2 way xover

[merlin el mago]

I'm looking to improve my passive xover for Seas Millenium T25CF002 & ScanSpeak 18W8545, I'm using attached xover but I'm not satisfied, ideas & suggestions will welcome.

 

[Zuhl]

You haven't got any BSC. I'd try something like 1.8 - 2.0mH in the bass instead of 0.56mH. You'll also need to reduce the tweeter level a bit, maybe a 4.7 - 5.6R resistor.

I would also try wiring the bass and tweeter in phase - you should be able to hear if you have a dip at the xo frequency if you haven't any measuring equipment.

 

[Jay1111]

I would try this for the woofer. Note the only resistor that's real is the green one.

[IMGDEAD]http://www.troelsgravesen.dk/Amish_files/18W-8545-00+9500_parallel_V2_final.png[/IMGDEAD]

Maybe this one for the tweeter, with a little more resistance added to R2

http://www.seas.no/images/stories/diykits/pdfdataheet/filter_froy.pdf

 

[merlin el mago]

Hey guys thanks for suggestions I will try soon.

 

[merlin el mago]

I would try this for the woofer. Note the only resistor that's real is the green one.

[IMGDEAD]http://www.troelsgravesen.dk/Amish_files/18W-8545-00+9500_parallel_V2_final.png[/IMGDEAD]

Maybe this one for the tweeter, with a little more resistance added to R2

http://www.seas.no/images/stories/diykits/pdfdataheet/filter_froy.pdf

When you say coil cored can be: ferrite, aronit, wood, p-core non ferrous, etc.

 

[Jay1111]

When you say coil cored can be: ferrite, aronit, wood, p-core non ferrous, etc.

Not sure what you're asking I didnt say anything about coils? Choose whatever coil matches the resistance shown for the coil in the xover.

 

[merlin el mago]

L2031 2.700mH 0.3-06 ohm cored?

 

[Jay1111]

Pick any resistor with a dcr within that range. A 18 guage iron core would likely be good enough.

 

[merlin el mago]

You haven't got any BSC. I'd try something like 1.8 - 2.0mH in the bass instead of 0.56mH. You'll also need to reduce the tweeter level a bit, maybe a 4.7 - 5.6R resistor.

I would also try wiring the bass and tweeter in phase - you should be able to hear if you have a dip at the xo frequency if you haven't any measuring equipment.

I like more only the woofer in phase.

 

[merlin el mago]

You haven't got any BSC. I'd try something like 1.8 - 2.0mH in the bass instead of 0.56mH. You'll also need to reduce the tweeter level a bit, maybe a 4.7 - 5.6R resistor.

I would also try wiring the bass and tweeter in phase - you should be able to hear if you have a dip at the xo frequency if you haven't any measuring equipment.

I tried 5.1R in place of 8R and I like more 8R

 

[Inductor]

I tried 5.1R in place of 8R and I like more 8R

I'm guessing here, from reading thread, that Zuhl meant Lpad (attenuation) the tweeter and not LCR (to notch).

 

[merlin el mago]

Where have I to put the L-pad: between the filter & the notch?

 

[merlin el mago]

L-Pad calculator pic for 6 ohms driver & 1dB attenuation, R1 = 0.65 Ohms 8.16 Watts
R2 = 49.17 Ohms 7.27 Watts, is OK?

 

[Dissi]

Hi Merlin,

I found the pictures of your speaker in your other thread:

http://www.diyaudio.com/forums/multi-way/236392-help-3-4-way-loudspeaker.html

Knowing cabinet and crossover I was able to do a simulation of your speaker. The driver voltage curves reveal a correctly calculated theoretical crossover at 2.5 kHz. Unfortunately this is not the whole story and the acoustic result doesn't look very good anyway. The simulation confirms everything Zuhl has been saying: The woofer has no baffle step correction and the tweeter is too lound and of wrong polarity. Further there is a unhandled surround resonance at 800 Hz and the impedance drops to 3 ohm at 5 kHz. This is what you have at the moment. Please give me some time to come up with a proposal for a improved crossover.

 

[merlin el mago]

Thank you Dissi

 

[merlin el mago]

Added 4R7 to attenuate the tweeter, a lot better

 

[merlin el mago]

Changed woofer coil for 2.0 mH = better sound.

 

[Dissi]

Hi Merlin,

I see you are making good progress with your crossover, great. Based on my simulation I propose some minor modifications you can try easily. Disconnect the zobel on the woofer, split the resistor of the tweeter and wire both drivers in phase. At least the simulation looks decent now and I hope the sound of your speaker doesn't tell the opposite.

 

[merlin el mago]

Thanks Dissi, coils available for the tweeter have other resistance:

0,24 mH 0,21 ohm
1,5 mH 0,38 ohm

Have I to change something?

 

[Zuhl]

I see you are getting close. I'm pleased I wasn't too far away myself

Once you have made the final changes as suggested you can start listening... and tweaking to taste...