First Time Crossover build Please Help

Jump to Latest
buadze007

buadze007

Member
Joined 2023
#1
Hello Dear friends i am building crossover for the first time

i have watched all videos on youtube and did some calculations but i still need your help

Woofer = GRS 12SFPC-B 12" Square Frame Paper Cone

Horn Driver: Eminence ASD1001B​



Crossover design:

crossover.jpg


Frequency response graph:

crossover1.jpg


Impedance graph :
crossover11.jpg


i like frequency response but when i look at impedance graph i think i should do better what you think?

Also i have attached Xsim file.

Parts list:

Dayton Audio DMPC-1.5 1.5uF 250V Polypropylene Capacitor
Dayton Audio DMPC-7.5 7.5uF 250V Polypropylene Capacitor
Dayton Audio DMPC-0.33 0.33uF 250V Polypropylene Capacitor
Dayton Audio DMPC-3.3 3.3uF 250V Polypropylene Capacitor
Dayton Audio DMPC-10 10uF 250V Polypropylene Capacitor

Dayton Audio IC181-5 1.5mH 18 AWG Laminated Steel I-Core Speaker Crossover Inductor Coil
Dayton Audio 0.33mH 18 AWG Perfect Layer Air Core Speaker Crossover Inductor Coil
Dayton Audio 0.10mH 18 AWG Perfect Layer Air Core Speaker Crossover Inductor Coil
Dayton Audio 1.5mH 18 AWG Perfect Layer Inductor Crossover Coil

Dayton Audio DNR-3.3 3.3 Ohm 10W Precision Audio Grade Resistor
Dayton Audio DNR-8.0 8 Ohm 10W Precision Audio Grade Resistor

Thanks
 

Attachments

#7
What horn are you using? Do you have angle measurements? The peak at 5k will be quite dominant in my experience.

It's often better to use a voltage divider instead of just a series resistor because you can adjust the level of the horn without shifting the crossover frequency
 
#9
Your speaker will sound bright / bass weak.

I am assuming the GRS woofer is measured by the manufacturer on a wide/ big IEC type baffle. therefore you are going to get baffle step losses putting it in a regular sized cabinet = a smaller baffle (assuming you aren't mounting these in a wall / very large baffle).

Your overall system sensitivity should target around 90dB after baffle step compensation (maybe less).

You should apply your baffle step and diffraction losses to the manufacturer responses, to get closer to reality.
 
  • Like
Reactions: ICG
#10
can somebody design crossover for me i would say big thank you and build by project, whole day i was designing crossover but still i am not getting any good values, thank everybody for reply i appreciated, also should i change woofers? to get more bass ?

Dayton Audio DC300-8 12" Classic Woofer will be better choice for my project?​

 
#11
The horn can be used and loads properly, however, the 12" GRS bass will be a lot narrower at 1,5kHz xo frequency. The Eminence CD got its resonance at this frequency which leads to a strong decay ridge there as well. Aside from that, the impedance peaks mounted on the horn makes it much more complicated to build a fitting crossover and you can't use the traced impedance because at the horn it will be nothing like in the data sheet.

Further: The driver is recommend to xo at 2,5kHz with 18dB. The Eminence ASD 1001B will perform really bad at 1,5kHz, will have high distortion and show very slow decay down there. Or in other words, you need a different CD or a different woofer or a mid driver, making it a 3-way.

Same goes for the GRS woofer, the impedance graph suggests that it got several resonances above 600Hz, which means it's likely not a good midrange and instead just a good use as a woofer.

E: You have to measure the impedance and response of the woofer and CD with the horn, complete mounted in the enclosure and time align the measurements because of the CD offset because of the horn, otherwise neither the fr, impedance nor the phase will be correct - and can't be used for any xo simulation.
 
Last edited:
#14
AllenB said:
Surely that's just for pro applications, it will be different in a domestic role.
Click to expand...

I would not use the driver for anything below 2k.

AllenB said:
You have evidence of this?
Click to expand...

I've seen the measurements in a German forum. The pictures are not online anymore though. It had a long decay delay ridge at the fs and one at 5kHz (much tamer but with k3/k5 peak) and several at the top. The biggest peak was at 18k with a high decay ridge. Not a good driver, no matter how you look at it, even if you ignore the decay.

My experience is not to use the small CDs at their fs at all.

E: that's from the datasheet, alone the high impedance peak shows a high Q resonance

1000026792.png
 
Last edited:
#18
AllenB said:
Surely that's normal for fs, and if you extend the response lower then it goes somewhere else..
Click to expand...

And where would you 'extend it lower' to? I wanted to know if you'd really want to contribute to the speaker but you didn't even look at the datasheet. Where's the mistake, mh? You just wanted to say I'm wrong but didn't invest any effort. Look at the datasheet, it's in there.

@buadze007: You already bought the Eminence CD. Okay, then it's best to go for a 3-way. Please tell what you want to do with the speaker? It's for use at home and not PA and without any subwoofers? Is that right?
 
#20
The first thing I did was to look at the voice coil diameter. By comparison I know that Earl Geddes has used the B&C DE250 down to 700Hz. It has a 44mm voice coil, 1" exit and has a recommended crossover frequency of 1.6kHz. I've used it down to 500Hz, equalised. Even crossed first order it can provide adequate output.

ICG said:
you didn't even look at the datasheet.
...
You just wanted to say I'm wrong but didn't invest any effort.
Click to expand...
I'm appalled that you would stoop to such tactics.. So it shall be with you.
 
You must log in or register to reply here.
Top Bottom