Is a cross-over required in full-range speakers?

[Soldermizer]

I just read this ancient thread. Like Nigel, I have owned Magnepans and they are good. BTW, Nigel you have a most English name and I think it was XTC wrote a song about making plans for you 🙂

One of my Soldermizer (= half-assed) experiments I have yet to try is OB. Why not with foam board (or coroplast?) I may give that a try, having a supply of Bose 901 drivers on hand. Also I have EQ available.

 

[nigel pearson]

One problem with SMGa's. You have no idea how loud they are as distortion is so low. I thought they must be 84 dB/w. I am told 6 db more!

I have built with low density materials and fell it works very well.

 

[juanito]

For the high pass filter you can get an approximation from a table like this. (simple filter, shallow slope).

6 db Crossover Table

or for a steeper slope (more power handling of the driver, but more components)

12 db Crossover Table

for a notch filter, that is to say to remove the part of the midrange, you can use this:

Parallel Notch Fliter Designer / Calculator

Ok, so if I want to make a High pass filter from 80Hz with a 4 ohm speaker, then 330 uF cap is needed for the signal, but what cap is good for this? I don`t find these values in "crossover" caps unless I search for electrolityc or power supply caps. What would you suggest?

 

[nigel pearson]

http://www.amazon.com/330uF-Electrolytic-Non-Polarized-Crossover-Capacitor/dp/B0002KR49S

These will work. I have seen them at 35 V cost far less. 35V should be OK if less than 50 watts. When a Quad 303 one can use a standard capacitor as it is a capacitor coupled amp. One would just replaces the one inside the amp. A 330 uF > 80 V would be OK as it sees 67V max.

 

[juanito]

https://tubedepot.com/products/jj-radial-can-capacitor-350f-385v
Should these give a significant improvement against the small electrolytic?

 

[nigel pearson]

They need to be non polar if used with a conventional amplifier. You can use 5 or 6 per side in the link below. The non polar I gave will be very OK as it is a higher voltage type. In making them suitable for higher voltage it also helps the high frequency ability. Non polar electrolytic can equal film types and can be used in critical signal areas of preamps as long as they never become polarised ( < 0.4 VDC ). Distortion can rival that of low voltage polyester ( 63 V ).

4.16.10.61.64 - DUCATI - CAPACITOR, 60UF 450VAC, TAB | CPC