Mazda3 Forums banner

1 - 11 of 11 Posts

·
Registered
Joined
·
2,756 Posts
Discussion Starter #1
A friend of my mine (S-EE btw) built a priliminary crossover for me a few days ago. As you may already know, I took out the CDT components. They sounded awesome, but I needed more. The sub drowns the CDTs with ease... but not my new setup.

So what I did was: re-installed the factory tweeter and a Dynaudio long throw 7.25" mid bass. Since the factory tweeter can only handle 25w, I made sure my friend built a protection circuit on the crossover.

The crossover frequencies are a kick ass 25Hz, 500Hz, and 5kHz... on a 24db slope. Im looking at putting in a 4.5" coax in the kick panels to further raise the front stage. The factory speakers are in the back.

First impressions: So much louder, and lower than the CDTs. The Dy's pound out bass like they were 10"s in the door. I had him crossover them low so the 4.5" can pick up the rest, virtutally making the Dy a subwoofer. Although I liked the way the CDTs sound on my burn in cd, the shear output of this setup now walks all over it. With my sub totally off, there is more than plenty of midbass filling the cabin. Keep in mind that the rear channel is nearly off (you can hear it if you put ur ear to it.) yet the sound is much more filling than the CDT setup.

The whole reason behind this was: an arguement that a bigger, higher quality silk tweeter will outperform a low grade metal tweeter. One valid point has punctured through this whole experiment: its not power, its not quality, its the crossover design. My friends' knowledge is very extensive in audio slopes and he shined when the I heard the setup for the first time.

Oh btw, these are one-off custom crossovers and wont be reproduced. He made them to prove a point (and to show off....). And since I was looking to make a SQL super car, I had to have something not out of a box. Our further plans include a center channel (already got a mono channel on both crossovers), possibly keep the factory tweeter, and a 4.5" coax. Sooner or later, I will make a plate for the rears and eliminate them.

Thoughts of multiple 8" or 10" subwoofers are in the works. Its possible I may add another 15" in a sealed enclosure.

Thought Id share the experiment with ya'll.
 

·
Registered
Joined
·
315 Posts
Hmmm, not too much to show off building 3-way custom xovers IMO :roll:

If anyone wants, I can do the exact same thing for $20+parts. Or if you want to save money, you can find out how to make a Linkwitz Riley crossover at 24dB/octave slope and build them yourself.
 

·
Registered
Joined
·
2,756 Posts
Discussion Starter #3
I never went to school, so it was kinda cool to make one myself. Im not talking its the baddest, but hell, first time I made one and it sounds awesome.

We used all high power components you wont find on a shelf. The coil for the woofer is rated up to 800w rms... show me where you can get one. His company makes some sweet high power components but I think they are mainly used for business networking.

But the crossovers arent nothing... for what I have coming next.
 

·
Registered
Joined
·
315 Posts
I bet I can beat your crossovers and any EQ you get ;)

And I thought you said the friend made the crossovers... makes a difference if you're not an EE and don't spend several hours a week soldering and doing that type of stuff!
 

·
Registered
Joined
·
947 Posts
vaBooM said:
So what I did was: re-installed the factory tweeter and a Dynaudio long throw 7.25" mid bass. Since the factory tweeter can only handle 25w, I made sure my friend built a protection circuit on the crossover.

The crossover frequencies are a kick ass 25Hz, 500Hz, and 5kHz... on a 24db slope. Im looking at putting in a 4.5" coax in the kick panels to further raise the front stage. The factory speakers are in the back.
:shock: You put speakers in the kick panels to raise the front stage? Unless the sound waves get a weird bounce from the windshield, which is an undesirable phenomenon in terms of imaging, how does a low-mount driver raise the front sound-stage?

I am also not sure how that cross-over works. Is the 25Hz a roll-off frequency? You are doing 500Hz and under to the mid-bass and 5K up to the tweeter? What are you using to fill in the middle there? How did you find out the impedance of the stock tweeter at 5KHz to build the crossover accordingly? 500Hz must have required one heck of a coil and capacitor, not to mention 25Hz, and 24dB!!! I guess you could use iron core instead of air core... But I'd love to see a picture of that monster.
 

·
Registered
Joined
·
947 Posts
vaBooM said:
I never went to school, so it was kinda cool to make one myself. Im not talking its the baddest, but hell, first time I made one and it sounds awesome.

We used all high power components you wont find on a shelf. The coil for the woofer is rated up to 800w rms... show me where you can get one. His company makes some sweet high power components but I think they are mainly used for business networking.

But the crossovers arent nothing... for what I have coming next.
Well, Solen inductors from Madisound are built with 14 gauge wire, which should be good for several hundred watts. They are tested not to saturate for up to 1500 volts so current is the only limiting factor. And 14 gauge will past a heck of a lot of current. But why would you need that much power anyway?
 

·
Registered
Joined
·
315 Posts
You put speakers in the kick panels to raise the front stage? Unless the sound waves get a weird bounce from the windshield, which is an undesirable phenomenon in terms of imaging, how does a low-mount driver raise the front sound-stage?
Firing the speakers up (at an angle) gives you the impression that the stage is higher.
 

·
Registered
Joined
·
947 Posts
bknauss said:
Firing the speakers up (at an angle) gives you the impression that the stage is higher.
How does that work? If you had a dog barking at you from your feet, you'd think it's from somewhere higher up?
 

·
Registered
Joined
·
2,756 Posts
Discussion Starter #9
High frequencies are more directional than lower. Essentially, pointing a woofer at your face gives you the impression its playing right in front of you.

My friend HELPED make the crossover. Actually he told me what I needed and I soldered it all. Didnt make it clear enough.

25, 500, and 5k are roll off points. Meaning they wont play frequencies under that. The midbass I have now is covering the middle. And doing a wonderful job at that.

The crossover board is about the size of a amplifier. Its pretty nasty, as there is wire going in every direction. I took some pics but I guess it was rather dark, so they didnt show up all that well. Ill take some more when I go back into the door.

I dont know the math on figuring nominal impedence and crossover slopes. What I posted is what I was told. I know what components are what but I dont have a clue on their values or function.

When we were building it, seemed like the IBM days. I was gettin all high from the solder.....
 

·
Registered
Joined
·
2,756 Posts
Discussion Starter #11
They actually fit in the door. Of course they are stuck against the backside of the door, but it holds just fine.

Soon that will be all scraped.. my employee discount at work will kick in and I have my eye on a prototype set of Focal's that have a 7" woofer, 5 1/4" midbass and 2 .75" silk tweeters.
 
1 - 11 of 11 Posts
Top