2-way project: SS 2905/9700 + 18w8545-01

[Botty]

Hi guys ,


Can anybody help me with this project :


SS 2905/9700 + 18w8545-01


http://www.scan-speak.dk/datasheet/pdf/d2905-970000.pdf


http://www.scan-speak.dk/datasheet/pdf/18w-8545-01.pdf



box reflex 18L (15L net volume + full wool damping) reflex tube: Monacor BR-70hp (max lenght 215mm) 56mm diameter


In the Attachments there are other input like speaker position, baffle and some simulation with boxsim. The frd & zma aren't real measurement.


Can anybody suggest to me the best way?



thanks
Luca

 

[Botty]

here third simulation with 1 resistor parallel on woofer

 

[Dissi]

Hi Luca, just a hint concerning Boxsim:

Your xyz coordinates are in mm, but Boxsim expects cm there. Since your speaker has a single cabinet only, it's simpler to use the option "Common outer housing" anyway.

 

[Botty]

Hi Dissi!
you are right!
I'm wrong with the Vertical dimension....i forgot one point.....tomorrow i try new simulation...... thanks

 

[Botty]

hi, here there is the correct position in my room and new simulation.


Does anybody have experience with these speakers xo?

 

[Botty]

now the correct frequency direnction

 

[Dissi]

Hi Luca,

I had a look at your project and came to the following assessment:

It's indeed difficult to get a better result with a crossover based on Troels Gravesen's CSM design. Inherently there's always too little baffle step correction and too low an impedance, no matter what you do.

A different crossover topology is required to overcome these limitations.

 

[Botty]

Hi Dissi,


thank you very much for your time!!....your xo is little complicated for me but i like it, specially on the woofer!........As you said, i copied "Troels Gravesen's CSM design" and try to change value for my box and room with boxsim simulation.


About low impedance, the specs of my amps (NAD326) say (theory) no problem.
About the diffraction i don't know if modify the xo is enough for best results.

For type of sound i prefer to emphasize the bass and little attenuate high frequency.



here there is your crossover in my simulation....

 

[Botty]

Hi Dissi,


thank you for your great low-pass. it works very good also in my simulation.

now i try to modify your high-pass for my preferences and boxsim simulation sistem (box, baffle and listening point).


What do you think about this?


Is the impedence good for you now?


bye
Luca

 

[Dissi]

That's fine.

Tweeter level always is a matter of taste. When you hear the speaker you will know if it's right for you...

With "low impedance" I didn't mean an impedance too low for the amplifier, but the woofer is 8 ohm nominally and a low-pass filter that drops the speaker impedance to 4 ohm is a bit unfortunate IMO.

 

[Botty]

With "low impedance" I didn't mean an impedance too low for the amplifier, but the woofer is 8 ohm nominally and a low-pass filter that drops the speaker impedance to 4 ohm is a bit unfortunate IMO.[/QUOTE]


Thank you Dissi, now i understand your words about impedance....thank for your support. Do you have any other tips for my project?


Bye
Luca