm. wanna do a writeup when you're done, or make an extra set? lol, I have kappa 6.5's. I put the tweeters and crossovers in my civic, but the drivers didnt fit. so i left them around for a year, then put them in my bimmer. i need x overs, i dont like highs coming out of these. doesn't sound right

[KenC]

hmm. wanna do a writeup when you're done, or make an extra set? lol, I have kappa 6.5's. I put the tweeters and crossovers in my civic, but the drivers didnt fit. so i left them around for a year, then put them in my bimmer. i need x overs, i dont like highs coming out of these. doesn't sound right

Now that you mention it, I'll probably bring my camera home and do one. It's cool because you can make them custom. And most likely they'll sound better than most of the stock cross-overs.

[Beej '86 325es]

I'd just wimp out and buy a damn Alpine 9813/9815 with the electronic crossovers and call it a day.

I have the 9813 and I'm not positive, but I think they crossovers only work if you are using external amplification. Someone correct me if I'm wrong, I haven't really been able to tell.

[KenC]

I'd just wimp out and buy a damn Alpine 9813/9815 with the electronic crossovers and call it a day.

I have the 9813 and I'm not positive, but I think they crossovers only work if you are using external amplification. Someone correct me if I'm wrong, I haven't really been able to tell.

If that were the case, then they would have to have xovers on the pre-amp outs. Sounds highly unlikely to me, but it may be true. I think it would make more sense to have one on the internal amp.

[Mystikal]

I have the 9813 and I'm not positive, but I think they crossovers only work if you are using external amplification. Someone correct me if I'm wrong, I haven't really been able to tell.

Even if it were true, the vast majority of people who even use cross-overs and know how to adjust them wouldn't be caught dead using an internal amp in the first place. I'm not sure if it's on the preouts, but it would still make sense to me.

[BMW BMXER]

Cross overs with a deck only wouldnt even really be needed. I think most decent decks can be set to cut off certain frequancies.

[M-technik-3]

Plenty of online electonic shops out there that have them made for the frequencies that you need. Heck even Radio Shack might have one in their catalog.

My local place is U-Do-It- Electonics. In Needham Mass.

[KenC]

I found a websit that did the calculations for you. I just put in what I wanted the x-over freq. to be, and then it tells you what size components to get. Then I just bought all of the stuff from Partsexpress.com

[M-technik-3]

Just to let you know the Human ear can hear those frequency but, most people can not hear them due to a variety of things.

ask any doctor and he will tell you that our range of hearing is considerably smaller. I have a HF hearing loss in my left ear that prevents me from hearing anything above 6k Hz. and it sucks. I see a hear specialist every year to keep track of it so it doesn't degrade anymore.